WO2018087176A1 - Ophthalmological apparatus and ophthalmological system for examination and/or treatment of an eye, and measurement method - Google Patents

Ophthalmological apparatus and ophthalmological system for examination and/or treatment of an eye, and measurement method Download PDF

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Publication number
WO2018087176A1
WO2018087176A1 PCT/EP2017/078657 EP2017078657W WO2018087176A1 WO 2018087176 A1 WO2018087176 A1 WO 2018087176A1 EP 2017078657 W EP2017078657 W EP 2017078657W WO 2018087176 A1 WO2018087176 A1 WO 2018087176A1
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WO
WIPO (PCT)
Prior art keywords
device
deformation
force
body
eye
Prior art date
Application number
PCT/EP2017/078657
Other languages
German (de)
French (fr)
Inventor
Benjamin JOHN
Dietmar Steinmetz
Jörg Seilwinder
Thomas Wollweber
Thomas Eilenberger
Original Assignee
Carl Zeiss Meditec Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to DE102016121469.8 priority Critical
Priority to DE102016121469.8A priority patent/DE102016121469A1/en
Application filed by Carl Zeiss Meditec Ag filed Critical Carl Zeiss Meditec Ag
Publication of WO2018087176A1 publication Critical patent/WO2018087176A1/en

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B3/00Apparatus for testing the eyes; Instruments for examining the eyes
    • A61B3/18Arrangement of plural eye-testing or -examining apparatus
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F9/009Auxiliary devices making contact with the eyeball and coupling in laser light, e.g. goniolenses
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F2009/00844Feedback systems

Abstract

A description is given of an ophthalmological apparatus (12) comprising a receptacle device (32) for fitting a patient interface (48) for coupling the apparatus (12) to an eye (24), a connection device (30) for securing to a housing (13), wherein the connection device (30) comprises a passage element (36), through which passes radiation for imaging and/or treatment of the eye (24) along an axis of incidence (OA), at least one deformation body (38) which has a first end (38a), which is rigidly connected to the receptacle device (32), and a second end (38b), which is rigidly connected to the connection device (30), and which is deformable by a force acting at least partly parallel to the axis of incidence (OA) between the receptacle device (32) and the connection device (30), a measuring device (58), which detects a deformation of the deformation body (38) and outputs a measurement signal corresponding to a degree of deformation, and an evaluation device (29), which is data-technologically connected to the measuring device (58) and determines a magnitude of the acting force from the measurement signal generated by the measuring device (58).

Description

 The invention relates to an ophthalmic device comprising a receiving device for attaching a patient interface for coupling the device to an eye and a connection device for attachment to a support arm. The

Connecting device has a passage element through which radiation and / or waves for imaging and / or treatment of the eye along an optical axis running / runs. The invention further relates to a measuring method for determining the force acting on the eye, and to methods for preventing eye pinching.

Further, the invention relates to an ophthalmologic system for examining and / or treating an eye comprising the above-mentioned ophthalmic device and a housing having a base body, a support arm to which the ophthalmic device is attached, and a drive for adjusting the position of the ophthalmic device

Device comprises.

Ophthalmic systems for the examination and / or treatment of ophthalmic diseases have lately been developing towards a higher complexity and a more compact design. The space occupied by the ophthalmic system should be as low as possible, since ophthalmic treatments often take place in a sterile environment. On the other hand, such systems should also be used to allow the patient to

Observation as well as the therapy in its location does not need to be changed. This is especially useful for treatments where there is a need to alternate between treatment and examination; Thus, the patient does not have to get up during treatment and / or therapy and the ophthalmic system does not have to get up each time before treatment

Treatment and / or therapy to be targeted to the patient. In the

For example, in ophthalmic treatment, incisions may be made in an eye tissue by means of a laser, or the ocular tissue may be ablated or coagulated while the eye is observed simultaneously with an observer. This is particularly useful in laser assisted ophthalmic surgery for correction of

Ametropia or for the treatment of eye diseases, such as cataract surgery, helpful where work steps for the characterization of the eye structures with surgical steps and steps for the verification of the surgical procedure or for Alternate support of the surgical procedure. For example, the eye structure can first be characterized by means of optical coherence tomography (OCT) or by means of ultrasound. Subsequently, an eye tissue can be cut or otherwise treated by means of a pulsed laser beam. The result of the treatment can then be verified by means of a surgical microscope and subsequent steps, such as, for example, in cataract surgery, the aspiration of a clouded eye lens which has been previously cut with the laser beam and / or shattered by ultrasound, under the control of the eye

Surgical microscope are performed. For this purpose, it is possible to work with an ophthalmological system which has a movable support arm with which a corresponding receiving device with a patient interface provided thereon is positioned on the eye of a patient so that, for example, therapy laser radiation is focused in the eye tissue or by means of a surgical microscope the corresponding eye can be observed.

In particular, when using laser radiation for ophthalmological purposes, it is advantageous to have a fixed positional relationship between the eye to be treated and a

Through element of the connection device, and thus to establish it for example between the eye and a therapy beam. Usually, this is done with one

Patient interfaces, which is attached on the one hand to the receiving device and on the other hand, the eye fixed by negative pressure reached. However, the fixation of the position of the receiving device relative to the eye can lead to unwanted interactions between the

Patient interface and the eye guide. For example, a restless patient by appropriate movement, an increase in the pressure force between the eye and the

Create a patient interface, which leads in the worst case to damage to the eye. Inadvertent operation of a patient's couch can also increase the pressure between the eye and the patient interface.

US 2006/0192921 A1 describes an ophthalmological device in which pressure sensors are arranged between a receiving device and the support arm, with the aid of which the pressure force between the eye and the patient interface can be determined.

 If the pressure force exceeds a predetermined value, the receiving device is moved away from the patient's eye with the support arm.

The object of the invention is to provide an ophthalmological device and an ophthalmic system which provide improved detection of a compressive force between an eye of the patient and a patient interface provided on a receiving device. The invention is defined in the independent claims. The dependent claims relate to preferred developments. An ophthalmological device comprises a connection device for attachment to a support arm, a receiving device for receiving a patient interface for coupling the device with an eye, at least one deformation element, a measuring device and an evaluation device. The connection device has a

Passage element through which radiation and / or waves for imaging and / or treatment of the eye along an axis of incidence is / is performed. Of the

 Deformation body has a first end which is rigid with the receiving device, and a second end which is rigidly connected to the connecting device, and is by a force parallel to the axis of incidence or by the component parallel to the optical axis of a force between the patient interface and the connecting device deformable. The

Receiving device and the connection device are movable under the force within certain limits along the direction of incidence, while the deformation body is deformed. The measuring device detects the deformation of the deformation body and outputs a measurement signal corresponding to the degree of deformation. The evaluation device is connected to the measuring device in terms of data technology and determined from that of the

Measuring device generated measurement signal a magnitude of force.

An ophthalmic system for examining and / or treating an eye comprises the above-described ophthalmic device, a control device and a housing, which has a main body, a support arm and a drive controllable by a control device. The support arm is attached to the connection device and by means of the support arm, the receiving device relative to the base body in different positions can be positioned. The drive moves to adjust the position of the receiving device, the support arm. The controller controls the drive, if the magnitude of the applied compressive or tensile force is above a predetermined threshold, such that the receiving device is moved away from the eye.

