KR20150084916A - Apparatus and method for operating a real time large diopter range sequential wavefront sensor - Google Patents

Abstract

The wavefront sensor includes a light source 172 that provides a light beam to illuminate the subject eye and a first beam deflection member 180 that deforms the light beam to compensate for lateral movement of the subject eye. The second beam deflecting member scans the beam around a small portion of the retina to dissipate energy.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus and method for operating a real-time high-diopter range sequential wavefront sensor,

The present invention claims priority to U.S. Provisional Application No. 61 / 723,531, filed November 7, 2012, entitled " Apparatus and Method for Operating a Real Time High Diopter Range Sequential Wavefront Sensor. &Quot;

One or more embodiments of the present invention are directed to a wavefront sensor used in a vision correction process. More particularly, the present invention relates to electronic devices and algorithms for processing, driving and controlling data of real time sequential wavefront sensors and other assemblies related to wavefront sensors.

Conventional wavefront sensors for the human eye's eye wave features are designed to take snapshots or multiple snapshots of the patient's eye wavefront as off or blinking room illumination. Such a wavefront sensor generally uses a CCD sensor or a CMOS sensor for capturing wavefront data, and it is necessary to use a relatively complicated data processing algorithm for grasping the wavefront aberration. Due to the fact that CCD or CMOS image sensors typically have a limited number of grayscales and can not be operated at frame rates exceeding the 1 / f noise range, these wavefront sensors offer a lock-in (lock-in) detection design. They can not employ a simple algorithm for quickly deriving the wavefront aberration. As a result, when these wavefront sensors are integrated into ophthalmic equipment, such as surgical microscopes, they do not provide accurate and repeatable real-time wavefront aberration measurements, especially with microscope illumination on.

There has been a need for an apparatus and method that not only implements real-time wavefront measurements but also represents a variety of issues, including the foregoing.

One or more embodiments satisfy one or more of the foregoing needs in the art. In particular, an embodiment is directed to an electronic control and drive circuit having software and associated algorithms for driving, controlling and processing data of a real time sequential wavefront sensor to achieve various functions.

The circuit includes a photoelectric position sensing detector / device (PSD) such as a quadrant photodiode / detector / cell / cellar or lateral effect position sensing detector, a transimpedance amplifier, an analogue digital (A / D) converter, A digital amplifier, a high-brightness diode (SLD or SLED) and its driving circuit, a wavefront scanning / shifting device and its driving circuit, a front end data processing unit (for example a processor, microcontroller, PGA, programmable device). The camera is also used to provide a real time video image of the eye from which the wavefront is measured. In addition, the latter data processing unit is employed to convert sequentially wavefront data from the previous processing unit to display ophthalmic medical information superimposed thereon or in a real-time image of the patient's eye. The circuit (the front end and / or the rear end) may be, for example, a respective device including an eye lateral position measuring device, an eye distance measuring device, an acceptable eye fixed target, a data storage device, Lt; RTI ID = 0.0 > and / or < / RTI >

In another embodiment, the information obtained from the real-time eye image is used to actuate various actuation devices of the wavefront sensor and to correct for wavefront measurement errors introduced by eye movement. In particular, in one embodiment, the real-time eye image specifies eye movement, measures eye pupil size, and senses, detects, or tracks the eye so that the incoming SLD beam enters the eye from a desired location in the eye, cornea or pupil Re-aligned / re-arranged. The algorithm is also programmed to adjust the wavefront sampling area / size to achieve dynamic adjustment and / or scaling and / or closed loop of the measured eye pupil size and location of the returned wavefront sensing area or position. The pupil information of the eye can be used to calibrate the wavefront data to achieve a high precision wavefront measurement even when the eye is not aligned or moving.

Another embodiment is a light source device that includes a light source for outputting a light beam irradiating a target eye, a first beam deforming member for intercepting the light beam and directing the light beam toward the target eye, And a control unit for controlling the beam deforming member to compensate for the lateral motion of the target eye.

In yet another embodiment, the wavefront sensor further comprises an image detector outputting an image of the subject eye, and a controller coupled to the image detector and processing the image to determine lateral motion of the subject eye.

In another embodiment, the wavefront sensor further comprises a second beam deflecting member (182) for receiving said light beam and for directing said light beam towards said target eye,

The control unit controls the second beam deflecting member to scan the light beam around a small portion of the retina of the subject's eye to disperse the optical energy in a larger area.

These and other aspects of the invention may be more fully understood by those of ordinary skill in the art by reviewing the following description of a preferred embodiment with reference to the accompanying drawings.

The present invention provides an apparatus and method for operating a real-time high diopter range sequential wavefront sensor.

