MXPA99002157A

MXPA99002157A - A tonometer system for measuring intraocular pressure by applanation and/or indentation

Info

Publication number: MXPA99002157A
Application number: MXPA/A/1999/002157A
Authority: MX
Inventors: Marc Aurelio Martins Abreu Marcio
Original assignee: Abreu Marcio M
Priority date: 1996-09-04
Filing date: 1999-03-04
Publication date: 2000-06-05

Abstract

A tonometer system for measuring intraocular pressure by accurately providing a predetermined amount of applanation of the cornea, and detecting the amount of force required to achieve the predetermined amount of applanation. The system is also capable of measuring intraocular pressure by identing the cornea using a predetermined force applied using an indenting element, and detecting the distance the indenting element (16) moves into the cornea when the predetermined force is applied, the distance being inversely proportional to intraocular pressure. Also provided is a method of using a tonometer system to measure hydrodynamic characteristics of the eye, especially outflow facility. The tonometer system includes a contact device for placement in contact with the cornea and an actuation apparatus (6) for actuating the contact device so that a portion thereof projects inwardly against the cornea to provide a predetermined amount of applanation. The system further includes a detecting arrangement (8) for detecting when the predetermined amount of applanation has been achieved, and a calculation unit responsive to the detecting arrangement (8) for determining intraocular pressure based on the amount of force the contact device must apply against the cornea in order to achieve the predetermined amount of applanation. An indentation distance detection arrangement is also provided for use when intraocular pressure is to be deteced by indentation. In carrying out the method, the system is used to detect intraocular pressure between successive steps of forcing intraocular fluid out from the eye.

Description

A TONOMETER SYSTEM FOR MEASURING INTRAOCULA PRESSURE THROUGH APPLIANCE AND / OR INDENTATION BACKGROUND OF THE INVENTION The present invention relates to a tonometer system for measuring intraocular pressure, providing precisely a predetermined amount of flattening to the cornea, and detecting the amount of force required to achieve the predetermined amount of flattening. The system can also measure the intraocular pressure by indentating the cornea using a previously determined force applied using an indentation element, and detecting the distance that moves and indentation element inside the cornea when the previously determined force was applied, being the distance inversely proportional to the intraocular pressure. The present invention also relates to a method for using the tonometer system to measure the hydrodynamic characteristics of the eye, especially the ease of outward flow. The tonometer system of the present invention can also be used to measure the hemodynamics of the eye, especially ocular blood flow and pressure in the blood vessels of the eye. Additionally, the tonometer system of the present invention can be used to increase and measure the pressure of the eye, and to evaluate, at the same time, the ocular effects of the increased pressure. Glaucoma is a cause that leads to blindness throughout the world, and although it is more common in adults over 3 years of age, it can occur at any age. Glaucoma occurs primarily when the intraocular pressure is increased to values that the eye can not support. The fluid responsible for the pressure in the eye is aqueous humor. It is a transparent fluid produced by the eye in the ciliary body, and collected and drained by a series d channels (trabecular meshwork, Schlemm's canal, and venous system). The basic disorder in most glaucoma patients is caused by an obstruction. or interference that restricts the flow of aqueous humor out of the eye. This obstruction or interference prevents the aqueous humor from flowing out of the eye at a normal speed. This pathological condition occurs long before there is a consequent elevation in intraocular pressure. This greater resistance to flow out of the aqueous humor is the main cause of increased intraocular pressure in patients affected by glaucoma. The increased pressure inside the eye causes progressive damage to the optic nerve. When the damage to the optic nerve occurs, characteristic defects in the visual field develop, which can lead to blindness if the skin remains undetected and untreated. Because of the insidious nature of glaucoma, and the gradual, painful loss of vision associated with glaucoma, glaucoma n produces symptoms that motivate an individual to seek help, but not until relatively late in its course, when a irreversible damage. As a result, millions of glaucoma victims are not aware that they have the disease and that they are facing eventual blindness. E glaucoma can be detected and evaluated by measuring the fluid pressure of the eye, using a tonometer and / or measuring the ease of flow out of the eye fluid. Currently, the most frequently used way to measure the ease of outward flow is to make the toneage d indentation. In accordance with this technique, the capacity for flow is determined by placing a tonometer on the eye. The weight of the instrument forces aqueous humor through the filtration system, and - the velocity at which the pressure in the eye declines over time is related to the ease with which the eye fluid exits. Individuals at risk for glaucoma, and individuals who will develop glaucoma, generally have less ability to flow outward. Therefore, measuring the ease of outward flow provides information that can help identify individuals who may develop glaucoma., and consequently, will allow early evaluation and institution of therapy before significant damage occurs. The measurement of outward flow ease useful for making therapeutic decisions, and for evaluating changes that may occur over time, age, surgery, or the use of medications to alter intraocular pressure. The determination of the ease of flow out is also an important research tool for the investigation of issues such as drug effects, the mechanism of action of different treatment modalities, evaluation of the property of glaucoma therapy, the detection of diurnal oscillations wide in pressure, and to study the pathophysiology of glaucoma. There are several methods and devices available for measuring intraocular pressure, ease of flow to the outside, and / or other different features of the eye related to glaucoma.The following patents give different examples of these devices and conventional methods: PATENTED PATENT 5,375,595 Sinha and collaborators 5,295,495 Maddess 5,251,627 Morris 5,217,015 Kaye and collaborators 5,183,044 Nishio and collaborators 5,179,953 Kursar 5,148,807 Hsu 5,109,852 Kaye and collaborators 5, 165,409 Coan 5, 076,274 Matsumoto 5, 005,577 Frenkel 4,951,671 Coan 4,947,849 Takahashi and collaborators 4,944,303 Katsuragi 4,922,913 Waters, Jr. collaborating 4,860,755 Erath 4,771,792 Seale 4,628,938 Read 4,305,399 Beale 3,724,263 Rose and collaborators 3,585,849 Grolman 3,545,260 Lichtenstein and collaborator Still other examples of conventional devices and / or methods are disclosed in Morey, Contact Len Tonometer, RCA Technical Notes, No. 602, December 1964; Russell and Bergmanson, Multiple Applications of the NCT: A Assessment of the Instrument's Effect on IOP, Ophthal. Physiol. Opt. , volume 9, April 1989, pages 212-214, Moses Grodzki, the Pneumatonograph: A Laboratory Study, Arch.

Ophthalmol., Volume 97, March 1979, pages 547-552; and C.C Collins, Miniature Passive Pressure Trans- pressor for Implantin in the Eye, IEEE Transactions on Bio-medical Engineering, April 1967, pages 74-83. In general, the pressure of the eye is measured by pressing flattening the surface of the eye, and then estimating the amount of force needed to produce the flattening or depression given. Conventional tonometry techniques that use the principle of flattening, can provide accurate measurements of intraocular pressure, but are subject to many errors in the way they are currently performed. In addition, the present devices require professional assistance for their use, or are too complicated, expensive, or inaccurate for individuals to use at home. As a result, individuals should visit a professional for eye care in order to verify the pressure of their eyes. The frequent self-checking of intraocular pressure is useful not only to monitor therapy and self-check patients with glaucoma, but also for the early detection of pressure elevations in individuals without glaucoma, for whom it was not detected. High blood pressure during your visit to the clinic: Pathogens that cause a severe eye infection and visual impairment, such as herpes and adenoviruses, as well as the virus that causes AIDS, can be found on the surface of the eye and on the film This can be transmitted from one patient to another through the tip of the tonometer or the probe, and probe covers have been designed to prevent the transmission of diseases, but they are not widely used because they are not practices and provide less accurate measurements. Also, tonometers have been designed to prevent the transmission of diseases, such as the type of tonometry "Air puff" but they are expensive and provide less accurate measurements. Any conventional direct contact tonometers can potentially transmit a variety of systemic and ocular diseases. The two main techniques for the measurement of intraocular pressure require a force that flattens, or d a force that indent, the eye, called tonometry d "flattening" and "indentation", respectively. The tonometry of flattening is based on the principle of Imbert-Fick. This principle states that, for an ideal dry thin-walled sphere, the pressure between the sphere is equal to the force needed to flatten the surface, divided by the flattening area. P = F A (e where P = pressure, F = force, A = area). In the tonometry d flattening, the cornea is flattened, and measuring the force d flattening and knowing the flattened area, deter-. na l intraocular pressure. In contrast, according to the tonometry d indentation (Schiotz), a known weight (or force against the cornea) is applied, and the intraocular pressure is estimated by measuring the linear displacement that results during the deformation of the cornea. by force indicates the intraocular pressure.In particular for standard forces and standard dimensions of indentation device, there are known tables that correlate the linear displacement and the intraocular pressure.The conventional measurement techniques that uses flattening and indentation, are subject to many errors The technique most frequently used in the clinical setting is contact applanation using Goldman tonometer.The sources of major errors associated with this method include the addition of extraneous pressure on the cornea by the examiner, the tightening of the eyelids or excessive enlargement of the eyelid fissure by the patient due to the discomfort caused by the tonometer probe resting on the eye, and an inadequate amount of dye (fluorescein). In addition, conventional techniques depend on the skill of the operator, require the operator to subjectively determine the alignment, the angle, and the amount of depression. Consequently, the variability and inconsistency associated with less valid measurements are problems encountered using conventional methods and devices. Another conventional technique involves air blown tonometers, where a puff of compressed air of a known volume and pressure is applied against the surface of the eye while the sensors detect the time necessary to reach a predetermined amount of deformation of the eye surface. , caused by the application of the air blower. This device is described, for example, in United States Patent No. 3,545.26 to Lichtenstein et al. Although the tonometer if contact (breath of air) does not use dye, and did not present problems, such as a strange pressure on the eye by the examiner, or the transmission of diseases, there are other problems associated with it. These devices, for example, are expensive, require a supply of compressed gas, are considered problematic to operate, or difficult to maintain in proper alignment, and depend on the skill and technique of the operator. In addition, and the tested individual usually complains of pain associated with the air discharged to the eye, and due to that discomfort, many individuals hesitate to undergo another measurement with this type of device. The primary benefit of the tonometer if contact, is its ability to measure pressure without transmitting diseases, but are generally not accepted because they provide inaccurate measurements, and are primarily useful for large-scale glaucoma classification programs. Tonometers that use gases, such as pneumotonometer, have several drawbacks and limitations This device is also subject to operator errors as with Goldman tonometry. In addition, this device uses Freon gas, which is not considered safe for the environment. Another problem with this device is that the gas is flammable, and as with any other can of type d aerosol, the can explode if it gets too hot. Gas can also leak and is susceptible to changes in cold weather, thus producing less precise measurements. The transmission of diseases is also a problem with this type of device if the probe covers are not used. In the conventional tonometry of indentation (Schiotz), the main sources of errors are related to the application of a relatively heavy tonometer (total weight of at least 16.5 grams) to the eye, and the differences in the compliance of the eye coatings. Experience has shown that a heavy weight causes discomfort, and raises intraocular pressure. Moreover, the test depends on a problematic technique where the examiner needs to gently place the tonometer on the cornea without. Press the tonometer against the balloon. The need for conventional indentation can also be reduced by inadequate instrument cleaning, as described below. The danger of transmitting infectious diseases, as with any contact tonometer, is also present with conventional indentation. A variety of methods have been devised using a contact lens; however, these systems suffer from a number of restrictions, and virtually none of these devices are being widely used or accepted in clinical settings, due to their limitations and inaccurate readings. Moreover, these devices typically include instrumented contact lenses, and / or problematic and complex contact lenses. Several prior art instruments employ a contact lens placed in contact with the sclera (the white part of the eye). These systems suffer from many disadvantages and disadvantages. The possibility of infection and inflammation increases due to the presence of a foreign body in direct contact with a vascularized part of the eye. As a consequence, an inflammatory reaction may occur around the device, possibly impacting the accuracy of any measurement. In addition, the level of discomfort is high, due to a long period of contact with a highly sensitive area of the eye. In addition, the device could slip, and consequently, lose an appropriate alignment, and again, prevent accurate measurements being taken. Moreover, the sclera is a thick and almost non-distensible coating of the eye, which can further impair the ability to acquire accurate readings. Most of these devices use costly sensors complicated electrical circuits embedded in the lens, which are expensive, difficult to manufacture, and sometimes problematic. Other methods for detecting pressure using a contact lens on the cornea have been described. Some of the methods of this prior art also employ costly and complicated electronic circuits and / or transductores embedded in the contact lens. In addition, some devices use a piezoelectric material in the lens, and metallization of the lens components that overlie the optical axis decreases the visual acuity of the patient using that type of device. Moreover, precision decreases, since the piezoelectric material is affected by small changes in temperature and speed with which force is applied. There are also contact lens tonometers that use fluid in a chamber to cause deformation of the cornea; however, these devices lack elements for alignment, and are accurate, as the flexible elastic material is unstable and can bulge forward. In addition, the fluid itself has a tendency to accumulate in the lower portion of the chamber, failing in this way to produce a stable flat surface, which is necessary for accurate measurement. Another mode uses a coil wound around the inner surface of the contact lens, and a magnet attached to an externally created magnetic field. A membrane with a conductive coating is compressed against a contact that completes a short circuit. The magnetic field forces the magnet against the eye, and the force required to separate the magnet from the contact is considered proportional to the pressure. This device suffers from many limitations and disadvantages. For example, there is a lack of precision, since the magnet will indentate the cornea, and when the magnet is pushed against the eye, the sclera and coatings of the eye will be easily distorted to accommodate the displaced intraocular content. This occurs because this method does not take into account ocular stiffness, which is related to the fact that the sclera of one person's eye stretches more easily than the sclera of another. An eye with low ocular stiffness will measure and read with an intraocular pressure lower than the actual eye pressure. Conversely, an eye with a high ocular rigid distends less easily than the average eye, resulting in a reading that is higher than the actual intraocular pressure. In addition, this design uses current and the lens, which, in turn, is in direct contact with the body. This contact is undesirable. The unnecessary cost the complexity of the design with circuits embedded in the lens and a lack of an alignment systemThey are also big drawbacks with this design. Another known contact lens configuration uses a resonant circuit formed from a single coil and a single capacitor, and a magnet that can be moved relative to the resonant circuit. An additional design of the same disclosure, involves a transducer comprised of a transistor sensitive to pressure, and complex circuits in the lens, which constitute the operating circuit for the transistor. The three modalities disclosed are considered impractical and even insecure to be placed on the oj of a person. Moreover, these contact lens tonometers are unnecessarily expensive, complex, problematic to use, and can potentially damage the eye. In addition none of these devices allow to measure the flattened area and therefore, in general they are not very practical. The prior art also fails to provide a technique or apparatus sufficiently accurate to measure the ease of outward flow. Conventional techniques and devices for measuring the ease of flow to the patient are limited in practice, and are more likely to produce erroneous results, because both are subject to operator, patient, and instrument errors. With respect to operator errors, the conventional test for ease of outward flow requires a long period of time during which there is no tilt of the tonometer. Therefore, the operator must place and maintain the weight on the cornea without moving the weight without compressing the balloon. With regard to patient errors, if during the test the patient blinks, squeezes, moves, holds the breath, or does not hold the fixation, the results of the test will not be accurate. Since the conventional tone takes approximately 4 minutes to perform, and requires the general placement of a relatively heavy tonometer against the eye, the chances of patients becoming anxious, and therefore reacting, to the mechanical weight placed on their eyes, they increase. With regard to instrument errors, after each use, the tonometer plunger and pat plate should be rinsed with water followed by alcohol, and then dried with a lint-free material. If any foreign matter dries into the leg plate, it can detrimentally affect the movement of the plunger, and may produce an incorrect reading. Therefore, conventional techniques are very difficult to perform, and require specialized trained personnel. Pneumotomography, in addition to having the problems associated with the pneumotonometer itself, was considered "totally inadequate for tonometry". (Report by the Committee on Standardization of Tonometers of the American Academy of Ophthalmology, Archives Ophthalmol., 97: 547-552, 1979). Another type of tonometer (the "non-contact" air-blown "Tonometer - United States Patent No. 3,545,260) was also considered inadequate for tonometry (Ophthalmic & amp;; Physiological Optics, 9 (2): 212-214, 1989). Currently, there is no truly acceptable element for the self-measurement of intraocular pressure and the ease of outward flow.

COMPENDIUM OF THE INVENTION In contrast to the different prior art devices, the apparatus of the present invention offers an entirely new approach for the measurement of intraocular pressure and hydrodynamics of the eye. The device offers a simple, accurate, inexpensive, and safe element to detect and measure the first of the abnormal changes that take place in glaucoma, and provides a method for diagnosing the first forms of glaucoma before it present any irreversible damage. The apparatus of this invention provides a rapid, safe, virtually automatic, direct reading, convenient, and accurate measurement, using a user-friendly, soft, dependable, and low cost device, which is suitable for use in the home. In addition to providing a novel method for a single measurement and self-measurement of intraocular pressure, the apparatus of the invention can also be used to measure the ease of outward flow and ocular rigidity. In order to determine ocular stiffness, it is necessary to measure the intraocular pressure under two different conditions, either with different weights on the tonometer, or with the tonometer d indentation and a flattening tonometer. Moreover, the device can perform the flattening tone that is not affected by ocular stiffness, because the amount of deformation of the cornea is so small that it moves slowly with very little change in pressure. Consequently, large variations in ocular stiffness have little effect on flattening measurements. In accordance with the present invention, s provides a system for measuring intraocular pressure by flattening. The system includes a contacting device d for contacting the cornea, and a driving device for actuating the contact device, such that a portion thereof projects into the cornea, to provide a predetermined amount. of flattening. The contact device is easily sterilized for multiple uses, or alternatively it can be done in an inexpensive manner to make the contact device disposable. Accordingly, the present invention eliminates the danger present in many conventional devices, of transmitting a variety of systemic and ocular diseases. The system further includes a detection configuration for detecting when the predetermined amount of flattening of the cornea has been reached, and a calculation unit that responds to the detection configuration, to determine the intraocular pressure based on the amount of force that must be applied. apply the contact device against the cornea, in order to achieve the amount of previously determined flattening. The contact device preferably includes a substantially rigid annular member, a flexible membrane, and a movable centerpiece. The substantially rigid annular member includes an internal concave surface configured to mate with an outer surface of the cornea, and having a hole defined therein. The subannular member d preferably has a maximum thickness in the hole, and a thickness progressively decreasing towards a periphery of substantially rigid annular member. The flexible membrane is preferably secured to the inner concave surface of the substantially rigid annular member. The flexible membrane is coextensive with when the hole is in the annular member, and includes at least a transparent area. Preferably, the transparent area extends throughout the flexible membrane, and the flexible membrane is coextensive with the entire inner concave surface of the rigid annular member. The moveable center piece is slidably disposed within the hole, and includes a substantially flat internal side secured to the flexible membrane. A substantially cylindrical wall is defined circumferentially around the orifice by virtue of the greater thickness of the rigid annular member at the periphery of the orifice. The movable centerpiece d preferably is slidably disposed against this wall in a piston-like manner, and has a thickness that is coupled with the height of the cylindrical wall. In use, the substantially flat inner side flattens a portion of the cornea to drive the moveable centerpiece by the drive apparatus. Preferably, the drive apparatus actuates the moveable centerpiece to cause sliding of the movable center piece in the piston-like manner towards the cornea. By doing so in this manner, the moving centerpiece a central portion of the flexible membrane projects into the cornea. In this way a portion of the cornea is flattened. The drive continues until a predetermined amount of flattening has been reached. Preferably, the moveable centerpiece includes a magnetically responsive element, configured to slide together with the moveable centerpiece, in response to a magnetic field, and the drive apparatus includes a mechanism for applying a magnetic field thereto. The mechanism for applying the magnetic field of preference includes a coil and circuits to produce an electrical current through the coil in a progressively increasing manner. By progressively increasing the current, s progressively increases the magnetic field. The magnetic repulsion between the drive apparatus and the movable centerpiece is consequently progressively increased, and this in turn causes a progressively greater force to be applied against the cornea, until the predetermined amount of flattening is reached. Using the known principles of physics, it is understood that the electrical current passing through the coil will be proportional to the amount of force applied by the central part movable against the cornea by means of the flexible membrane. Since the amount of force required to achieve the predetermined amount of flattening is proportional to the intraocular pressure, the amount of current required to achieve the predetermined amount of flattening will also be proportional to the intraocular pressure. Accordingly, the preferential calculation unit includes a memory for storing a current value qu indicating the amount of current that passes through the coil when the predetermined amount of flattening is reached, and also includes a conversion unit for converting torque. the current value in an indication of pressure i? traocular. The magnetically responsive element is circumferentially surrounded by a transparent peripheral portion. The transparent peripheral portion is aligned with the transparent area, and allows light to pass through the contact device to the cornea, and also allows light to be reflected from the back of the cornea outside the contact device through the transparent peripheral portion. The magnetically responsive element d preferably comprises an annular magnet having a central vision hole through which a patient can see while the contact device is located on the patient's cornea. The central vision hole is aligned with the transparent area of the flexible membrane. Preferably, a visual display is provided to numerically display the intraocular pressure detected by the system. In an alternative way, the visual display can be configured to give indications of whether the intraocular pressure is within certain ranges. Preferably, since different patients may have different sensitivities or reactions to the same intraocular pressure, the ranges are calibrated for each patient by a attending physician. In this way, patients who are more susceptible to the consequences of increased intraocular pressure can be alerted to seek medical care when they have a lower pressure than the pressure at which they alert other patients less susceptible to take the same action. . The preferential detection configuration comprises an optical flattening detection system. And addition, preferably a vision configuration is provided to indicate when the driving apparatus and detection configuration are properly aligned with the contact device. Preferably, the vision configuration includes the central vision hole in the movable central part, through which a patient can see while the device is located on the patient's cornea. The central viewing hole is aligned n the transparent area, and the patient preferably achieves a generally appropriate alignment by directing the vision through the central viewing hole towards a marking: active in the driving apparatus.

The system also preferably includes an optical distance measurement mechanism to indicate whether the contact device is spaced at a suitable axial distance from the drive apparatus and the detection configuration. The optical distance measurement mechanism is preferably used in conjunction with the vision setting, and preferably provides a visual indication of which corrective action should be taken whenever an inappropriate distance is detected. The system also preferably includes an optical alignment mechanism to indicate whether the contact device is properly aligned with the drive apparatus and the detection configuration. The optical alignment mechanism of preference provides a visual indication of what corrective action should be taken, provided that it detects misalignment, and is preferably used in conjunction with the vision configuration, such that the mechanism of optical alignment is merely provides indications of minor alignment corrections, while the vision configuration provides an indication of greater alignment corrections. In order to compensate for deviations in corneal thickness, the system of the present invention may also include a configuration for multiplying the intraocular pressure detected by a coefficient (or gain) that equals one for corneas of a normal thickness, less of one for unusually thick corneas, and a greater gain of one for unusually thin corneas. Similar compensations can be made for the curvature of the cornea, the size of the eye, the ocular rigidity and the like. For levels of the curvature of the cornea that are higher than normal, the coefficient would be less than one. The same coefficient would be greater than one for curvature levels of the cornea that are more flat than normal. In the case of an eye size compensation, eyes larger than normal would require a coefficient that is less than one, while eyes that are smaller than normal would require a coefficient greater than one. For patients with "stiffer" eye stiffness than normal, the coefficient is less than one, but for patients with softer eye stiffness, the coefficient is greater than one. The coefficient (or gain) can be selected manually for each patient, or alternatively, the gain can be selected automatically by connecting the apparatus of the present invention to a known pachymetry apparatus when compensating the thickness of the cornea, or keratometer. known when compensating the curvature of the cornea, and / or a known biometer when the size of the eye is compensated. The contact device and the associated system of the present invention can also be used to detect intraocular pressure by indentation. When using indentation techniques in the measurement of the intraocular pressure, a predetermined force is applied against the cornea, using an indentation device. Due to the force, the indentation device travels inside the cornea, indentating the cornea as what goes The distance traveled by the inward indentation device of the cornea in response to the previously determined force is known as inversely proportional to the intraocular pressure. In accordance with the above, there are different known tables that, for certain standard sizes of standard indentation and force devices, correlate the distance traveled and the intraocular pressure. Preferably, the movable contact device centerpiece also functions as the indentation device. In addition, the circuit is switched to operate in an indentation mode. When switching to indentation mode. When switching to the indentation mode, the circuit that produces the current supplies a predetermined amount of current through the coil. The amount of current previously determined corresponds to the amount of current necessary to produce one of the above mentioned standard forces. In particular, the amount of current previously determined creates a magnetic field in the drive apparatus. in turn, this magnetic field causes the movable centerpiece to push inward against the cornea by means of the flexible membrane. Once the predetermined amount of current has been applied, and a standard force is pressed against the cornea, it is necessary to determine how far the movable centerpiece moved into the cornea. In accordance with the foregoing, when measurement of the intraocular pressure by indentation is desired, the system of the present invention further includes a distance detection configuration for detecting a distance traveled by the movable centerpiece, and a portion of computation in the calculation unit for determining intraocular pressure, based on the distance traveled by the movable central part in the application of the previously determined amount of force. Preferably, the computing portion responds to the current-producing circuits, such that, once the predetermined amount of force is applied, the computing portion receives an output voltage from the distance detection configuration.