An advantage of the invention is that the receiving device is connected via the deformation body with the connection device and therefore with the support arm. Since the

Deformation body is rigidly connected to the connection device and the receiving device, the position of the connection device relative to the eye changes upon the application of a compressive force between the eye and the patient interface only to the extent that deforms the deformation body length. Decisive for this is the length of the Deforming body along the axis of incidence. Any deformation of the deformation of the deformation body inevitably leads to a change in the distance between the receiving device to which the patient interface the eye couples, and the connection device to which the support arm is to be attached. Since each force measurement requires a measuring stroke, in the prior art, for. As in US 2006/0192921 A1, ensured by a special optical design that the irradiation of optical radiation is independent of a lifting or lowering the patient's head. By this measure, the device for the measuring stroke, which is required for force measurement, insensitive and it could be measured without limiting the measuring stroke. The invention here is a completely different way and provides through the special deformation body before a measuring stroke, which takes place so that the change in length of the deformation body remains low and in terms of and the leadership of the radiation to a negligible extent. The use of the

Deforming body allows to keep the change in length occurring during the measurement small compared to the fixing accuracy with which the eye is to be coupled. In embodiments, the deformation body and the on in the measurement is carried out so that the change in length of the deformation body and thus the movement of the receiving device relative to the connection device is not more than 20 μιτι, preferably at most 10 μιη and more preferably at most 5 μιη. In this way it can be ensured that the positional relationship between a radiation source and the eye remains constant within a tolerance range which is given for the radiation / waves which are coupled in. This is very important in particular for surgical laser radiation, since otherwise the effect produced by the laser radiation would not arise at the correct position. At the same time a force between the eye and the receiving device can be reliably detected with the aid of the deformation body. This means that the ophthalmic device according to the invention ultimately ensures both an eye within the tolerance range fixed positional relationship between the eye and the connection device, as well as monitors a force between the eye and the connection device. The device detects at least one component of a force which is parallel to an optical axis along which radiation or waves pass through the passage element, since this direction is of particular importance. However, it is equally possible to design the deformation body and the measuring device so that the force not only in terms of a component along the axis of incidence, but with their direction, z. B.

three-dimensional, is determined. As far as in this description of "the size" of the force is spoken, this is the amount of force includes.This amount may refer to a spatial direction, for example along the axis of incidence absolute amount of force can be given as the magnitude of the force. In a particularly complete embodiment, the magnitude of the force and its three-dimensional direction is measured as the magnitude of the force. The device detects the force between two elements. This can be a

Pressure force or a traction act. For example, the ophthalmic device may be configured to have forces between minimum -6 N, -3 N or 0 N and maximum 20 N, 5 N or 3 N with a resolution of, for example, ± 0.3 N, ± 0.2 N or ± 0.1 N can detect. As far as subsequently spoken of compressive force or tensile force, this is to be understood as an example only. Ultimately, the two forces differ in the

 Measuring device in preferred embodiments only by the sign. It is also possible in a simplified construction, however, that the measuring device is only capable of a compressive force (positive sign) of the receiving device on the

To measure connection device. It has been found that compressive forces caused by undesirably reducing the distance between the device and the eye have a much higher damage potential than tensile forces. This is also the case because excessive traction can be prevented by attaching the

Patient interfaces on the eye opens, for example because a maximum suction force of a negative pressure attachment is exceeded. In the case of an opposite movement of the eye towards the device (or the device towards the eye), this safety measure is not possible, which is why pressure forces are of particular interest in the measurement.

The ophthalmic system may, for example, a surgical microscope, a

Laser treatment device, a device for generating ultrasound and / or an optical coherence tomograph (OCT) have. The surgical microscope can for

Observation of the eye can be used. By means of the laser treatment device, cuts can be made in or on the eye. The means for generating ultrasound can be used to observe the eye. By means of the optical coherence tomograph, for example, the eye lens or the fundus is measured or observed. The devices mentioned can be positioned with respect to the eye using the housing. There are also several support arms possible m withtels which the individual devices, but also the receiving device, are positioned relative to the eye. The support arm and / or the support arms can be configured as described in DE 102005001249 A1. The support arm is preferably movably attached to a base body. The housing may be any device by means of which the ophthalmic device can be supported. In particular, the housing has the main body, the at least one support arm and the at least one drive. The main body can be arranged, for example, on a floor of a room in which the ophthalmological system is provided, or attached to a wall. The support arm can be attached via a hinge to the base body. The main body has, for example, a chamber in which optionally parts of the control device, lasers for the laser treatment device and / or other components of the ophthalmic system are housed. The support arm has one or more joints, so that the free end of the support arm can be positioned in many layers. At the free end of the support arm, the connection device is attached. The support arm may have springs which facilitate the positioning of the free end of the

Support arm. Furthermore, a drive is provided on the support arm and / or on the base body, via which the free end of the support arm can be positioned. The drive may have motors, but also springs and / or weights, so that by means of the drive, the free end of the support arm can be moved. In particular, the drive with the

 Control means connected and the control means can drive the drive such that the control means can adjust the free end of the support arm. Optionally, the drive is configured such that the free end of the support arm can be quickly moved away from the patient's eye. In this way, it is possible if the force between the eye and the receiving device exceeds a predetermined limit, the

 To move recording device quickly away from the patient's eye, so that an excessive increase in the force between the eye of the patient and the receiving device can be avoided. The ophthalmic device may also be referred to as an applicator and in particular indicates an element which is arranged between the patient interface and the support arm. The ophthalmic device or applicator has the

Connecting device for attachment to the support arm and the receiving device for attachment of the patient interface.

The evaluation device, which serves to determine the force between the eye and the receiving device, can be designed as a microprocessor and optionally attached to the deformation device. The control device may comprise a computer, which is provided for example in the base body. The evaluation device may be part of the control device. The connection device may for example be formed as a plate having a central opening. The opening serves as a passage element. However, the connection device can also be designed as a thread or screw, by means of which the receiving device, in particular the deformation body, can be attached to the support arm. The passage element can be formed as an opening or recess, in particular centrally in the connection device. Furthermore, the passage element can be realized in that the connection device releases a space through which radiation or waves, such as ultrasound, can be guided. The passage element may be formed as a radiation guide, which optics, for example, one or more lenses, or other optical elements, such as a diaphragm may have, by means of which radiation can be guided. Further, the passage member may be adapted to guide waves, such as ultrasound. The opening and / or the optics define / fix the axis of incidence. The incident axis is the optical axis of the incident radiation in the case where the passage element transmits optical radiation. For ultrasonic waves, it would be the major axis of the ultrasonic waves passing through the passage member. In

In the following description, the term "optical axis" will be used in some places, without it being intended to be a definition of optical radiation which passes through the passage element, rather, the term "optical axis" is used for better clarity and is intended to both the main axis of optical radiation as well as the main axis of ultrasonic waves. The radiation guided through the passage element can be, for example, the radiation for observation and / or treatment of the eye. Further, the eye can serve for observation or treatment of the eye by means of waves guided or transmitted through the passage element. For example, the connection device can not only with the support arm, but also with a

Laser treatment device to be connected, which by the

 Laser treatment device generated laser radiation is guided through the passage element. The radiation used for a surgical microscope is also guided in particular through the passage element. The receiving device serves, in particular, to establish a connection between the support arm and / or the laser treatment device and the eye. The

Receiving device may be formed as known from the prior art. At the receiving device, a patient interface can be attached, which is in contact with the eye of the patient. The patient interface can be attached to the receiving device by means of negative pressure. The patient interface can be designed as sterile optics to be used once, which can be docked via suction structures on the eye. The patient interface can also be a fluid patient interface, z. B. with a terminating optic, which dips into a fluid located in the patient interface through which radiation is transmitted to the eye. In both cases, a negative pressure is created between the eye and the patient interface. The patient interface can rest on the receiving device via a mechanical contact point. In particular, the contact point is designed such that the patient interface is arranged centered to the optical axis on the receiving device. The contact point may be annular, wherein the center of the ring is optionally located on the optical axis. The holding force between the receiving device and the patient interface is realized for example by negative pressure, so that the patient interface is firmly positioned relative to the receiving device, whereby the eye of the patient in the correct position and reproducible to the

 Recording device can be positioned. The mechanical contact point is optionally designed such that forces between the patient's eye and the patient interface are absorbed by the patient interface and transmitted to the receiving device and the deformation body.

Vacuum between the receiving device and the patient interface can be constructed via a line which is optionally arranged on the receiving device, which is connected to a vacuum pump, which is arranged for example in the housing, optionally in the main body. To generate the negative pressure, the receiving device must have a closed surface in the area of the patient interface. Because in the

Recording device also an applicator optics, such as lenses or other optical elements, may be provided, the receiving device on the

End facing the patient eye by means of a transparent surface, such as a glass or plastic disc, be closed. This transparent surface may be part of an exit optics. The optionally provided in the receiving device

 Applicator optics may also be aligned with the optical axis of the passage member. The patient interface itself may have one or more lenses.