1 shows an embodiment of the optical structure of a high-level diopter range real-time sequential wavefront sensor integrated into a surgical microscope.
Fig. 2 shows an example of an electronic device which is interfaced to the optical system of the wavefront sensor of Fig. 1 in which such a potentially active device is connected to an electronic control circuit.
FIG. 3 shows that there is no corresponding change formed for the wavefront sampling design and that the eye occurs in the wavefront sampling period on the corneal surface upon lateral movement.
Figure 4 illustrates how to compensate for the lateral motion of the eye by DC offsetting the wavefront beam scanner and to scan the same properly centered annular ring when the eye moves in the lateral direction.
Figure 5 shows what is measured in refractive errors or wavefront errors when the eye is moved axially from a designed position.
FIG. 6 shows an overall block diagram of an example example of inching of an electronic system for controlling and driving the associated device and sequential wavefront sensor shown in FIGS. 1 and 2;
FIG. 7 is a block diagram of an exemplary embodiment of a real-time image camera and a front end electronic processing system mounted in a sequential wavefront sensor module and a rear end electronic processing system mounted in the host computer and display module shown in FIG.
Figure 8 illustrates an exemplary internal calibration target that is moved into the wavefront relay beam path to generate one or more reference wavefronts for internal calibration and / or verification.
Figure 9A shows an example of an electronic block diagram to achieve the task of digital gain control and automatic SLD indexing to optimize the signal to noise ratio.
FIG. 9B shows a quadrant detector in which the optical image spot is initially positioned at the center and the second is positioned slightly away from the center.
FIG. 9C illustrates the case where, in many cases for planar wavefronts, defocused wavefronts, astigmatism wavefronts, when the associated image spots are located on the quad-detector behind the sub-wavefront focus lens and are represented as 2D data point patterns on the monitor, It is a picture showing sequential movement of position.
10 shows an exemplary processed blow block diagram for optimizing the signal to noise ratio by varying the gain and SLD output of a variable gain amplifier.
Figure 11 shows an example of a composite transimpedance amplifier having a lock-in detector that can be used to amplify a signal from one of four quadrant photodiodes, such as used in the position sensing detector circuit of Figure 9.
Figure 12 shows an example of a complex of a common transimpedance amplifier with a lock-in detection circuit.
Figure 13A shows when a MEMS scan mirror is oriented such that the entire wavefront is shifted down when the SLD pulse is started, in which case the aperture samples a portion at the top of the circular wavefront section.
Fig. 13B shows the case when the wavefront is shifted down when the SLD pulse is started so that the aperture on the right side of the circular wavefront section samples a portion.
13C shows the aperture sampling a portion at the bottom of the circular wavefront section when the wavefront is shifted upward when the SLD pulse is initiated.
13D shows that when the wavefront is shifted to the right when the SLD pulse is started, the aperture samples a portion from the left side of the circular wavefront section.
Figure 13E shows the equivalent of a sequential scan order of four pulses per cycle to sample the wavefront section with four detectors arranged in a ring form.
Figure 13f shows the positions of the eight SLD pulses that are initiated with respect to the X and Y axes of the MEMS scanner, with four even or odd pulses of the eight pulses aligned on the X and Y axes of the MEMS scanner, Lt; RTI ID = 0.0 > X < / RTI > and Y axes.
Figure 14 shows that four SLD pulse start positions initially aligned in the X, Y axis of a wavefront scanner as shown in Figure 13f shift 15 degrees from the X, Y axis by slightly delaying the SLD pulse.
FIG. 15 shows the accumulated effect of sampling the wavefront at an offset angle of 0 degrees in the first frame, 15 degrees in the second frame, and 30 degrees in the third frame.
Figure 16 shows an example of a theoretically determined relationship between a PSD ratio predicted center displacement or position and an actual center displacement or position along the X or Y axis.
Figure 17 is an exemplary flow diagram illustrating how calibration should be performed in order to achieve a corrected relationship and more accurate wavefront aberration measurements.
Figure 18 shows a graph of a sequential oval using trigonometry where U (t) = a · cos (t) and V (t) = b · sin And the ellipse is rotated in the counterclockwise direction at a point (U (t0), V (t0)) in the first quadrant of the UV cartridge coordinate.
Figure 19 shows a corresponding graph of similar sequential ellipses using trigonometry where U (t) = -a cos (t), V (t) = -b * sin , So that the ellipse is rotated counterclockwise at point U (t0), V (t0) in the third quadrant of the UV plate coordinate.
Figure 20 shows a corresponding graph of a similar sequential ellipse using trigonometry where U (t) = a * cos (t), V (t) = -b * sin , So that the ellipse is rotated counterclockwise at point U (t0), V (t0) at the fourth quadrant of the UV plate coordinate.
Figure 21 shows the corresponding graph of similar sequential ellipses using trigonometry where U (t) = -a cos (t), V (t) = b * sin (t), a>b> 0 , So that the ellipse is rotated counterclockwise at point U (t0), V (t0) in the second quadrant of the UV plate coordinate.
Figure 22 shows an example of a sequential central data point that is expected from a spherical wavefront that diverges and, as a result, a data point location and a polarity.
Figure 23 shows another example of a converging spherical wavefront and, as a result, a sequential central data point expected from a data point location and a polarity.
Figure 24 shows a Cartesian coordinate system rotated to UV coordinates of eight sequentially sampled central data points that are translated and rotated to Xtr-Ytr coordinates that were translated in the original XY coordinates and then fitted to a sequential ellipse .
Figure 25 shows the eight central data points on the UV coordinate system and the coordinates of the central coordinate system of the coordinate rotation transformation, which corresponds to the converging spherical wave front with the negative principal axis and the minor axis, Fig.
Fig. 26 shows a processing flow diagram of an embodiment for decoding spherical diopter and cylindrical de-hopper and cylindrical axis angles.
Figure 27 shows an exemplary process flow diagram of an eye tracking algorithm.
28 illustrates an exemplary process flow diagram illustrating the concept of using a real-time eye image to determine the maximum wavefront for sampling an annular ring diameter and to achieve a more improved diopter resolution for water-anhydrous measurement.
Figure 29 illustrates a wavefront sensor signal that detects the presence of an unintended object in the eye movement and wavefront relay beam path from a desired location range so that the SLD is off and the error 'name' or 'arm' Fig. 2 depicts an exemplary process flow diagram illustrating a concept using eye images.

 Reference will now be made to various embodiments of the invention. Examples of such embodiments are shown with reference to the accompanying drawings. The present invention will be described with reference to these embodiments, but the present invention is not limited to any embodiments. On the contrary, the invention includes optional examples, modifications, and equivalents which fall within the spirit and scope of the invention as defined by the appended claims. In the following description, specific numerical values are provided for understanding various embodiments. However, the invention may be practiced without some or all of these specificities. In other instances, well-known processes are not described in detail to the extent that they do not impose unnecessary limitations on the present invention. In addition, the appearances of the "exemplary embodiments" in various places in the specification are not necessarily all referring to the same exemplary embodiment.

In a conventional wavefront sensor used to measure the wavefront aberration of the human eye, the wavefront from the eye pupil or corneal plane is relayed to a wavefront that senses or samples the plane once or several times using the known 4-F relay principle For example, 1949-1957, J. Opt. Soc. Am A11, "Measurement of wavefront aberration of human eye using Hartmann-color wavefront sensor ", 1994. J. Liang J. J. Wicker, "Design of high-speed color-Hartmann wavefront sensor using commercial off-the-shelf optics", Applied Optics, 45 (2), 383-395; see US Patent No. 7654672). This single or multiple 4-F relay system allows phase information of the incident wavefront to be preserved while relaying it without harmful propagation effects. In addition, by constructing an infinite-focus imaging system using two lenses of different focal lengths to implement a 4-F relay, such a relay can be used to create a 4-F relay that has an associated incident wavefront diverging or convergence- (Eg, J. W. Goodman, Introduction to FUERO-OPTICS, Second Edition, McGraw-Hill, 1996).

It has recently been recognized that there is a need for a real time wavefront sensor that provides vivid feedback on various vision correction methods such as LRI / AK correction, laser enhancement and cataract / refractive surgery. In this process, any interference to general surgery is undesirable, particularly when turning off surgical microscope illumination and waiting for wavefront data capture and processing. Medical staff would like to have real-time feedback provided to them during the surgical procedure. In addition, most healthcare providers prefer to be synchronized and superimposed immediately following the real-time display / motion of the eye in real time, as the results of the real-time wavefront measurements shown in succession are either quantitatively or qualitatively or quantitatively qualitative It is preferable to be combined and displayed. Another major issue is the movement of the eye relative to the wavefront sensor during vision fixation, as the wavefront is measured in real time. Previous wavefront sensors did not provide a means to compensate for eye movement, and instead, the eye needed to be reordered on the wavefront sensor for meaningful wavefront measurements.

A pending patent application (US patent application no. 20120026466), which is assigned to the same applicant as the present applicant, describes a large diopter range of sequential wavefront sensors particularly suitable for showing problems encountered during the vision correction process. Although various optical design / fabrication possibilities have been described in the above co-pending application, detailed electronic control and data processing aspects of operating such a large diopter range of sequential wavefront sensors have not been described. Additional measurement capabilities of the other subassemblies have not been described in detail. In the present application, electronically controlled drive features having various features and associated algorithms performing various functions are described.