Then, the computational portion, based on displacement associated with the particular output voltage, determines the intraocular pressure. In addition, the present invention includes alternative modalities, as will be described later herein, to perform measurements related to the indentation of the eye. Accordingly, clearly, the present invention is not limited to the aforementioned example indentation device. The aforementioned indentation device of the present invention can also be used to non-invasively measure the hydrodynamics of an eye, including the ease of outward flow. The method of the present invention preferably comprises several steps, including the following: According to a first step, an indentation device is placed in contact with the cornea. Preferably, the indentation device comprises the contact device of the present invention. Next, at least a movable portion of the indentation device moves into the cornea, using a first predetermined amount of force, to achieve indentation of the cornea. An intraocular pressure is then determined based on a first distance traveled towards the cornea by the movable portion of the indentation device during the application of the first predetermined amount of force. Preferably, the intraocular pressure is determined using the aforementioned system to determine the intraocular pressure by indentation. Thereafter, the movable portion of the indentation device is rapidly reciprocated into the cornea and away from the cornea at a previously determined first frequency, and using a second amount of force previously determined during the movement towards the cornea, to force this way the intraocular fluid is out of the eye. The second amount of force previously determined preferably is equal to, or greater than, the first amount of previously determined force. However, it is understood that the second amount of force previously determined may be less than the first amount of force previously determined. Then move the movable portion inward of the cornea using a third amount of force previously determined, to achieve again the indentation of the cornea. A second intraocular pressure is then determined based on a second distance traveled towards the cornea by the movable portion of the indentation device during the application of the third amount of force previously determined. Since the intraocular pressure decreases as a result of forcing the intraocular fluid out of the eye during rapid reciprocation of the movable portion, it is generally understood that, unless the eye is defective so that no fluid flows out of it, the second intraocular pressure will be lower than the first intraocular pressure. This reduction in intraocular pressure indicated the ease of outward flow. Next, the movable portion of the indentation device is rapidly reciprocated back into the cornea and away from the cornea, but at a previously determined frequency, and using a fourth amount of previously determined force during movement toward the cornea. The fourth amount of previously determined force is preferably equal to, or greater than, the second amount of previously determined force; however, it is understood that the fourth amount of force previously determined may be less than the second amount of previously determined force. In this way, the extra intraocular fluid was forced out of the eye. The movable portion subsequently moves into the cornea using a fifth amount of previously determined force to again achieve indentation of the cornea. Later, a third intraocular pressure is determined based on a third distance traveled to the cornea by the movable portion of the indentation device during the application of the fifth amount of previously determined force. The differences between the first, second, and third distances are then preferably calculated, the differences of which indicate the volume of the intraocular fluid leaving the eye, and therefore, also indicate the ease of outward flow. It is understood that the difference between the first and last distances can be used, and in this aspect, it is not necessary to use the differences between the three distances. In fact, the difference between any two of the distances will suffice. Although the relationship between the ease of flow out and the differences detected varies when the different parameters of the method and the dimensions of the indentation device change, the relationship for the given dimensions can be easily determined by known experimental techniques, and / or by using the known Friedenwald tables. Preferably, the method also comprises the step of plotting the differences between the first, second, third distances, to create a graph of the differences, and compare the resulting graph of differences with that of a normal eye, to determine if there is irregularity. ^ nl ease of flow outwards present. The above and other objects and advantages 1 * *: will become clearer when reference is made to the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic block diagram illustrating a system for measuring intraocular pressure in accordance with a preferred embodiment of the present invention. Figures 2A-2D schematically illustrate a preferred embodiment of a contact device according to the present invention. Figure 3 schematically illustrates a view of a patient when using the system illustrated in Figure 1 Figures 4 and 5 schematically illustrate optical elements of multiple filters in accordance with a preferred embodiment of the present invention. Figures 5A-5F illustrate a preferred embodiment of an applicator for gently applying the contact device to the cornea in accordance with the present invention. Figure 6 illustrates an exemplary circuit for performing different aspects of the embodiment illustrated in Figure 1. Figures 7A and 7B are block diagrams illustrating a configuration that can compensate for deviations in corneal thickness in accordance with the present invention. invention. Figures 8A and 8B schematically illustrate a contact device using a bar code technology in accordance with a preferred embodiment of the present invention. Figures 9A and 9B schematically illustrate a contact device using color detection technology in accordance with a preferred embodiment of the present invention. Figure 10 illustrates an alternative contact device in accordance with still another preferred embodiment of the present invention. Figures HA and 11B schematically illustrate an indentation distance detection configuration according to a preferred embodiment of the present invention. Figure 12 is a cross-sectional view of an alternative contact device in accordance with another preferred embodiment of the present invention. Figures 13A-15 are transverse sectional views of alternative contact devices in accordance with other embodiments of the present invention. Figure 16 illustrates schematically an alternative modality of the system for measuring the intraocular pressure by flattening, in accordance with the present invention. Figure 16A is a graph illustrating the force (F) as a function of the distance (x) separating a movable central part from the pole of a magnetic actuator in accordance with the present invention. Figure 17 illustrates schematically an alternative optical alignment system in accordance with the present invention. Figures 18 and 19 schematically illustrate configurations for guiding the patient during the alignment of his eye in the apparatus of the present invention. Figures 20A and 20B illustrate schematically an alternative embodiment for measuring intraocular pressure by indentation. Figures 21 and 22 schematically illustrate the embodiments of the present invention, which facilitate placement of the contact device on the sclera of the eye. Figure 23 is a plan view of an alternative contact device that can be used to measure episcleral venous pressure in accordance with the present invention. Figure 24 is a cross-sectional view of an alternative contact device that can be used to measure the episcleral venous pressure according to the present invention. Figure 25 schematically illustrates an alternative embodiment of the present invention, which includes a contact device with a pressure transducer mounted thereon. Figure 25A is a cross-sectional view of the alternative embodiment illustrated in Figure 25. Figure 26 is a cross-sectional view illustrating the pressure transducer of Figure 25. Figure 27 illustrates schematically the alternative embodiment of the Figure 25 when it is located in the eye of a patient. Figure 28 illustrates an alternative mode where two pressure transducers are used. Figure 29 illustrates an alternative embodiment using a centrally disposed pressure transducer. Figure 30 illustrates a preferred assembly of the alternative embodiment for eyeglass frames. Figure 31 is a block diagram of a preferred circuit defined by the alternative embodiment illustrated in Figure 25.

DESCRIPTION OF THE PREFERRED MODALITIES APPLICATION Now a preferred embodiment of the present invention will be described with reference to the drawings. In accordance with the preferred embodiment illustrated in Fig. 1, a system for measuring intraocular pressure by flattening is provided. The system includes a contact device 2 to be placed in contact with the cornea 4, and its actuating apparatus 6 for actuating the contact device 2, such that a portion thereof projects inwardly against the cornea 4, to provide a amount of flattening previously determined. The system further includes a detection configuration 8 for detecting when the predetermined amount of flattening of the cornea 4 has been reached, and a calculation unit 10 which responds to the detection configuration 8, for determining the intraocular pressure, based on the amount of force that the contact device 2 must apply against the cornea in order to achieve the amount of previously determined flattening. The contact device 2 illustrated in Fig. 1 has an exaggerated thickness to distinguish it more clearly from the cornea 4. Figures 2A-2D more accurately illustrate a preferred embodiment of the contact device _, which includes a substantially rigid annular member 1- , a flexible membrane 14, and a movable centerpiece 1- E The substantially rigid annular member 12 includes an internal concave portion 18 configured to engage an outer surface of the cornea 4, and having a hole 2 defined therein. The substantially rigid annular member 12 has a maximum thickness (preferably approximately 1 millimeter) in the hole 20, and a progressively decreasing thickness towards a periphery 21 of the substantially rigid annular member 12. The diameter of the rigid annular member is approximately 11 millimeters , and the diameter of the hole 20 is approximately 5.1 millimeters in accordance with a preferred embodiment. Preferably, the substantially rigid annular member 12 is made of transparent polymethyl methacrylate; however, it is understood that many other materials, such as glass and appropriately rigid polymer plastics, can be used to make the annular member 12. Preferably, the materials are selected so as not to interfere with light directed toward the cornea or reflected from the same The flexible membrane 14 is preferably secured to the inner concave surface 18 of the substantially rigid annular member 12, to provide comfort for the user, by preventing scrapes or abrasions to the epithelial layer of the cornea. The flexible membrane 14 is coextensive with at least the hole 20 in the annular member 12, and includes at least one transparent area 22. Preferably, the transparent area 22 extends throughout the flexible membrane 14, and the flexible membrane 14 is coextensive with the entire inner concave surface 18 of the rigid annular member 12. In accordance with a preferred configuration, only the periphery of the flexible membrane 14 and the periphery of the rigid annular member 12 are secured to each other. This tends to minimize any resistance that the flexible membrane could exert against the displacement of the moving centerpiece 16 towards the cornea 4. In accordance with an alternative configuration, the flexible membrane 14 is coextensive with the rigid annular member, and is heat sealed same over its entire extension, except for a circular region within about 1 millimeter of the hole 20. Although the flexible membrane 14 preferably consists of a soft and thin polymer, such as a transparent silicone elastic, transparent silicone rubber (used in conventional contact lenses), transparent flexible acrylic (used in conventional intraocular lenses), transparent hydrogel, or the like, it is well understood that other materials may be used in the manufacture of flexible membrane 14. Movable centerpiece 16 Sliding inside the hole 20, and includes a substantially flat internal side 24 secured to the flexible membrane 14. The engagement of the inner side 24 to the flexible membrane 14 is preferably provided by adhesion or thermal contact techniques. However, it is understood that other different techniques can be used in order to securely couple the inner side 24 to the flexible membrane 14. Preferably, the movable centerpiece 16 has a diameter of approximately 5.0 millimeters, and a thickness of approximately 1. millimeter. A substantially cylindrical wall 42 is defined circumferentially around the hole 20, by virtue of the increased thickness of the rigid annular member 12 at the periphery of the orifice 20. The movable centerpiece 16 is slidably disposed against this wall 42 in a piston-like manner, and preferably it has a thickness which is coupled with the height of the cylindrical wall 42. In use, the substantially flat inner side 24 flattens a portion of the cornea 4 upon actuation of the movable centerpiece 16 by the driving apparatus six. The overall dimensions of the substantially rigid annular member 12, the flexible membrane 14, and the movable centerpiece 16, are determined by balancing various factors, including the desired range of forces applied to the cornea 4 during flattening, the patient's discomfort tolerances. , the minimum desired area of flattening, and the required stability of the contact device 2 on the cornea 4. In addition, the dimensions of the movable central part 16 are preferably selected such that the relative rotation between the central part is precluded movable 1 and the substantially rigid annular member 12, without impeding the aforementioned piston-type sliding. The materials used to manufacture the contact device 2 are preferably selected to minimize any interference with the light incident on the cornea 4 or reflected therefrom. Preferably, the drive apparatus 6 illustrated in Figure 1 operates the movable centerpiece 16, to cause sliding of the movable centerpiece 1 in a piston-like manner toward the cornea 4. In doing so, the part movable central 16 and a central portion of the flexible membrane 14 project inwardly against the cornea 4. This is shown in Figures 2C and 2D. In this way a portion of the cornea 4 is flattened. The drive continues until a predefined amount of flattening is reached. Preferably, the movable center piece 16 includes a magnetically responsive member 26 configured to slide together with the movable centerpiece 16 in response to a magnetic field, and the actuator apparatus 6 includes a mechanism 28 for applying a magnetic field thereto. While it is understood that the mechanism 28 for applying the magnetic field may include a selectively positioned bar magnet, in accordance with a preferred embodiment, the mechanism 28 for applying the magnetic field includes a long wire coil 30 wound on a narrowly packed propeller, and the circuits 32 to produce an electrical current through the coil 30 in a progressively increasing manner. By progressively increasing the current, the magnetic field is progressively increased. The magnetic repulsion between the drive apparatus 6 and the movable centerpiece 16, accordingly, increases progressively, and in turn, this causes a progressively greater force to be applied. against the cornea 4, until s reaches the predetermined amount of flattening. Using the known principles of physics, it is understood that the electric current passing through the coil 30 will be proportional to the amount of force applied by the movable centerpiece 16 against the cornea 4 by means of the flexible membrane 14. Since the amount of force required to achieve the amount of flattening previously determined is proportional to the intraocular pressureThe amount of current required to achieve the predetermined amount of flattening will also be provided at the intraocular pressure. Therefore, a conversion factor can easily be determined to convert a current value into a pressure value ipt i-scale experimentally on the dimensions of the s - the magnetic responsiveness of the element that r ^ -. magnetically 26, the number of turns of the coil, similar. In addition to using experimental techniques, the conversion factor can also be determined using known techniques to calibrate a tonometer. These known techniques are based on a known relationship that exists between inward displacement of an indentation device and changes in volume and pressure in the indented eye. Examples of these techniques are stipulated in Shiotz, Communications: Tonometry, The Brit. J. of Ophthalmology, June 1920, pages 249-266; Friedenwald, Tonometer Calibration, Trans. Amer. Acad. of O. & O., January-February 1957, pages 108-126; and Moses, Theory and Calibration of the Schiotz Tonometer VII: Experimental Results of Tonometric Measurements: Scale Reading Versus Indentation Volume, Investigative Ophthalmology, September 1971, Volume 10, No. 9, pages 716-723. In light of the relationship between current and intraocular pressure, the calculation unit 10 includes a memory 33 for storing a current value which indicates the amount of current that passes through the coil 30, when the amount of current is reached. flattening previously determined. The calculation unit 10 also includes a conversion unit 34 for converting the current value to an indication of the intraocular pressure.

Preferably, the calculation unit 10 responds to the detection configuration 8, such that, when s reaches the predetermined amount of flattening, the value of the current is immediately stored (which corresponds to the amount of current flowing through it). of the coil 30) in the memory 33. At the same time, the calculation unit 10 produces an output signal which directs the current producing circuit 32 to terminate the current flow. In turn, this ends the force against the cornea 4. In an alternative embodiment, the current producing circuit 32 s could cause it to respond directly to the detection configuration 8 (ie, not through the calculation unit 10) , to automatically terminate the flow of current through the coil 30 upon reaching the predetermined amount of flattening. The current producing circuit 32 can constitute any circuit appropriately configured to reach the progressively increasing current. However, a preferred current producing circuit 32 includes a commutator and a direct current power supply, the combination of which can produce a step function. The preferred current-producing circuit 32 also comprises an integrating amplifier which integrates the function per step to produce the progressively increasing current. The magnetically responsive element 26 is circumferentially surrounded by a transparent peripheral portion 36. The transparent peripheral portion 36 is aligned with the transparent area 22, and allows the lu to pass through the contact device 2 to the cornea 4, also allows the the light from the cornea 4 d is reflected back out of the contact device 2, through the transparent peripheral portion 36. Although the transparent peripheral portion 36 may consist entirely of air gap, for reasons of precision, and to provide u Smoother sliding of the movable centerpiece 16 through the rigid annular member 12, it is preferred that a transparent solid material forms the peripheral transparent portion 36. The transparent solid materials for example include polymethyl methacrylate, glass, hard acrylic, plastic polymers , and similar. The magnetically responsive element 26 preferably comprises an annular magnet having a central viewing hole 38 through which a patient can see while the contact device 2 is located on the cornea of the patient 4. The central vision hole 38 it is aligned with the transparent area 22 of the flexible membrane 14, and is preferably at least 1 to 2 millimeters in diameter. Although the preferred embodiment includes an annular magnet as the magnetically responsive element 26, it is understood that other different magnetically responsive elements 26 may be used, including different ferromagnetic materials and / or particle suspensions that respond magnetically in liquid. The magnetically responsive element 26 can also consist of a plurality of small bar magnets configured in a circle, thus defining an opening equivalent to the illustrated central vision orifice 38. A transparent magnet can also be used. Preferably, a visual display 4 is provided to numerically display the intraocular pressure detected by the system. The visual display 40 preferably comprises a liquid crystal display (LCD) or a visual display of a light emitting diode (LED) connected to and responding to the conversion unit 34 of the calculation unit 10. Alternatively, the 40 s visual display can be set to give indications of whether the intraocular pressure is within certain ranges. In this aspect, visual display 40 may include a green light emitting diode 40A, a yellow light emitting diode 40B, and a red light emitting diode 40C. When the pressure is within a previously determined alt range, red light emitting diode 40C is illuminated to indicate that medical attention is needed. When the intraocular pressure is within a normal range, the green light emitting diode 40A is illuminated. The yellow light emitting diode 40B is illuminated when the pressure is between the normal range and the high range, to indicate that the pressure is a little high and that, although medical attention is not currently needed, it is recommended to monitor carefully and frequently . Preferably, since different patients may have different sensitivities or reactions at the same intraocular pressure, the ranges corresponding to each light emitting diode 40A, 40B, 40C are calibrated for each patient by a physician attending. In this way, patients who are more susceptible to the consequences of increased intraocular pressure can be alerted to seek medical attention at a pressure lower than the pressure at which other less susceptible patients are alerted to take the same measure. Range calibrations can be made using any known 40D calibration device, including variable gain amplifiers or voltage divider networks with variable resistors. The detection configuration 8 preferably comprises an optical detection system including two primary beam emitters 44, 46; two light sensors 43, 50; and two converging lenses 52, 54. Any of a plurality of commercially available beam emitters such as emitters 44, 46, including low power laser beam devices and infrared beam emitting devices ( GO) . Preferably, the device i and the primary beam emitters 44, 46 are configured one with respect to the others, in such a way that each of the primary beam emitters 44, 46 emits a primary beam of light towards the cornea through the transparent area 22 of the device, and demods that the primary light beam is reflected back through device 2 via cornea 4, to thereby produce the reflected light beams 60, 62 with a direction d propagation dependent on the amount of flattening of the cornea. The two light sensors 48, 50 and the two converging lenses 52, 54 are preferably configured to be aligned with the reflected beams 60, 62 of the light, only when the predetermined amount of flattening of the cornea 4 has been reached. preferably, primary beams 56, 58 pass through the substantially transparent peripheral portion 36. Although Figure 1 shows the reflected beams 60, 62 of the divergent light moving away from each other, and far away from the two converging lenses 52, 54, and the light sensors 48, 50, it is understood that, as the cornea 4 is flattened, you make it reflected 60, 62 the two light sensors 48, 50 and the two converging lenses 52, 54 will be approximated. When s reaches the predetermined amount of flattening, the reflected beams 60, 62 are directly aligned with the converging lenses 52, 54 and the sensors 48, 50. Accordingly, the sensors 48, 50 can detect when the predetermined amount of flattening has been reached, merely by detecting the presence of the reflected beams 60 62. Preferably, it is considered that the previously determined flattening amount exists when all the sensors 48, 50 receive a respective beam of the reflected ones 60, 62. Although the configuration illustrated in general and effective using two primary beam emitters 44, 46 and of light sensors 48, 50, it is possible to To achieve better accuracy in patients with astigmatism, by providing four beam emitters and four light sensors orthogonally configured with respect to each other around the longitudinal axis of the driving apparatus 6. As in the case with two beam emitters 44, 46 and light sensors 48, 50, s consider that the predetermined amount of flattening preferably exists when all the sensors receive a respective beam of the reflected beams. Preferably a vision configuration is provided to indicate when the drive apparatus 6 and the detection configuration 8 are properly aligned with the device 2. Preferably, the vision configuration includes the central vision hole 38 in the movable centerpiece 16, through which a patient can see while the device 2 is located on the cornea of the patient 4. The central vision hole 38 is aligned with the transparent area 22. In addition, the operating apparatus 6 includes a tubular housing 64 which has a first extremity 66 for positioning on an eye equipped with the device 2 and a second opposite end 68 having at least one marking 70 configured in such a way that, when the patient goes through the central vision hole 38 at the mark 70, The device 2 is appropriately aligned with the drive apparatus 6 and the detection configuration 8. Preferably, the second Extreme 68 includes an inner mirror surface 72, and the mark 70 generally comprises a set of crossed capillaries. Figure 3 illustrates the view that is seen by a patient through the central vision hole 38 when the device 2 is properly aligned with the driving apparatus 6 and the detection configuration 8. When an appropriate alignment is achieved, the reflected image 74 of the central viewing hole 38 appears on the mirror surface 72 at the intersection of the crossed capillaries, which constitute the mark 70. (The size of the image 74 is exaggerated in Figure 3 to distinguish more clearly from other elements of the drawing) . Preferably, at least one light 75 is provided inside the tubular housing 64 to illuminate the interior of the housing 64, facilitate visualization of the cross capillaries and the reflected image 74. Preferably, the inner mirror surface 72 acts as a mirror only when the light 75 is on top, and becomes largely transparent when the light 75 is deactivated, due to the darkness inside the tubular housing 64. For this purpose, the second end 6 of the tubular housing 68 can be manufactured using "glass one way ", which is frequently found in the security and surveillance equipment. Alternatively, if the device is to be used primarily by doctors, optometrists, the like, the second end 68 may be merely transparent. On the other hand, if the device is going to be used by patients to self-monitor, it is understood that the second end 68 can merely include a mirror. The system also preferably includes an optical distance measuring mechanism, to indicate whether the device 2 is separated at an appropriate axial distance from the driving apparatus 6 and the detection configuration 8. The optical distance measuring mechanism of preference It is used in conjunction with the vision configuration. Preferably, the optical distance measurement mechanism includes a distance measurement beam emitter 76, for emitting an optical distance measurement beam 78 towards the device 2. The device 2 may reflect the distance measurement beam 78, to produce a first reflected distance measurement beam 80. Configured in the path of the first reflected distance measurement beam 80, there is preferably a convex mirror 82. The convex mirror 82 reflects the first reflected distance measurement beam 80 to create a second reflected distance measuring beam 84, and serves to amplify any variations in the first reflected propagation direction. The second reflected distance measurement beam 84 is generally directed towards a distance measurement beam detector 86. The distance measurement beam detector 86 is configured in such a way that the second reflected distance measurement beam 84 impacts a previously determined portion of the distance measurement beam detector 86 only when the device 2 is located at the appropriate axial distance from the driving apparatus 6 and the detection configuration 8. When the appropriate axial distance is missing, the second measuring beam of reflected distance impacts on another portion of beam detector 86. Preferably an indicator 88 is connected, such as a visual display of liquid crystal display or light emitting diode, and it responds to beam detector 86 to indicate that the appropriate axial distance, when the reflected distance measuring beam impacts the previously determined portion of the beam detector Distance measurement. Preferably, as illustrated in FIG. 1, the distance measurement beam detector 86 includes a multiple filter optical element 90 configured to receive the second reflected distance measuring beam 84. The multi-filter optical element 90 contains a plurality of optical filters 92. Each of the optical filters 92 filtered a different percentage of light, the predetermined portion of the detector 86 being defined by a particulate filter of the optical filters 92 and a percentage of filtering associated therewith. The distance measurement beam detector 8 further includes a beam intensity detection sensor 94, for detecting the intensity of the second reflected distance measuring beam 84, after the beam 84 passes through the multi-filter optical element. 90. Since the optical element of multiple filters causes this intensity to vary with the axial distance, the intensity indicates whether the device 2 is at the appropriate distance from the drive apparatus 6 and the detection configuration 8. Preferably, a convergent lens 96 between the multiple filter optical element 90 and the beam intensity detecting sensor 94, for focusing the second reflected distance measurement beam 84 on the beam intensity detecting sensor 94, after the beam passes 84 through the optical element of multiple filters 90. Preferably, the indicator 88 responds to the beam intensity detection sensor 94, to indicate which m The corrective eddy should be taken, when the device 2 is not at the appropriate axial distance from the driving apparatus 6 and the detection configuration 8, in order to reach the proper distance. The indication given by the indicator 88 s is based on the intensity at which the plurality of optical filters 92 reaches the particular intensity by virtue of the percentage of filtration associated with them. For example, when the device 2 is too far away from the driving apparatus 6, the second reflected distance measuring beam 84 passes through a dark filter of the filters 92. Consequently, there is a reduction in the intensity of the beam which causes the Beam intensity sensing sensor 94 drives the indicator 88, with a signal indicating the need to bring the device 2 closer to the driving apparatus. The indicator 88 responds to this signal by communicating the need to a user of the system. In an alternative way, the signal indicating the need to bring the device 2 closer to the drive apparatus, can be applied to a computer that makes the corrections automatically. In a similar manner, when the device 2 is excessively close to the driving apparatus 6, the second reflected distance measurement beam 84 passes through a lighter filter of the filters 92. Consequently, there is an increase in the intensity of the beam, which causes the beam intensity sensing sensor 94 to pulse the indicator 88, with a signal indicating the need to move the device further away from the driving apparatus. The indicator 8 responds to this signal by communicating the need to a system user. In addition, the computer controlled movement of the drive apparatus farther from the device 2, s can be achieved automatically by providing an appropriate computer controlled movement mechanism responsive to the signal indicating the need to move the device 2 m away from the drive apparatus . With reference to Figure 3, the indicator 88 d preferably comprises three light emitting diodes configured in a horizontal line through the second receiving end 68. When illuminated, the left light emitting diode 88a, which is preferably yellow , indicates that the contact device 2 is too far from the actuator 6 and the detection configuration 8. In a similar manner, when illuminated, the right light emitting diode 88b, which is preferably red, indicates that the device of contact 2 is too close to the drive apparatus 6 and the detection configuration 8. When the appropriate distance is reached, the light-emitting diode d-88c is illuminated. Preferably, the central lu emitting diode 88c is green. The light-emitting diodes 88a-88c s selectively illuminate by the beam intensity detection sensor 94, in response to beam intensity. Although Figure 1 illustrates a configuration d filters 92 where a reduction in intensity meant a need to move the device closer, it is understood that the present invention is not limited to this configuration. The multi-filter optical element 90, for example, can be inverted, such that the darker filter of the filters 92 is placed adjacent the end 68 of the tubular housing 64. When this configuration is used, an increase in the intensity of the beam would mean a need to move the device 2 further away from the driving apparatus 6. Preferably, the driving apparatus 6 (or at least the coil 30 thereof) is slidably mounted inside the housing 64, and a knob mechanism is provided. and gear (e.g., rack and pinion) to selectively move the drive apparatus 6 (or coil 30 thereof) axially through the housing 64 in a perfectly linear fashion, until the appropriate axial distance 'is reached from the device 2. When this configuration is provided, the first end 66 of the housing 64 serves as a positioning mechanism for the contact 2 against which the patient compresses the facial area surrounding the eye to be examined. Once the facial area rests against the first extremity 66, the knob and gear mechanism is manipulated to place the driving apparatus 6 (or the coil 30 thereof) at the appropriate axial distance from the contact device 2. Although the Facial contact with the first end 66 improves stability, it is understood that facial contact is not an essential step in the use of the present invention. The system also preferably includes an optical alignment mechanism to indicate whether the device 2 is properly aligned with the driving apparatus 6 and the detection configuration 8. The optical alignment mechanism includes two alignment beam detectors 48 ', 50' to detect respectively the reflected light beams 60, 62 before any flattening. The alignment beam detectors 48 ', 50' are configured in such a way that the reflected light beams 60, 62? T.clock respectively a predetermined portion of the alignment beam detectors 48 ', 50' before the flattening, only when the device Z is appropriately aligned with respect to the actuating drive i: and the detection configuration 8. _: __.-. or the device 2 is not properly aligned, the reflected ones 60, 62 impact another portion of the alignment beam detectors 48 ', 50', as will be described later herein. The optical alignment mechanism further includes an indicator configuration that responds to the alignment beam detectors 48 ', 50'. The preferred indicator configuration includes a set of light emitting diodes 98, 100, 102, 104 which indicate that appropriate alignment has been achieved only when the reflected light beams 60, 62 respectively impact the previously determined portion of the light detectors. alignment beam 48 ', 50' before flattening. Preferably, each of the alignment beam detectors 48 ', 50' includes a respective multiple filter optical element 106, 108. The multiple filter optical elements 106, 108 are configured to receive the reflected light beams 60, 62 Each optical element of multiple filters 106, 108 contains a plurality of optical filters 11010-110g0 (Figures 4 and 5), each of which filters a different percentage of light. In Figures 4 and 5, the different percentages are labeled between 10 and 90 percent in increments of 10 percent. However, it is understood that many other configurations and increments will suffice. For the illustrated configuration, it is preferred that the centrally located filters 11050 that filter 50 percent of the light, represent the predetermined portion of each alignment beam detector 48 ', 50'. Accordingly, an appropriate alignment is considered to exist when the reflected light beams 60, 62 pass through the filters 11050, and the intensity of the beams 60, 62 is reduced by 50 percent. Each of the alignment beam detectors 48 ', 50' also preferably includes a beam intensity detector 112, 114, for respectively detecting the intensity of the reflected light beams 60, 62 after which the reflected light beams 60, 62 pass through the optical elements of multiple filters 106, 108. The intensity of each beam indicates whether the device 2 is properly aligned with respect to the driving apparatus 6 and the detection configuration. A converging lens 116, 118 is preferably located between each optical multi-filter element 106, 108 and its respective beam intensity detector 112, 114. The converging lens 116, 118 focuses the reflected light beams 60, 62 on the detectors of beam intensity 112, 114, after the reflected beams 60, 62 pass through the multiple filter optical elements 106, 108. Each of the beam intensity detectors 112, 114 has its output connected to a circuit of detecting the alignment beam which, based on the respective outputs from the beam intensity detectors 112, 114, determines whether there is an appropriate alignment, and if not, drives the appropriate diode of the light emitting diodes 98, 100, 102 , 104, to indicate the corrective action that should be taken. As illustrated in Figure 3, the light emitting diodes 98, 100, 102, 104 are respectively configured above, to the right of, below, and to the left of, the intersection of the crossed capillaries 70. No light-emitting diode 98, 100, 102, 104 it lights up, unless there is a bad alignment. Accordingly, a lack of illumination indicates that the device 2 is properly aligned with the driving apparatus 6 and the detection configuration 8. When the device 2 on the cornea 4 is too high, the light beams 56, 58 impact a portion. inferior of the cornea 4, and due to the curvature of the cornea, they are reflected in a more downward direction. Accordingly, the reflected beams 60, 62 impact on the lower half of the multiple filter elements 106, 108, and the intensity of each reflected beam 60, 62 is reduced by no more than 30 percent. Then the respective intensity reductions are communicated to the alignment detection circuit 120 by the beam intensity detectors 112, 114. The alignment detection circuit 120 interprets this intensity reduction, as a result of the misalignment, wherein the device 2 is too high The alignment detection circuit 120, therefore, causes the upper light emitting diode 98 to light up. This illumination indicates to the user that the device 2 is too high, and that it must be lowered with respect to the drive apparatus 6 and to the detection configuration 8. In a similar manner, when the device 2 on the cornea 4 is too low, the light beams 56, 58 impact an upper portion of the cornea 4, and due to the curvature of the cornea, are reflected in a upward direction Accordingly, the reflected beams 60, 62 impact on the upper half of the multiple filter elements 106, 108, and the intensity of each reflected beam 60, 62 is reduced by at least 70 percent. The respective intensity reductions are then communicated to the alignment detection circuit 120 by the beam intensity detectors 112, 114. The alignment detection circuit 120 interprets this particular intensity reduction as a result of the misalignment between the device 2 which it is too low The alignment detection circuit 120, therefore, causes the lower light emitting diode 102 to illuminate. This illumination indicates to the user that the device 2 is too low, and that it must be raised with respect to the driving apparatus 6 and the detection configuration 8. With reference to Figure 1, when the device 2 is too far to the right, the beams 56, 5 impact one side further to the left of the cornea 4, due to the curvature of the cornea, are reflected in a more direction to the left. Accordingly, the reflected ones 60, 62 impact on the left halves of the elements of multiple filters 106, 108. Since the filtering percentages decrease from left to right in the element of multiple filters 106, and increase from left to right in the multiple filter element 108, there will be a difference in the intensities detected by the beam intensity detectors 112, 114. In particular, the beam intensity detector 112 will detect less intensity than the beam intensity detector 114. Then it will be communicates the different intensities to the alignment detection circuit 120 by the beam intensity detectors 112, 114. The alignment detection circuit 120 interprets the difference in intensity, wherein the intensity in the beam intensity detector 114 is more high that that in the beam intensity detector 112, as a result of a misalignment, where the device 2 is too far towards the right in Figure 1 (too far to the left in Figure 3). The alignment detection circuit 120, therefore, causes the left light emitting diode 104 to light up. This illumination indicates to the user that the device 2 is too far to the left (in Figure 3), and that it must be moved towards the right (to the left in Figure 1) with respect to the drive apparatus 6 and the detection configuration 8. In a similar manner, when the device 2 of Figure 1 is too far to the left, the beams 56, 58 impact one side further to the right of the cornea 4, and due to the curvature of the cornea, are reflected in a direction further to the right. Accordingly, the reflected beams 60, 62 impact on the right halves of the multiple filter elements 106, 108. Since the filtering percentages decrease from left to right in the multiple filter element 106, and increase from left to right in the multiple filter element 108, there will be a difference in the intensities detected by the beam intensifier detectors 112, 114. In particular, the beam intensity detector 112 will detect more intensity than the beam intensity detector 114. Then it will be communicate the different intensities to the alignment detection circuit 120 by the beam intensity detectors 112, 114. The alignment detection circuit 120 interprets the difference in intensity, wherein the intensity in the beam intensity detector 114 is lower than that in the beam intensity detector 112, as a result of a misalignment, wherein the device 2 is too far to the left in Figure 1 (too far to the right in Figure 3). Accordingly, the alignment detection circuit 120 causes the right light emitting diode 100 to illuminate. This illumination indicates to the user that the device 2 is too far to the right (in Figure 3), and that it must be moved toward the left (to the right in Figure 1) with respect to the drive apparatus 6 and to the detection configuration 8. The combination of light-emitting diodes 98, 100, 102, 104, and the alignment detection circuit 120, accordingly , constitutes a visual display configuration that responds to beam intensity detectors 112, 114, and indicates which corrective action must be taken, when device 2 is not properly aligned, in order to achieve an appropriate alignment. Preferably, the substantially transparent peripheral portion 36 of the movable centerpiece 16 is sufficiently ax to allow the passage of the bundles 56, 58 towards the cornea 4, even during misalignment. It is understood that an automatic alignment correction can be provided by means of a computer controlled movement of the drive apparatus up, down, to the right, and / or to the left, whose computer controlled movement can be generated by a Appropriate computer-controlled movement mechanism that responds to the optical alignment mechanism.