The deformation element is optionally designed as a web which connects the receiving device to the connection device, in particular exclusively. The deformation body may be part of a receiving device and the connecting device connecting

Be deforming device. The deformation body may be connected at the first end to a first body and at the second end to a second body, wherein the deformation body and the two bodies form the deformation means. The two bodies | Ai] are integrally solid and in particular have an elasticity that is smaller by 1, 2 or 3 orders of magnitude than the elasticity of the deformation body. In this way, a rigid connection between the receiving device and the connection device be realized. Generally speaking, the rigid connection refers to the fact that the elasticity of the deformation is kung body by 1, 2 or 3 orders of magnitude greater than the elasticity of the connection with the receiving device, in particular with the first body, and / or with the connection device, in particular the second body , is. The second body may be formed as part of the connection device. The first body may be part of the receiving device. Preferably, the receiving device is rigidly formed in comparison to the deformation of the body, so that at a pressure force between the

Connection device and the eye of the patient exclusively or mainly the deformation ungskörper and not the receiving device, the connecting device, the first body and / or the second body are deformed. The deformation body is in particular arranged such that it is deformed at a force along the optical axis or a portion of a force parallel to the optical axis, d. H. that the elasticity of the

Deform ungskörpers, for example, due to its material, its shape and / or its location, designed such that it is greatest along a direction parallel to the optical axis. For example, the deformation ungskörper at a force perpendicular to the optical axis can also be considered as rigid, d. H. the deformation element has an elasticity parallel to the optical axis which is 1, 2 or 3 orders of magnitude greater than perpendicular to the optical axis. The elasticity of the deformation body can be achieved compared to the receiving device, the first body, the second body and / or the connection device body only due to the shape of the deformation, for example, the material of the first body, the second body and the web is the same the bridge is made thinner than the two bodies. The receiving device, the first body, second body, the

Deformation ungskörper and / or the connection device may be made of metal, in particular stainless steel, or of an aluminum alloy. However, the deformation body is designed such that it deforms in the application of a force of 0 to 20 N, preferably 0 to 5 N, by a maximum of 20 μιτι, 10 μιη or 5 μιη in the direction of the force. In this way it can be achieved that the receiving device relative to the

Connection device and thus with respect to the laser therapy device within a tolerance range has the same position.

The measuring device is designed to detect the deformation of the deformation body caused by the force between the receiving device and the eye. The

Measuring device can, for example, capacitive, inductive or m ittels optical

Distance measurement, such. B. by means of photoelectric sensors, in particular by means of fork coupler or metal lug, the deformation tion of the deformation ungskörpers capture. The sheet metal flag is z. B. on attached to the moving part and immersed in the fork coupler (= light barrier), which is mounted on the non-movable base part, a. As a result, the amount of light that sees the sensor in the fork coupler, regulated and gives a wegäquivalentes sensor signal (distance information = force information in the known system). The assignment of the elements to fixed and moving parts can also be reversed. Furthermore, the measuring device may comprise one or more strain gauges. The measuring device generates a measuring signal that can be assigned to a degree of deformation of the deformation body.

For example, the measurement signal is proportional to the deformation of the deformation body. The measuring device can be mounted directly on the deformation body or spaced therefrom.

The evaluation device is connected to the measuring device via lines or by radio

data technically connected such that they can read the measurement signals generated by the measuring device. In the evaluation device, for example, a relationship, such as a formula or a table, be deposited, by means of which the measurement signal, a size of the force acting between the eye and the receiving device, can be assigned. For this purpose, the evaluation device a memory, for. B. a RAM (random access memory), have. If the force determined in this way exceeds a certain limit value, the

Control means the drive so that the receiving device is moved away from the eye. For this purpose, the evaluation device is optionally connected to the control device.

To be able to determine the force particularly precisely, it is preferred in a development that the deformation body is designed as a web which extends transversely, optionally perpendicular, to the optical axis, preferably distributed around the passage element. In particular, the web has a longitudinal extension which is transverse, in particular perpendicular, to the optical axis.

The web may, for example, comprise one or more bending beams which extend longitudinally / transversely to the axis of incidence between an upper part and a lower part. The upper part is connected to the connecting device and the passage element, the lower part connected to the receiving device or provided. Bending beam, upper part and lower part may be integrally formed.

In embodiments, when the web extends in its longitudinal direction transversely, in particular perpendicular, to the optical axis, it is deformable along a direction parallel to the optical axis with the least expenditure of force. At the same time the change in length of the deformation body is minimized during the measurement. The passage element can be centrally located in the Connection means may be arranged, wherein the web extends along a circumference of the passage member. For example, the web can at least partially limit the passage element in the circumferential direction. Furthermore, the web may extend parallel to the circumference of the passage member. When the passage member has a circular circumference, the land may be curved according to the curvature of the circumference of the passage member. In this way it can be achieved that the ophthalmic device has a small dimension in a radial direction to the optical axis, since the web extends along the passage member, which is responsible for the radial extent of the ophthalmological device.

In order to be able to determine the direction of the compressive force between the eye and the receiving device in a particularly precise manner, it is preferred in a development that at least three deformation bodies, e.g. Webs or bending beams, which are provided around the

Passage element are arranged distributed. In particular, three deformation bodies are provided, each with the first body and the second body. In this construction as well, the deformation bodies can each extend laterally transversely to the axis of incidence between an upper part and a lower part. The upper part is then also connected to the connecting device and the passage element, and the lower part is likewise connected or provided with the receiving device.

Optionally, a plurality of deformation bodies are evenly distributed around the passage member. For example, the deformation bodies can be spaced apart from one another by 120 ° relative to the optical axis. The three deformation bodies preferably provide the only mechanical connection between the connection device and the

Each deformation element is preferably provided with a measuring device, so that a total of three measuring signals are generated. The sum of the three forces determined by the measuring signals is the force acting on the receiving device. In a preferred embodiment, the three forces are compared in a circuit and thus the direction of the force, in particular a force component parallel to the optical axis and a force component perpendicular to the optical axis, erm ttelt. In a further additional or alternative embodiment, the average of the three forces is calculated. The product of the mean value of the three forces and the number of deformation bodies, in this case three pieces, indicates the force parallel to the optical axis and the difference between the mean and the sum of the forces represents the force acting perpendicular to the optical axis on the receiving device. Due to the spacing of the deformation bodies by 120 °, the measurement of the forces is symmetrical, so that the resulting forces can be determined particularly easily. The use of three deformation bodies is advantageous, because by three points a plane is clearly spanned, so that the resulting force can be clearly determined. By using four or more

Deformation bodies with appropriate measuring devices, the determination of the resulting force is overdetermined; However, this can bring advantages in the precision of certain forces. In the context optionally stored in the evaluation device, in particular the respective magnitude of the force and direction of the force is stored step by step for the size of each of the three measurement signals. By interpolation can for each of the three

Measurement signals are assigned a specific magnitude of the force and direction of the force. The magnitude and / or the direction of the force can also be determined via a formula from the measurement signals.

A particularly reliable determination of the force can be achieved in that in a development, the measuring device comprises at least one strain gauge, which is attached to the deformation body. For example, the strain gauge may be adhered to or otherwise secured to the deformation body. In the

 Deformation of the deformation body, the strain gauge is stretched or compressed by the attachment to the deformation body, whereby the strain gauge generates a measurement signal corresponding to the deformation. For example, the resistance of the strain gauge changes depending on the elongation or compression of the strain gauge

Strain gauge, which is caused by the deformation of the web.