According to one or more embodiments of the present invention, a lock-in detection electronic system related to an associated algorithm for wavefront measurement with high level of accuracy is described. The electronic system obtains an electronic signal from the optoelectronic position sensing device / detector, amplifies the analog signal with a complex trans-impedance amplifier, converts the analog signal into a digital signal using an A / D converter, Amplifies the digital signal, and processes the data using the data processing unit. The electronic system is connected to some or all of these electromagnetic actuating devices of the wavefront sensor module to achieve different functions. Examples of such working devices include a light source such as a superluminescent diode (SLD) that produces a measured objective wavefront, a SLD beam focusing and / or steering module, a wavefront scanning / shifting device such as a MEMS scan mirror, Position and distance sensing / measuring devices, eye fixation targets, various variable focus active lenses, one or more data processing and storage devices, input devices available to end users and display devices.

FIG. 1 shows an embodiment of the optical structure of a real-time sequential wavefront sensor in a large diopter range integrated into a surgical microscope, and FIG. 2 is an electronic device connection vision wavefront sensor with such an active device connected to an electronic system Lt; / RTI >

Referring to Figures 1 and 2, the first lens 104/204 of the 8-F wavefront relay is disposed at the lightest input port of the wavefront sensor module. The first lens 104/204 is shared by a surgical microscope and a wavefront sensor module. The advantage of placing the first lens 104/204 of the 8-F wavefront relay as close as possible to the patient's eye is that the designed focal length of this first lens can be as short as the requirements of the 8-f wavefront relay, The overall optical path length of the sensor can be made the shortest. When the combined wavefront relay beam path is broken, the wavefront sensor module becomes compact. Also, a measurement range of a large diopter of a wavefront from the eye can be achieved compared to a lens of the same diopter, which is placed further downstream of the optical beam path. Also, since there was always a need for a wavefront sensor with an optical window at this position, the lens would be able to perform the dual purpose of the window and the first lens for the wavefront relay system and the microscope. However, the first lens 104/204 may be disposed after the beam splitter 161/261 of the dichroic or short end path.

The dichroic or short-path beam splitter 161/261 shown in Figures 1 and 2 applies a near-infrared wavefront relay beam (at least covers the optical spectral range of the high-brightness diode or SLD 172/272) to the remaining wavefront sensor module, Is used to reflect / refract with high efficiency, and most of the visible light (for example, 85%) passes through. The dichroic or short-path beam splitter 161/261 allows some of the visible and / or near-infrared rays outside the SLD spectrum range to be refracted / refracted so that a clear, real- As shown in FIG.

The compensation lens 102/202 on the dichroic or short-path beam splitter 161/261 is used to fulfill several functions. First, in order to ensure that the surgical sight is visible to the medical staff by the surgical microscope, it is not affected by the use of the first lens 104/204 of the 8-F relay, Can be designed to compensate for the influence of the first lens 104/204 relative to the visual part of the microscope. Next, the compensation lens 102/202 functions as an upper optical window that may be required to seal the wavefront sensor module. The third function of the compensating lens 102/202 is to direct the irradiation beam from the surgical microscope from the optical axis to cause the specular reflection from the lens 104/204 to be reflected on the surgical sight It is not possible to go back to the two pairs of viewing angle paths of the surgical microscope which interferes with the view of the medical staff. Finally, the compensating lens 102/202 may be coated to reflect and / or absorb the near-infrared and ultraviolet spectra of the light and allow the light to transmit only visible light. In this way, the near-infrared portion of the light corresponding to the SLD spectrum from the microscopic light source can be used to saturate the position sensing device, or to transmit backlight of the near-infrared light back into the eye that can enter the wavefront sensor module It is not visible to the patient's eye to form. On the other hand, such a coating can emit or absorb ultraviolet radiation from the light source of the microscope. However, if the first lens is disposed behind the dichroic or short-path low beam splitter 161/261, the need for a compensating lens is eliminated, so that a window having a certain wavelength filtering function is sufficient.

In Figures 1 and 2, the wavefront from the eye is relayed downstream of the wavefront sampling image plane 8-F where the wavefront sampling apertures 118/218 are located. The wavefront relay further includes, in addition to the first lens 104/204, two cascaded 8s including a second lens 116/216, a third lens 140/240, and a fourth lens 142/242. -F wavefront relay or a 4-F relay stage. The wavefront relay beam path is deflected by a polarizing beam splitter (PBS) 174/274, a mirror 152/252, and a MEMS beam scanning / shifting / refraction mirror 112/212 to make the wavefront sensor module compact . Along the wavefront relay beam path, the bandpass filter 176/276 can be placed anywhere between the dichroic or short-path beam splitter 161/261 and the quadrant detector 122/222, Lt; RTI ID = 0.0 > SLD < / RTI > The aperture 177/277 also limits the cone angle of the light from the eye to prevent light from sticking outside the mirror surface area of the MEMS scanner 112/212 disposed in the second Fourier transform plane, May be disposed in a first Fourier transform plane between the PBS 174/274 and the mirror 152/252 to perform a function to ensure that the diopter measurement range of the wavefront of the wavefront is in the desired range.

 The MEMS scan mirror 112/212 is arranged to scan the object beam angularly so that the wavefronts relayed in the final wavefront image plane can be shifted laterally with respect to the wavefront sampling apertures 118/218. Is placed in the second Fourier transform plane. The wavefront sampling apertures 118/218 may be a fixed-size aperture or a variable aperture. The sub-wavefront focusing lens 120/220 behind the apertures 118/218 are sequentially placed on a position sensing device / detector (PSD: 122/222: quadrant detector / sensor or lateral effect position sensing detector) And focuses the sampled sub-wavefront. The electronic system may be at least connected to the SLD 172/272, the wavefront shifting MEMS scan mirror 112/212, the PSD 122/222 to pulse the SLD, scan the MEMS mirror, So that signals are collected from the PSD.

At this point, notwithstanding Figures 1 and 2, the first lens of the wavefront relay is disposed at the input port position of the wavefront sensor module or enclosure, so that it does not need to be a case. The first lens 104/204 may be disposed behind the dichroic or short-axis low beam splitter 161/261, and a glass window may be placed at the input port position. Thus, the remainder of the wavefront relay is redesigned so that the optical function of the compensation lens or window 102/202 can be modified so that the microscope image looks good to the medical staff.

In addition to the folded wavefront relay beam path, three additional optical beam paths are shown in Figures 1 and 2, one for imaging the eye and the other for orienting the fixed target relative to the eye, and The other is to visually illuminate a high intensity diode (SLD) beam for generation of a wavefront relay beam from an eye having eye wavefront information.

The image beam splitter 160/260 splits at least a portion of the image light reflected by the dichroic or short-path beam splitter 161/261 or back from the eye into a 2D-pixel To an image sensor 162/262, such as an array CCD / CMOS sensor. The image sensor 162/262 may be a monochrome or color CMOS / CCD image sensor coupled to the electronic system. The image sensor 162/262 provides a coplanar motion image or still image of the subject's eye and is focused on the image in the back or front of the eye. The fixed / image beam splitter 166/266 also includes a fixed target 164/264 (not shown) formed by a set of lenses or lenses 170/270 along with the first lens 104/204 along the reverse path to the patient's eye. ) Image. The lens 168/268 on the front of the image sensor 162/262 is designed to work in conjunction with the first lens 104/204 and is designed to act on the display (not shown in Figures 1 and 2) For example, if it is necessary to ensure that the image sensor plane is conjugated with respect to the eye pupil plane so that a clear eye pupil image can be obtained, It can be used to manually adjust the focusing. In the case of auto-focusing, the lens 168/268 needs to be connected to the electronic system.