The optical alignment mechanism of preference is used in conjunction with the vision configuration, so that the optical alignment mechanism merely provides indications of minor alignment corrections, while the vision configuration provides an indication of greater alignment corrections. However, it is understood that the optical alignment mechanism s can use instead of the viewing mechanism, if the substantially transparent peripheral portion 36 becomes sufficiently wide. Although the above alignment mechanism used the same reflected beams 60, 62, used by the detection configuration 8, it is understood that separate alignment beam emitters can be used in order to provide separate separate alignment beams. The above configuration is preferred because it saves the need to provide additional emitters, and therefore, is less expensive to manufacture. However, the optional alignment beam emitters 112, 124 are illustrated in Figure 1. The alignment mechanism that uses these emitters of r. The optional alignment 112, 124 would operate essentially the same way as its counterpart using the mirrored 60, 62. In particular, each of the emitters i ^:. The alignment beam 122, 124 emits an optical alignment beam to the device 2. The alignment beam is reflected by the cornea 4 to produce a reflected alignment beam. - The alignment beam detectors 48 ', 50' are configured to receive, not the reflected light beams 60, 62, but rather the reflected alignment beams, when the alignment beam emitters 122, 124. are present. more specifically, the reflected alignment beams impact a previously determined portion of each alignment beam detector 48 '50' before flattening, only when the device 2 is properly aligned with respect to the driving apparatus 6 and the detection configuration 8. The rest of the preferred system includes the same components, and operates in the same manner as the system that does not use the optional alignment beam emitters 122, 124. The system may further include an applicator for gently positioning the contact device 2 on the cornea 4. As illustrated in Figures 5A-5F, a preferred embodiment of the applicator 127 includes an annular piece 127A at the tip of the applique. 127. The annular member 127A engages the shape of the movable centerpiece 16. Preferably, the applicator 127 also includes a conduit 127CN having an open end that opens toward the annular member 127A. An opposite end of conduit 127CN is connected with a clamping bulb 127SB. The squeeze bulb 127SB includes a one-way valve 127V that allows air flow into the squeeze bulb 127SB, but prevents the flow of air out of the squeeze bulb 127SB through the valve 127V. When the tightening bulb 127SB is depressed, and then released, a suction effect is created at the open end of the conduct 127CN, when the tightening bulb 127SB tries to expand to its shape before tightening. This suction effect s can be used to retain the contact device 2 at the tip of the applicator 127. In addition, a pivoted lever system 127B is configured to separate the movable centerpiece 16 from the annular piece 127A, when the knob is depressed 127C in the base of the applicator 127, thereby separating the contact device 2 from the annular part 127A. Alternatively, the tip of the applicator 127 can be magnetized and demagnetized selectively, using electric current flowing through the annular part 127A. This configuration replaces the pivoted lever system 127B with a magnetization mechanism that can provide a magnetic field that repels the movable centerpiece 16, thereby applying the contact device 2 to the cornea 4. In Figure 6 it is schematically illustrated a preferred circuit configuration for implementing the above element combination. In accordance with the preferred circuit configuration, the beam intensity detectors 112, 114 comprise a pair of photosensors which provide a voltage output proportional to the intensity of the detected beam. The output from each beam intensity detector 112, 114 is connected respectively to the non-inverting input terminal of a filtering amplifier 126, 128. The reversing terminals of the filtering amplifiers 126, 128 are connected to ground . The amplifiers 126, 128, therefore, provide a filtering and amplification effect. In order to determine whether there is an appropriate vertical alignment, the output of the filtering amplifier 128 is applied to an inverting input terminal of vertical alignment comparator 130. The vertical alignment comparator 130 has its input terminal which is of investment connected to a reference voltage Vrefx. The reference voltage Vrefx is selected in such a way that s approaches the output from the filtering amplifier 128, provided that the light beam 62 impacts the central row d filters 11040_60 of the multi-filter optical element 10 (i.e. reaches the appropriate vertical alignment). Accordingly, the output from the comparator 130 and approximately 0 when an appropriate vertical alignment is reached, "is significantly negative when the contact device 2 is too high, and is significantly positive when the contact device 2 is too low. This output from the comparator 130 is then applied to a vertical alignment switch 132. The vertical alignment switch 132 is logically configured to provide a positive voltage to an AND (Y) gate 134 only when the output from the comparator 130 is approximately 0. , to provide a positive voltage to the light-emitting diode 98 only when the output from the comparator 130 is negative, and to provide a positive voltage to the light-emitting diode 102 only when the output from the comparator 130 is positive. In this way the light-emitting diodes 98, 102 are illuminated only when there is a bad vertical alignment, and each illumination clearly indicates which corrective action must be taken. In order to determine whether there is an appropriate horizontal alignment, the output from the filtering amplifier 126 is applied to a non-inverting input terminal of a horizontal alignment comparator 136, whthe inverting input terminal of the comparator of horizontal alignment 136 is connected to the output from the filtering amplifier 128. Accordingly, the comparator 136 produces an output that is proportional to the difference between the intensities detected by the beam intensity detectors 112, 114. This difference is zero always light beams 60, 62 impact the central column d filters 11020. 11050, 11080 of the optical elements d multiple filters 106, 108 (ie, when appropriate horizontal alignment is reached). Accordingly, the output from the comparator 13 is zero when the proper horizontal alignment is reached, it is negative when the contact device 2 is too far to the right (in Figure 1), and it is positive when the contact device 2 is too large. to the left (e Figure 1). This output is then applied from the comparator 130 to a horizontal alignment switch 138. The horizontal alignment switch 138 is logically configured to provide a positive voltage to the AND (Y) gate 134, only when the output from the comparator 136 is zero , to provide a positive voltage to the light-emitting diode 104 only when the output from the comparator 136 is negative, and to provide a positive voltage to the light-emitting diode 100 only when the output from the comparator 136 is positive. In this way the light-emitting diodes 11, 104 only when there is a bad horizontal alignment, and lighting illumination clearly indicates which corrective measure - must be taken. In accordance with the configuration of: - the preferred option shown in Figure 6, the beam intensity detection sensor 94 of the distance measurement beam detector 86 includes a photosensor 140 which produces a voltage output proportional to the beam intensity detected. This voltage output is applied to the non-reversing input terminal of a filtering amplifier 142. The reversing termination of the filtering amplifier 142 is connected to ground. In accordance with the foregoing, the filtering amplifier 142 filters and amplifies the voltage output from the photosensor 140. The output from the filtering amplifier 142 is applied to the non-inverting input terminal of a distance measuring comparator. 14 The compared 144 has its inversion terminal connected to a voltage d reference Vref2. Preferably, the reference voltage Vref2 is selected such that it is equal to the output of filtering amplifier 142, only when the appropriate axial distance separates the contact device 2 from the actuating device 6 and from the detection configuration 8. Accordingly, the output from the comparator 144 is zero provided that the appropriate axial negative e-distance is reached provided that the second reflected beam 84 passes through a dark portion of the multiple filter optical element 90 (ie, as long as the axial distance is too large), and is positive as long as the second reflected beam 8 passes through a light portion of the optical element d of multiple filters 90 (ie, provided the distance axia is too short). The output from the comparator 14 is then applied to a distance measurement switch 146. The distance measurement switch 146 drives the light-emitting diode 88c with a positive voltage, provided that the output from the comparator 144 is zero, drives the light emitting diode 88 only when the output from comparator 144 is positive, and drives light emitting diode 88a only when output from comparator 144 is negative. In this way, the light-emitting diodes 88a, 88b are illuminated only when the axial distance separating the contact device 2 from the actuator 6 and the detection configuration 8 is inappropriate. Each illumination clearly indicates the corrective measure that must be taken. Of course, when the light emitting diode 88c is illuminated, no corrective action is needed. With respect to the detection configuration 8, the preferred circuit configuration illustrated in Figure 6 includes the two light sensors 48, 50. The outputs from the light sensors 48, 50 are applied to, and are summed by, an adder. 147. The output from the adder 147 is then applied to the non-inverting input terminal of a filtering amplifier 148. The inverting input terminal of the same amplifier 148 is connected to ground. As a result, the filtering amplifier 148 filters and amplifies the sum of the output voltages from the light sensor 48, 50. The output from the filtering amplifier 148 s then applies to the input terminal which is not reversed from a flattening comparator 150. The inverting input terminal of the flattening comparator 150 is connected to the reference voltage Vref3. Preferably, the reference voltage Vref3 is selected to be equal to the output from the filtering amplifier 148 only when the predetermined amount of flattening is reached (ie, when the reflected beams 60, 62 impact the lu sensors 48, fifty) . Accordingly, the output from the flattening comparator 150 remains negative until the predetermined amount of flattening is reached. The output from the smoothing comparator 150 s connects to a smoothing switch 152. The smoothing switch 152 provides a positive output voltage when the output from the smoothing comparator 150 is negative, and terminates its positive output voltage whenever the output from the flattening comparator 150 'becomes positive. Preferably, the output from the flattening switch 152 is connected to a flattening horn 154, which audibly indicates when the predetermined amount of flattening has been reached. In particular, the bobbin 154 is activated whenever the output voltage of the flattening switch 152 initially disappears. In the preferred circuit of FIG. 6, the coil 3 is electrically connected to the current producing circuit 32, which, at its It also includes a signal generator which can produce the progressively increasing current in the coil 30. The current producing circuit 32 is controlled by a start / stop switch 156, which is selectively activated and deactivated by an AN (Y) gate. 158. The AND gate (Y) 158 has two inputs, both of which must exhibit positive voltages in order to activate the start / stop switch 156 and the current producing circuit 32. A first input 160 of the two inputs, is the output from the flattening switch 152.

Since the flattening flattening switch 152 normally has a positive output voltage, the first input 160 remains positive, and the AN gate is enabled.

(Y) at least with respect to the first input 160. However, as long as the predetermined amount of flattening is reached (ie, as long as the positive output voltage is no longer present at the output from the flattening switch 152 ), the AND (Y) gate 158 deactivates the current producing circuit 32 by means of the start / stop switch 156.