A particularly accurate determination of the magnitude of the force results in a development in that four strain gauges for the measuring device are provided on the deformation body, wherein the strain gauges are connected to a Wheatstone bridge and the measurement signal measured with the Wheatstone bridge

Tension is. The strain gauge is optionally a semiconductor strain gauge. The four strain gauges may be mounted in pairs on opposite sides of the deformation body. For example, two strain gauges on a seen in the direction of the optical axis upper side of the deformation body, z. B. of the web, and two gauges on the lower side of the deformation body, z. B. of the web attached. Optionally, the strain gauges cover the largest possible area of the deformation body, since this can increase the accuracy of the measurement. It is also possible to choose the position of the strain gauges on the deformation body so that they are placed on the regions with the greatest local deformation. Due to the arrangement of the strain gauges on two opposite sides of the deformation body, when the deformation body deforms in the direction of the optical axis, an expansion of the one measuring strip is opposite to a compression of the other measuring strips. The Strain gauges on one side of the deformation body optionally form one side of the Wheatstone bridge, while the strain gauges arranged on the other side of the deformation body form the other line of the Wheatstone bridge. The bridge voltage between both lines of the Wheatstone bridge forms the measurement signal here. Preferably, four strain gauges are provided for each of the three deformation bodies.

The strain gauges can be coupled with additional resistors to compensate for differences in the strain gauges. For example, can be caused by the attachment of the strain gauges on the deformation body stresses or compressions in the strain gauges, which can lead to a change in the resistance of the respective strain gauge. Therefore, it is optional that the Wheatstone bridge, i. H. the individual strain gauges with the associated resistors are calibrated prior to use; for example, to the effect that the measuring voltage, when no force is applied, is equal to zero.

In an alternative to the use of strain gauges, which directly detect the deformation of the deformation body, per inductive body, which in turn can be executed as a bending beam, an inductive or capacitive sensor or

Sensor double be used. This sensor or double sensor is based on the fact that a distance between a web, which is firmly connected to one end of the deformation body, and an electronic component, such as a coil or an electrode of a capacitor, fixed to the other end of the deformation body is connected, is measured. The clearance creates a gap and the gap size varies with the deformation of the deformation body, e.g. of the bending beam. For an inductive measurement, a construction is particularly easy to implement, which uses a planar coil, which in a plane parallel to the deformation body and substantially perpendicular to

Force introduction direction is located and spaced by the perpendicular to this plane extending distance from said web. With the distance, the inductance of the planar coil changes. In this way, the corresponding measurement signal is obtained. At a

Sensor double are on both sides of the web corresponding sensors, so that in a deformation of the deformation of the body body, the gap increases on one side and reduced on the other side. The physical model of the deformation body, in particular of the web, corresponds to the cantilever clamped on both sides. By appropriate placement and interconnection of the strain gauges results in force due to the resulting Discriminate the resistance of the strain gauges a changing, equivalent to the force bridge voltage. This can be evaluated according to the calibration described above as a measurement signal, thereby determining the magnitude of the force. In order to be able to provide repeatable measurements of the force between the receiving device and the eye, it is important that the deformation body only in the elastic

Deformation area is deformed, d. H. that there is no plastic deformation on the deformation body. Especially with unwanted shocks before or after the treatment and / or observation of the patient against the receiving device can lead to unintentional large force on the deformation body. This could be too plastic

Deformations lead the deformation of the body, whereby the force measurement would be useless. Therefore, it is preferred in a development that the ophthalmic device has a stopper having a limiting device, which limits the movement of the receiving device relative to the connection device to limit the deformation of the deformation. In particular, the limiting device is designed such that the receiving device can be moved to the maximum possible deflection, so for example 20 μιτι, 15 μιη or 5 μιη. In this way the deformation of the deformation body is limited. Limiting the movement of the

Receiving device relative to the connection device takes place in particular in three dimensions, but can also take place only in the direction along the optical axis, so that it is ensured that a force between the eye and the receiving device along the optical axis can always be detected.

A particularly simple realization of the limiting device is achieved in a further development in that the limiting device in an undeformed state of the deformation body at least one gap between the receiving device and the

Connection device comprises. The stops can be designed as part of the receiving device, optionally of the first body, and / or of the connecting device, preferably of the second body. For example, between the first body and the

Connection means provided the gap extending in the direction of the optical axis. Preferably, three first bodies are provided, so that three gaps are provided, whereby at three points a limitation of a movement of the receiving device along the optical axis to the connecting device can be achieved. In order to be able to achieve a limitation of the movement of the receiving device away from the connecting device parallel to the optical axis, it is provided, for example, that at

Connecting device protrudes a pin in the direction of the optical axis, on which a projection, for example, perpendicular to the optical axis, protrudes. This lead engages behind a part of the receiving device, for example, the first body. Between the projection and the receiving device, a gap is arranged in a non-deformed state of the web, so that the movement of the receiving device away from the

Connection device can be limited. In order to limit the movement of the receiving device radially to the optical axis relative to the connecting device, it is for example provided that the pin is guided with a gap in the receiving device, for example in the first body. For example, the first body has an opening into which the pin is inserted. Preferably, three pins are provided. Precision measurements, such as the measurement of force between the

 Recording device and the eye, often have a temperature dependence. Especially when using strain gauges, a temperature dependence of 0.5% per degree Kelvin can occur. This has a relatively large influence on the measurement signal at the low deformation of the deforming body deformation of 20, 1 0 or 5 μιη. This can account for up to 30% of the signal to be measured, i. H. 2 N Measurement error with a force of 6 N to be measured. Therefore, it is provided in a development that the ophthalmic device has a temperature sensor which measures the temperature, optionally in an environment of the measuring device, wherein optionally in the evaluation a relationship between the size of the force on the one hand and the temperature and the measurement signal on the other hand deposited and wherein the evaluation device determines the magnitude of the force with the context. The connection will not only be related to that of the measuring device

Provided provided measurement signal or the measurement signals, but also with respect to the temperature of the measuring device. Thus, the evaluation reads both the

Measurement signals as well as the temperature provided by the temperature sensor and determines the size and / or the direction of the force. This can be the

 Temperature sensor by means of cables or by radio data technically m it connected to the evaluation. To determine the context, for example, the

Measuring device, in particular the strain gauges, gradually heated by an external heat source. After a certain time to set a thermic

Equilibrium, a predetermined force is applied and detects the corresponding measurement signal. This is repeated for different temperatures and forces, so that in this context, for example, a lookup table is stored. In this way, the temperature dependence can be reduced by up to 90%. A temperature change also leads to a change in the attachment of the

Strain gauges on the deformation body, since, for example, the

Strain gauges and the deformation body differently depending on the Expand or contract temperature; this leads to a relative deformation between the deformation body and the strain gauge. To compensate for this, optionally, the relationship between the magnitude and / or the direction of the force and the measurement signals is calibrated as described above.

The temperature dependence of the measuring device can also be reduced by the fact that each strain gauge is associated with a resistor, the resistance of which depends on the temperature inversely as the resistance of the strain gauge. It is preferred that the associated resistors for the strain gauges are arranged close to the strain gauges, so that the resistors and the

 Strain gauges have approximately the same temperature. Furthermore, the

Temperature dependence of the measuring device can be countered by the

Measuring device by a cooling and / or heating device, such as a Peltier element and / or a heating element is kept at a constant temperature. For this purpose, for example, the Peltier element or the heating element may be attached to the deformation body. The Peltier element can be used for cooling. By means of the heating element, the measuring device can be adjusted to a certain temperature at which the relationship between the measuring signal and force was determined. When used in conjunction with a surgical microscope, it is often helpful to illuminate the eye. Therefore, in a further development, the ophthalmologic device is provided with an illumination device for illuminating the eye, which comprises at least one decoupling point attached to the connection device and a decoupling point attached to the acquisition device for receiving radiation emitted at the decoupling point, wherein between the decoupling point and the decoupling point undeformed deformation body is a gap. The decoupling point may for example be part of a surgical microscope, which with the

Connection device is connected. In this case, the decoupling point is indirectly connected to the connection device. The decoupling point can, however, also directly to the

Attachment be attached. The decoupling, for example, a light

Emitting Diode (LED) or halogen lamp. However, the decoupling point can also be the end of a light guide. Preferably, a plurality of decoupling points on the