The lens 170/270 in front of the fixed target 164/264 can be designed to provide the patient's eye with a comfortable fixed target of the correct size and brightness. It can be used to adjust focusing to ensure that the fixation target is conjugated to the retina of the eye, fix the eye at different distances, orientations, and even blur the eyes. Through this, the lens 170/270 needs to be activated and connected to the electronic system. The stationary light source 164/264 may be driven by an electronic system to flash or flash at a desired rate, for example, to distinguish the light source from the illumination light of the surgical microscope. The color of the fixed light source 164/264 may be variable. The fixed target may be a microdisplay with a pattern or spot visible variably with respect to the desires of the medical staff. Microdisplays based on fixed targets can also be used to guide patients to view in different directions so that a 2D array of eye aberration maps can be measured and generated and used to measure the visual sensitivity of the patient's peripheral vision.

The fixed target 164/264 may be a red or green or yellow (or any color) light emitting diode (LED) as an output light source dynamically controllable by an electronic system based on different background light conditions. For example, when the relatively strong illumination light from the surgical microscope is turned on, the brightness of the stationary light source 164/264 is increased so that the ball can easily find and fix the stationary target. A variable diaphragm or aperture (not shown in FIGS. 1 and 2) is disposed in front of the lens 168/268 prior to the image sensor and is connected to the electronic system to control the depth of field of the real-time image in front of and behind the eye. By dynamically varying the aperture size, the degree of blur of the eye image can be controlled as the eye moves away from the designed distance in the axial direction, and the degree of blur of the eye image as a function of the diaphragm and aperture size, The relationship between positions can be used as a signal to determine the axial distance of the eye. As an optional example, the eye distance may be measured by known means, such as trigonometry, based on the corneal scattered and reflected image spot positions of the one or more near-infrared light sources. A low coherence interferometry based on non-distance measurements as described below may be employed.

The rings or multiple rings of LEDs (or arrays) 135/235 may be placed in a circle around the input port of the wavefront enclosure to perform multiple functions. One function simply provides over-illumination light within the wavelength spectrum so that light returned to the eye in this spectrum can reach the image sensor 162/262. In this manner, visible light can be filtered to reach the eye when there is no illumination from the surgical microscope or illumination light from the surgical microscope, and the contrast of the eye image captured by the image sensor 162 / Within a range. As an example, the image sensor may be a monochrome UI-1542LE-M, which is an extremely compact board-level camera with a resolution of 1.3 megapixels (1280 x 1024 pixels). The NIR bandpass filter can be arranged along the image path such that only the flood illumination light reaches the image sensor and a relatively constant contrast of the real time eye image is maintained.

The second function of the LED 135/235 forms a specular image spot back from the optical interface of the cornea and / or the eye lens (natural or artificial) to form a perkinetic image of the LED 135/235 Purkinje image) to be captured by the image sensor 162/262. Through the image processing of the Perkin image, the lateral position of the patient's eye is determined. In addition, the top and / or bottom surface profile or topographical profile of the cornea and / or eye lens (natural or artificial) may be understood such that the corneal topographer and / or keratometer / . This obtained information can be used to determine changes in corneal shape or even some other eye biological / anatomic parameters. The measured change can be used to set the refraction to be targeted or anticipated during or immediately after refractive surgery to ensure that the final refraction of the eye is as desired when the invasion or wound formed on the cornea of the eye is fully treated.

A third function of the LEDs 135/235 is to create a light spot on the white portion of the eye to form a light spot that can be captured by the image sensor 162/262 to implement eye distance measurement using the principle of optical trigonometry. Projected and optionally partially lighted. A change in the center position of the imaged light spot can be processed to read the eye distance.

In addition to providing an actual eye pupil / iris or corneal image and imaging a flood irradiation effect, the image sensor signal may be used for other purposes. For example, the real-time image may be used to detect the size, distance, and lateral position of the eye pupil from the first lens 104/204. When it is found that the size of the pupil is small, the wavefront sampling area can correspondingly be reduced. In other words, the pupil size information can be used in a closed loop for scaling and / or automatic adjustment and / or manual adjustment of the wavefront sensing area for each pupil size.

One embodiment of this disclosure is to correct for wavefront measurement errors as a result of eye position changes within any position range. The calibration can be applied to the eye axial positional change and the eye lateral positional change. In one embodiment, the amount of lateral movement of the eye or pupil with respect to the wavefront sensor module is such that if the eye or pupil is not adequately centered properly, i. E., Is not adequately aligned with respect to the optical axis of the wavefront sensor, The same area of the corneal image is always sampled since it is used to calibrate the measured wavefront error to be introduced by lateral movement of the eye or the pupil or to adjust the driving signal of the wavefront sampling scanner.

The lateral position of the eye or pupil may be determined using a real-time eye image or other means. For example, the edge can provide a reference for where the eye is, that is, the boundary between the pupil and the iris can provide a reference for where the eye is. Also, the specular flood radiation from the cornea front surface, captured by a real-time eye camera as a bright light spot or sensed by an additional position sensing detector, can be used to provide information on the lateral position of the eye. Also, the specular SLD light from the corneal anterior surface can be detected by an additional position sensing detector, which is captured by a real time eye camera as a bright light spot or determines the lateral position of the eye. The SLD beam can be scanned in two sizes to find the regular reflection of the strongest corneal apex and determine the lateral position of the eye.

Figure 3 shows what would happen in the wavefront sampling area on the corneal plane if the eye was moved in the lateral direction and no corresponding change in the wavefront sampling design occurred. The SLD beam is fixed coaxially with respect to the wavefront sensor optic axis and the wavefront sensor is sampled about an annular ring that is radial or rotationally symmetric about the optical axis of the wavefront sensor on the corneal plane. When the eye is properly aligned, the SLD beam 302 enters the eye through the center of the pupil and the apex of the cornea, and is formed on the retina near the center fovea. The returned wavefront is sampled in a radially or rotationally symmetrical annular ring centered on the apex of the cornea as shown in the cross-sectional corneal plane on the right side. Consider whether the eye is moving downward and laterally with respect to the SLD beam and the wavefront sensor. The SLD beam 312 enters the eye from the center of the eye and is located on the retina near the center of the eye even if the exact position is slightly different depending on the aberration of the eye. Since the wavefront sampling area is fixed relative to the SLD beam, on the corneal plane, the sampled annular ring is located at the center of the eye pupil or at the top of the cornea, as shown by the annular ring 314 of the cross- Lt; / RTI > Such non-radial or non-rotationally symmetric wavefront samples will cause errors in the wavefront measurement. In one embodiment of the invention, as information on the lateral position of the eye or pupil, the wavefront measurement error can be corrected by software and data processing.