The second input to gate AND (Y) 158, is the output from another gate AND (Y) 162. The other gate AN (Y) 162 provides a positive output voltage only when the squeeze action switch 164 is depressed, only when the contact device 2 is located at the appropriate axial distance from, and is appropriately aligned both vertically and horizontally with, the apparatus d drive 6 and the detection configuration 8. Accordingly, the current producing circuit 32 can not be activated unless there is an appropriate alignment and that s has reached the appropriate axial distance. In order to achieve this operation, the output from gate AND (Y) 13 is connected to a first input of gate AND (Y) 162, and the action switch to press 164 is connected to the second gate input AND (Y) 162. A delay element 163 is electrically located between the AND gate (Y) 134 and the AND gate (Y) 162. The delay element 163 maintains a positive voltage at the first input terminal to the AND gate ( Y) 162 for a predetermined period of time after which a positive voltage first appears in the salt terminal of the AND gate (Y) 134. The primary purpose of the delay is 163. to prevent the deactivation of the -i: current producing unit 32, which would arise from another -n. ^ a in response to changes in the direction of propagation. : - »the reflected beams 60, 62 during the initial stages of flattening. The pre-determined time period of preference is selected according to the maximum amount of time that could be taken to reach the predetermined amount of flattening. In accordance with the preferred circuit illustrated in Figure 6, misalignment and inappropriate axia separation of the contact device 2 with respect to the driving apparatus 6 and the detection configuration 8, is audibly announced by a loudspeaker 166, and causes the deactivation of a visual display 167. Visual display 167 and loudspeaker 166 connect and respond to an AN (Y) gate 168. The AND (Y) gate 168 has an inversion input d connected to the oppressor action switch 164, another input connected to the OR gate (or) of three input 170. The visual display 167 and the loudspeaker 166 are connected and respond to an AND gate (Y) 168. The AND gate (Y) 168 has an inversion input connected to the action switch of pressing 164, and another input connected to the compuert OR (ó) of three inputs 170. Therefore, when the action switch of pressing 164 is activated, the inverting input terminal of the AND (Y) gate 168 prevents a positive voltage from appearing at the output from the gate. AND (Y) 168. In this way the activation of the horn 166 is precluded. However, when the action switch d is not activated, any positive voltage at any of the three inputs to the OR gate (or) 170 will activate the horn 166. The three inputs to the OR gate (or) 170 are respectively connected to the outputs from three other OR gates (or) 172, 174, 176. In turn, the gates OR (or) 172, 174, 17 they have their inputs respectively connected to the light-emitting diodes 100, 104, to the light-emitting diodes 98, 102, and the light-emitting diodes 88a88b. Accordingly, whenever any of these light emitting diodes 88a, 88b, 98, 100, 102, 104 is activated, the OR gate (ó) 17 produces a positive output voltage. As a result, s will activate horn 166 whenever any of the light emitting diodes 88a, 88b, 98, 100, 102, 104 is activated, while the squeeze action switch 164 remains deactivated. Turning now to the current producing circuit 32, the output from the current producing circuit 32 is connected to the coil 30. In turn, the coil 30 is connected to the current to voltage transducer 178. The output voltage from the transducer current to voltage 178 is proportional to the current flowing through coil 30, and is applied to the calculation unit 10. Calculation unit 10 receives the output voltage from transducer 178, and converts this output voltage to indicates the current, at an output voltage that indicates the intraocular pressure. Initially, an output voltage from the filtering amplifier 142 indicating the distance axia separating the contact device 2 from the drive apparatus 6 and the detection configuration 8, s is multiplied by a reference voltage Vref4 using a multiplier 180. The Reference voltage Vref4 represents a distance calibration constant. The output from the multiplier 180 is then squared by a multiplier 182, to create an output voltage that indicates the distance to the square (d2). The output from the multiplier 182 is then supplied to an input terminal of a divider 184. The other input terminal of the divider 184 receives the output voltage indicating the current from the current-voltage transducer 178. Therefore, the divider 184 produces an output voltage that indicates the current in coil 30 divided by the distance squared (l / d2). The output voltage from the divider 184 is then applied to a multiplier 186. The multiplier 18 multiplies the output voltage from the divider 184 by a reference voltage Vref5. The reference voltage Vref5 corresponds to a conversion factor to convert the value of (I / d2) to a value that indicates the force in Newtons that is being applied by the movable centerpiece 16 against the cornea 4. Therefore, the voltage output from the multiplier 186 indicates the force in Newtons that is being applied by the movable centerpiece 16 against the cornea. Next, the output voltage from the multiplier 186 is applied to an input terminal of a divider 188. The other input terminal of the divider 188 receives a reference voltage Vref6. The reference voltage Vref6 corresponds to a calibration constant to convert the force (in Newtons) to pressure (in Passes), depending on the surface area of the substantially flat inner side 24 of the movable centerpiece. The output voltage from the divider 188, therefore, indicates the pressure (in Passes) that is exerted by the cornea 4 against the inner side of the movable centerpiece 16, in response to the displacement of the movable centerpiece 16. Since the pressure exerted by the cornea 4 depends on the surface area of the substantially flat inner side 24, the output voltage from the divider 188 indicates the intraocular pressure only when the cornea 4 is being flattened over the entire surface area of the inner side 24. To its This corresponds to the predetermined amount of flattening. Preferably, the output voltage indicating the intraocular pressure is applied to an input terminal of a multiplier 190. The multiplier 190 has another input terminal d connected to a reference voltage Vref7. The reference voltage Vref7 corresponds to a conversion factor to convert the pressure in Paséales to a pressure in millimeters d mercury (mmHg) The voltage output from the multiplied 190, p consequent, indicates the intraocular pressure and millimeters of mercury (mmHg), provided that the predetermined amount of flattening is reached. The output voltage from the multiplier 190 is then applied to the visual display 167, which provides a visual display of the intraocular pressure, based on this output voltage. Preferably, the visual display 167 or the calculation unit 10 includes a memory device 33, which stores a pressure value associated with the output voltage from the multiplier 190, provided that s reaches the predetermined amount of flattening. Since the current producing circuit 32 is deactivated automatically and immediately upon reaching the predetermined amount of flattening, the intracicle pressure corresponds to the pressure value associated with the vol -ed peak output from the multiplier 190. Therefore, the memory can be triggered to store the highest pressure value upon detecting a drop in the output voltage - ^ ie the multiplier 190. Preferably, the memory is res. to. ece automatically before any subsequent measurements of intraocular pressure. Although Figure 6 shows the visual display 16 in a digital form, it is understood that the visual display 16 can have any known shape. The visual display 16 may also include the three light-emitting diodes 40A, 40B, 40C illustrated in Figure 1, which give a visual indication of the pressure ranges which, in turn, are calibrated for each patient. As indicated above, the calculation unit 1 illustrated includes separate and distinct multipliers 180, 182, 186, 190, and dividers 184, 188, for converting the output voltage indicating the current, to an output voltage which indicates the pressure intraocular in millimeters of mercury (mmHg). The separate and different multipliers and dividers are preferably provided in such a way that variations in the characteristics of the system can be compensated by appropriately changing the reference voltages Vref4, Vref5, Vrefg and / or Vref7. However, it is understood that, when the characteristics of the system remain the same (for example, in the surface area of the inner side 24 and the desired distance separating the contact device 2 from the drive apparatus 6 and the detection configuration 8), and the conversion factors do not change, you can use a single conversion factor derived from the combination of each of the other conversion factors, together with a multiplier or divider sun, to achieve the results provided by the different multipliers and divisore shown in Figure 6. Although the combination of anterior and general elements is effective in precisely measuring the intraocular pressure in a substantial majority of patients, some patients have unusually thin or unusual thick corneas. In turn, this may cause slight deviations in the measured infra-ocular pressure. In order to compensate for these deviations, the circuit of Figure 6 can also include a variable gain amplifier 191 (illustrated in Figure 7A) connected to the output from the multiplier 190. For most patients, the gain amplifier variable 191 is adjusted to provide a gain (g) d one. The variable gain amplifier 191, therefore, would have essentially no effect on the output from "the multiplier 190. However, for patients with unusually thick corneas, the gain (g) is adjusted to a positive gain less than one. A gain (g) less than one is used, because unusually thick corneas are more resistant to flattening, and as a result, result in an indication of pressure that exceeds, but by a small amount, the actual intraocular pressure. Consequently, the adjustable gain amplifier 191 reduces the output voltage from the multiplier 190 by a selected percentage proportional to the deviation of the cornea from the normal corneal thickness.For patients with unusually thin corneas the opposite effect would be observed. previous, for these patients, the gain (g) is adjusted to a positive gain greater than one, such that the adjustable gain amplifier 191 increases the output voltage from the multiplier 190 by a selected percentage proportional to the deviation of the cornea from normal corneal thickness. Preferably, the gain (g) is selected manually for each patient, using any known element to control the gain of a variable gain amplifier, eg, a potentiometer connected to a voltage source. As indicated above, the particular gain (g) used depends on the thickness of the cornea of each patient, which, in turn, can be determined using known corneal pachymetry techniques. Once the thickness of the cornea is determined, deviation from the normal thickness is calculated, and gain (g) is established according to the same. Alternatively, as illustrated in FIG. 7B, the gain (g) can be selected automatically by connecting an output (indicating the thickness of the cornea) from a known pachymetry apparatus 193 to a buffer zone circuit. 195. The buffer zone zone circuit 195 converts the detected horn thickness e to a gain signal associated with the deviation of the thickness detected from the normal corneal thickness. In particular, the gain signal produces a gain (g) of one when the deviation is zero, produces a gain (g) greater than one when the detected horn thickness is less than the normal thick, and produces a lower gain (g) than one when the detected horn thickness is greater than the normal thickness. Although Figures 7A and 7B illustrate a configuration that only compensates for the corneal thickness, it is understood that similar configurations can be used to compensate for the curvature of the cornea, the size of the eye, the ocular rigidity, and the like. For levels of curvature of the cornea that are higher than normal, the gain would be less than one. The gain would be greater than one for levels of curvature of the cornea that are flatter than normal. Normally, each increase in a diopter of the curvature of the cornea is associated with an increase of 0.34 mmHg of pressure. The intraocular pressure rises 1 mmHg for every 3 diopters. Therefore, the gain can be applied according to this general relationship. In the case of a compensation for the size of the eye, eyes larger than normal would require a gain of less than one, while eyes smaller than the norm would require a gain that is greater than one. For patients with "stiffer" eye rigidities than normal, the gain is less than one, but for patients with softer eye stiffness, the gain is greater than one. As when the thickness of the cornea is compensated, the gain can be selected manually for each patient, or alternatively, the gain can be selected in an automatic way by connecting the apparatus of the present invention to a known keratometer when compensation is compensated for. curvature of the cornea, and / or a known biometer when it compensates for the size of the eye. Although not illustrated, it is understood that the system includes a power supply mechanism to selectively energize the system using either battery or household alternating current. The operation of the preferred circuit will now be described. Initially, the contact device 2 is placed on the surface of the cornea of a patient, and is centrally located in the front of the eye 4 in essentially the same way as conventional actuation lenses. The patient then looks through the central vision device 38 at the intersection of the cross-currents defining the mark 70, preferably, while the light 75 provided inside the tubular housing 64 is illuminated, so as to facilitate the visualization of the crossed capilare and the reflected image 74. In this way an approximate alignment is achieved. right away, the preferred circuit provides indications of misalignment or an inappropriate axia distance if either or both exist. The patient responds to these indications by taking the indicated corrective measure. Once the proper alignment is achieved there is the appropriate axial distance between the drive apparatus 6 and the contact device 2, the push action switch 164 is activated, and the AND gate (Y) 158 and the start switch / stop 156 activates the current producing circuit 32. In response to activation, the current producing circuit 32 generates the progressively increasing current in coil 30. The progressively increasing current creates a progressively increasing magnetic field in coil 30. The magnetic field progressively increasing, in turn, causes the axial displacement of the movable centerpiece 16 towards the cornea 4, by virtue of the repulsion effect of the magnetic field on the magnetically responding element 26. Since the axial displacement of the movable centerpiece 16 produces a progressively increasing flattening of the cornea 4, the reflected beams 60, 62 begin to oscillate angularly so that s light sensors 48, 50. This axial displacement increasing flattening continues until both reflected 60, 62 reach the light sensors 48, 50, and d this way it is considered that there is the amount of previously determined flattening. At that moment, the current producing circuit 32 is deactivated by the input 16 to the AND gate (Y) 158; the horn 154 is activated momentarily to give an audible indication that the flattening has been achieved, and the intraocular pressure is stored in the memory device 33, and is displayed on the screen 167. Although the previously described embodiment illustrated includes different preferred elements , it is understood that the present invention can be achieved by using other different individual elements. For example, the detection configuration 8 may use other different elements, including elements that are typically used in the technique of reading bar codes. With reference to Figures 8A and 8B, a contact device 2 'can be provided with a bar code type pattern 300 which varies in the displacement response of the moveable centerpiece 16'. Figure 8 illustrates the preferred pattern 300 prior to displacement of the movable centerpiece 16 '; and Figure 8B shows the preferred pattern 300 when the predetermined amount of flattening is reached. Accordingly, the detection pattern would include a bar code reader generally directed to the contact device 2 'and which can detect differences in the bar code pattern 300. Alternatively, as illustrated in FIGS. 9A and 9E, the contact device 2 'may be provided with a multi-color pattern 310 which varies in response to displacement of the movable centerpiece 16'. Figure 9A schematically illustrates the preferred colo pattern 310 prior to displacement of the movable centerpiece 16 ', while Figure 9B schematically shows the preferred pattern 310 when the previously determined flattening amount d is reached. Accordingly, the detection configuration would include a beam emitter pair emitting a light beam towards the pattern 310, and a detector receiving a beam reflected from the pattern 310, and detecting the reflected colo to determine whether the flattening has been achieved. Yet another way of detecting the displacement of the movable centerpiece 16 is by using a two-dimensional array of photosensors that detect the location of a reflected light beam. Capacitive and electrostatic sensors can then be used, as well as changes in the magnetic field, to encode the position of the reflected beam, and consequently, the displacement of the movable centerpiece 16.

In accordance with yet another alternative embodiment illustrated in Figure 10, a miniature light-emitting diode 320 is inserted into the contact device 2 '. The piezoelectric ceramic is driven by ultrasonic waves, alternatively energized by electromagnetic waves. The brightness of the miniature light emitting diode 320 s is determined by the current flowing through the miniature light emitting diode 320, which in turn can be modulates by means of a variable resistor 330. Movement of the movable central part 16 'varies the variable resistance 330 According to the foregoing, the intensity of the light from the miniature light emitting diode 320 indicates the amount of displacement of the central part movable. A miniature low voltage battery 340 can be inserted into the contact device 2 'to energize the miniature light emitting diode 320. With respect to yet another preferred embodiment of the present invention, it is understood that a tear film normally covers the eye, and that a surface tension resulting therefrom may cause an underestimation of the intraocular pressure. According to the foregoing, the contact device of the present invention of preference has an internal surface of flexible hydrophobic material, in order to diminish or eliminate this potential source of error.

It should be noted that the drawings are merely schematic representations of the preferred embodiments Therefore, the actual dimensions of the preferred modalities and the physical configuration for the different elements are not limited to what is illustrated. Different configurations and dimensions will become easily apparent to ordinary experts in this field. The size of the movable centerpiece, for example, can be modified for use in experimental animals or techniques. In the same way, the contact device can be made with smaller dimensions for use with children and patients with abnormalities in the eyelid. A preferred configuration of the present invention includes a handle portion extending from below the housing 64, and connected distally to a platform. The platform acts as a base to be placed on a flat surface (eg, a table), the handle projecting upwards therefrom, to support the actuator 6 above the flat surface.

INDENTIATION The contact device 2 and the asymmetric system illustrated in Figures 1 to 5 can also be used to detect intraocular pressure by indentation. "When indentation techniques are used in the media: intraocular pressure, a predetermined force is applied against the cornea, using an indentation device." Due to the force, the indentation device travels towards the cornea, indentating the As the distance traveled by the inward indentation device of the cornea in response to the previously determined force, it is known as inversely proportional to the intraocular pressure According to the above, there are different known tables that, for Certain standard sizes of standard indentation and force devices correlate the distance traveled and the intraocular pressure.In the use of the illustrated indentation configuration, the movable centerpiece 16 of the contact device 2 functions as the indentation device. the current producing circuit 32 is switched to operate in an indentation mode When switching to the dimming mode, the current-producing circuit 32 supplies a predetermined amount of current through the coil 30. The predetermined amount of current corresponds to the amount of current necessary to produce one of the standard forces previously mentioned . The predetermined amount of current creates a magnetic field in the drive apparatus 6. In turn, this magnetic field causes the movable centerpiece 16 to push inward against the cornea 4 by means of the flexible membrane 14. Once the predetermined amount of current d has been applied, and a standard force compresses against the cornea, it is It is necessary to determine how far the moving centerpiece 16 moves towards the inside of the cornea 4. In accordance with the foregoing, when measurement of the present intraocular is desired by indentation, the system illustrated in Figure 1 further includes a detection configuration. distance, to detect a distance traveled by the movable centerpiece 16, and a computing portion 199 in the calculation unit 10, to determine the intraocular pressure, based on the distance traveled by the movable centerpiece 16 in the application d amount of force previously determined. In FIGS. HA and 11B a preferred indentation distance detection pattern 200 is illustrated, preferably includes a beam emitter 202, and a beam sensor 204. Preferably, the lenses 205 are arranged in the optical path between the emitter. beam 202 and beam sensor 204. Beam emitter 202 is configured to emit a beam 206 of light towards movable centerpiece 16. Light beam 206 is reflected back from movable centerpiece 16 to create a beam Reflected 208. The beam sensor 204 is positioned to receive the reflected beam 208, provided that the device 2 is located at the appropriate axial distance and an appropriate alignment with the driving apparatus 6. D preferably, the appropriate distance and alignment is achieved using all or any combination of the vision mechanism, the optical alignment mechanism, and the aforementioned optical distance measurement mechanism. Once the proper alignment and the appropriate axial distance is achieved, the beam 206 impacts a first portion of the movable centerpiece 16, as illustrated in FIG. HA. As the beam 206 is reflected, the reflected beam 20 impacts a first portion of the beam sensor 204. In FIG. HA, the first portion is located on the beam sensor 204 toward the right side of the pattern. However, as the indentation progresses, the movable centerpiece 16 becomes more distant from the beam emitter 202. This increase in distance is illustrated in FIG. HA. Since the movable centerpiece 16 moves linearly away, the beam 206 impacts progressively more to the left on the movable centerpiece 16. Accordingly, the reflected beam 206 changes to the left, and hits 204 in a second portion that is the left of the first portion. The beam sensor 204 is configured to detect the change in the reflected beam 206, which change is proportional to the displacement of the movable centerpiece 16. Preferably, the beam sensor 204 includes a beam detector that responds to the intensity 212, the which produces a output voltage proportional to the detected intensity of the reflected beam 208 and an optical filter element 210 that progressively filters more light as the lu incident point moves from a portion of the filter to an opposite portion. In Figures HA and 11B, the optical filter element 210 comprises a filter with a progressively increasing thickness, in such a way that the light passing through a thicker portion has a significantly lower intensity than the light passing through it. through a thinner portion of the filter. Alternatively, the filter can have a constant thickness and a progressively increasing filtration density, where a filtering effect progressively increases as the point of incidence moves through a longitudinal section of the filter. As illustrated in Figure HA, when it has passed it has reflected 208 through a thinner portion of the optical filter element 210 (eg, before indentation), s reduces the intensity of the reflected beam only by a small amount. Accordingly, the beam detector qu which responds to the intensity 212 provides a relatively high output voltage, which indicates that no movement of the movable centerpiece 16 has occurred towards the cornea 4.

However, as the indentation progresses, the reflected beam 208 progressively changes to the thicker portions of the optical filter element 210, which filter out more light. The intensity of the reflected beam 208 therefore decreases proportionally to the displacement of the movable central part 16 towards the cornea 4. Since the detector d that responds to the intensity 212 produces a d output voltage proportional to the intensity of the reflected beam, it is output voltage decreases progressively as s increases the displacement of movable center piece 16 The output voltage from the beam detector responding to intensity 212, therefore, indicates the displacement d of the movable centerpiece. Preferably, the computing portion 19 responds to the current producing circuit 32, such that, once the predetermined amount of force is applied, the output voltage from the ha sensors 212 is received by the computing portion. 199. Then, the computational portion, based on the displacement as well as the particular output voltage, determines the intraocular pressure. Preferably, the memory 33 includes a memory location for storing a value that measures the intraocular pressure. Also, the computing portion 199 of pri ^: jnci has access to one of the previously mentioned electronically or magnetically stored tables. Since the tables indicate which intraocular pressure corresponds to certain distances traveled by the movable centerpiece 16, the computing portion 199 can determine the intraocular pressure merely by determining which pressure corresponds to the distance traveled by the movable centerpiece 16. The system of the The present invention can also be used to calculate the stiffness of the sclera. In particular, the system was first used to determine the intraocular pressure by flattening, and then it was used to determine the intraocular pressure by indentation. The differences between the infraocular pressures detected by the two methods would then be indicative of the scleral rigidity. Although the above description of the preferred systems generally refers to a combined system which can detect both intraocular pressure and flattening as well as indentation, it is understood that it is not necessary to create a combined system. That is, the system capable of determining the intraocular pressure mediant flattening can be constructed independently of a separate system to determine the infraocular pressure by indentation, and vice versa.

MEASUREMENT OF THE EYE HYDRODYNAMIC The indentation device of the present invention can also be used to measure in an n invasive manner the hydrodynamics of an eye, including the ease of outward flow. The method of the present invention preferably comprises several steps, including the following According to a first step, an indentation device is placed in contact with the cornea. Preferably, the indentation device comprises the contact device 2 illustrated in Figures 1 and 2A-2D. Next, at least a moving portion of the indentation device is moved towards the cornea, using a first predetermined amount of force, to achieve indentation of the cornea. When the indentation device is the contact device 2, the movable portion consists of the movable centerpiece 16. An intraocular pressure is then determined based on a first distance traveled towards the cornea by the movable portion of the indentation device during the application of the first amount of force previously determined. Preferably, the intraocular pressure is determined using the aforementioned system to determine the intraocular pressure by indentation. Next, the movable portion of the indentation device rapidly reciprocates towards the cornea away from the cornea at a first predetermined frequency., and using a second amount of force previously determined during the movement towards the cornea to force the intraocular fluid towards the eye in this way. The second predetermined amount of force is preferably equal to, or greater than, the first predetermined amount of force d. However, it is understood that the second amount of previously determined force may be less than the first amount of force previously determined. The reciprocation, which preferably continues for 5 seconds, in general should not exceed 10 seconds The movable portion then moves towards the cornea using a third amount of force previously determined, to achieve the indentation of the cornea again. A second intraocular pressure is then determined based on a second distance traveled towards the cornea by the movable portion of the indentation device during the application of the third amount of force previously determined. This second intraocular pressure is also preferably determined using the abovementioned system to determine the intraocular pressure mediant indentation. Since the intraocular pressure decreases as a result of forcing the intraocular fluid out of the eye during rapid reciprocation of the movable portion, it is generally understood that, unless the eye is defective so that it does not flow to fluid out of it. , the second intraocular pressure will be lower than the first intraocular pressure. This reduction in intraocular pressure indicated the ease of outward flow. Next, the movable portion of the indentation device is rapidly reciprocated back towards the cornea and away from the cornea, but at a second predetermined frequency, and using a fourth amount of force previously determined during movement towards the cornea. The fourth amount of previously determined force is preferably equal to, or greater than, the second predetermined force amount d. However, it is understood that the fourth amount of previously determined force may be less than the second amount of force previously determined. In this way, the additional intraocular fluid is forced out of the eye. This reciprocation, which also preferably continues for 5 seconds, should generally not exceed 10 seconds. The movable portion subsequently moves towards the cornea using a fifth amount of force previously determined, to achieve again the indentation of the cornea. Subsequently, a third intraocular pressure is determined based on a third distance traveled to the cornea by the movable portion of the indentation device during the application of the fifth amount of previously determined force. The differences between the first, second, and third distances are then preferably calculated, and differences indicate the volume of the infraocular fluid leaving the eye, and therefore, also indicate the ease of outward flow. It is understood that the difference between the first and last distances can be used, and in this aspect, it is not necessary to use the differences between the three distances. In fact, the difference between any two of the distances will suffice. Although the relation between the ease of flow out and the differences detected varies when different parameters of the method and dimensions of indentation device change, the relationship for the given dimensions can be easily determined by known experimental techniques, and / or by using the known Friedenwald tables. The method of the present invention is preferably carried out using an indentation surface which is millimeters in diameter and a computer equipped in a data acquisition board. In particular, the ccrp_-.?dor generates the forces previously determined by means of a digital-to-analog converter (D / A) connected to a current generator circuit 32. Then the computer receives signals indicating the first, second, and third distances previously determined by means of an analog-to-digital (A / D) convert. These signals are analyzed by the computer using the aforementioned relationship between the differences in distance and the ease of flow out. Based on this analysis, the computer created an output signal that indicates the ease of flow out. The preferred output signal is applied to a visual display screen, which, in turn, provides a visual indication of the ease of outward flow. Preferably, the method further comprises the steps of plotting the differences between the first, second, third distances, to create a graph of the differences, and comparing the resulting graph of differences with that of a normal eye, to determine if there are irregularities present in the ease of outward flow. However, as indicated above, it is understood that the difference between the first and last distances can be used, and in this respect, it is not necessary to use the differences between the three distances. In fact, the difference between any two of the distances will suffice. Preferably, the first frequency previously determined and the second frequency previously determined are substantially equal, and are approximately 20 Hertz. In general, any frequency up to 35 Hertz can be used, although lower frequencies of one Hertz are generally less desirable, since the relaxation of tension of the external layers of the eye would contribute to changes in pressure and volume. The fourth amount of force previously determined preferably is at least twice the second amount of force previously determined, and the third amount d force previously determined preferably about half the first amount of force previously determined. However, it is understood that other relationships will be sufficient, and that the present method is not limited to the above preferred relationships. According to a preferred use of the method, the first amount of force previously determined is between 0.01 Newton and 0.015 Newton.; the second amount of force previously determined is between 0.005 Newton and 0.007 Newton; the third amount of force previously determined is between 0.005 Newton and 0.0075 Newton; the fourth amount d force previously determined is between 0.0075 Newton 0.0125 Newton; the fifth amount of force previously determined is between 0.0125 Newton and 0.025 Newton; The first frequency previously determined is between 1 Hert and 35 Hertz; and the second previously determined frequency is also between 1 Hertz and 35 Hertz. However, the present method is not limited to the above preferred ranges. Although the method of the present invention is preferred using the aforementioned device, it is understood that other different tonometers can be used. Accordingly, the method of the present invention is not limited in scope to its use in conjunction with the claimed system and the illustrated contactor device.

ALTERNATIVE MODALITIES OF THE CONTACT DEVICE Although the foregoing description utilizes a modality of the contact device 2 that includes a flex membrane 14 on the inner surface of the contact device, it is readily understood that the present invention is not limited to this configuration. Actually, there are many variations of the contact device that fall well within the scope of the present invention. The contact device 2, for example, can be manufactured without a flexible membrane, with the flexible membrane on the external surface of the contact device 2 (ie the side away from the cornea), with the membrane flexed on the inner surface of the contact device 2, with the flexible membrane on both sides of the contact device 2.

Also, the flexible membrane 14 can be made to have an annular shape, thus allowing light to pass without distortions directly towards the movable centerpiece 16 and the cornea to be reflected by the same. In addition, as illustrated in Figure 12, the movable central part 16 can be formed with a similar annular configuration, such that a transparent central portion d thereof merely contains air. In this way, the light passing through the entire contact device 2 directly impacts the cornea without suffering any distortion due to the contact device 2. Alternatively, the transparent center portion can be filled with a transparent solid material . Examples of these transparent solid materials include polymethyl methacrylate, hard acrylic glass, plastic polymers, and the like. In accordance with a preferred configuration, glass is used that has a refractive index substantially greater than that of the cornea, to improve the light reflection by the cornea when the light passes through the contact device 2. Preferably, the index of refraction for glass e greater than 1.7, compared with the typical refractive index of 1.37 associated with the cornea. It is understood that the outer surface of the movable central part 16 can be covered with an antireflective cap, in order to eliminate the foreign reflections from that surface, which could otherwise interfere with the operation of the alignment mechanism and detection configuration. Flattening The interconnections of the different components of the contact device 2 are also subject to modifications without departing from the scope and spirit of the present invention. Accordingly, it is understood that there are many ways to interconnect or otherwise maintain working relationship between the movable centerpiece 16, rigid annular member 12, and the membranes 14. When using one or two flexible membranes 1 for example, the substantially rigid annular member 12 can join either or both of the flexible membranes 14 using any known binding techniques, such as adhesion, heat bonding, and the like. In an alternative manner, when using two flexible membranes 14, the components can be interconnected or maintained otherwise in a working relationship, without having to directly attach the flexible membrane 14 to the substantially rigid annular member 12. Instead, the substantially rigid annular member 12 can be retained between the two flexible membranes 14 by connecting the membranes one to the other around their peripheries, while the rigid annular member 12 sandwiching between the membranes 14.