Connection device provided, which are optionally arranged distributed around the passage element. For example, infrared LEDs and white light LEDs are alternately arranged around the passage element. The coupling-in point is spaced around the free space in the direction of the optical axis to the outcoupling point and in particular spaced from the connection device on the

Recording device attached. The clearance is such as to allow deformation of the deformation body within the clearance set by the restriction means. The coupling point may be part of a light guide, which are made for example of glass or plastic. The coupling-in point can be an optical input surface, which is arranged at a distance from the coupling-out point and couples light into the optical waveguide. An optical output surface, from which the coupled-in light leaves the light guide, can be arranged facing the eye. The light guide may be part of the receiving device and direct the radiation provided by the decoupling point from the decoupling point to the patient's eye. The light guide and / or the coupling-in point can be designed such that it surrounds the receiving device in the circumferential direction. In order to be able to determine the relation between the measuring signal and the magnitude of the force, in particular also the direction of the force, a calibration device is provided for calibration, optionally the calibration device comprises a force generating device for generating a test force having a contact element, and a

Force receiving device comprises, wherein the force receiving device on the

Receiving device is mounted and a spherical segment surface which contacts the contact element for transmitting the test force to the force receiving means comprises. The

Force receiving device may be provided, for example, instead of the patient interface. Optionally, the force receiving device by means of negative pressure at the

Receiving device are attached. In particular, the patient interface and the force receiving device have such an embodiment that they are identical at the contact point of the receiving device. The force receiving device has the

Force generating device, in particular the contact element, facing a

Sphere segment surface on. The spherical segment surface is on its outside like a

Ball segment, such as a hemisphere, shaped. The ball segment surface may be part of a solid ball segment. The contact element of the force-generating device may be formed, for example, as a flat surface. The force defined by the force-generating device is transmitted to the spherical segment surface via the contact element. From the spherical segment surface, the force by means of the force receiving device on the

Transfer recording device, so that the web is deformed. That of the

Detection device generated measurement signal is read and set in conjunction with the test load. In this way, the device, in particular the context, is calibrated. The use of the spherical segment surface has the advantage that the test force is centric, friction-free and / or torque-free initiated. Therefore, a parallel and in particular identical to the optical axis acting test force can be applied to the receiving device. As a result, if three measuring devices are used and these are arranged symmetrically, they are equally loaded. This simplifies the calibration.

In order to apply the test force centrally to the receiving device and in particular to a test force acting identically to the optical axis, it is preferred that the optical axis represents an axis of symmetry of the spherical segment surface. A radius of the spherical segment surface is accordingly on the optical axis.

The force generating device is optionally designed such that it provides a defined test force away from the path. For this purpose, the force-generating device is formed in a development such that it comprises a beam with a first and a second end, wherein the beam between the first end and the second end is rotatably mounted, wherein the contact element is arranged at the first end and wherein the second end is provided a fastener for attaching weights. The

Force generating device may be formed for example as a beam balance. The beam is rotatably mounted about a rotation axis, wherein the rotation axis optionally with the

Focus of the beam coincides, so if no weights in the

Fastener are arranged, the bars in balance relative to his

Symmetry axis is. For this purpose, for example, slidable on the beam

Adjustment weights may be arranged to balance the bar.

At the first end is the contact element and on the other side is the

Attachment provided for attaching weights. The fastener may be, for example, a rod with a receiving surface on which the weights can be pushed.

The initially and subsequently described aspects of the device equally apply to a method for measuring or preventing eye pinching. The latter is carried out independently of a treatment of the eye, since it is only intended that the eye rests on the patient interface. The treatment effect which can be achieved by the radiation passing through the passage element is completely irrelevant to the force measurement and the prevention of eye pinching.

To determine the force acting on the eye when examined with an ophthalmic device or ophthalmic system, or before and / or while being treated, a receiving device for attaching a

Patient interfaces provided. Further, a connection device for attachment to the ophthalmological device is provided, wherein the connection device a

Passage element through which radiation and / or waves for imaging and / or treatment of the eye along an incident axis runs / runs. Then, at least one deformation body is arranged between the receiving device and the connecting device, which has a first end and a second end. The first end is rigidly connected to the receiving device. The second end is rigidly connected to the connection device. Since receiving device and connection device are movable relative to one another, the deformation element is deformable by a force which acts at least partially along the axis of incidence. Deformation of the deformation body is detected and a magnitude of the force is determined therefrom. To perform this method, for example, the said ophthalmic device can be used. The procedure may be further developed to avoid eye squeezing during examination and / or treatment of the eye caused by excessive force between the eye and the eye

Patient interface would be created. Since the force between the receiving device and the connection device is measured, one also knows the pressure force between the eye and the patient interface. It is therefore to protect the eye from bruising in one

Training provided that when exceeding the determined force the

Recording device and thus the patient interface is moved away from the eye.

It is understood that the features mentioned above and those yet to be explained not only in the specified combinations, but also in others

Combinations or alone can be used without departing from the scope of the present invention.

The invention will be explained in more detail for example with reference to the accompanying drawings, which also disclose characteristics essential to the invention. 1 is a schematic view of an ophthalmic system;

 FIG. 2 is an enlarged sectional view of an ophthalmic device of the ophthalmic system of FIG. 1; FIG.

Fig. 3 is a perspective enlarged view of a deformation device of

 ophthalmic device of Fig. 2;

FIG. 4 is an enlarged fragmentary sectional view of the ophthalmic device of FIG. 2; FIG. Fig. 5 is a perspective view of the ophthalmic device of Fig. 2 and a calibrating device; Fig. 6 is a plan view of the ophthalmic device and the calibration device of Fig. 5;

 7 shows a course of the measurement signals generated by a measuring device of the ophthalmological device as a function of an angle on the

 ophthalmic device applied forces;

 Fig. 8 is a graph showing the magnitude of the measurement signals shown in Fig. 7; 9 is a perspective view of a deformation device with inductive

 Measurement of deformation;

10 is another view of the deformation device of Fig. 9, and

Fig. 1 1 is a schematic representation of a circuit board for inductive measurement of deformation.

An ophthalmic system 10 comprises an ophthalmic device 12, a housing 13, which has a base body 14, at least one support arm 16 and / or at least one drive 18, and optionally a laser treatment device 20 and / or a surgical microscope 22. The device 12 is located on a Eye 24 one

Patients. The device 12 can be positioned relative to the base body 14 in many different positions. The housing 13 may be configured as any device that supports the ophthalmic device 12. In the embodiment shown in Fig. 1, the base body 14 of the housing 13 supports the support arm 16 of the housing 13 and the elements attached thereto. The main body 14 may be fastened, for example, with a wall. The support arm 16 has a plurality of joints 26, so that a free end of the support arm 16 relative to the base body 14 can be changed. The free end of the support arm 16 can be moved by means of the drive 18. The drive 18 can

For example, be provided at each hinge 26 to move the respective portion of the support arm 16 can. The drive 18 may include, for example, a motor or a spring. Furthermore, the drive 18 is connected to a control device 28, for example via not shown in Fig. 1 lines. The control device 28 can drive the drive 18 in such a way that the free end of the support arm 16 can be positioned in the desired position. At the free end of a support arm 16, the device 12 and the laser treatment device 20 are provided. The laser treatment device 20 may be as known from the prior art laser treatment devices for

Treatment of the eye 24 may be formed. At the free end of the other support arm 16, the surgical microscope 22 may be provided. This surgical microscope 22 may be constructed like surgical microscopes of the prior art.

The device 12 has an evaluation device 29, a connection device 30, a receiving device 32 and a deformation device 34. The connection device 30 is m connected to the free end of the support arm 16. For example, one of the joints 26 is further provided between the free end of the support arm 16 and the terminal device 30. Further, the laser treatment apparatus 20 is attached to the terminal device 30. The connection device 30 has, as can be seen in particular in Fig. 4, a

Passage element 36, by means of which radiation or waves of the

 Laser treatment device 20 and / or the surgical microscope 22 via the

Receiving device 32 can be guided to the eye 24. The passage element 36 may comprise an optical system, but in the simplest case is only one passage opening. The passage element 36 is optionally arranged centrally in the connection device 30 and defines an optical axis OA. The connection device 30 may be formed, for example, as a ring-shaped plate.