In one embodiment of the invention, with the information on the lateral position of the eye or pupil, the SLD beam is scanned to follow or track the eye or pupil, and the SLD beam is scanned, for example, by a specular SLD beam returned by the cornea The cornea always enters from the same cornea as it is designed to prevent entry into the PSD of the wavefront sensor (slightly off the apex of the cornea). The real-time eye image may be used to determine the presence of an eye and thus to turn on / off the SLD / wavefront detection system. To ensure that the SLD beam always enters the eye at the desired corneal position and is not partially or completely blocked by the iris as a result of lateral movement of the eye (within any eye movement range) A scan mirror 180/280 that scans the SLD beam as it is can be placed in the back focal plane of the first wavefront relay lens 104/204. In this case, the SLD beam can be scanned in the lateral direction with respect to the corneal plane by scanning the scan mirror 180/280. An image sensor or other eye lateral position detection means for capturing a real time image of the eye can be used to read the lateral position of the eye center and provide a feedback signal for driving the scan mirror 180/280, Will be able to track eye movements or eyes.

In another embodiment of the present invention, the wavefront beam scanner 112/212 is driven with an appropriate DC offset to follow the eye lateral movement or track the eye such that the wavefront sampling is always performed in the same region of the eye pupil . For example, the sampling may be performed on an annular ring that is radially or rotationally symmetric about the center of the eye pupil. To see how this is possible, remember that the wavefront beam scanner is placed on the second Fourier transform plane of the 8-F wavefront relay structure. When the eye moves in the lateral direction, in the 4-F wavefront image plane, the image of the wavefront can be optically enlarged or reduced in proportion to the focal length ratio of the first lens and the second lens to be moved in the lateral direction. When the wavefront beam scanner does not perform any scanning and has no DC offset, when the wavefront moving laterally in the intermediate wavefront image plane is additionally relayed to the final wavefront sampling image plane, it is displaced transversely with respect to the sampling aperture . As a result, the wavefront beam scanner performs each rotation scan. The annular ring region scanned effectively on the corneal plane is shifted in the center as shown in the lower part of Fig.

Figure 4 shows how DC offset of the wavefront beam scanner can compensate for lateral movement of the eye and continue to scan equally appropriately centered annular rings even if the eye moves in the lateral direction. 4, when there is a lateral movement of the eye, the SLD beam 448 enters the center-shifted eye, and the wavefront in the corneal plane, which is the object to be relayed by the 8-F relay, . Thus, the intermediate wavefront image 402 is displaced in the transverse direction, and if there is no DC offset of the wavefront beam scanner, the intermediate wavefront image without scanning the wavefront beam in the second Fourier transformed image plane will have a laterally displaced wavefront image 432 ) To the final wavefront sampling surface. In this case, if the wavefront beam scanner is scanned in the form of a circular angular rotation for a DC offset angle of 0 degrees, then the sampled wavefront is non-radial or non-radial relative to the center of the eye as shown by the annular ring 444. [ - It will be a rotating symmetrical annular ring. However, if the wavefront beam scanner 462 as shown on the right in FIG. 4 has any DC offset appropriately determined based on the lateral displacement of the eye and the final wavefront image 482 following it, then the final wavefront sampling image When relocated relative to the plane, may be laterally displaced so as to be again centered relative to the wavefront sampling aperture 458. [ In this case, the SLD beam 498 enters an eye that is out of the center, and the object to be relayed by the 8-F relay is a target, and the wavefront in the corneal plane is passed through the first, second, axis state, but after the wavefront scanner, the relay is calibrated by the wavefront scanner and is now on-axis. Thus, an additional angular scan of the wavefront beam scanner for this DC offset results in sampling a radially or rotationally symmetrical annular ring 494 about the center of the eye.

One embodiment of the invention thus controls the DC offset of the wavefront scanner in response to lateral movement of the eye, which can be determined by a real-time eye camera or other means. The wavefront image along the wavefront relay path may be an optically introduced aberration including, for example, a coma or a prism inclination, as it is done off-axis, but not on-axis along part of the image path. Additional aberrations introduced as a result of the off-axis wavefront relays can be managed through calibration and can be handled with calibration and data processing to eliminate the inherent aberrations of the optical image or relay system.

In another embodiment of the present invention, if it is known that the eye is not axially disposed at a predetermined distance from the object plane of the wavefront sensor, the amount of axial displacement of the eye with respect to the predetermined axial position is determined, Is used to correct the measured wavefront error introduced by the directional motion. Figure 5 shows what happens to the measured wavefront or refractive error when the eye is moved axially from a predetermined position.

In the left column of FIG. 5, three regular views are shown as an upper portion 504 further moved from the wavefront sensor and a lower portion 508 moved toward the wavefront sensor, and a middle portion 506 disposed at a predetermined axial position of the wavefront sensor. do. As shown, the wavefronts appearing from this regular view are flat, so that in a predetermined object plane 502 where the wavefronts are relayed to the final wavefront sampling surface, the wavefronts 514, 516, 518 are all flat in all three cases. Thus, if the eye is on time, if the eye is slightly displaced from the predetermined position in the axial direction, the wavefront measurement is not affected.

However, if the eyes of the eye lens 525, 527, 529 are shown thick and the eyes 524, 526, 528 are shown as relatively long, as shown in the middle column of FIG. 5, Converges to points 535, 537 and 539 and the diopter value of the wavefront in the corneal plane is determined by the distance from the corneal plane of the eye to the convergence point. In this case, if the eye is moved slightly further from the wavefront sensor as shown in the upper example of the middle column, the wavefront at the object surface 522 of the wavefront sensor is not the same as the wavefront at the eye's corneal plane do. Indeed, the convergent radius of curvature of the wavefront in the object plane of the wavefront sensor is smaller than that in the corneal plane. Thus, when the wavefront 534 in the object plane of the wavefront sensor is measured by the wavefront sensor, the measurement result is that the radius of curvature of the wavefront 534 is less than the radius of curvature of the wavefront 536, 536). On the other hand, if the eye is to move closer to the eye toward the wavefront sensor as shown in the lower example of the middle column, then the wavefront 538 in the object plane 5232 of the wavefront sensor is located in the corneal plane of the eye It is not the same as wavefront 536 again. Indeed, the radius of curvature of the wavefront 538 in the object plane of the wavefront sensor is greater than the wavefront 536 in the corneal plane. As a result, the measured wavefront results at the wavefront object plane are again different from those at the corneal plane of the eye.

If the crystalline lens of the eye is removed and the eyes 544, 546 and 548 are of the circular shape as shown in the right column of Fig. 5, which is shown as being shorter than the general one simulating a short anisometropic eye, The emerging wavefront will be diverted by the diverging ray back end, and it will be possible to find the vertical focus points 555, 557, and 559 from which the rays originate. The raw diopter value of the wavefront at the corneal surface is determined by the distance from the corneal plane of the eye to the virtual focus point. In this case, if the eye is further moved by the eye from the wavefront sensor as shown by the upper example of the right column, the wavefront 554 of the wavefront sensor's object plane 542 is the wavefront 556 at the corneal plane of the eye, . ≪ / RTI > The radius of divergence of wavefront 554 in the object plane of the wavefront sensor is greater than the radius of divergence of wavefront 556 in the corneal plane. Thus, when this wavefront 554 in the object plane of the wavefront sensor is measured by the wavefront sensor, the measured result is different from wavefront 556 in the corneal plane. If, on the other hand, the eye is moved closer to the wavefront sensor as shown by the lower example of the right column, the wavefront 558 in the object plane 542 of the wavefront sensor, the wavefront 556 in the corneal plane of the eye, Will be different. The radius of curvature of the diverging wavefront 558 in the object plane of the wavefront sensor is less than the wavefront 556 in the corneal plane. As a result, the measured wavefront results at the wavefront object plane will be different from those at the corneal plane of the eye.