Although the movable centerpiece 16 can be attached to the flexible membrane 14 by adhesion, heat bonding, the like, it is understood that this attachment is not necessary. Instead, one or both of the flexible membranes 14 can be configured to completely or partially block the movable centerpiece 16, to prevent it from falling out of the orifice of the substantially rigid annular member 12. When using the aforementioned annular version of the flexible membranes 14, as illustrated by way of example in Figure 12, the diameter of the hole in at least one of the flexible annular membranes 14 is preferably smaller than that of the hole in the substantially rigid annular member 12, such that one portion radially internal 14A of the flexible annular membrane 14 s overlaps with the movable centerpiece 16, and thus prevents the movable centerpiece 16 from falling out of the orifice of the substantially rigid annular member 12. As illustrated in Figure 13A, another way d to prevent the movable centerpiece 16 from falling out of the orifice of the substantially rigid annular member 12, is to provide arms 16A extending radially outward from the movable center piece 16, and which are slidably received in respective grooves 16B. The grooves 16B s form in the rigid annular member 12. Each groove 16 has a longitudinal dimension (vertical in Figure 13) which is selected selectively to restrict the range of movement of the movable centerpiece 16 to within predetermined limits. Although Figure 13 shows a modality in which the grooves are in the substantially rigid annular member 12, and the arms extend outwardly from the movable centerpiece 16, it is understood that an equally effective configuration can be created by inverting the configuration, as so that the grooves are located in the movable center piece 16, and the arms extend radially from the substantially rigid annular member 12. Preferably, the grooves 16B includes elastic elements, such as miniature springs, which force the position of the movable centerpiece 16 to a desired starting position. In addition, the arms 16A can include distally located miniature wheels, which significantly reduce the friction between the arms 16A and the walls of the grooves 16B. Figure 13B illustrates another way to prevent the movable centerpiece 16 from falling out of the orifice of the substantially rigid annular member 12. In Figure 13B, the substantially rigid annular member 12 is provided with fins extending radially inwardly 12F on the outer surface. of the annular member 12. One of the above-mentioned annular membranes 14 is preferably disposed on the inner side of the substantially rigid annular member 12. Preferably, a portion of the membrane 14 extends radially inward, passing through the walls of the orifice of the annular member. rigid ring member. The combination of the annular membrane 14 and the fins 12F, prevents the movable centerpiece 1 from falling out of the hole in the substantially rigid annular member 12. The fins 12F can also be used to achieve or facilitate the driving of the movable centerpiece 16 In a magnetically driven embodiment, for example, the fins 12F can be magnetized so that the fins 12F s move inwardly in response to an externally applied magnetic field. With reference to Figure 14, an alternative modality of the contact device 2 is made using soft contact lens material 12A having a progressively decreasing thickening toward its outer circumference. A cylindrical hole 12B is formed in the soft contact lens material. 12A. However, hole 12B does not extend entirely through soft lens lens 12A. Instead, the hole has a closed bottom defined by a thin portion 12C of the soft contact lens material 12A. The movable centerpiece 16 s slidably disposes within the hole 12B, and preferably, the thin portion 12C is not greater than: -0. millimeters thick, thus allowing the movable central part 16 to reach flattening or indentation when moving against the closed bottom of the hole towards the cornea, with very little interference from the thin portion 12C. Preferably, a substantially rigid annular member 12D is inserted, and secured to the soft contact material 12A, to define a more stable wall structure circumferentially around the hole 12B. On the other hand, this provides more stability when the moving centerpiece 16 moves in the hole 12B. Although the preferred soft lens material 12A comprises hydrogel, silicone, flexible acrylic, or the like, it is understood that any other suitable materials may be used. In addition, as indicated above, any combination of flexible membranes may be added to the embodiment of Figure 14. Although the movable centerpiece 16 of Figure 14 is illustrated as annular, it is understood that any other form may be used. For example, any of the movable center pieces described above 16 would suffice. In a similar manner, the annular version of the movable central part 16 can be modified by adding a transparent lower plac (not shown) that defines a transparent flat bottom surface. the movable centerpiece 16. When modified in this manner, the movable centerpiece 1 has a generally cup-like appearance. Preferably, the transparent and flat bottom surface is placed towards the cornea to improve the flattening effect of the movable centerpiece 16; however, it is understood that the transparent plate can be located on the outer surface of the movable centerpiece 16 if so desired. Although the movable centerpiece 16 and the hole e the substantially rigid annular member 12 (or the hole e the soft contact lens material 12A) is illustrated having complementary cylindrical shapes, it is understood that the complementary forms are not limited to a cylinder but which may rather include any shape that allows sliding of the movable centerpiece 16 with respect to the surrounding structure. It is also understood that the movable centerpiece 1 can be mounted directly on the surface of a flexible membrane 14 without using a substantially rigid annular member 12. Although this configuration defines a working mode of the contact device 2, s stability, precision, and level of comfort, are reduced in a significant way, compared with those of a similar modality using the substantially rigid annular member 12 with a periphery that is progressively thinned. Although the illustrated embodiments of the movable centerpiece 16 include generally flat outer surfaces with well defined lateral edges, it is understood that the present invention is not limited to these configurations. For example, the present invention may include a movable central piezo 16 with an external surface. rounded to improve comfort and / or to coincide with the curvature of the external surface of the substantially rigid annular member 12. The movable centerpiece can also be made to have any combination of curved and flat surfaces defined on its inner and outer surfaces, the inner surface being the surface in the cornea, and the outer surface being the surface generally directed away from the cornea. With reference to Figure 15, the movable centerpiece 16 may also include a centrally disposed projection 16P directed toward the cornea. The 16P projection d is created by extending the transparent solid material towards the cornea at the center of the movable centerpiece 16.

ALTERNATIVE MODALITY FOR MEASURING INTRAOCULAR PRESSURE THROUGH FLUSHING With reference to Figure 16, an alternative modality of the system for measuring intraocular pressure by flattening is now described. The preferred alternative mode uses the version of the contact device 2, which includes a transparent central portion.

According to the alternative embodiment, the schematically illustrated coil 30 of the drive apparatus includes an iron core 30A for improving the magnetic field produced by the coil 30. The iron core 30A preferably has an axially extending hole 30B (of approximately 6 millimeters in diameter) which allows the passage of light through the core of iron 30A, and also allows to mount two lenses L3 and L4 in it. In order for the system to operate successfully, the force of the magnetic force applied by the coil 30 on the movable centerpiece 16 should be sufficient to flatten the patient's corneas over at least the entire range of infra-ocular pressures found clinically. (ie from 5 to 50 mmHg). According to the alternative modality illustrated, infraocular pressures from one to more than 100 millimeters of mercury can be evaluated, using the present invention. The forces necessary to flatten against this infraocular pressure can be obtained with reasonably direct design and economic materials, as will be demonstrated by the following calculations: It is known that the force F exerted by an external magnetic field on a small magnet is equal to the moment d magnetic dipole of the magnet m multiplied by the magnetic field induction vector gradient of the external field "grad B" which acts in the dipole moment direction of the magnet.

F = m * grad B (1) The magnetic dipole moment m for the magnetic version of the movable central part 16, can be determined using the following formula: m = (B * V) / u0 (2) where B is the magnetic induction vector just on the surface of one of the poles of the movable centerpiece 16, V is its volume, and u0 is the magnetic permeability of the free space having a value of 12.57 10 Henry / meter. A typical value of B for magnetized Alnico movable centerpieces 16 is 0.5 Tesla. If the movable central part 16 has a thickness of 1 millimeter, a diameter of 5 millimeters, and 50 percent of its initial volume, its volume V = 9.8 cubic millimeters (9.8 * 10"9 cubic meters) is ground. values in Equation 2, s produces the value for the magnetic dipole moment of the movable centerpiece, that is, m = 0.00390 Amp * (Metro'2.) Using the above calculations, the specifications of the drive apparatus can be determined The gradient of magnetic field_ "grad B" is a function ie the measured distance x is from the front face of the drive unit, and can be calculated as follows: grad B = u0 * X * N * I * (RAD) 2 * . { [(x + L) 2 + RAD2] "3 2 - [x2 + RAD2] _ 3 2.}. 2 * L where X is the magnetic susceptibility of the iron core, N is the number of turns in the wire of the coil, I is the electric current carried by the wire, is the length of the coil 30, and RAD is the bobin radio . The preferred values for these parameters in the alternative mode are: X = 500, N = 200, I = 1.0 Amp, L 0. 05 meters and RAD = 0.025 meters. However, it is understood that the present invention is not limited to these preferred parameters. As usual u0 = 12.57 * 10"7 Henry / meter The force F exerted by the magnetic actuator on the movable centerpiece 16 is found from equation 1, using the above-mentioned preferred values as the parameters in the equation 3 and the previous result for m = 0.00390 Amp * (Meter) 2. In Figure 16 A, a graph of F is shown as a function of the distance x separating the movable centerpiece 16 from the pole of the magnetic drive apparatus. the cornea of a patient 4, when covered by the contact device 2 holding the movable central part 16, can be conveniently placed at a distance x = 2.5 centimeters (0.025 meters) from the actuating device, it is noted, starting from of Figure 16A, that the magnetic driving force is approximately F = 0.06 Newtons, then this force is compared to Frequent (3) is really necessary force to flatten a cornea 4 over a flattening area typical, when the intraocular pressure is as high as 50 mmHg. In Goldman tonometry, the diameter of the flattened area is approximately 3 millimeters, and consequently, the typical flattened AREA equals 7.55 square millimeters. The typical maximum pressure d 50 mmHg can be converted to a metric form, producing a pressure of 0.00666 Newtons / square millimeter. Then s can determine the value of Frequency using the following equation: ^ required = PRESSURE * AREA 4 After the mathematical substitution, ^ 0.050 Newtons required. Comparing the calculated magnetic driving force F with the required force Frequent, it becomes clear that Frequent is smaller < 3) the available magnetic impulse force F. Therefore, the maximum force required to flatten the cornea 4 for the determinations of the intraocular pressure, is easily reached using the drive apparatus and movable centerpiece 16 of the present invention. - It is understood that, if a greater force is required for any reason (for example, to provide distance between the contact device 2 and the actuator), the different parameters can be manipulated and / or the current can be increased the coil 30, to achieve a satisfactory configuration. In order that the drive apparatus appropriately actuate the movable centerpiece 16 in a practical manner, the magnetic driving force (e associated magnetic field) must increase from 0, reach a maximum in about 0.01 seconds, and then return zero in approximately another 0.01 seconds. Accordingly, the power supply to the preferred drive apparatus includes circuits and a power source which can drive a "current pulse" of a pic magnitude in the range of 1 ampere through a fairly large inductor (i.e., the coil) 30). For the "single pulse" operation, a direct current voltage power supply can be used to charge a capacitor C through a load resistor. One side of the capacitor is grounded, while the other side ("high" side) can be at a direct current potential of 50 volts. The "high" side of the capacitor can be connected by means of a switch that carries high current to a "discharge circuit" consisting of coil 30 and resistor damper R. This configuration produces an RLC series circuit similar to that which is conventionally used to generate large electric current pulses for applications such as obtaining large driven magnetic fields, and laser energy systems that operate by impulses. By appropriately selecting the values of the electrical components and the starting voltage of the capacitor, a "current pulse" of the kind described above can be generated and supplied to the coil 30, to operate the drive apparatus in this manner. However, it is understood that the mere application of a current pulse of the kind described above to a large inductor, such as coil 30, will not necessarily produce a zero magnetic field after the current pulse has ended. Instead, there will normally be an undesirable residual magnetic field from the iron core 30A, even when no current is flowing into the coil 30. This residual field is caused by the magnetic hysteresis, and would tend to produce a magnetic force on the centerpiece. movable 16 when you do not want this force. Accordingly, the alternative embodiment includes preferably elements for zeroing the magnetic field outside the drive apparatus after its operation. This zeroing can be provided by a demagnetizing circuit connected to the iron core 30A. The methods for demagnetizing an iron core are generally known, and are easy to implement. This can be done, for example, by inverting the current in the coil repeatedly, while decreasing its magnitude. The easiest way to do this is to use a step-down transformer, where the input is a sine-wave voltage at 60 Hz that starts in a "line voltage" of 110 VAC, and that is gradually damped to cer volts, and where the output of the transformer is connected to the coil 30. Therefore, the drive apparatus can include two power circuits, ie , a "single impulse" current source used to drive the flattening measurements, and a "demagnetization circuit for zeroing the magnetic field of coil 3 immediately after each flattening measurement." As illustrated in Figure 16, and more specifically in Figure 17, the alternative mode used for flattening also It includes an alternative optical alignment system.The alignment is very important because, as indicated by the graph of Figure 16A, the force exerted by the driving apparatus on the movable centerpiece 16 depends greatly on its relative positions. addition to the axial location the movable centerpiece with respect to the i-lent action apparatus (x-direction), the magnetic force exerted on the movable central part 16 also depends on its lateral (y-direction) and vertical (direction) positions z), as well as the orientation (tip and inclination) with respect to the center axis of the drive apparatus, considering the variation of the force F with the distance At axial x shown in Figure 16A, it is clear that the movable centerpiece 16 should be placed in the x direction with an accuracy of approximately +/- one millimeter, for reliable measurements. In a similar manner, since the diameter of the coil 30 is preferably 50 millimeters, the location of the movable centerpiece 16 with respect to the directions y and z (ie, perpendicular to the longitudinal axis of the coil 30), should be keep within +/- 2 millimeter (a region where the magnetic field is approximately constant) of the longitudinal axis of the coil. Finally, since the force on the movable centerpiece 16 depends on the cosine of the angle between the longitudinal ej of the coil and the tip or the tilting angle of movable centerpiece 16, it is important that the range of the patient's gaze be maintained. with respect to the longitudinal ej of the coil within approximately +/- 2 ° to have reliable measurements. In order to satisfy the above criteria, the alternative optical alignment system facilitates precise alignment of the apex of the patient's cornea (located centrally behind the movable centerpiece 16 with longitudinal axis of the coil, the precise alignment of which can be achieved independently. For a patient without the assistance of a trained medical technician or health care professional, the alternative optical alignment system works according to the way in which light is reflected and refracted on the surface of the cornea. The following description of the alternative optical alignment system and Figures 16 and 17, do not refer specifically to the effects of the transparent center portion of the moveable centerpiece on the optical system operation, primarily because the transparent center portion of the movable centerpiece 16 preferably s configured so as not to affect the behavior of the optical rays passing through the moving centerpiece 16. Also, for simplicity, Figure 17n shows the iron core 30A and its associated hole 30B although it is understood that the alignment beam (described later in FIG. present) passes through the perforated orifice 30B, and that the lenses L3 and L4 are mounted inside the bore hole 30B. As illustrated in Figure 16, a point type light source 350, such as a light emitting diode, is located in the focal plane of a positive (ie convergent) lens Ll. The positive lens Ll is configured to collimate a light beam from the source 350. The collimated beam passes through a beam splitter BS1, and a beam transmitted from the collimated beam continues through the beam splitter BS1 to a positive lent L2. The positive L2 lens focuses the beam transmitted at a point inside the L3 lens located in the focal plane of an L4 lens. The light rays that pass through L4 are collimated once more, and enter the patient's eye, where they focus on the retina 5. Therefore, the transmitted hast is perceived by the patient as a point tip light. Some of the rays that reach the eye are reflected from the surface of the cornea in a divergent manner due to the curvature of the pre-flattening of the cornea, as shown in Figure 18, and are returned to the patient's eye by a partially flat surface. in mirror of lent L4. These rays are perceived by the patient as a reflection of the cornea that guides the patient during and alignment of his eye on the instrument, as described later in the present. The rays that are reflected by the convex cornea and pass from right to left through lens L4, are made a little more convergent by L4 lens. From the L3 lens perspective, these rays appear to come from a virtual point object located at the focal point. Therefore, after passing through L3, the rays are once again collimated and enter the lens L2, which focuses the rays at a point on the surface of the beam splitter BS1 The beam splitter BS1 is tilted at 45 ° , and consequently deflects the rays towards an L5 lens, which, in turn, collimates the rays. Then these rays hit the surface of an inclined reflective beam splitter BS2. The collimated rays reflected from the beam splitter BS2 enter the lens L6, which focuses them on the small aperture of a silicon photodiode, which functions as an alignment sensor DI. Accordingly, when the curved cornea 4 is appropriately aligned, an electric current is produced by the alignment sensor DI. The alignment system is very sensitive, because it is a confocal configuration (ie, the point image of the alignment light due to the reflection of the cornea - Purkinje image in its fiduciary position, it is conjugated with the small sensitive aperture the light of the silicon photodiode). In this way, an electrical current is obtained from the alignment sensor only when the cornea 4 is properly aligned with respect to the lens L4, which, in turn, is preferably mounted on the end of the magnetic actuator. The focal lengths of all the lenses shown in Figure 17 are preferably 50 millimeters, with the exception of lens L3, which preferably has a focal length of 100 millimeters. An electrical circuit capable of operating the DI alignment sensor is direct to design and build. The silicon photodiode operates without any polarization voltage ("photovoltaic mode"), thus minimizing the inherent noise of the detector. In this mode, a voltage d signal, corresponding to the light level on the silicon surface, appears through a small resistor that extends at the diode terminals. Ordinarily, this voltage signal is too small to be subsequently displayed or processed.; however, many magnitude orders can be amplified using a simple transimpedance amplifier circuit. Preferably, the alignment sensor DI is used in conjunction with this amplified photodiode circuit. Preferably, the circuit connected to the alignment sensor DI is configured to automatically activate the drive apparatus immediately upon detection, by means of the DI sensor, of the existence of an appropriate alignment. However, if the output from the alignment sensor DI indicated that the eye is not properly aligned, the circuit d preferably prevents activation of the drive apparatus. In this way, the alignment sensor DI, and not the relative, determines when the drive apparatus will be operated. As indicated above, the s? S ^ d optical alignment preferably includes a conf i. _r ació to guide the patient during the alignment of his eye on and instrument. These configurations are illustrated, for example, in Figures 18 and 19. The configuration illustrated in Figure 18 allows a patient to precisely position his eye translationally in all directions x-y-z. In particular, the L4 s lens is made to include a flat surface, this flat surface being partially reflective, so that the patient can see an amplified image of his pupil with a bright point source of light located somewhere near the center of the iris. This point source image s owes to the reflection of the input alignment beam from the curved corneal surface (referred to as the first Purkinje image), and its subsequent reflection from the mirror or partially reflective planar surface of lens L4. Preferably, the L4 lens causes the reflected rays to be parallel when they return to the eye, which focuses them on the retina 5. Although Figure 18 shows the eye well aligned, d such that the rays are focused at a central location the surface of the retina 5, it is understood that the movements of the eye towards or away (direction x) of the lent L4, will blur the reflection image of the cornea, and that the movements of the eye in any direction and or z will tend to displace the image of the cornea reflex, either to the right / left or up / down. Therefore, the patient performs an alignment operation looking directly at the alignment light, and moving his eye slowly in three dimensions until the point image of the cornea's reflection is as clear as possible (placement x), and emerges with the point image of the alignment light (placement y and z) that passes straight through the cornea 4. As illustrated in Figure 19, the L4 n lens needs to have a partially reflecting portion if the act merely establishes an address Appropriate view provides enough alignment. Once the alignment is achieved, a logical signal from the active optical alignment system and "impulse circuit", which, in turn, energizes the drive apparatus. After the drive apparatus is activated, the magnetic field in the patient's cornea is continually increased for a period of time of about 0.01 seconds. The effect of this growing camp is to apply a continuously increasing force to the movable centerpiece 16 resting on the cornea, which in turn, causes the cornea 4 to become increasingly flat over time. Since the size of the flattening area e proportional to the force on the movable centerpiece 16 (Pressure = Force / Area), the intraocular pressure (IOP) s finds by determining the proportion of the force to the force-flattened area. In order to detect the flattened area provide an electrical signal indicating the size of the flattened area, the alternative mode includes a flattening sensor D2. The rays that are reflected from the surface of the flattened cornea, are reflected in a generally parallel manner by virtue of the planar surface presented by the flattened cornea 4. When the rays pass d right to left through the L4 lens, they are focused inside the L3 lens, which, in turn, is in the focal plane of lens L2. Consequently, after passing through the lent L2, the beams are once again collimated and hit the surface of the beam splitter BS1. Since the BS1 splitter is inclined at 45 °, the beam splitter BS1 deflects these collimated rays towards the lens L5, which focuses the rays at a point at the center of the beam splitter BS2. The BS2 splitter has a small transparent portion or hole in the center, which allows the direct passage of the rays towards the lens L7 (preferably focal length of 50 millimeters). The L7 lent belongs to a flattening detector arm of the alternative mode. The focal point on the beam splitter BS2 is in the focal plane of the lens L7. As a result, the rays that emerge from the lens L7 are collimated once more are collimated once more. These collimated rays impact on the Ml mirror, d preferably at an angle of 45 °, and deviate towards a positive lent L8 (focal length of 50 mm), which focused the rays on the small aperture of a silicon photodiode that defines the flattening sensor D2. It is understood that the rays that impact the cornea 4 slightly outside the center, tend to reflect away from the L4 lens when the curvature of the cornea remains unchanged. However, as the flattening progresses, and the cornea becomes increasingly flat, more d these rays are reflected towards the L4 lens. The light intensity on the flattening sensor D2, therefore, increases, and as a result, an electric current is generated by the flattening sensor D2, whose electric current is proportional to the degree of flattening. Preferably, the electrical circuit used by the flattening sensor D2 is identical or similar to that used by the alignment sensor DI. The electrical signal indicating the flattening area can then be combined with signals that indicate the time needed to achieve this flattening and / or the amount of current (which in turn corresponds to the applied force) used to achieve flattening , and that combination of information can be used to determine the intraocular pressure using the Pressure = Force / Area equation. The following are the preferred operating steps for the drive apparatus during a measurement cycle 1) While the drive apparatus is switched off, there is no magnetic field directed towards the contact device 2. 2) When the drive device is activated, the magnetic field initially remains at zero. 3) Once the patient is in position, the patient begins to align his eye with the actuator. Until the eye is properly aligned, the magnetic field remains at zero. 4) When the eye is properly aligned (com is automatically detected by the optical alignment sensor), the magnetic field starts to increase from cer (driven by a continuously increasing electric current). 5) During the time period of the current increase (approximately 0.01 seconds), the force on the movable center piece is also continuously increased. 6) In response to the increasing force of the moveable center piece, the surface area of the -clean adjacent to the moveable centerpiece is flattened growing. 7) The light from the flat surface area i * ie the cornea is reflected towards the detection configuration, which detects when a predetermined amount of flattening has been reached. Since the amount of light reflected directly back from the cornea is proportional to the size of the flattened surface area, it is possible to determine exactly when the predetermined amount of flattening has been reached, preferably a circular area of 3.1 mm in diameter. cornea. However, it is understood that any diameter from 0.1 millimeters to 10 millimeters can be used. 8) The time required to achieve the flattening of the particular surface area (ie, the predetermined amount of flattening) is detected by a time circuit which is part of the flattening detection configuration. Based on the previous calibration and on a resulting conversion table, this time becomes an indication of intraocular pressure. The more time required to flatten a specific area, the higher the intraocular pressure, and vice versa. 9) After the predetermined amount of flattening has been reached, the magnetic field is deactivated. 10) The intraocular pressure is then displayed by means of a reading meter, and all circuits are preferably completely deactivated for a period of 15 seconds, so that the automatic measurement cycle is not repeated immediately if the patient's eye remains aligned . However, it is understood that the circuits can remain activated and that a continuous measurement of the intraocular pressure can be achieved by creating an automatic measurement cycle. The data provided by this automatic measurement cycle can then be used to calculate the blood flow. 11) If the main power supply has not been deactivated, all the circuits are switched off again after 15 minutes, and in this way they are ready for the next measurement. Although there are several methods to calibrate the different elements of the system to measure the intraocular pressure by flattening, the following are illustrative examples of how this calibration can be achieved: Initially, after the manufacture of the different components, each component is tested to ensure that the component operates properly. This includes a preference to verify that there is a free movement of the piston type (without twisting) of the movable centerpiece in the contact device; verify the structure integrity of the contact device during routine handling evaluate the magnetic field on the surface of the movable centerpiece, in order to determine its magnetic dipol moment (when the magnetic drive is used) verify that the current pulse electric that creates the magnetic field that drives the magnetically responsive element of the movable centerpiece, has an appropriate magnitude and peak duration, and ensures that there are no "buzzes"; verifying the effectiveness of the "demagnetization circuit" to remove any residual magnetization in the iron core of the drive apparatus after it has been driven; measure the magnetic field as a function of time along and near the longitudinal axis of the coil where the movable centerpiece will eventually be placed; determine and plot the grad B as a function of time in various locations x (that is, at several distances from the coil); and placing the magnetic center piece (device d contact) in various locations x along the longitudinal length of the coil, and determining the force F acting on it as a function of time during operation and pulses of the driving apparatus. The optical alignment system is then tested to determine that it has an appropriate operation. When the optical alignment system comprises the configuration illustrated in Figures 16 and 17, for example, s can use the following calibration test procedure: a) First, a convex vidri surface (one face of a lens) having a radius of curvature approximately equal to that of the cornea, for similar l cornea and its superficial reflection. Preferably, this glass surface is placed in a mounting configuration fitted with a micrometer along the longitudinal axis of the coil. The assembly configuration adjusted with micrometer allows rotation around two axes (tip inclination), and translation in three-dimensional space x-y b) With the DI detector connected to a voltage or current meter, the convex glass surface located at its design distance of 25 millimeters from the L4 lens will be perfectly aligned (tip / inclination / x / y / z) , maximizing the output signal in the meter d reading. c) After perfect alignment is achieved, the alignment detection setting s "tune" for each of the degrees of freedom of position (tip / tilt / x / y / z), and curves are plotted for each degree of freedom, in order to define in this way the sensitivity of the system to alignment. d) Alignment sensitivity will be compared with the tolerances desired in the reproducibility of the measurements, and may also be based on the variation of the magnetic force on the movable centerpiece as a function of the position. e) Subsequently, the sensitivity of the alignment system can be changed as necessary, by means of procedures such as changing the aperture size of the silicon photodiode, which functions as the DI alignment sensor, and / or changing an aperture stop in the L4 lent. The detection configuration is then tested to determine that it has an appropriate operation. When the detection configuration comprises the d optical detection configuration illustrated in Figure 16, for example, s can use the following calibration test procedure: a) A flat glass surface is used (e.g., a face of a polished rod) short) with a diameter of preferably 4 to 5 millimeters, to simulate the flattened cornea and its superficial reflection. b) A mechanism is defined that defines a black opaque opening (that defines transparent internal openings with diameters of 0.5 to 4 millimeters, and that has an external diameter equal to that of the rod), to partially cover the face of the rod, simulating of this -a er different stages of flattening. c) The flat surface rod is placed in a mounting along the longitudinal axis of the coil, - :. a setting configuration adjusted with micrometer, which can rotate around two axes (tip and tilt), and s translates in the three-dimensional space x-y-z. d) Then the flattening sensor D2 is connected to a voltage or current meter, while the rod remains located at its design distance of 25 mm from the L4 lens, where it is perfectly aligned (tip / tilt / x / y / z), maximizing the output signal from the flattening sensor D2. In this case, the alignment n is sensitive to the placement of the x axis. e) After a perfect alignment is achieved, the alignment for each of the degrees of freedom of position (tip / tilt / x / y / z) is "detuned" and curves are plotted for each degree of freedom, defining the this way the sensitivity of the system to alignment. The data of this class are obtained for the openings d different sizes (ie different degrees of flattening) on the face of the rod. f) The alignment sensitivity is then compared to the tolerances required for reproducing flattening measurements, which depends, in part, on the results obtained in the aforementioned test and calibration method associated with the alignment apparatus. g) Then the sensitivity of the flattening detection configuration is changed as necessary, by procedures such as changing the size of the opening in front of the flattening sensor D2, and / or changing the opening stop (small hole) in the splitter of has BS2. Other calibration measurements can be made as follows: After the calibration and test procedures mentioned above have been performed on the individual subassemblies, all parts can be combined, and the system is tested as an integrated unit. For this purpose, 10 eyes of enucleated animals and 10 human eyes enucleated in two separate series are measured. The procedures for both types of eyes are the same. The eyes are mounted on non-magnetic fasteners, each having a central opening that exposes the cornea part of the sclera. Then a 23 gauge needle attached to a short piece of polyethylene tubing is inserted behind the limbus through the sclera and the silane body, and advanced in such a way that the tip passes between the lens and the iris. Lateral gates in the cannulae are drilled approximately 2 millimeters from the tip, to help prevent blockage of the cannula by the iris or lens. This cannula is attached to a pressure transducer with an appropriate visual display element. A normal serum reservoir of an adjustable height is also connected to the piping system of the pressure transducer. The hydrostatic pressure applied to the eye by this reservoir is adjustable between 0 and 50 mmHg, and the intraocular pressure over this range can be measured directly with the pressure transducer. In order to verify that the above equipment is properly established for each new eye, a standard Goldman flattening tonometer can be used to independently measure the intraocular pressure of the eye at a single height of the reservoir. The intraocular value measured using the Goldman system is then compared to a simultaneously determined intraocular pressure measured by the pressure transducer. Any problems encountered with the equipment can be corrected if the two measurements are significantly different. The reservoir is used to change the intraocular pressure of each eye in a sequential range of 5 mmHg over a pressure range of 5 to 50 mmHg. At each of the pressures, a measurement is taken using the system of the present invention. Each measurement taken by the present invention consists in recording three separate variable time signals over the time duration of the driven magnetic field. The three signals are: 1) the current flowing in the coil of the drive apparatus as a function of time, labeled as I (t), 2) the voltage signal as a function of time from the flattening detector D2 labeled as APLN (t) and 3) the voltage signal as a function of time from the alignment sensor DI, labeled ALIN (t). The three signals, associated with each measurement are then acquired and stored in a computer equipped with a "data acquisition and processing" board of multiple inputs, and related software. The computer allows many things to be done with the data, including: 1) recording and storing many signals for subsequent retrieval, 2) displaying graphs of the signals against time, 3) numerical processing and analysis in the manner desired , 4) graphing of the final results, 5) application of statistical analysis to groups of data, and 6) labeling of the data (for example, labeling of an established measurement with its associated infra-ocular pressure). The relationship between the three variable time signals and the intraocular pressure is as follows: 1) I (t) is an independent input signal that is consistently applied as the current pulse from the power supply that drives the drive apparatus. This signal I (t) is essentially constant from one measurement to another, with the exception of minor variations from trip to trip. I (t) is a "reference" waveform with which the other waveforms, APLN (t) ALIN (t), are compared as discussed further below. 2) APLN (t) is a dependent output signal.