The receiving device 32 is about the deformation ungseinrichtung 34 m with the

Connection device 30 connected. The deformation device 34 has one, optionally three, deformation bodies 38, which are optionally connected to a first body 40 at a first end 38a and to a second body 42 at a second end 38b. The deformation body 38 is rigidly connected to the first body 40 and the second body 42 so that the receiver 32 and the connector 30 are rigidly connected to the deformation body 38. Rigid in this context means that the elasticity of the deformation body 38 in the direction of the optical axis OA is greater by one, two or three orders of magnitude than the connection of the deformation body 38 with the first body 40 and the second body 42. Furthermore, the elasticity the deformation body 38 in the direction of the optical axis OA by one, two or three orders of magnitude greater than elasticity of the first body 40, the second body 42, the receiving device 32 and / or the connecting device 30. The deformation of the body 38, the first body 40 and / or the second body 42 may be solid. The deformation of the body 38 may be formed as a web or bar, which extends transversely, in particular perpendicularly, to the optical axis OA. The deformation body 38 extends, in particular, along a circumference of the passage element 36. If optionally three deformation bodies 38 are provided, these are distributed uniformly in the circumferential direction around the passage element 36, for example by being spaced apart by 120 °, as shown particularly in FIG , 6 can be seen. The second body 42 may be used as part of

Connection device 30 may be provided. However, the second body 42 may also provide the terminal device 30 alone. In this case, the passage member 36 is fixed to the second body 42. The evaluation device 29 may be attached to the second body 42 and be part of the control device 28. The receiving device 32 has an applicator optics 44, an exit optics 46, a light guide 50 and / or a tube 52. The applicator optics 44 may also have an optical axis which optionally coincides with the optical axis OA of the passage member 36. Instead of the applicator optics 44, however, a cavity may also be provided. In the direction of the eye 24, the receiving device 32 is optionally closed by the exit optics 46. The exit optics 46 is transparent and may be made of glass or plastic, for example. It is executed in the simplest case as a mere passage opening, but can also be designed depending on the application as a lens. It forms the element 24 closest to the eye for guiding the beam of the ophthalmic device 12. A peripheral surface of the receiving device 32, the light guide 50 and the exit optics 46 form an airtight surface on which a patient interface 48 can abut. The

Patient interface 48 has optional interface optics 47 and may be one-time-use optics. The peripheral surface of the receiving device 32 has a, in particular annular, contact point 56 for the patient interface 48. With the help of the tube 52, a negative pressure between the patient interface 48 and the

Receiving device 32 are generated so that the patient interface 48 at the

Recording device 32 stops. For fixing the patient interface 48 to the eye 24, a negative pressure between the eye 24 and the patient interface 48 can be generated by means of a vacuum connection 54. In this way, the receiving device 32 is fixed relative to the eye 24 of the patient. The interface optics 47 may contribute to the deformation of the eye 24 and / or may form the optics closest to the eye 24.

The device 12 also has a measuring device 58, by means of which the deformation of the deformation body 38 can be detected. The measuring device 58 has, for example four strain gauges 60, wherein two of the strain gauges 60 at a

Top of the deformation body 38 and two strain gauges 60 are attached to an underside of the deformation body 38. The strain gauges 60 may be semiconductor strain gauges whose resistance varies depending on strain or compression of the strain gages 60. The deformation body 38 acts as a two-sided clamped beam, so that two of the strain gauges 60 register a compression of the deformation body 38 and the other two strain gauges 60 an elongation of the deformation body 38. The strain gauges 60 are connected to the

Evaluation device 29 connected via lines not shown. The

Evaluation device 29 may have a connection for forwarding signals to the

Control device 28 have. The strain gauges 60 are connected like a Wheatstone bridge, wherein the bridge voltage as a measuring signal from the evaluation device 29 is processed further. The strain gauges 60 are glued to the deformation body 38.

The device 12 further comprises a temperature sensor 62 (see FIG. 3), by means of which the temperature prevailing at the measuring device 58 can be detected. Of the

Temperature sensor 62 is optionally provided on the first body 40. Since the first body 40 is in thermal contact with the deformation body 38, the temperature of the strain gauges 60 can be determined by means of the temperature sensor 62. The temperature sensor 62 is connected via not shown lines to the evaluation device 29 and / or the

Control device 28 connected.

The device 12 further comprises a limiting device 64 having a stop, by means of which the movement of the receiving device 32 relative to the

Connection device 30 can be limited. This serves to avoid damaging the deformation body 38, in particular that the deformation body 38 deforms into the plastic area. By the limiting device 64 can be achieved that the deformation body 38 is deformed only in its elastic range. The limiting device 64 may, for example, be realized by at least one gap 66 which, as shown in FIG. 4, is provided between the connecting device 30 and the first body 40. The connection device 30 serves as a stop for the first body 40. In this way, a movement of the receiving device 32 in the direction of the optical axis OA can be limited to the connection device 30. The gap 66 has, for example, a width of 100-150 μm (depending on the part tolerance). This still ensures the use in the elastic range. The useful signal is within an allowable movement of z. B. 5 μιη measured. In order to limit also a limitation of the movement of the receiving device 32 away from the connecting device 30 along the optical axis OA, the limiting device 64 comprises a pin 68, which differs from the

Connection device 30 projects parallel to the optical axis OA and at the end of a projection 70 is attached. The pin 68 extends, for example, through a passage 72 in the first body 40, wherein the projection 70 engages behind the first body 40. Between the first body 40 and the projection 70, a gap 66 for limiting the movement of the receiving device 32 away from the connection device 30 is likewise provided. In addition, a gap 66 is also provided between the pin 68 and the passage 72, so that movement perpendicular to the optical axis OA is limited by the pin 68 and the passage 72. As can be seen in particular in FIG. 4, the device 12 further comprises a lighting device 74. The lighting device 74 has a coupling-out point 76, which is fastened to the connecting device 30, optionally to the second body 42, and a light guide 50, which attached to the receiving device 32. The of the

Decoupling point 76 provided radiation is passed through the light guide 50 and the patient interface 48 in the eye 24. Between the decoupling point 76 and the light guide 50, in particular a coupling-in point 50a of the light guide 50, a free space is greater than or equal to the range of motion that is provided by the limiting device 64 is provided. The light guide 50 has, for example, near the

Decoupling point 76, the coupling-in point 50a and adjacent to the patient interface 48, a light output surface. The radiation provided by the coupling-out point 76 is coupled into the light guide 50 from the coupling-in point 50a.

The device 12 also has a calibration device 78, which has a

Force generating device 80 and a force receiving device 82 has. The

Force receiving device 82 is optional instead of the patient interface 48 at the

Receiving device 32, in particular in the same manner as the patient interface 48 attached. For this purpose, the force receiving device 82 at its to the

Receiving device 32 facing side as the patient interface 48 may be formed. In particular, the force receiving device 82 is also located at the abutment point 56. Furthermore, the force receiving device 82 on a spherical segment surface 84, which in the direction of the force generating device 80, in particular a contact element 86 of the

Force generating device 80, facing. The spherical segment surface 84 is optionally formed by a spherical segment, wherein a center of the spherical segment lies on the optical axis OA, so that the spherical segment surface 84 is symmetrical to the optical axis OA.

Due to the spherical segment surface 84, the test force generated by the force-generating device 80 can be applied to the receiving device 32 in a friction-free, torque-free and / or central manner. The force generator 80 includes a beam 88 having a first end 90 and a second end 92. At the first end 90, the contact element 86 is provided, while at the second end 92, a fastener 96 is arranged for attaching weights. The beam 88 is rotatably mounted about a rotation axis 94. The beam 88 and the fastener 96 and the contact member 86 have a center of gravity that coincides with the axis of rotation 94. For this purpose, adjustment weights can be provided at the first end 90 and the second end 92. For calibrating the device 12, a predetermined test force is applied to the receiving device 32 by means of the calibration device 78. This takes place at a predetermined temperature, which is detected by means of the temperature sensor 62. Subsequently, the measuring signal, which is detected by the measuring device 58, in particular by the bridge voltage of the Wheatstone bridge of the strain gauges 60, from the evaluation device 29. The relationship between temperature and measurement signal on the one hand and the corresponding test load on the other hand is stored in a context, such as a lookup table. The test force is applied centrally, so that each of the three measuring devices 58 generates the same measurement signal. This is repeated for a wide variety of test loads and temperatures.