In one embodiment of the present invention, real-time means for detecting the axial position of the eye to be tested is fitted so that information on the axial axial movement of the eye relative to the object plane of the wavefront sensor module in real time Lt; RTI ID = 0.0 > wavefront < / RTI > As will be discussed later, the eye axial position measurement means includes optical triangulation and interferometry of optically low coherence as is known to those of ordinary skill in the art. Calibration can be used to determine the relationship between the axial position of the eye and the calming wave front aberration of the eye relative to the wavefront aberration in the object plane of the wavefront sensor as measured by the wavefront sensor. A reference table can be used to calibrate the wavefront measurement error in real time. In the case of cataract surgeries, the surgical microscope will give the medical staff a relatively sharply focused view of the patient's eye within an axial range of about + -2.5 mm when fully zoomed out. Therefore, when a medical practitioner focuses the patient's eye under the surgical microscope, the change in the axial position of the patient's eye should be within a range of about + -2.5 mm. Thus, calibration can be done in this range, and reference tables will be made in this range.

In one embodiment of the invention, the eye is moisturized with water / solution, optical bubbles are present, the lid of the eye is in the optical path, or the hands of the elderly skin or medical staff or the medical staff are in the field of view of the image sensor, When it is found that the path is partially or totally blocked, the wavefront data may be abandoned or filtered to exclude "name" or "cancer" data, and at the same time the SLD 172/272 may be turned off. In another embodiment of the present invention, the wavefront sensor can be used to determine whether the eye is dry or not, and a reminder as a video or audio signal is sent to the medical staff to alert the medical staff when the eye is moisturized. In addition, the signal from the image sensor 162/262 can be used to confirm whether the patient's eye is hydrated, uncorrected, or semi-static, so that the SLD pulse can only be turned on when needed. This approach is capable of reducing the total time the patient is exposed to the SLD beam and allowing high peak power or SLD pulses of long duration in increasing the ratio of noise versus wavefront measurement signal. Additionally, the algorithm may be adapted to measure the optimal distance to the eye through the effective blur of the resulting image and / or alongside the triangulation criteria.

In Figures 1 and 2, a large size polarizing beam splitter (PBS) 174/274 is used to illuminate the SLD beam in the patient's eye. The reason for using a large window size is to ensure that the wavefront relay beam from the eye in the desired large diopter measurement range is intercepted entirely, rather than partially, by the PSB 174.274. In one example, the beam from SLD 172/272 is preferably p-polarized such that the beam is transmitted through PBS 174/274 and reaches the eye to produce a wavefront of the eye. The SLD beam may be manipulated and manipulated such that when the beam enters the eye in the corneal plane, the beam may be partially defocused or collimated (in a diverging or converging manner) in the corneal plane, . When the SLD beam is focused on the retina as a relatively small light spot or a slightly elongated light spot, it will scatter in a relatively large angular range and the resulting reflected beam will have its original polarization and perpendicular polarization. As is known to those of ordinary skill in the art, in ophthalmic wavefront sensor applications, only the vertical polarization element of the wavefront relay beam is used for eye wavefront measurement. This is because there is a relatively strongly reflected SLD light wavelength from the eye lens and the cornea, which causes errors in the wavefront measurement. Another function of the large PBS 174/274 is to allow the vertically polarized wavefront relay beam to be reflected by the PBS 174/274 if there is a regular reflection of the SLD beam to the wavefront sensor module by the cornea or eye lens, 174/274) and to orient the polarized light wavelength back to the original direction used for other purposes for monitoring.

1 and 2, the bandpass filter 176/276 eliminates any visible light and / or ambient background light and provides a relatively narrow spectrum of the desired level of wavefront relay beam light generated by the SLD, To enter the remainder of the wavefront relay beam path.

In addition to the point at which the SLD beam is scanned to follow the lateral movement of the eye, the SLD beam can be scanned to fit a small scanned area on the retina by control from an electronic system including a front end electronics processor and a host computer have. In one example, in order to ensure that the SLD beam will always enter the eye at the desired corneal position and not be blocked in part or in whole by the iris (as within any eye movement) as a result of eye movement, And a scan mirror 180/280 that scans the SLD beam as shown in FIG. 2 may be disposed in the back focal plane of the first wavefront relay lens 104/204. In this case, the angular scan of the scan mirror (180/280) will cause the lateral scan of the SLD beam to the corneal plane, but if the eye is a regular eye, the SLD beam will be at the same oblivion position. Image sensor of the eye pupil The captured real-time image is used to grasp the lateral position of the eye pupil center, provide a feedback signal to drive the scan mirror (180/280), and allow the SLD beam to follow or track the movement of the eye.

In one embodiment, the other scan mirror 182/282 shown in FIGS. 1 and 2 is positioned on the SLD beam-shaped working lens 184/282 so that the SLD beam can be formed around a small area on the retina and scanned around it. 284 in the posterior focal plane of the corneal plane. Another lens 186/286 may be used to focus, collimate, or shape the SLD beam onto the scan mirror 182/282 from the output port of a single mode fiber, such as, for example, polarization maintaining single mode fiber. Scanning of the SLD beam for a small area on the retina offers several advantages, one of which is to reduce the speckle effect that has an SLD beam that always stays on the same retina spot area, especially when the spot size is very small, The advantage is that by splitting the optical energy for a slightly larger retinal region, the SLD beam, which is pulsed at high peak power or for long periods of time, becomes visible, thereby increasing the signal to noise ratio for optical wavefront measurement, The wavefront measurement error can be averaged, detected, or quantified, resulting from the topographic non-uniformity of the retina. Alternatively, by controlling the focusing and defocusing of the SLD beam using the lens 186/286 or 184/284, the SLD beam spot size on the retina can be controlled to achieve a similar purpose.

Scanning of the SLD beam to the retina or cornea can be performed independently, simultaneously and synchronously. In other words, the two SLD beam scanners 180/280, 182/282 may be operated independently of each other, but may be operated simultaneously. In addition, a laser beam that is an eye surgical light beam (not shown in FIGS. 1 and 2) can be combined with the SLD beam and delivered to the eye through the same optical fiber or other free space beam beam combiner, or to the same scanner for the SLD beam As it is delivered to another scanner, the eye surgery laser beam can be scanned to perform refractive surgery on the eye, such as limb-releasing incision (LRI) or other manipulations of the cornea. SLD and eye surgery lasers can have a variety of wavelengths and can be combined using fiber optic based wavelength division multiplexing couplers or free space dichroic combiners.

The internal calibration target 199/299 can be moved to the wavefront relay beam path when calibration / verification is done. The SLD beam can be oriented coaxially with the wavefront relay optical beam path axis when the internal calibration target is moved to a certain location. The calibration target may be made of a material that will scatter light in a manner very similar to a certain degree of relaxation of the eye's retina so that a reference wavefront can be generated and measured by a sequential wavefront sensor for calibration / . The generated reference wavefront may be a nearly flat wavefront or a typical anhydrostatic wavefront, or it may be a divergent or converging wavefront with an arbitrary level of divergence / convergence.