APLN (t) has a value of zero when I (t) is zero (ie at the beginning of the current pulse in the coil of the drive unit). The reason for this is that when 1 = 0, n there is a magnetic field, and consequently, there is no force d flattening on the movable centerpiece. As s increases I (t), so does the degree of flattening, and d correspondingly, APLN (t) does. It is important to note that the rate at which APLN (t) increases to increase I (t), depends on the intraocular pressure of the eye Since eyes with low infraocular pressures flatten more easily than eyes with high infraoculare pressures in response to a flattening force, it is understood that APL (t) increases more rapidly for an eye that has a low intraocular pressure, which it does for an eye that has a high intraocular pressure. Therefore, APLN (t) s increases from zero to a speed that is inversely proportional to the intraocular pressure, until it reaches a maximum value when a complete flattening is achieved. 3) ALIN (t) is also a dependent output signal. Assuming that one eye is aligned at settling, the signal ALIN (t) starts at some maximum value when I (t) is zero (that is, at the beginning of the impulse d current to the coil of the drive apparatus. is that when 1 = 0, there is no magnetic field, and consequently, there is no force on the moving part that would otherwise tend to alter the curvature of the cornea, since the reflection of the cornea is which gives place to the alignment signal, as • I (t) increases causing the flattening (and correspondingly, a decrease in the degree of curvature of the cornea), the signal ALIN (t) decreases until It is important to note that the rate at which ALIN (t) decreases with increasing I (t) depends on the intraocular pressure of the eye, since the extraocular pressure flattens more easily than the eyes with a high presidio infraocular, it is understood that ALIN (t) d It decreases more rapidly for an eye that has a low intraocular pressure, than for an eye that has a high intraocular pressure. Therefore, ALIN (t) decreases from some maximum value at a rate that is inversely proportional to the infraocular pressure until it reaches zero when a complete flattening is achieved. From the foregoing, it is clear that the rate of change of both output signals APLN and ALIN, in relation to the input signal I, is inversely proportional to the intraocular pressure. Accordingly, the measurement of the intraocular pressure using the present invention may depend on the determination of the INCLINATION of the measurement data of "APLN against I" (also, although probably with less certainty, the inclination of the measurement data of " ALIN against I ").

For brevity, the following description limits the data of "APLN against I"; however, it is understood that the data of "ALIN against I" can be processed in a similar way. Graphs of "APLN versus I" can be displayed on the computer monitor for different measurements (all different infraocular pressures for each eye), and s can use regression analysis (and other data reduction algorithms), with the objective to obtain the INCLINATION d "best fit" for each measurement. Time can be used in order to optimize this data reduction procedure. The final result of a series of pressure measurements different infraocular pressures on one eye (determined by the aforementioned pressure transducer) will be a corresponding series of TILTINGS (determined by the system of the present invention). Next, a single graph is prepared for each eye, showing the INCLINATION against the intraocular pressure data points, as well as the best fit curve through the data. Ideally, all the curves for the 1 pig eyes are perfectly coincident - being the same true for the curves obtained for the 10 human eyes. If the ideal is realized, any of the curves (since they are all the same) can be used as a CALIBRATION for the present invention. However, in practice the ideal may not be realized. Therefore, all the data of INCLINATION against the intraocular pressure for the 10 pig eyes is superimposed on a single graph (in the same way for the TILT data against intraocular pressure for 10 human eyes). These overlays generally produce an "averaged" CALIBRATION curve, and also an indication of the reliability associated with CALIBRATION. Then, the data of the simple graphs can be analyzed statistically (one for the pig eyes, one for the human eyes), which in turn show u composed of all the TILT data against the intraocular pressure. From the statistical analysis, it is possible to obtain: 1) a CALIBRATION curve averaged for the present invention, from which the "most possible intraocular pressure" associated with a value d TILTING measured, 2) the Standard Deviation can be obtained (or variation) associated with any determination of the intraocular pressure made using the present invention, essentially the expected "ability" of the present invention to replicate the measurements, and 3) the "reliability" or "precision" of the curv of CALIBRATION of the present invention, which is found from an analysis of "standard error of the average" of the data. In addition to the data obtained with the aligned eye, it is also possible to investigate the sensitivity of the intraocular pressure measurements made using the present invention to poor translational-and rotational-aligning.

ALTERNATIVE MODALITY FOR MEASURING INTRAOCULAR PRESSURE THROUGH INDENTATION With reference to Figures 20A and 20B, we will now describe an alternative modality for measuring intraocular pressure by indentation. The alternative embodiment includes a configuration d detecting the indentation distance and a contact d device. The contact device has a movable centerpiece 16, of which only the outer surface is illustrated in Figures 20A and 20B. The external surface of the movable centerpiece 16 is at least partially reflective. The indentation distance detection configuration includes two converging lenses Ll and L2, a beam split BS1; an LS light source to emit a beam of light that has a width; and a light detector LD that responds to the diameter of a reflected beam that impacts on a surface thereof. Figure 20A illustrates the alternative mode before actuation of the movable centerpiece 16. Before actuation, the patient is aligned with the indentation distance detection pattern, such that the external surface of the movable centerpiece 16 s locate at the converging lens focal point L2. When the movable centerpiece 16 is located in this way, the light beam from the light source LS impacts the has splitter BS, and is deflected through the converging lens Ll to strike as a point on the reflecting outer surface of the beam. The movable centerpiece 16. The reflecting outer surface of the movable centerpiece 16 then reflects this beam of light back through the converging lens Ll, through the beam spot BS, and then through the converging lens L2, couple impacting a surface of the light detector LD. Preferably, the light detector LD is located at the focal point of the converging lens L2, such that the reflected beam strikes a surface of the light detector LD as a point of virtually zero diameter when the outer surface of the movable centerpiece remains at the focal point of the converging lens Ll. Preferably, the indentation distance detection configuration is connected to a visual display device, to generate an indication of the zero offset when the outer surface of the movable centerpiece 16 has yet to be displaced, as shown in the Figure 20 A.

Upon subsequent actuation of the moving centerpiece 16 using a drive device (preferably similar to the drive device described above), the outer surface of the movable centerpiece 16 moves, progressively away from the converging lens point of the converging lens Ll, as shown in FIG. illustrated in Figure 20B As a result, the beam of light striking the reflecting outer surface of the movable centerpiece 16 has a progressively increasing diameter. This progressive increase in diameter is proportional to the displacement from the focal point of the convergent lens Ll. Accordingly, the resulting reflected has a diameter proportional to displacement, and passes back through the convergent lent Ll, through beam splitter BS, through converging lens C2, and then impacts the light detector surface LD with a diameter proportional to displacement of the movable centerpiece 16. Since the light detector LD responds, as indicated above, to the diameter of the reflected light beam, any displacement d of the movable centerpiece 16 causes a proportional change in the output from the LD light detector. Preferably, the light detector LD is a photoelectric converter connected to the aforementioned visual display device, and can provide an output voltage proportional to the reflected light beam diameter that impacts on the light detector LD. Visual display provides a visual indication of the displacement, based on the output voltage from the LD light detector. Alternatively, the output from the light detector LD can be connected to a configuration, as described above, to provide an indication of the intraocular pressure based on the displacement of the movable centerpiece 16.

ADDITIONAL CAPABILITIES In general, the present apparatus and method makes it possible to evaluate the intraocular pressure, as indicated above, as well as the ocular rigidity, the hydrodynamics of the eye, such as the ease of outward flow and the rate of fluid flow into the fluid. of the eye, the hemodynamics of the eye such as pressure in the episclerotic veins and pulsatile ocular blood flow, and also has the ability to artificially increase intraocular pressure, as well as the continuous recording of intraocular pressure. With respect to the measurement of intraocular pressure by flattening, the above description stipulates several techniques for performing this measurement, including a variable force technique in which the force applied against the cornea varies with time. However, it is understood that a variable area method can also be implemented. The apparatus can assess the amount of flattened area by a known force. The pressure is calculated by dividing the force by the amount of area that is flattened. The amount d flattened area is determined using the optical element and / filters previously described. A force equivalent to placing 5 grams of weight on the cornea, for example, will flatten a first area if the pressure is 30 mmHg, a second area if the pressure is 20 mmHg, a third area if the pressure is 15 mmHg, and so on. Therefore, the flattened area indicates the intraocular pressure. Alternatively, infraocular pressure can be measured using a non-rigid interface and general flattening techniques. In this embodiment, a flexible centerpiece enclosed by the magnet of the movable centerpiece is used, and the transparent part of the movable centerpiece acts as a micro-globe. This method is based on the principle that the interface between two spherical balloons of unequal radius will be flat if the pressures on the two glcccs are equal. The central piece with the balloon is compressed cent to the eye until the interface of the eye / center piece remains wool, as determined by the aforementioned optical element. Also, with respect to the configuration described above, which measures the intraocular pressure by indentation, an alternative method may be implemented, such as a modality wherein the apparatus measures the force required to indentate the cornea by a previously determined amount. This amount of indentation is determined by optical elements, as described above. The movable centerpiece is compressed against the cornea to indentate the cornea, for example, 0.5 millimeters (although it is understood that virtually any other depth can be used). The range of the previously determined depth is detected by the optical element and the filters described above. According to the tables, the infraocular pressure can be determined later from the force. Still another technique whose use facilitates the present invention, is the ballistic principle. According to the ballistic principle, a parameter of a collision between the known mass of the movable centerpiece and the cornea is measured. This measured parameter is then theoretically or experimentally related to intraocular pressure. The following are example parameters: Impact Acceleration The movable centerpiece is directed towards the cornea at a well-defined speed. It hits the cornea, and after a certain time of contact, it bounces back. You can study the time-speed relationships during and after the impact. The central leveler may have a spring that connects to the rigid annular contact device member. If the surface of the cornea lasts, the impact time will be short. In the same way, if the surface of the cornea is soft, the impact time will be longer. The optical sensors can optically detect the duration of the impact and the time it takes for the movable centerpiece to return to its original position. Impact duration Intraocular pressure can also be estimated by measuring the contact duration of a spring-loaded movibl centerpiece, with the eye. The amount of time left by the flattened cornea can be assessed by the optical element described above. Rebound velocity The distance traveled per unit of time after bouncing, also indicates the rebound energy, and this energy is proportional to the intraocular pressure. Principle of vibration The intraocular pressure can also be estimated by measuring the frequency of a vibrating element in contact with the contact device, and the resulting changes in the reflection of light are related to the pressure in the eye.

Time The apparatus of the present invention can also be used, as indicated above, to measure the time needed to flatten the cornea. The harder the cornea is, the higher the intraocular pressure, and therefore, the more time it will take to deform the cornea. On the other hand, the softer the cornea, the lower the intraocular pressure, and therefore, the poorer. Time will be needed to deform the cornea. Therefore, the amount of time it takes to deform the cornea is proportional to the intraocular pressure. Additional uses and capabilities of the present invention relate to alternative methods for measuring ease of outward flow (tone). These alternative methods include the use of conventional indentation techniques, constant depth indentation techniques, constant pressure indentation techniques, constant pressure flattening techniques, constant area flattening techniques, and constant force flattening techniques. 1. Conventional Indentation When conventional indentation techniques are used, the movable centerpiece of the present invention is used to indentate the cornea, and thereby artificially increase the intraocular pressure. This artificial increase in infraocular pressure forces fluid out of the eye more quickly than normal. As the fluid flows out of the eye, the pressure gradually returns to its original level. The rate at which the intraocular pressure drops depends on how well the drainage system of the eye is working. The pressure drop as a function of time is used to calculate the C value or the outward flow ease coefficient. The C value indicates the degree to which a change in intraocular pressure will cause a change in the outward flow velocity of the fluid. This, in turn, indicates the resistance to outward flow provided by the eye's drainage system. The different procedures for determining the ease of outward flow are generally known as tongaging, and the C value is usually expressed in terms of microliters per minute per millimeter of mercury. The C value is determined by raising the intraocular pressure using the movable centerpiece of the contact device, and observing the subsequent decay in intraocular pressure with respect to time. Elevated intraocular pressure increases the rate of aqueous outward flow, which, in turn, provides a change in volume. This change in volume can be calculated from the Friedenwald tables, which correlate the change in volume with changes in pressure. The velocity d decrease in volume is equal to the velocity of flow to the outside. The change in intraocular pressure during the phonographic procedure can be calculated as an arithmetic average of pressure increases for successive 1/2 minute intervals. Then the C value is derived from the following equation: C =? V / t (Pave-Po), where t is the duration of the procedure, Pave is the elevation of the average pressure during the test and can be measured, Po is the initial pressure and is also measured, and? V is the difference between the initial and final volumes, and can be obtained from the known tables. The flow ("F") of fluid is then calculated using the formula F = C * (Po-Pv), where Pv is the pressure in the episclerotic veins, which can be measured, and general has a constant value of 10. . 2. Constant Depth Indentation When using constant depth indentation techniques, the method involves the use of a variable depth, which is necessary to cause a certain predetermined amount of indentation in the eye. The apparatus of the present invention, therefore, is configured to measure the force required to indentate the cornea for a predetermined amount. This amount of inden. Acid can be detected using an optical element as described above. The movable centerpiece is pressed against the cornea to indent the eye, for example, - po approximately 0.5 millimeters. The amount of indentation is detected by the optical element and the filters previously described. With the centerpiece indentating the corneum using a force equivalent to a weight of 10 grams, s will achieve an indentation of 0. 5 millimeters under normal pressure conditions (for example, an intraocular pressure of 1 mmHg) and assuming there is a curvature of the average cornea With that amount of indentation, and using conventional dimensions for the central piece, 2. cubic millimeters of fluid will be displaced. The force recorded by the present invention suffers a slow decline, and a more or less continuous state value is leveled after 2 to minutes. The decay in the pressure is measured based on the difference between the value of the first indentation of the central piez and the final level reached after a certain amount of time. The pressure drop is due to the return of the pressure to its normal value, after it has been raised artificially by the indentation caused by the movable central piez. A standard decay value known as a reference is used, and compared with the values obtained. Since the above provides a continuous record of the pressure over time, this method can be an important tool for physiological research showing, for example, an increase in pressure during a forced expiration. The impulse wave and the impulse amplitude can also be evaluated, and the pulsatile blood flow can be calculated. 3. Constant Pressure Indentation When using constant pressure indentation techniques, the intraocular pressure is kept constant by increasing the magnetic field, and thus increasing the force against the cornea as the eye fluid exits. At any constant pressure, the force and flow velocity outward are linearly related according to the Friedenwald tonometry tables. L intraocular pressure is calculated using the same method as described for conventional indentation tonometry. Volume displacement is calculated using tonometry tables. The ease of outward flow (C) can be calculated using two different techniques. According to the first technique, C can be calculated from 2 phonograms of constant pressure at different pressures according to the equation C =. { [(AV1 / t1) - (AV2 / t2)] / (? > 1 - P2)} , where corresponds to a measurement at a first pressure, and corresponds to a measurement at a second pressure (which is higher than the first pressure). The second way to calculate is from a phonogram of constant pressure, and an independent measurement of the infraocular pressure using flattening tonometry (Pa), in C = [(? V / t) / (P-Pa-? Pe) ], e where? Pe is a correction factor for an elevation in the episcleral venous pressure with indentation tonometry, and P is the intraocular pressure obtained using the indentation tonometry. 4. Constant Pressure Flattening When constant pressure flattening techniques are used, the intraocular pressure is kept constant by increasing the magnetic field, and consequently, the force, as the fluid flows out of the eye. If the cornea is considered to be a portion of a sphere, a mathematical formula relates the volume of a spherical segment to the radius of curvature of the sphere and the radius of the base of the segment. The displaced volume is calculated based on the formula V = A2 / (4 * 7r * R), where V is the volume, A is the area d the base of the segment, and R is the radius of curvature of the spher ( is the radius of curvature of the cornea). Since A = weight / pressure, then V = / (4 * TG * tR> * pP2 -) The weight is constituted by the force in the electromagnetic field, R is the curvature of the cornea, and can be measured with a Keratometer, P is the pressure in the eye and can be measured using the same method as described for conventional flattening tonometry. Accordingly, it is possible to calculate the displaced volume and the C value or the ease of outward flow. For example, the displaced volume can be calculated intervals of 15 seconds, and is plotted as a time function.