If the receiving device 32 is in contact with the eye 24 via the patient interface 48 and a pressure force is generated by the eye 24 on the receiving device 32, a measuring signal is generated by means of the deformation body 38 and the measuring device 58. If three measuring devices 58 and three deformation bodies 38 are used, an amount of the force is determined for each of the measuring signals. The sum of the magnitudes of the forces is the acting force, and its mean value of the forces is the proportion of the force along the optical axis OA. The difference of the respective forces to the mean value represent the force components perpendicular to the optical axis OA. Depending on the direction of the force acting on the receiving device 32, the individual measuring signals have a sinusoidal course, as illustrated, for example, in FIG. 7 in a standardized manner. In order to determine the direction of the force, it is compared where the three measuring signals to the angle-dependent progressions of the individual measuring signals have the smallest distance. This then indicates the direction of the force.

The procedure described above requires a comprehensive table for the assignment of the individual measured values to the direction of the corresponding force. If the evaluation device 29 is designed as a microcontroller, it is sometimes not possible to maintain such a table. Therefore, the following procedure can be used in this case. In Fig. 8, the amount of change of the respective measurement signals to 1000 normalized is shown. It can be seen that the measuring signals between 0 and 30 ° are repeated alternately mirrored. By presorting the three measurement signals, for example by determining which measurement signal is positive or negative, it is sufficient to evaluate the table only in an angular range of 30 ° and to add an angle offset on the basis of the sorting. In this way, the angle of the force introduction can be calculated. To calculate the two components in a plane perpendicular to the optical axis OA of the force, the amount of force is needed. The measurement signal of the first of the three

Strain gauge corresponds to sina χ amount of force. The amount of force is thus calculated as a measurement signal of the strain gauge 1 / sina. For the three measurement signals, the magnitude of the force is now determined individually and the mean value is calculated. The x-component of the force applied to the receiving device 32 is the force sina χ of the force, the y-component is cosa χ the amount of the previously determined force, while the z-component, ie parallel to the optical axis OA, the average of is three of the forces associated with individual measurement signals.

FIGS. 9 and 10 show further embodiments of the measuring device. They measure the deformation of the deformation body 38 indirectly. The deformation of the m at least one deformation ungskörpers 38 (in the present case, in turn, three examples

Deformed ungskörper provided) is not directly measured by a respective arranged on the deformation body 38 strain gauges, but by a capacitive or inductive sensor, which is parallel to the deformation body 38, that is also arranged substantially perpendicular to the direction of force. In the construction of Fig. 9, the sensor is simple, in the construction of Fig. 10 executed in duplicate, as will be explained below. In both cases, the sensor is based on the principle of measuring an inductance change. This arises because a web 98 approaches or moves away from a planar coil arranged in a plane. The planar coil is fixedly connected to one end of the deformation body 38, the metal part to the other end. As a result of the deformation of the deformation body 38, a gap between the web 98 and the planar coil thus changes, which leads to an inductance change in the coil, which is detected electronically. In a similar manner, a capacitance change can also be detected when the metal part is made as one electrode of a capacitor and the planar coil is replaced by the other electrode of the capacitor.

In the construction of Fig. 9, the planar coil 100 is on a circuit board 102 which is mounted on a circuit board holder 1 04. This is with one end of the

 Deformation body 38 firmly connected. Opposite the planar coil 100 is a metal part in the form of a web 98 which is fixedly attached to the first body 40 and is connected to the other end of the deformation body 38. In case of deformation of the

Deforming body 38 changes an air gap between the planar coil 100 and web 98. An attached to the circuit board 102 electronics detects the change in inductance in the

Coil 100 and generates therefrom the measurement signal for the deformation of the deforming body 38. The two parts 100, 98 move relative to deformation of the deformation body 38 to each other. The movement is ultimately an up / down movement along the optical axis. The relative movement is directly proportional to the force acting on the deformation body 38.

Preferably, two planar coils 100 are arranged per deformation body 38, around a

To achieve doubling of the measurement signal, since the distance (gap) increases on one side and simultaneously reduced on the other side. This embodiment is shown in FIG. 10. The web 98 is located between two planar coils 100, so that when the deformation of the deformation body 38 is deformed, the gap to a planar coil 100 increases

opposite planar coil 100 reduced. With this structure can also

Temperature influences by subtraction are particularly easy elim iniert. The

 Temperature compensations explained with respect to the strain gauge 60 can be equally applied.

The measuring principle of the planar coils 100 provides that the coil lies in a plane which essentially, i. within the manufacturing tolerances, perpendicular to the axis of

 Force effect is. The same applies to the gap between the planar coil 100 and web 98. The gap lies dam it substantially parallel to the deformation body 38. The planar coil 1 00 can then be particularly easily designed as a printed circuit board coil, as shown in FIG. 1 1. It is located on the printed circuit board 1 02, which also carries electronics 1 10, which detects the inductance of the planar coil 100. The magnetic field is formed in the planar coil 100 in all directions, with the highest sensitivity perpendicular to the circuit board 102, ie along the axis OA results. This will best capture top or bottom approaches. In order to concentrate the magnetic field on the relevant area in the direction of the axis OA, ferrite can be applied to an outer layer of the printed circuit board in preferred embodiments. This concentrates the field lines of the detecting magnetic field. The size of the

 Induction change depends largely on the diameter of the planar coil 1 00. In one embodiment, the printed circuit board 102 has a width of 8 mm and the planar coil 100 has an outer diameter of 7.5 mm. Further, it is preferable to lead the connection cable 106 to the electronics 1 10 ungeinrichtung over an outer periphery of the deformation 34, as shown in FIG. 1 0 shows.

The actual measuring signal is the change of the inductance of the planar coil. It is, for example m with the help of an LC resonant circuit detected in the electronics 1 10, which is also provided on the circuit board 1 02. The resulting change in oscillation frequency is proportional to the gap size between planar coil 100 and fin 98. Of course, in embodiments, the inductance could also be measured differently; However, the use of an LC resonant circuit is particularly easy to set up and at the same time robust. The detection of the deformation due to the action of force can also be done by a capacitive measurement. Again, a detuning of an LC resonant circuit can be detected.