In the eye wavefront measurement, only the beam returned from the retina as a vertical polarized light is used, but this does not mean that the returned light wavelength is useless from the retina with the cornea, the eye lens and the circularly polarized portion. Conversely, this returned light wavelength as circularly polarized light can provide very useful information. Figures 1 and 2 show that the optical wavelength returned by the circularly polarized light is dependent on the eye distance from the wavefront sensor module, the position of the eye lens (artificial or natural) in the eye (i.e., the effective lens position), the front chamber depth, And can be used to measure anterior and / or posterior vital or anatomical parameters of the eye. 1 and 2, the returned light wavelengths passing through the PBS 174/274 are optically low coherence interferometry (OLCI) or low coherence tomography (OCT) as is commonly employed for optical coherence tomography (OCT) Lance fiber optic interferometer. The SLD output fiber 188/288 may be a single all (SM) and may be coupled to a conventional single mode (SM) fiber (or polarization maintaining single mode fiber) A portion is sent to the wavefront sensor and another portion of the SLD light is sent to the reference arm 192/292. The optical path length of the reference arm is roughly matched to correspond to the optical path length of the optical wavelength returned from the eye. The light wavelength returned from the other part of the eye is recombined with the reference light wavelength returned through the reference fiber arm 192/292 in the optocoupler 190/290 which is caused by optically low coherence interference. The interfering signal may be detected by a detector 194/294 as shown in Figures 1 and 2. Although the same fiber couplers (190/290) in Figures 1 and 2 are used to splice and recombine optical wavelengths in the Mickelson type of optical interferometry structure, other fiber optic interferometry structures such as fiber couplers A Mach-Zender type structure using two fiber couplers with fiber circulators in the sample arm may be used to effectively orient the recombining sampling arm return wavelength.

Various OLCI / OCT architecture and detection schemes can be employed, including spectral demosaic, swept source, time domain, and balanced detection. In order to keep the wavefront sensor module (e.g., attached to a surgical microscope or slit lamp biomicroscope) compact, a detection module 194/294, a reference arm 192/292 (including a reference mirror and a fiber loop) Even the SLD 172/272 and the fiber coupler 190/290 can be placed outside the wavefront sensor enclosure. The reason for doing this may be enacted according to the design in which the detection module 194/294 and / or the reference arm 192/292 and / or the SLD source 172/272 are used for OLCI / OCT operation. Electronic devices that operate the OLCI / OCT subassembly may be located inside or outside the wavefront sensor enclosure. For example, if a balanced detection design is employed as described in U.S. Patent No. 7815310, a fiber optic circulator (not shown) needs to be mounted on the SLD fiber arm. If time domain detection is employed, the reference arm 192/292 needs to include a fast scanning optical delay line (not shown) or a light path length scanner that needs to be controlled by an electronic device. If a spectral domain detection design is employed, the detection module needs to include a line scan camera (not shown) and an optical spectrometer that need to be controlled by the electronic device. If a sweeping source detection design is employed, the light source needs to include a wavelength scanner (not shown) that needs to be controlled by the electronic device.

In one embodiment, the scan mirrors 180/280 (and / or 182/282) are controlled by an electronic system so that a relatively strong OLCI / OCT signal is collected, for example in the cornea, Natural or artificial) and relatively strong specular reflection from the retina, returning to the fiber-optic interferometer, so that the axial distance of the optical interface of these eye-surface components to these wave-sensor modules or to each other can be measured. Such work can be sequentially separated from eye wavefront measurements as in the latter case and specular reflection should be avoided. Alternatively, two different wavelength bands may be used and spectral separation may be employed. On the other hand, the OLCI / OCT signal intensity can be used as an indication of whether the specular reflection has been collected by the wavefront sensor module, and if so, the wavefront sensor data can be abandoned.

In another embodiment, the SLD beam may be scanned across an anterior segment of the eye, or across any space of the retina, and biometric or anatomical tank measurements may be made on various portions of the eye. One particularly useful measurement is for the corneal surface and thickness profile.

In one embodiment, beam scanners 112/212 used for shifting and scanning the wavefront and those used for scanning the SLD beam may have dynamic DC offsets that provide additional benefits for the present invention. For example, the scanner 112/212, which is used to shift and / or scan the wavefront, may be configured such that the wavefront sampling is rotationally symmetric about the center of the pupil of the eye, Lt; RTI ID = 0.0 > and / or < / RTI > On the other hand, the reference point on the position sensing device / detector (PSD) can be adjusted if necessary for each compensated image spot through calibration. If there is a DC offset that forms any angle of the sampled image spot relative to the PSD reference point, this can be managed by calibration and data processing. A scanner 180/280 for scanning the SLD beam may be employed to track the lateral movement of the eye within any range through the feedback signal from the image sensor 162/262. If the eye is moved relative to the wavefront sensor module, the SLD beam will enter the eye through the same corneal position at the same angle as when the eye is centered relative to the wavefront sensor module, Will be displaced laterally relative to the optical axis of the module. As a result, the relayed wavefronts in the wavefront sampling image plane are displaced laterally. In this case, the DC offset of the scanner 112/212 used to shift the wavefront may be employed to compensate for this displacement and cause the scanned wavefront beam to be rotationally symmetric with respect to the wavefront sampling apertures 118/218 . In this case, there will be coma, prism inclination or other additionally introduced aberrations, which can be processed by calibration and data processing. In this way, any wavefront measurement error that is manifested by the change in eye position / placement is corrected and compensated.

Combining the information provided by the image sensor, wavefront sensor, specular reflector and / or low coherence interferometry combines some or all of the information for implementing the automatic selection of the calibration calibration curve and / or calibration data processing algorithm . On the other hand, a data integration indicator, or a trust indicator, or glaucomatous opacity indicator, or an indicator of the presence of optical bubbles may be communicated to the medical staff via video or audio or other means, or coupled to other means of providing feedback. The combined information can be used for intraocular pressure (IOP) detection, measurement and / or calibration. For example, a change in pressure in the anterior chamber of the patient's heartbeat-induced external acoustic wave-generated eye may be detected by a low coherence interferometry and / or wavefront sensor synchronized with an oxygen meter to monitor the patient's heartbeat signal have. A syringe with a pressure gauge is used to inject viscoelastic gel into the eye and to measure intraocular pressure to inflate the eye. The combined information can be used to detect and / or identify centering and / or tilting of an implanted intraocular lens (IOL) such as a lens in a multi-focal intraocular lens. The combined information may be used to detect eye conditions, including anhydrous, watery, and half-water. The wavefront sensor signal may be coupled to an OLCI / OCT signal that represents and measures the degree of light scatter and / or the opacity of the eye lens or optical media of the ophthalmic system. The wavefront sensor signal can be combined with the OLCI / OCT signal to measure the tear film distribution on the cornea of the patient's eye.