. Constant Area Flattening When using constant-area flattening techniques, the method consists primarily of evaluating the pressure decay curv while the flattened area remains constant. The aforementioned optical flattening detection configurations can be used, in order to keep the flattened area constant by the movable central part. The amount of force required to keep the flattened area constant decreases, and this decrease is recorded. The amount of volume displaced according to the different areas of flattening is known. For example, a central piece that flattens 5 millimeters displaces a volume of 4.07 cubic millimeters for the radius of the average cornea of 7.8 millimeters. Using the formula? V /? T = l / (R *? P), it is possible to calculate R, which is the reciprocal of C. Since s provides a continuous record of the pressure over time, this method can be a tool important to investigate and evaluate blood flow. 6. Constant Force Flattening When using constant force flattening techniques, the same force is constantly applied, and the flattened area is measured using any of the aforementioned optical flattening detection configurations. Once the flattened area is measured by a force The pressure can be calculated by dividing the force by the amount of area that is flattened. As the fluid flows out of the eye, the amount of area flattened with time is increased. This method consists primarily of evaluating a resulting area increase curve while applying constant force. The amount of volume displaced according to the different areas of flattening is known. Using the formula? V /? T = l / (R *? P), it is possible to calculate R, which is the reciprocal of C. Still additional uses of the present invention relate to the detection of the eye frequency response , using indentation tonometry. In particular, if an oscillating force is applied using the movable centerpiece 16, the speed of the movable centerpiece 16 indicates the frequency response of the eye. The system oscillates at the resonant frequency determined primarily by the mechanism of the movable centerpiece 16. By varying the force frequency, and by measuring the response, the intraocular pressure can be evaluated. The evaluation can be made mid-frequency resonant and a significant variation in the resonant frequency can be obtained as a function of the intraocular pressure. The present invention can also be used with the conventional techniques of indentation above, but e where the intraocular pressure used for the calculation is measured using the principles of flattening. Since the flattening virtually does not alter the hydrodynamic balance because it displaces a very small volume, this method can be considered more accurate than the intraocular pressure measurements made using traditional indentation techniques. Another use of the present invention involves a manner related to the time of measuring outward flow resistance. In particular, resistance to outward flow is detected by measuring the amount of time needed to transfigure the cornea with flattening or co-indentation. The time required to displace, for example, 5 microliters of eye fluid, would be one second for normal patients, and greater than two seconds for individuals afflicted with glaucoma. Still another use of the present invention involves measuring the flow into the fluid of the eye. E particular, this measurement is done by applying the formula F =? P / R, where? P is P-Pv, and P is the intraocular pressure of continuous state, and Pv is the episclerotic venous pressure that, for purposes of calculation is consider constant at 10. R is the resistance to outward flow, which is the reciprocal of C that can be calculated. Then you can calculate F, e units of volume / minute. The present invention is also useful for measuring ocular stiffness, or distensibility of the eye in response to increased intraocular pressure. The coefficient of ocular rigidity can be calculated using a nomogram, which is based on two tonometric readings with different weights. Friedenwald developed a series of conversion tables to calculate the coefficient of ocular rigidity. The technique to determine the ocular rigidity is based on the concept of differential tonometry, using two tonometric readings d indentation with different weights, or more precisely using an indentation reading and a flattening reading, and plotting these readings in the nomogram. And that the present invention can be used to measure intraocular pressure using both flattening and indentation techniques, a more accurate assessment of ocular stiffness can be achieved. Intraocular pressure measurements using the apparatus of the present invention can also be used to evaluate hemodynamics, in particular the hemodynamics of the eye and the pulsatile ocular blood flow. Pulsatory ocular blood flow is the component of the total ocular arterial flow that causes a rhythmic fluctuation of the infraocular pressure. The intraocular pressure varies with each impulse due to the pulsed inflow of a bolus of arterial blood into the eye with each heartbeat. This bolus is bled into the infraocular arteries with each heart beat, causing a temporary increase in intraocular pressure. The period of inward flow causes a stretching of the eye walls, with a concomitant increase in pressure, followed by a relaxation to the anterior volume, and a return to the anterior pressure, when blood drains from the eye. If this process of expansion during systole (contraction of the heart) and contraction during diastole (heart relaxation) occurs at a certain impulse velocity, then the rhythm of the blood flow would be the incremental change in the volume of the eye by the velocity of the heart. impulse. The fact that intraocular pressure varies with time according to the cardiac cycle is the basis for measuring pulsatile ocular blood flow. The cardiac cycle is approximately on the order of 0.8 Hz. The present invention can measure the time variations of the intraocular pressure with a frequency that is greater than the heart rate of the fundamental human heart, allowing the evaluation and recording of the intraocular impulse. In the normal human eye, the infraocular impulse has a magnitude of approximately mmHg, and is practically synchronous with the cardiac cycle. As described, measurements of the intraocular pressure show a variation of time that is associated with the pulsatile component of blood pressure. Experimental results provide means to transform changes in ocular pressure in changes in eye volume. Each bolus of blood entering the eye increases ocular volume and intraocular pressure. The changes observed in the pressure reflect the fact that the volume of the eye must change to accommodate the changes in intraocular blood volume induced by the arterial blood impulse. This impulse volume is small in relation to the ocular volume, but because the walls of the eye are rigid, and the pressure increase required to accommodate the impulse volume is significant, and can be measured. Accordingly, provided that the relationship between increased intraocular pressure and increased ocular volume is known, s can determine the volume of the fluid bolus. Since this relationship between pressure change and volume change has been well established (Friedenwald 1937, McBain 1957, Yttebor 1960, Eisenlohr 1962, McEwen 1965), pressure measurements can be used to obtain the volume of a bolus. blood, and in this way, determine blood flow. The output of the tonometer for instant pressure can be converted into an instantaneous change in eye volume as a function of time. The time derivative of change in ocular volume is the net instantaneous pulsatile component of ocular blood flow. Under these conditions, the velocity of pulsatile blood flow through the eye can be evaluated from the instant measurement of the intraocular pressure. In order to quantify the rapid analysis of the intraocular impulse, the signal can be digitized from the tonometer, and can be fed to a computer. Furthermore, measurements of intraocular pressure can be used to obtain intraocular volume through the use of a pressure-volume relationship determined in an independent manner, such as with the Friedenwald d equation (Friedenwald, 1937). You can also use a mathematical model based on experimental data from the pressure-volume relationship (Friedenwald 1937, McBai 1957, Eisenlohr 1962, McEwen 1965) to convert a change in ocular pressure, a change in ocular volume . In addition, a model can also be constructed to estimate ocular blood flow from the appearance of the intraocular pressure waveform. The luxury curve is related to parameters that come from the volume change curve. This curve is measured indirectly, since the intraocular pressure is the actual measured amount; It is transformed into volume change through the use of the measured pressure-volume ratio. Then the flow is calculated by taking the change in volume Vmax-Vmin, multiplied by a constant that is related to the length of the time interval of the inward flow and the total pulse duration. Known mathematical calculations can be used to evaluate the pulsating component. of ocular blood flow. Since the present invention can also be used to measure ocular rigidity, this parameter of the ocular rigidity coefficient can be used in order to calculate precisely the individual differences in pulsatile blood flow. Moreover, since the driving device 6 and contact device 2 of the present invention preferably include transparent portions, the pulsatile blood flow can be directly evaluated optically to quantify the change in the size of the vessels with each heartbeat. Accordingly, a more accurate evaluation of blood flow can be achieved by combining changes in intraocular impulse with changes in vessel diameter, which can be measured optically automatically. A large amount of data can be obtained about the vascular system of the eye and the central nervous system, knowing the changes in intraocular pressure over time, and the amount of pulsatile ocular blood flow. The intraocular pressure and the intraocular impulse are usually symmetrical in the pairs of eyes. Consequently, a loss of symmetry can serve as an early sign of ocular or cerebrovascular disease. Patients afflicted with diabetes, macular degeneration, and other vascular disorders may also have decreased ocular blood flow, and benefit from the evaluation of the hemodynamics of the eye using the apparatus of the present invention. The present invention can also be used to artificially raise intraocular pressure. The artificial elevation of intraocular pressure is an important tool in the diagnosis and prognosis of disorders of the eye and brain, as well as an important tool for research. The artificial elevation of the intraocular pressure using the present invention can be performed in different ways. According to a manner, the contact device of the present invention is modified in its shape to be placed on the sclera (target of the eye.) This configuration, which will be described later herein, is illustrated in Figures 21 and 22, in FIG. wherein the movable centerpiece 16 can be of a larger size, and preferably is operated against the sclera in order to raise the intraocular pressure.The amount of indentation can be detected by the previously described optical detection system. artificially increasing the intraocular pressure, is placing the contact device of the present invention on the cornea, in the same way as s described above, but using the movable centerpiece to apply a greater amount of force in order to achieve an indentation This convenient technique allows the visualization of the eye while the force is exerted since the central portion Movable contact device is preferably transparent. In accordance with this technique, the size of the movable central part can also be increased to indentate a larger area, and thus create a higher artificial increase in intraocular pressure. Preferably, the drive apparatus also has a transparent central portion, as indicated above, to facilitate direct visualization of the eye and retina while the intraocular pressure is increasing. When the intraocular pressure exceeds the ophthalmic arterial diastolic pressure, the impulse amplitude and blood flow decrease rapidly. The blood flow reaches zero when the intraocular pressure is equal to or higher than the ophthalmic systolic pressure. Po consequent, by allowing the direct visualization of the retinal vessels, the exact moment at which the impulse disappears * can be determined, and the pressure necessary to promote the cessation of the impulse, which in turn is the equivalent of the impulse pressure in the ophthalmic artery. Therefore, the present invention allows the measurement of pressure in the arteries of the eye. Also, by placing a fixation light at a rear portion of the driving apparatus, and asking the patient to indicate when he can no longer see the light, one can also record the pressure at which the vision of a patient ceases. This would also correspond to the cessation of the impulse in the artery of the eye. You can also determine the pressure at which the vessels open, increasing the intraocular pressure until the impulse disappears, and then gradually lowering the intraocular pressure until the impulse reappears. Therefore, the intraocular pressure necessary for opening the vessels can be evaluated. It is important to note that the above measurements can be made in an automatic way using an optical detection system, for example, by directing a beam of light into the blood vessel in pulsation. The impulse cessation can be detected optically, and the pressure is recorded. A pulsation attenuation can also be used as the end point, and can be detected optically. The device also allows direct visualization of the pupil of the optic nerve, while an increased intraocular pressure is produced. Therefore, the physical and chemical changes that occur within the eye can be evaluated due to the artificial increase in intraocular pressure, at the same time as the pressure is measured. In a convenient way, the previous test can be performed in patients with medium opacities that prevents the visualization of the posterior part of the eye. In particular, the aforementioned procedure, wherein the patient indicates when vision ceases, is particularly useful in patients with medium opacities. The fading of the peripheral vision corresponds to the diastolic pressure, and the fading of the central vision corresponds to the systolic pressure. • The present invention, by raising the intraocular pressure, as indicated above, and by allowing direct visualization of blood vessels in the back of the eye, can be used to tamponade (bleeding block by indirect pressure application) hemorrhagic processes. , such as those that occur, for example, in diabetes and macular degeneration. Elevation of intraocular pressure can also be beneficial-in the treatment of retinal detachments. As yet another use of the present invention, the aforementioned apparatus can also be used to measure the outward flow pressure of the eye fluid. In order to measure the outward flow pressure in the fluid of the eye, the contact device is placed on the cornea, and measurable pressure is applied to the cornea. The pressure causes the aqueous vein to increase in its diameter when the pressure in the cornea is equal to the pressure of flow outward. The pressure on the cornea is proportional to the outward flow pressure. The flow of fluid from the eye to the outside of the eye is regulated according to the Law of Poiseuille for laminar currents. If a resistance is inserted into the formula, the result is a formula similar to Ohm's Law. Using these known formulas, the flow rate (volume per time) can be determined. E change in the diameter of the vessel, which is the reference point, can be detected manually by direct observation and visualization of the change in diameter, or it can be done automatically using an optical detection system capable of detecting a change in the reflectivity due to the amount of fluid in the vein, and the change in surface area. The actual cross section of the vein can be detected using an optical detection system. The eye and brain are hemodynamically linked by the carotid artery and the autonomic nervous system. Pathological changes in the carotid, in the brain, in the heart, and in the sympathetic nervous system, they can affect in a secondary way the blood flow to the eye. The eye and the brain are a low vascular resistance system with high reactivity. The arterial flow to the brain is provided by the carotid artery. The ophthalmic artery branches off the carotid at an angle of 90 °, and approximately 0.5 millimeters in diameter compared to the carotid, which measures 5 millimeters in diameter. Consequently, most of the processes that affect brain flow will have a profound effect on the eye. Furthermore, the pulsation of the central retinal artery can be used to determine the systolic pressure in the ophthalmic artery, and due to its anatomical relationship with the cerebral circulator system, the pressure in the vessels of the brain can be estimated. A total or partial obstruction of the vascular system to the brain can be determined by evaluating the ocular blood flow. There are numerous vascular and nervous system lesions that alter the amplitude of the eye impulse and / or the intraocular pressure curve of the eye. These pathological situations can produce asymmetry of measurements between the two eyes, and / or a decrease in central retinal artery pressure, a decrease in pulsatile blood flow, and alter pulse amplitude. An obstruction in the flow of the carotid (cerebral circulation) can be evaluated by analyzing the amplitude of the impulse and the ocular area, the impulse decay and the amplitude of the impulse, the shape of the wave, by means of harmonic analysis of the impulse. ocular. The pulsation of the eye can be recorded optically according to the change in the reflection of the beam of lu projected towards the cornea. The same system used to record the distance traveled by the movable central part during indentation, over the bare cornea, can be used to detect the changes in the volume that occur with each pulsation. The optical detection system records the variations in distance from the surface of the cornea, which occur with each beat of the heart. These changes in the position of the cornea are induced by the volume changes in the eye. Because of the pulsatile nature of these changes, blood flow to the eye can be calculated. With the aforementioned technique of artificial elevation of pressure, it is possible to measure the time needed for the eye to recover to its baseline, and this recovery time is an indicator of the presence of glaucoma coefficient of outward flow ease . The present invention can also be used to measure the pressure in the vessels on the surface of the eye, and particularly the pressure in the episclerotic veins. The external pressure necessary to collapse a vein in this measurement is used. The method involves applying a variable force on a constant conjunctive area that overlaps the episcleral vein, until a desired fine point is obtained. The pressure is applied directly on the vessel itself, and the preferred end point is when the vessel collapses. However, different endpoints can be used, such as bleaching of the vessel that occurs prior to collapse. The end point pressure is determined by dividing the force applied between the area of the centering flattener in a manner similar to that used for tonometry. The glass can be seen through a movable centerpiece transparent leveler using a slotted lamp biomicroscope. The modality for this technique preferably includes a modified contact device that fits over the sclera (Figure 23). The preferred size of the tip is 250 microns at 500 microns. The detection of the endpoint can be achieved either manually or in an automatic way. According to the manual configuration, the actuator is configured for direct visualization of the vessel through a transparent rear window of the actuator, and the collapse time is manually controlled and recorded. According to an automatic configuration, an optical detection system is configured in such a way that, when the bloodstream can no longer be seen, there is a change in a reflected light beam, in the same way as described above for tonometry , and the consequence, you can automatically identify the pressure for collapse. The final point that marks both situations is the disappearance of the sanguine corrient, one detected by the vision of the operator, and the otr detected by an optical detection system. Preferably, in both cases, the contact device is designed in a manner to adjust the average curvature of the sclera the movable centerpiece, which may be of a rigid or flexible material, which is used to compress the vessel. The present invention can also be used to provide a real-time recording of the intraocular pressure. A single-chip integrated microprocessor can be made to respond to intraocular pressure measurements over time, and can be programmed to create and display a curve that relates pressure to time. The relative position of the movable centerpiece can be detected, as indicated above, using an optical detection system, and it can be quickly collected and analyzed the position detected in combination with the information regarding the amount of current flowing through of the coil of the drive apparatus, by means of the microprocessor, to create the aforementioned curve. It is understood that the use of a microprocessor is not limited to the configuration where curves are created. In fact, the microprocessor technology can be used to create at least the aforementioned calculation unit 10 of the present invention. A microprocessor d preferably evaluates the signals and the force that is applied. The resulting measurements can be recorded or stored electronically in a number of ways. Changes in the current over time, for example, can be recorded in a strip chart recorder. Other methods can be used to record and store the data. Logic microprocessor control technology can also be used to better evaluate the data. Still other uses of the present invention relate to the evaluation of the deformable material pressure in industry and in medicine. An example is the use of the present invention to evaluate soft tissue, such as organs removed from corpses. The dissection of corpses is a fundamental method of learning and studying the human body. The deformability of tissues, such as brain, liver, spleen, and the like, can be measured using the present invention, and the depth of indentation can be evaluated. In this aspect, the contact device of the present invention can be modified to fit over the curvature of an organ. When the movable central part rests on a surface, it can be operated to project into the surface po a distance that is inversely proportional to the tension of the surface and the rigidity of the surface to the deformation. The present invention can also be used to evaluate quantifying the amount of scarring, especially in the therapy of scars from burns. The present invention can be used to evaluate the firmness of the scar in comparison with normal skin areas. The tension of the skin in the scar is compared to the value of the tension in the normal skin. This technique can be used to monitor the therapy of patients with scars from burns, allowing a numerical quantification of the healing course. This technique can also be used as an early indicator for the development of hypertrophic scarring (grossly elevated). With the apparatus, the evaluation of tissue pressure and deformability in a variety of conditions is also possible., such as: a) lymphedema, b) subsequent effects to surgery, such as with breast surgery, and c) endoluminal pressures of hollow organs. In the above cases, the piston type configuration provided by the contact device does not have to be placed in an element that is configured as a contact lens. On the contrary, any shape and size can be used, preferably the flat bottom surface and not curved as a contact lens. Still another use of the present invention relates to providing a bandage lens, which can be used for extended periods of time. Glaucoma and increased intraocular pressure are causes that lead to the rejection of corneal transplants. Many conventional tonometers in the market are unable to precisely measure intraocular pressure in patients with corneal disease. For patients with corneal disease, and who have recently undergone corneal transplantation, a leaner and larger contact device is used, and this contact device can be used for a longer period of time. The device also facilitates the measurement of intraocular pressure in patients with corneal disease who require the use of contact lenses as part of their treatment. The present invention can also be modified to non-invasively measure the intracranial pressure of infants, or to provide instantaneous and continuous monitoring of blood pressure through an intact wall of a blood vessel. The present invention can also be used in conjunction with a digital pulse meter, to provide synchronization with the cardiac cycle. Also, by providing a contact microphone, blood pressure can be measured. The present invention can also be used to create a double tonometer configuration in one eye. A first tonometer can be defined by the contact device of the present invention applied to the cornea, as described above. The second tonometer can be defined by the contact device previously mentioned, which is modified to be placed on the temporal sclera. In the use of the double tonometer configuration, it is desirable to allow vision inside the eye in the background while the contact device is being operated. According to the above, at least the movable central part of the contact device placed on the cornea is preferably transparent, so that the background can be observed with a microscope. Although the above-illustrated embodiments of the contact device generally show only a movable centerpiece 16 in each contact device 2, it is understood that more than one movable centerpiece 16 can be provided without departing from the scope and spirit of the present invention. Preferably, multiple movable center pieces 16 would be concentrically configured in the contact device 2, interconnecting at least one of the flexible membranes 14 to the concentrically configured movable center pieces 16. This configuration of multiple movable center pieces 16 can be combined with any of the aforementioned characteristics to achieve a desired overall combination.

Although the above preferred embodiments include at least one movable centrally operated part 16, it is understood that there may be many other techniques for operating the movable center part 16. For example, s can use sound or ultrasonic generation techniques to drive the centerpiece movable. In particular, sonic or ultrasonic energy can be directed towards a completely transparent version of the movable centerpiece which, in turn, moves inwardly of the cornea in response to the application of this energy. In a similar manner, the movable centerpiece can provide elements for retaining a static electric charge. In order to drive this movable central part, a drive mechanism associated therewith would create an electric field of similar polarity, thereby causing rejection of the movable centerpiece away from the source of the electric field. Other driving techniques, for example, include the discharge of fluid or gas to the movable centerpiece, and according to a less desirable configuration, physically connecting the movable centerpiece to a mechanical drive device which, for example, can be driven by motor, and can use a voltage gauge. Alternatively, the contact device can be eliminated in favor of a movable centerpiece in a drive apparatus. According to this configuration, the movable central part of the actuator can be connected to a sliding arrow of the actuator whose arrow is driven by a magnetic field or other actuating element. Preferably, a physician applies the movable centerpiece of the actuator to the eye, presses a button that generates the magnetic field. In turn, it drives the arrow and the movable centerpiece against the eye. Preferably, the drive apparatus, the arrow, and the movable central part of the actuator are appropriately configured with transparent portions, such that the interior of the patient's eye remains visible during actuation. Any of the detection techniques described above may be used, including the technique of optical detection, with alternative drive techniques. Also, the movable centerpiece 16 can be replaced by an inflatable bladder (not shown) disposed in the substantially rigid annular member 12. When inflated, the bladder extends outwardly from the orifice of the substantially rigid annular member 12, and toward the cornea . In a similar manner, although some of the above preferred embodiments use an optical configuration to determine when the predetermined amount of flattening has been reached, it is understood that there are many other techniques for determining when flattening occurs. The contact device, for example, may include an electrical contact configured to make or break an electrical circuit, when moving the moving central part by a distance corresponding to that which is necessary to produce the flattening. The making or breaking of the electrical circuit is then used to signify the occurrence of flattening. It is also understood that, after the flattening has occurred, the time required for the movable central part 16 to return to the initial position after completion of the actuation force, will indicate the intraocular pressure. When the intraocular pressure is high, the movable central part 16 returns more quickly to the initial position. In a similar manner, for lower infraoculare pressures, more time is needed for the movable centerpiece 16 to return to its initial position. Accordingly, the present invention can be configured to also consider the return time of the movable centerpiece 16 in determining the measured intraocular pressure. As stated above, the present invention can be formed with a transparent central portion in the contact device. This transparent central portion conveniently allows the visualization of the interior of the eye (for example, the optic nerve), while the intraocular pressure is artificially increased using the movable central foot. Some of the effects of increased intraocular pressure on the optic nerve, retina, vitreous, therefore, can be easily observed through the present invention, while simultaneously measuring intraocular pressure. With reference to Figures 21 and 22, although the above examples describe the placement of the contact device 2 on the cornea, it is understood that the contact device 2 of the present invention can be configured with an almost triangular shape (defined by the member). ring substantially rigid), to facilitate placement of the contact device 2 on the sclera of the eye. With reference to Figures 23 and 24, the contact device 2 of the present invention can be used to measure the episcleral venous pressure. Preferably, when the episcleral venous pressure is to be measured, the movable centerpiece 16 has a centrally disposed transparent truncconical projection 16P. The mode illustrated in "Figure 24 conveniently pe visualization of the subject through at least the transparent central region of the movable centerpiece 16. In addition, as indicated above, the invention also It can be used to measure the pressure and other parts of the body (for example, the pressure of cicatri in the context of plastic surgery), or on surfaces of different objects. The contact device of the present invention, therefore, is not limited to the curved shape conforming to the cornea illustrated in relation to the exemplary embodiments, but rather may have other configurations, including a generally flat configuration.

ALTERNATIVE MODALITY ACTIVATED BY THE CLOSURE OF THE PARPADO With reference to Figures 25 to 31, an alternative modality of the system will now be described. The apparatus and alternative method utilizes the force and movement generated by the eyelid during blinking and / or closing of the eyes, to act as the actuator, and to activate at least one transducer 400 mounted on the contact device 402, when the contact device 402 is on the cornea. The method and device facilitate remote monitoring of pressure and other physiological events, by transmitting information through the tissue of the eyelid, preferably by means of electromagnetic waves. The transmitted information is retrieved in a remotely located receiver 404 with respect to the contact device 402, which receiver 404 is preferably mounted in the frame 408 of a pair of spectacles. This alternative modality also facilitates the use of forced closure of the eyelid to measure the ease of outward flow. The transducer is preferably a microminiature pressure sensitive transducer 400 that alters a radiofrequency signal in a manner that indicates the physical pressure exerted on the transducer 400. Although the signal response from the transducer 40 may be communicated by wire, preferably it is transmitted in an active or passive way, wirelessly, to the receiver 404, which is remotely located with respect to the contact device 402. The data represented by the transducer signal response 400 can then be stored and analyzed. The information derived from these data can also be communicated by telephone using conventional elements. According to the alternative embodiment, the apparatus comprises at least one pressure sensitive transducer 400, which is preferably activated by closing the eyelid, and mounted on the contact device 402. In turn, the contact device 402 is located about e eye. In order to calibrate the system, it is evaluated and calculates the amount of movement and tightening of the contact device 402 during the movement / closure of the eyelid. When the upper eyelid descends during the blinking, it pushes down and presses the contact device 402, thus forcing the contact device 402 to undergo a sliding movement and combined tightening. Since normal individuals flash in an unintentional manner approximately every two to 10 seconds, this alternative embodiment of the present invention provides for frequent actuation of the transducer 400. In fact, normal individuals using a contact device 402 of this type will experience a increase in the number of involuntary blinks, and in turn, this tends to provide almost continuous measurements. During sleep or with closed eyes, since there is an uninterrupted pressure on the eyelid, the measurements can be taken continuously. As indicated above, during the closure of the eye, the contact device 402 undergoes a combined tightening and sliding movement caused by the eyelid during its closing phase. Initially, the upper eyelid descends from the open position, until it meets the upper edge of the contact device 402, which is then pushed down by approximately 0.05 millimeters to 2 millimeters. This distance depends on the type of material used to make the structure 412 of the contact device 402, and also depends on its diameter. When a rigid structure 412 is used, there is little initial overlap between the eyelid and the contact device 402. When a soft structure 412 is used, there is a significant overlap, even during this initial phase of eyelid movement. After making this small initial excursion, the contact device 402 comes to rest, and then the eyelid slides on the external surface of the contact device 402, squeezing it covering it. It is important to note that, if the diameter of the structure 412 is greater than the eyelid opening or greater than the diameter of the cornea, the upper eyelid may not impact the upper edge of the contact device 402 at the beginning of a blink. The movement of the contact device 402 terminates approximately at the junction of the cornea-sclera, due to an inclination change of approximately 13 ° in the area of intersection between the cornea (radius of 9 millimeters) and the sclera (radius of 11.5 millimeters). At this point, the contact device 402, whether with a rigid or soft structure 412, remains immobile and still while the eyelid proceeds to cover it entirely. When a rigid structure 412 is used, the contact device 402 is normally pushed down from 0.5 millimeters to 2 millimeters, before reaching rest. When a soft structure 412 is used, the contact device 402 is normally pushed down 0.5 millimeters or less before it comes to rest. The larger the diameter of the contact device 402, the smaller the movement, and when the diameter is sufficiently large, there can be a vertical movement of zero. Despite these differences in movement, the tightening effect is always present, thus allowing accurate measurements to be taken, regardless of the size of the structure 412. The use of a thicker structure 412, or of one with a surface flatter, results in a greater tightening force on the contact device 402. The eyelid margin makes a reentrant angle d approximately 35 ° with respect to the cornea. A combination of forces, possibly caused by the contraction of the Riolan muscle near the rim of the eyelid and the orbicularis muscle, is applied to the contact device 402, via the eyelid. A horizontal force is applied (normal force component) of approximately 20,000 a ,000 dynes, and a vertical force (tangential force component) of approximately 40 to 50 dynes, on the contact device 402 by the upper eyelid. In response to these forces, the contact device 402 moves both forwardly of the eye, and tangentially relative thereto. At the time of maximum closure of -o, tangential movement and force are zero, and normal movement and motion are at maximum. The horizontal force of the eyelid of 20,000 to 100,000 dynes, which presses the contact device 402 against the eye, generates sufficient movement to activate the transducer 40 mounted on the contact device 402, and to allow measurements to be made. This force and movement of the lid towards the surface of the eye can also sufficiently deform many types of transducers or electrodes, which can be mounted on the contact device 402. During the blinking, the eyelids are in complete contact with the device. contact 402, and the surface of the transducer 400 is in contact with the cornea / film d tears and / or internal surface of the eyelid. The microminiature pressure sensitive radiofrequency transducer 400 preferably consists of an endodradiosonde mounted on the contact device 402, which in turn is preferably placed on the cornea, and activated by the movement and / or closing of the eyelid. The force exerted by the eyelid on the contact device 402, as indicated above, compresses it against the cornea. In accordance with a preferred alternative embodiment illustrated in Figure 26, the endodradiosonde includes two opposite coupled coils that are placed inside of a small granule. The flat walls of the granule act as diaphragms, and are attached to each coil, so that compression of the diaphragm by the eyelid causes the coils to move closer to each other. Since the coils are very close to each other, the minimum changes in their separation affect the resonant frequency. A remote absorption oscillator 41 can be mounted at any convenient location near the contact device 402, for example, over a hat or cap worn by the patient. The remote absorption oscillator 414 was used to induce oscillations in the transducer 400. The resonant frequency of these oscillations indicates the intraocular pressure. Briefly stated, the contact of the eyelid with the diaphragms forces a pair of parallel coaxial spiral co-axial coils in the transducer 400, to move closer together. The coils constitute a resonant circuit of high distributed capacitance having a resonant frequency that varies according to the relative separation of the coil. When the coils approach each other, there is an increase in capacitance and mutual inductance, thus lowering the resonant frequency of the configuration. To repeatedly explore the frequency of an inductively coupled external oscillating detector of the absorption type, s detect the electromagnetic energy that is absorbed by the transducer 400 at its resonance, through the intervening eyelid tissue. The pressure information from the transducer 400 d is preferably transmitted by radio link telemetry. Telemetry is a preferred method, since it can reduce the collection of electrical noise, and eliminates the risks of electric shock. F (frequency modulation) methods are preferred, since the modulated frequency transmission is less noisy, and requires less gain in the modulation amplifier, thereby requiring less power for a given transmission force. The modulated frequency is also less sensitive to variations in the amplitude of the transmitted signal. Other different transducer means can be used to acquire a signal indicating the intraocular pressure from the contact device 402. Po exampleActive telemetry can also be used by using transducers that are energized by batteries, or by using cells that can be recharged in the eye by an external oscillation, and active transmitters that can be energized from a biological source. The preferred method for acquiring the signal, however, involves at least one of the aforementioned passive pressure sensitive transducers 400, which does not contain an internal energy source, and which operates using the energy supplied from an external source to modify the frequency emitted by the external source The signals indicating the intraocular pressure are based on the frequency modification, and are transmitted to remote extraocular radiofrequency monitors. The resonant frequency of the circuit can be detected remotely, for example, by means of an absorption meter. In particular, the absorption meter includes the aforementioned receiver 404, where the resonant frequency of the transducer 400 can be measured after it is detected by the external induction coils 415 mounted near the eye, for example, in the spectacle frames. near the receiver, or in the portion of the eyeglass frames that surround the eye. The use of eyeglass frames and especially practical, because the distance between the external induction coil 415 and the radiosonde is within the working limits typical of them. However, it is understood that the external induction coils 415, which essentially serves as a receiving antenna for the receiver 404, can be located anywhere that minimizes the attenuation of the signal. The signal from the external induction coils 415 (or receiving antenna) is then received by the receiver 404 for amplification and analysis. When underwater, the signal can be transmitted using modulated sound signals, because the sound is less attenuated by water than radio probes. Sonic resonators can be made that respond to changes in temperature and voltage. Although the above description includes some preferred methods and devices in accordance with the alternative embodiment of the present invention, it is understood that the invention is not limited to these preferred devices and method. For example, many other types of miniature pressure-sensitive radio transmitters can be used and can be mounted on the contact device, and any microminiature pressure sensor can be used to modulate a signal from a radio transmitter. , and send the modulated signal to a nearby radio receiver. Other devices, such as tension gauges, preferably piezoelectric pressure transducers, can also be used on the cornea, and are preferably activated by closing and blinking the eyelid. It is also possible to mount any displacement transducer contained in a distensible box in the contact device. In fact, many types of pressure transducers can be mounted, and can be used by the contact device. Of course, virtually any transducer that can translate mechanical deformation into electrical signals can be used. Since the eye changes its temperature in response to changes in pressure, a pressure-sensitive transducer may also be used that does not require movement of the parts, such as a thermistor. From an alternative alternative, the dielectric constant of the eye, which changes in response to changes in pressure, can be used to determine the intraocular pressure. In this case, a pressure-sensitive capacitor can be used. Piezo and piezo-resistive transducers, silicon voltage calibrators, semiconductor devices, and the like can also be mounted and can be activated by blinking and / or closing the eyes. In addition to providing a novel method for performing simple measurements, continuous measurements, and self-measurement of intraocular pressure during blinking or with closed eyes, the apparatus can also be used to measure the ease of outward flow and other physiological parameters. The method and device of the invention offers a unique approach for measuring the ease of flow out in a physiological manner and without alterations by placing an external weight on the eye. In order to determine the ease of flow out in this way, it is necessary that the eyelid creates the excessive force necessary to press the fluid out of the eye. Because the present invention allows the measurement of pressure with the patient's eyes closed, the eyelids can remain closed throughout the procedure, and the measurements can be taken concomitantly. In particular, this is done by forced tightening of the closed eyelids. Pressures of approximately 60 mmHg will be present, which are sufficient to press the fluid out of the eye, and in this way evaluate the ease of outward flow. The intraocular pressure will decrease over time, and the decay of the pressure with respect to time correlates with the ease of outward flow. In normal individuals, the infraocular fluid is forced out of the eye with the forced closing of the eyelid, and the pressure decreases in accordance with the same; however, in patients with glaucoma, outward flow is compromised, and therefore, does not decrease eye pressure at the same rate in response to forced closure of the eyelids. The present system allows to have a real time and continuous measurement of the eye pressure, and since the signal can be transmitted through the eyelid to an external receiver, the eyes can remain closed throughout the procedure. Telemetry systems can be used to measure pressure, electrical changes, dimensions, acceleration, flow, temperature, bioelectric activity, chemical reactions, and other important physiological parameters, and power switches to externally control the system , in the apparatus of the invention. The use of integrated circuits and technical advances that occur in the technology of transducers, power supplies, and signal processing, allow for extreme miniaturization of the components, which in turn allows several sensors to be mounted in a contact device. , as illustrated, for example, in Figure 28. Modern resolutions of integrated circuits are of the order of a few microns, and facilitate the creation of very high density circuit configurations. Preferably, the modern techniques for manufacturing integrated circuits are exploited in order to make the electronic components sufficiently small to be placed on the spectacle frame 408. The receiver 404, for example, can connect to different electronic and miniature components 418, 419 420, as schematically illustrated in Figure 31, capable of processing, storing, and even displaying the information derived from the transducer 400. Radio frequency and ultrasonic microcircuits are available, and can be mounted on the contact device for use by the same . There are also a number of different ultrasonic and pressure transducers available, and they can be used and mounted on the contact device. It is understood that additional technological advances will be presented that will allow additional applications of the inventive apparatus. The system may further comprise a contact device for positioning on the cornea, and having a transducer capable of detecting chemical changes in the tear film. The system may further include a contact device to be placed on the cornea, and have a radiofrequency transducer sensitive to gas and microminiature (for example, sensitive to oxygen). It can also use a contact device that has a radiofrequency transducer sensitive to the speed of the blood in microminiature, to be mounted on the conjunctiva, preferably activated by the movement of the eyelid and / closing of the eyelid. The system may also comprise a contact device in which a radiofrequency transducer capable of measuring the negative resistance of the nerve fibers in the contact device, which in turn is placed on the cornea, and preferably activated by the patient, is mounted. eyelid movement and / or eyelid closure. By measuring the electrical resistance, the effects of microorganisms, drugs, poisons, and anesthetics can be evaluated. The system of the present invention may also include a contact device in which a radiofrequency transducer sensitive to radiation and microminiature is mounted in the contact device, which in turn is placed on the cornea, and preferably activated by the eyelid movement and / or eyelid closure. In any of the above embodiments, having a transducer mounted on the contact device, s can use an absorption meter to measure the frequency characteristics of the tuned circuit defined by the transducer. In addition to using passive telemetry techniques as illustrated by the use of the above transducers, active telemetry can also be used with active transmitters and a microminiature battery mounted on the contact device. The contact device preferably includes a rigid or flexible transparent structure 412, wherein at least one of the transducers 400 is mounted in the holes formed in the transparent structure 412. Preferably, the transducers 400 are positioned to allow light to pass through the visual axis. The structure 412 d preferably includes a concave inner surface configured to mate with an outer surface of the cornea. As illustrated in Figure 29, a larger transducer 400 may be centrally configured in the contact device 402, while retaining a transparent portion 416 thereof of the visual axis of the contact device 402. The structure 412 preferably has a thick maximum in the center, and a thickness that decreases progressively towards a periphery of the structure 412. The transducts. Preferably, they are secured to the structure 412, such that the front side of each transducer 400 is contiguous with the inner surface of the eyelid during blinking, and so that the back side of each transducer 400 is contact with the cornea, thereby allowing the eyelid movement to squeeze the contact device 40 and its associated transducers 400 against the cornea. Preferably, each transducer 400 is fixed to the structure 412, such that only the diaphragms of the transducers undergo a movement in response to pressure changes. The transducers 400 can also have any suitable thickness, including the coupling or go beyond the surface of the structure 412. The transducers 400 can also be placed to support only against the cornea, or alternatively only against the inner surface of the eyelid. The transducers 400 may also be placed protruding towards the cornea, such that the posterior part flattens a portion of the cornea when the eyelid is closed. In a similar manner, the transducers 400 can also be placed in an outstanding manner towards the inner surface of the eyelid, in such a way that the anterior part of the transducer 400 is pressed by the eyelid, the back part being covered by a flexible membrane that allows the interaction with the cornea when closing the eyelid. A flexible membrane of the type used in flexible or hydrogel lenses can enclose the contact device 402 for convenience, provided that it does not interfere with the acquisition and transmission of the signal. Although the transducers 400 may be positioned in a manner that counteracts each other, as illustrated in Figure 28, it is understood that a counterweight may be used to maintain an appropriate balance. Although the present invention has been described with reference to the preferred embodiments thereof, it is understood that the present invention is not limited to these embodiments, but rather by the scope of the appended claims.