Claims

claims
1 . Ophthalmic device comprising
- A receiving device (32) for attaching a patient interface (48) for coupling the device (12) with an eye (24),
 a connection device (30) for attachment to a housing (13), wherein the connection device (30) has a passage element (36) through which radiation and / or waves for imaging and / or treatment of the eye (24) along a
Incidence axis (OA) runs / runs,
 at least one deformation body (38) having a first end (38a) rigidly connected to the receiver (32) and a second end (38b) rigidly connected to the connector (30), and which is deformable by a force acting at least partially parallel to the axis of incidence (OA) between the receiving device (32) and the connecting device (30),
 a measuring device (58) which detects a deformation of the deformation body (38) and outputs a measurement signal corresponding to a degree of deformation, and
 an evaluation device (29), which is data-technologically connected to the measuring device (58) and determines a magnitude of the acting force from the measuring signal generated by the measuring device (58).
2. Apparatus according to claim 1, characterized in that the at least one deformation is kung body (38) as receiving means (32) and connection means (30) mechanically connecting elongated web or bending beam is formed, which is transversely, in particular perpendicular, to the axis of incidence (OA) extends longitudinally.
3. Device according to one of the above claims, characterized in that the measuring device (58) m least one strain gauge (60) which is attached to the deformation of the body (38).
4. The device according to claim 3, characterized in that on the deformation of the body (38) four strain gauges (60) are provided, wherein the strain gauges (60) are connected to a Wheatstone bridge and the measurement signal with the Wheatstone'schen Measuring bridge measured voltage includes.
5. Device according to one of claims 1 or 2, characterized in that the measuring device (58) detects the deformation of the deformation body (38) capacitively, inductively or by means of optical distance measurement. 6. The device according to claim 5, characterized in that the measuring device (58) has a planar coil (100) which is fixedly connected to one end of the deformation body and spaced by a gap over a metal part (98), which is with the other End of the deformation body (38) is firmly connected, so that the inductance of the planar coil (100) depends on the size of the gap, which in turn depends on the deformation of the deformation body (38).
7. The device according to claim 6, characterized in that two planar coils (100) are provided, which are arranged on opposite sides of the metal part (98), so that the gap between the metal part (98) and the first planar coil (100) at a Deformation of the deformation body (38) opposite to the gap between the metal part (98) and the second planar coil (100) changes.
8. Device according to one of the above claims, characterized in that at least three deformation bodies (38) are provided which are arranged distributed around the passage element (36), wherein the measuring device (58) detects the deformation of each of the three deformation bodies (38) and optionally determines a direction of the force.
9. Device according to one of the above claims, characterized by at least one stop having limiting means (64) which limits the movement of the receiving device (32) relative to the connection device (30) to limit the deformation of the deformation body (38), preferably to max. 20 μπτι.
10. Device according to one of the above claims, characterized by a
Temperature sensor (62) which measures the temperature, wherein in the evaluation device (29) is a relationship between the magnitude of the force on the one hand and the temperature and the measurement signal on the other hand deposited and wherein the evaluation device (29) determines the size of the force by means of the context.
11. Device according to one of the above claims, characterized by a
Illuminating device (74) for illuminating the eye (24), which has at least one decoupling point (76) attached to the connecting device (30) and one at the
Receiving device (32) mounted coupling point (50 a) for receiving at the Outcoupling (76) emitted radiation comprises, wherein between the coupling-out (76) and the coupling-in point (50a) at undeformed deformation body (38) there is a gap.
12. The device according to claim 1 1, characterized in that the decoupling point is a luminous element, in particular an LED, halogen lamp or a light guide end, and that the coupling-in point comprises an optical input surface is coupled into the decoupled from the coupling-out light, wherein the Einkoppelstelle in particular of glass or plastic. 13. Device according to one of the above claims, characterized by a
Calibration device (78), wherein the calibration device (78) a
A force generating device (80) having a test force emitting contact element (86) and a force receiving device (82), wherein the force receiving means (82) on the receiving device (32) is mounted and a Kugelsegmentfläche (84), which the test force from Contact element (86) receives.
14. The apparatus of claim 1 1, characterized in that an axis of symmetry of the spherical segment surface (84) coincides with the axis of incidence (OA). 15. The apparatus of claim 1 1 or 12, characterized in that the
 Force generating means (80) comprising a beam (88) having a first end (90) and a second end (92), the beam (88) being rotatably mounted between the first end (90) and the second end (92), the contact element (86) is arranged at the first end (90) and at the second end (92) a fastening element (96) is provided for attaching weights.
16. An ophthalmic system for the examination and / or treatment of an eye (24), comprising
 a device (12) according to one of the above claims and
- A housing (13) having a base body (14), a support arm (16) on which the connection device (30) is fixed and with which the receiving device (32) relative to the base body (14) is positionable, and one of a control device controlled drive (18) which for adjusting the position of the receiving device (32) moves the support arm (16) comprises, and
- wherein the control device (28), if the size of the force above a predetermined
Limit value, the drive (18) controls such that the receiving device (32) of the eye (24) is moved away.
17. A method for measuring a force between an ophthalmic device (12) and an eye (24) which is couplable to a patient interface (48), the following steps being performed:
- Provision of a receiving device (32) for attaching a patient interface (48), providing a connection device (30) for attachment to the ophthalmic device (12), wherein the connection device (30) has a passage element (36) through which radiation and / or Waves for imaging and / or treating the eye (24) along an axis of incidence (OA) run / run,
Arranging at least one deformation element (38) between the receiving device (32) and the connecting device (30), the at least one deformation element (38) having a first end (38a) rigidly connected to the receiving device (32), and a second end (38b) rigidly connected to the terminal means (30), and by a force at least partially parallel to the axis of incidence (OA) between the
Receiving device (32) and the connection device (30) acts, is deformable,
 Detecting a deformation of the deformation body (38) and determining a magnitude of the force.
A method of preventing ocular crushing, characterized in that the method of claim 1 7 is carried out and the receiving means (32) of the eye
(24) is moved away if the magnitude of the force is above a predetermined limit.
19. The method according to any one of claims 17 or 18, characterized in that the at least one deformation ungskörper (38) as a receiving device (32) and
Connecting device (30) is formed mechanically connecting elongate web or bending beam, which extends transversely, in particular perpendicularly, to the axis of incidence (OA).
20. The method according to any one of claims 17 to 19, characterized in that the deformation of the deformation deformation body (38) by means of at least one strain gauge
(60) is recorded directly.
21. Method according to one of claims 17 to 19, characterized in that the deformation of the deformation deformation body (38) by means of capacitive, inductive or by means of optical distance measurement is detected indirectly.
A method according to claim 21, characterized in that a planar coil (100) fixedly connected to one end of the deformation body and spaced a gap above a metal part (98) is provided, which is at the other end of the Deforming body (38) is firmly connected, so that the inductance of the planar coil (100) changes with the size of the gap, which in turn from the deformation of the
Deformation body (38) depends.
23. The method according to claim 22, characterized in that per deformation body (38) has two planar coils (100) are used, which are arranged on opposite sides of the web (98), so that the gap between the web (98) and the first planar coil (100) in a deformation of the deformation body (38) inversely to the gap between the web (98) and the second planar coil (100) changes.
24. The method according to any one of claims 17 to 23, characterized in that at least three deformation ungskörper (38) are used, which around the
 Passage element (36) are distributed, wherein the deformation of each of the three deformation ungskörper (38) is detected and optionally a direction of the force is determined.
25. The method according to any one of claims 17 to 24, characterized in that at least one limiting device (64) having a stop is used, which for limiting the deformation of the deformation body (38) movement of the receiving device (32) relative to the connection device (30). limited, preferably to max. 20 μιη. 26. The method according to any one of claims 17 to 25, characterized in that for illuminating the eye (24) at m at least one decoupling point (76) at the
Connection device (30) is mounted, radiated radiation and this radiation at a Einkoppelstelle (50 a), which is attached to the receiving device (32) is recorded, wherein between the decoupling point (76) and the coupling point (50 a) in undeformed deformation ungskörper ( 38) there is a gap.
27. The method according to any one of claims 17 to 26, characterized in that the determination of the magnitude of the force is calibrated by the following steps are carried out:
 Providing a calibration device (78) comprising a force generating device (80) having a contact element (86) and a force receiving device (82) having a spherical segment surface (84),
Attaching the force receiving device (82) to the receiving device (32) and Arranging the force-generating device (80) so that the contact element (86) the
 Ball segment surface (84) touched,
 Transmitting a test force from the contact element (86) to the ball segment surface (84), determining the magnitude of the force, and determining a deviation between test force and determined magnitude of the force.
28. The method according to claim 27, characterized in that an axis of symmetry of the spherical segment surface (84) is aligned with the axis of incidence (OA).
29. The method according to any one of claims 27 or 28, characterized in that the force generating means (80) comprises a beam (88) having a first, the contact element (86) carrying end (90) and a second end (92), wherein the Beam (88) between the first end (90) and the second end (92) is rotatably supported and at the second end (92) a weight is attached.
PCT/EP2017/078657 2016-11-09 2017-11-08 Ophthalmological apparatus and ophthalmological system for examination and/or treatment of an eye, and measurement method WO2018087176A1 (en)

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US4523597A (en) * 1982-12-29 1985-06-18 Minolta Camera Kabushiki Kaisha Apparatus and method for measuring the intraocular pressure of an eyeball and auxiliary device for using therewith
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