Claims

1. A device for contacting a cornea, and for flattening or indentating the cornea, this device comprising: a substantially rigid annular member having a concave inner surface configured to engage an outer surface of the cornea, and having a defined orifice in the same; a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten or indentate a portion of the cornea, when the device is located on the cornea; and a flexible membrane secured to the concave inner surface of the substantially rigid annular member, this flexible membrane being coextensive with at least the hole in the annular member, and having at least one transparent area.

2. The device of claim 1, wherein the substantially rigid annular member has a maximum thickness in the hole, and a progressively decreasing thickness towards a periphery of the substantially rigid annular member.

3. The device of claim 2, wherein the substantially rigid annular member has a substantially cylindrical wall defined circumferentially around the orifice, the movable centerpiece being slidably disposed within the orifice in a piston-like manner.

4. A device for contacting a cornea, and for flattening or indentating the cornea, this device comprising: a substantially rigid annular member having a concave inner surface configured to engage an outer surface of the cornea, and having a hole defined therein; a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten or indentate a portion of the cornea, when the device is located on the cornea; the movable centerpiece including a magnetically responsive element configured to cause sliding of the moveable centerpiece in response to a magnetic field, the circumferentially magnetically responsive element being surrounded by a transparent peripheral portion that allows light to pass through it. up to the cornea, and that allows the reflection of this light of the cornea, through the transparent peripheral portion. The device of claim 4, and further comprising a flexible annular membrane connected to the substantially rigid annular member, and also connected to the movable centerpiece, such that a membrane orifice in the flexible annular membrane is aligned with the transparent central region of the ring magnet. 6. A system for measuring intraocular pressure by flattening, this system comprising: a device for contacting a cornea, and for flattening the cornea, this device comprising: a substantially rigid annular member having a concave internal surface configured to engage with an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side, to flatten a portion of the cornea while the device is located on the cornea; a driving apparatus for driving the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea, to flatten that portion of the cornea; a detection element for detecting when a predetermined amount of flattening of the cornea has been reached; and an element for determining intraocular pressure, based on an amount of force that the movable centerpiece must apply against the cornea, in order to achieve the predetermined amount of flattening; the movable centerpiece including at least one transparent area, and wherein the detection element comprises an optical detection system including: a light source for emitting a primary light beam towards the cornea through the at least one transparent area , this beam of primary light being reflected back through the device by the cornea, when the device is located on the cornea, in a manner that indicates the amount of flattening of the cornea; and a light sensor configured with respect to the reflected light beam, to produce an output signal indicating the amount of flattening. The system of claim 6, wherein the element for determining the intraocular pressure includes: a memory element for storing a value indicating the amount of force when the predetermined amount of flattening is reached; and an element to multiply this amount of force by a conversion factor that converts the amount of force into intraocular pressure. 8. The system of claim 6, and further comprising a visual display for exhibiting intraocular pressure. The system of claim 8, wherein the visual display is configured to indicate whether the intraocular pressure is within certain ranges, each of these ranges being associated with the action, if any, to be taken in connection with intraocular pressure, and where ranges are adjustable to compensate for different sensitivities of patients to changes in intraocular pressure. The system of claim 6, wherein the movable centerpiece includes a magnetically responsive element, configured to produce a sliding of the moveable centerpiece in response to a magnetic field; and wherein the driving apparatus includes an element for applying a magnetic field to the movable centerpiece. The system of claim 10, wherein: the element for applying a magnetic field includes a coil and an element for producing an electric current through the coil, in a progressively increasing manner, until the amount of flattening is reached previously determined, the electric current being proportional to the amount of force applied by the movable central part; and the element for determining the intraocular pressure includes an element for storing a current value indicating an amount of current that passes through the coil when the predetermined amount of flattening is reached, and an element for converting this current value to an indication of intraocular pressure. 12. A system for measuring intraocular pressure by flattening, this system comprising: a device for contacting a cornea, and for flattening the cornea, said device comprising: a substantially rigid annular member having a concave internal surface configured to engage with an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side, to flatten a portion of the cornea, while the device is located on the cornea; a driving apparatus for driving the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea, to flatten that portion of the cornea; a detection element for detecting when a predetermined amount of flattening of the cornea has been reached; an element for determining intraocular pressure, based on an amount of force that the movable centerpiece must apply against the cornea, in order to achieve the predetermined amount of flattening; and an alignment element for indicating whether the device is properly aligned with the driving apparatus and the detection element. The system of claim 12, wherein the alignment element includes an optical alignment mechanism. 14. An indentation device for contacting a cornea, and for indentating the cornea, this indentation device comprising: a substantially rigid annular member having a concave inner surface configured to engage an outer surface of the cornea, and it has a hole defined in it; and a movable center piece slidably disposed within the hole, this movable center piece being configured in such a way that its sliding towards the cornea causes the indentation of a portion of the cornea, when the indentation device is located on the cornea; a driving apparatus for driving the moveable center piece, in order to cause sliding of the moveable center piece, such that the movable center piece projects inward against the cornea beyond a flattening of the cornea, to indent in this way that portion of the cornea using a predetermined amount of force; a distance detecting element for detecting a distance traveled by the moving centerpiece; an element for determining the intraocular pressure based on the distance traveled by the moving centerpiece in response to the amount of force previously determined; a visual display to show the intraocular pressure, and indicate if the intraocular pressure is within certain ranges, in order to determine if some measure should be taken in relation to the intraocular pressure; and these ranges are adjustable to compensate for the different sensitivities of patients to changes in intraocular pressure. The system of claim 14, wherein the moveable centerpiece includes a magnetically responsive element configured to cause sliding of the moveable centerpiece in response to a magnetic field; and wherein the driving apparatus includes an element for applying a magnetic field to the movable centerpiece. The system of claim 15, wherein: the element for applying a magnetic field includes a coil, and an element for producing an electric current through the coil, in a progressively increasing manner, until the amount of previously determined force, this electrical current being proportional to the amount of force applied by the movable central part. 17. A method for non-invasively measuring the ease of outward flow of the eye, this method comprising the steps of: placing an indentation device in contact with a cornea; moving at least a portion of the indentation device toward the cornea using a first predetermined amount of force to achieve indentation of the cornea; determining an intraocular pressure based on a first distance traveled towards the cornea by the at least one portion of the indentation device during the application of the first predetermined amount of force; rapidly reciprocating the at least one portion towards and away from the cornea at a previously determined first frequency, and using a second amount of previously determined force during movement toward the cornea, to thereby force the intraocular fluid out of the eye, being the second amount of previously determined force less than the first amount of force previously determined; moving the at least one portion toward the cornea using a third amount of previously determined force to achieve indentation of the cornea; determining a second intraocular pressure based on a second distance traveled towards the cornea by the at least one portion of the indentation device during the application of the third predetermined amount of force; again rapidly reciprocating the at least one portion toward and away from the cornea, at a previously determined second frequency, and using a fourth amount of force previously determined during movement toward the cornea, to thereby force more intraocular fluid out of the eye, the fourth amount of previously determined force being greater than the second amount of previously determined force; subsequently moving the at least one portion toward the cornea using a fifth amount of previously determined force to achieve the indentation of the cornea again; determining a third intraocular pressure based on a third distance traveled to the cornea by the at least one portion of the indentation device during the application of the fifth force amount previously determined; calculate the differences between the first, second, and third distances, indicating these differences the amount of intraocular fluid that leaves the eye, and therefore indicating the ease of outward flow. 18. The method of claim 17, and further comprising the steps of: plotting the differences between the first, second, and third distances to create a graph of these differences; and compare the graph of the differences with that of a normal eye, to determine if there are irregularities in the ease of outward flow present. 19. A contact device for detecting intraocular pressure, said contact device comprising: a contact structure configured to be placed on the cornea of a patient; a transducer disposed in the contact structure, this transducer responding to the pressure exerted on the transducer, to provide an output signal indicating the pressure, this transducer responding to the pressure generated by the sliding and tightening of the transducer by an eyelid during the closing of the eyelid 20. A method for detecting pressure, which comprises the steps of: mounting, on a surface of the cornea of an eye, a pressure sensitive transducer that responds to the pressure generated by the sliding and tightening of this transducer sensitive to pressure by an eyelid during closing of the eyelid associated with the eye; and activating the pressure-sensitive transducer by sliding and tightening the pressure-sensitive transducer through the eyelid during eyelid closure. 21. A device for contacting a cornea, and for flattening or indentating the cornea, this device comprising: a substantially rigid annular member having a concave inner surface configured to engage with the outer surface of the cornea, and having a hole defined therein; and a movable centerpiece slidably disposed within the hole, and having a substantially flat internal side to flatten or indentate a portion of the cornea when the device is located on the cornea; the movable centerpiece having a substantially transparent peripheral portion. 22. A device for contacting a cornea, and for flattening or indentating the cornea, this device comprising: a substantially rigid annular member having a concave inner surface configured to engage an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten or indentate a portion of the cornea, when the device is located on the cornea; and the movable centerpiece including a transparent central portion. 23. A device for contacting a cornea, and for flattening or indentating the cornea, this device comprising: a substantially rigid annular member having a concave inner surface configured to engage an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten or indentate a portion of the cornea, when locating the device on the cornea; an element for actuating the moveable center piece, to cause sliding of the movable center piece, in such a way that the movable center piece projects inwardly against the cornea, to flatten or indentate that portion of the cornea, the actuating element being configured in such a way that the inner side of a patient's eye remains visible during the actuation. 24. A device for contacting a cornea, and for flattening and indentating the cornea, this device comprising: a substantially rigid annular member having a concave inner surface configured to engage an outer surface of the cornea, and having a hole defined therein; a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten or indentate a portion of the cornea when the device is located on the cornea; the movable centerpiece including a magnetically responsive element configured to produce the sliding of the movable centerpiece, in response to a magnetic field, including the magnetically responsive element, an annular magnet with a transparent central region through which a patient it can see while the device is located on the cornea of the patient, and that it allows the light to pass through it to the cornea, and that it allows the reflection of the light from the cornea through the transparent central region. The device of claim 24, and further comprising a flexible annular membrane connected to the substantially rigid annular member, and also connected to the movable centerpiece, such that a membrane orifice in this flexible annular membrane is aligned with the transparent central region of the ring magnet. 26. A system for measuring intraocular pressure by flattening, this system comprising: a device for contacting a cornea, and for flattening the cornea, this device comprising: a substantially rigid annular member having a concave internal surface configured to engage with an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten a portion of the cornea, while the device is located on the cornea; a driving apparatus for driving the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea, to flatten that portion of the cornea; a detection element for detecting when a predetermined amount of flattening of the cornea has been reached; an element for determining intraocular pressure, based on an amount of force that the movable centerpiece must apply against the cornea, in order to achieve the predetermined amount of flattening; and a viewing element for indicating when the driving apparatus and the sensing element are properly aligned with the device. 27. A system for measuring intraocular pressure by flattening, this system comprising: a device for positioning with contact with a cornea, and for flattening the cornea, this device comprising: a substantially rigid annular member having a concave internal surface configured to engage with an outer surface of the cornea, and that has a hole defined in it; and a movable center piece slidably disposed within the hole, and having a substantially flat inner side to flatten a portion to the cornea, while the device is located on the cornea; a driving apparatus for driving the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea, to flatten that portion of the cornea; a detection element for detecting when a predetermined amount of flattening of the cornea has been reached; an element for determining the intraocular pressure based on an amount of force that the movable centerpiece must apply against the cornea, in order to achieve the predetermined amount of flattening; and a distance measuring element for indicating whether the device is at an appropriate axial distance from the driving apparatus and the sensing element. 28. A system for measuring the intraocular pressure by flattening, this system comprising: a device for positioning with contact with a cornea, and for flattening the cornea, this device comprising: a substantially rigid annular member having a concave internal surface configured to engage with an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten a portion of the cornea, while the device is located on the cornea; a driving apparatus for driving the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea, to flatten that portion of the cornea; a detection element for detecting when a predetermined amount of flattening of the cornea has been reached; an element for determining the intraocular pressure based on an amount of force that the movable centerpiece must apply against the cornea, in order to achieve the predetermined amount of flattening; and the driving apparatus being configured in such a way that an interior of a patient's eye remains visible during actuation. 29. A system for measuring intraocular pressure by indentation, this system comprising: an indentation device for contacting a cornea, and for indentating the cornea, said indentation device comprising: a substantially rigid annular member having an internal surface concave configured to mate with an outer surface of the cornea, and having a hole defined therein; and a movable center piece slidably disposed within the hole, the movable centerpiece being configured in such a way that its sliding towards the cornea causes the indentation of a portion of the cornea when the indentation device is located on the cornea; a driving apparatus for actuating the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea beyond a flattening of the cornea, to indentate in this manner that portion of the cornea, using a predetermined amount of force; a distance detecting element for detecting the distance traveled by the movable centerpiece; and an element for determining the intraocular pressure based on the distance traveled by the moving centerpiece in response to the predetermined amount of force; the movable centerpiece having a substantially reflective portion, and wherein the distance detecting element comprises an optical distance detection system including: a light source for emitting a primary light beam towards the substantially reflecting portion, this beam being of primary light reflected by the substantially reflecting portion in a manner indicating the distance traveled by the movable centerpiece towards the cornea, to thereby produce a reflected light beam; and a light sensor configured with respect to the reflected light beam, to produce an output signal indicating the distance traveled. 30. A system for measuring intraocular pressure by flattening, this system comprising: a device for positioning with contact with a cornea, and for flattening the cornea, this device comprising: a substantially rigid annular member having a concave internal surface configured to engage with an outer surface of the cornea and that has a hole defined in it; and a movable center piece slidably disposed within the hole, and having a substantially flat internal side to flatten a portion of the cornea while the device is located on the cornea; a driving apparatus for driving the moveable centerpiece, to cause sliding of the moveable centerpiece, such that the moveable centerpiece projects inwardly against the cornea, to flatten that portion of the cornea; a detection element for detecting when a predetermined amount of flattening of the cornea has been reached; and an element for determining the intraocular pressure based on an amount of force that the movable central force must apply against the cornea, in order to achieve the predetermined amount of flattening; the actuator being configured in such a way that the interior of a patient's eye remains visible during actuation. 31. A contact device for detecting intraocular pressure, said contact device comprising: a contact structure configured to be placed on the cornea of a patient; a transducer disposed in the contact structure, this transducer responding to the pressure exerted on the transducer, to provide an output signal indicating the pressure; this transducer being a passive transducer that has a resonant frequency that varies according to the pressure. 32. A device for contacting a part of the body, and for flattening or indentating the part of the body, the device comprising: a substantially rigid member having an internal surface configured to engage an external surface of the body part, and having a hole defined therein; a movable center piece slidably disposed within the hole, and having a substantially flat internal side for flattening or indentating a portion of the body part, when the device is located on the body part; and a flexible membrane secured to the inner surface of the substantially rigid member, the flexible membrane being coextensive with at least the orifice of the rigid member, and having at least one transparent area. 33. A system for measuring the internal pressure by indentation, this system comprising: an indentation device for contacting a part of the body, and for indentating the body part, this indentation device comprising: a substantially rigid member having an internal surface configured to mate with an external surface of the body part, and having a hole defined therein; and a movable center piece slidably disposed within the hole, the movable center piece being configured in such a way that its sliding towards the body part causes the indentation of a portion of the body part, when the indentation device is located on the part of the body part. body; a driving apparatus for driving the moveable center piece, to cause sliding of the moveable center piece, such that the movable center piece projects inward against the body part beyond a flattening of the body part, with the purpose of indenting in this way that portion of the body part, using a predetermined amount of force; a distance detecting element for detecting a distance traveled by the moving centerpiece; and an element for determining the internal pressure based on the distance traveled by the movable centerpiece and in response to the predetermined amount of force; the movable centerpiece having a substantially reflective portion, and wherein the distance detecting element comprises an optical distance detection system including: a light source for emitting a primary light beam towards the substantially reflective portion, the beam being of primary light reflected by the substantially reflecting portion in a manner indicating the distance traveled by the movable central part towards the body part, to thereby produce a reflected light beam; and a light sensor configured with respect to the reflected light beam, to produce an output signal indicating the distance traveled. 34. A contact device for detecting internal pressure, said contact device comprising: a contact structure configured to be placed on a part of a patient's body; a transducer disposed in the contact structure, this transducer responding to the pressure exerted on the transducer, to provide an output signal indicating the pressure; the transducer being a passive transducer having a resonant frequency that varies according to the pressure. 3

5. A method for detecting pressure as claimed in claim 20, wherein the signals indicating pressure are transmitted through the eyelid by electromagnetic waves. 3

6. A method for measuring the hydrodynamics and movement of fluid out of an eye, comprising this method: rapidly reciprocating, using an oscillatory movement, a device in contact with the eye, at a previously determined frequency that prevents stress relaxation of the eye coating, and determining a change in the pressure in the eye between the initial pressure of the eye before the oscillatory movement of the device is applied, and a pressure inside the eye after the oscillatory movement of the device is applied, which indicates a quantity of flow out of the eye. 3

7. A method for the early detection of glaucoma, comprising this method: artificially increasing the pressure in one eye progressively, and simultaneously measuring the pressure in the eye, while identifying the physical and chemical changes that occur in the eye. eye according to each level of progressive pressure, by monitoring the accumulation of compounds in the fluid or tissues of the eye, and monitoring the change in the transparency of the fluid or tissues of the eye. 3

8. A method for the early detection of glaucoma as claimed in claim 37, wherein one of the compounds being monitored is glutamate. SUMMARY A tonometer system for measuring intraocular pressure, providing precisely a predetermined amount of flattening of the cornea, and detecting the amount of force required to achieve the predetermined amount of flattening. The system can also measure the intraocular pressure by indentating the cornea, using a previously determined force applied using an indentation element, and detecting the distance that the indentation element (16) moves into the cornea when the previously determined force is applied. , the distance being inversely proportional to the intraocular pressure. A method for using a tonometer system to measure the hydrodynamic characteristics of the eye, especially the ease of outward flow, is also provided. The tonometer system includes a contact device to be placed in contact with the cornea, and an actuator (6) for actuating the contact device, such that a portion thereof projects inwardly against the cornea, with the order to provide a predetermined amount of flattening. The system further includes a detection configuration (8) to detect when the predetermined amount of flattening has been reached, and a calculation unit that responds to the detection configuration (8), to determine the intraocular pressure, based on the amount of force that the contact device must apply against the cornea in order to achieve the predetermined amount of flattening. An indentation distance detection configuration is also provided, to be used when the intraocular pressure is to be detected by indentation. In carrying out the method, the system is used to detect the intraocular pressure between the successive steps of forcing the intraocular fluid out of the eye.