One requirement for real-time ophthalmic and wavefront sensors is the large diopter measurement dynamic range encountered in glaucomatous surgeries when the natural eye lens is removed and the eyes are anechoic. Although the optical wavefront relay structure is designed to cover a large diopter measurement dynamic range, its sequential nature eliminates the crosstalk problem, and lock-in detection technology filters DC and low frequency 1 / f noise , And this dynamic range can be limited by the position sensing device / detector (PSD). In one embodiment, the optical system is optimally designed such that, in the desired diopter coverage range, the image / light spot size on the PSD will always be within a certain range and its center will be sensed by the PSD. In another embodiment, the dynamic wavefront / defocus offset device 178/278 as shown in Figures 1 and 2 is placed in a 4-F plane that is conjugated to the intermediate wavefront image plane, the corneal plane and the wavefront sampling plane do. The dynamic wavefront / defocus offset device 178/278 may be a drop-in lens, a focus variable lens, a liquid crystal based transmissive wavefront manipulator, or a variable shaping based wavefront manipulator. When the PSD becomes a limiting factor for measuring large diopter values (positive or negative values), the electronic system activates the wavefront / defocus offset device to partially or wholly compensate or offset some or all of the wavefront aberration . For example, in the anhydrous state, the wavefront from the patient's eye is relatively divergent so that the positive lens offset the spherical defocus element of the wavefront to form the image / light spot on the PSD within range, Plane waveguide relay beam path so that the PSD sequentially senses / measures the center of the sampled sub-wavefront.

In other cases, such as high myopia, high intensity, relatively large astigmatism or spherical aberration, the wavefront / defocus offset device 178/278 can be scanned and a careful offset can be applied to one or more specific aberration elements in a dynamic manner have. In this way, some low order aberrations can be offset and information about other specific high order wavefront aberrations can be highlighted to indicate important medical properties of the remaining wavefront aberration that need to be further corrected. By doing so, the vision correction specialist or medical staff can tune the vision correction process and minimize the residual wavefront aberration in real time.

FIG. 6 shows an exemplary overall block diagram of an electronic system 600 for controlling and driving a sequential wavefront sensor and other associated actuation devices as shown in FIGS. 1 and 2. In this embodiment, the power module 605 converts the AC power to DC power for the entire electronic system 600. The wavefront data and the image / image of the eye are synchronized and captured in a streaming manner or stored. The host computer & display module 610 visually displays the wavefront information overlapped with the post-processing operation including synchronizing the wavefront measurement result with the real-time eye image, or displays the eye image of the patient side-by-side. The host computer & display module 610 mixes the digital image / image of the eye to form a composite image, transforms the wavefront data into a synchronized computer graphic, and displays the composite image on the display synchronized to the real- And the image is displayed.

The host computer & display module 610 communicates with the wavefront sensor module 615 sequentially through a serial or parallel data link 620 to supply power. The optical system shown in Figs. 1 and 2 is installed with several front-end electronics of the sequential wavefront module 615. Fig. In one embodiment of the present invention, the host computer & display module 610 and the progressive wavefront sensor module 615 communicate via the usb connection 620. However, other common serial, parallel or wireless data communication protocols will also work. The host computer & display module 610 allows for the downloading of wavefronts, video, and other processed or unprocessed raw data onto an external network (not shown) for subsequent purposes such as data analysis and playback. Lt; RTI ID = 0.0 > 625 < / RTI >

The display is not limited to a single display as shown coupled to the host computer. Such a display may include a built-in head-up display, a translucent micro-display of the eye path of the surgical microscope, a post-projection display capable of projecting superimposed information on a real-time microphotograph seen by the medical personnel, Monitor. In addition to having the wavefront measurement data superimposed on the image of the patient's eye, the wavefront measurement results (or other measurement results from the image sensor and low coherence interferometry) may be displayed adjacent or on different display windows of the same screen Can be displayed separately on the display / monitor.

Compared to conventional wavefront sensor electronic systems, the electronic system of the present invention allows the host computer & display module 610 to provide post-processing that includes the task of synchronizing real-time eye images with sequential wavefront measurement data, It is distinguished in that the wavefront information is superimposed on the image or the wavefront information is displayed adjacent to the real-time eye image to display the synchronized information. In addition, the front-end electronics in the sequential wavefront sensor module 615 (which will be briefly described) will operate the sequential real-time ophthalmic and wavefront sensors in the lock-in mode and transmit real time eye image data to the host computer & Processed wavefront data synchronized with the received wavefront data.

FIG. 7 shows a block diagram of an embodiment of a front end electronic processing system 700 mounted in the wavefront sensor module 615 shown in FIG. In this embodiment, the real-time image camera module 705 (CCD or CMOS image sensor / camera) provides a real-time image to the patient's eye, the data being transmitted to the host computer & display module 610 ) So that the wavefront data appears superimposed on the real-time image of the patient's eye. The front end processing system 710 includes an SLD drive and control circuit 715 (which performs SLD beam focusing and SLD beam adjustment as described above with respect to Figures 1 and 2 in addition to pulsing the SLD), a wavefront scanner drive Circuit 720 and the position sensing detector circuit 725. [ Compared to conventional wavefront sensor electronic systems, the shear electronic processing system described in this application is useful for real-time ophthalmic and wavefront measurement and display, particularly when combined with one or the other, . The light source used to generate the wavefront from the eye is used in pulse and / or burst mode. The pulse repetition rate or frequency is higher than the typical frame rate of a standard two-dimensional CCD / CMOS image sensor (typically about 25-30 Hz (frames per second)) (kHz range level). In addition, the position sensing detector can be operated in a lock-in detection mode that is two-dimensional with a sufficiently high response speed and is synchronized with the pulsed light source at frequencies exceeding the noise frequency range of 1 / f. The front end processing system 710 is at least electrically connected to the SLD driving and control circuit 715, the wavefront scanner driving circuit 720, and the position sensing detector circuit 725. The front-end electronics are configured to phase-lock the operation of the light source, the wavefront scanner, and the position sensing detector.

Further, the front end processing system 710 is electrically connected to the internal fixing and LED driving circuit 730 and the internal calibration target position circuit 735. 1 and 2, the LED driving circuit 730 may include a multi-LED driver and may include a display LED, a flood illumination LED for a real-time image camera of the eye And other LEDs including LEDs for triangulation based on the distance range of the eye. The internal calibration target position circuit 735 can be used to generate a reference wavefront measured by a sequential wavefront sensor for calibration / verification purposes.

The front end and rear end electronic processing systems include one or more digital processors and non-temporary computer readable memory for storing data with executable programs. The various control and drive circuits 715-735 are implemented as hard-wired circuits, digital processing systems, or combinations thereof, as is known.

8 illustrates an exemplary internal calibration and / or verification target 802/832/852 that is moved into the wavefront relay beam path to generate one or more reference wavefronts for internal calibration and / or verification. In another embodiment, the internal calibration and / or confirmation target includes a lens 804 (such as an aspherical lens) and includes a dispersed reflective or scattering material, such as a portion of a spectralon 806. The spectral lens 806 can be disposed at a short distance from the front and rear of the rear focusing plane of the aspherical lens 804. [ Aspheric lens 804 may be anti-reflection coated to substantially reduce the specular reflection from the lens itself.

When the internal calibration and / or confirmation target 802 is moved to the wavefront relay beam path, it can be stopped, for example, by a magnetic stopper (not shown), so that the aspherical lens 804 is centered, And coaxial with the optical axis. The SLD beam is intercepted by the aspheric lens with the minimum specular reflectivity and the SLD beam is at least somewhat focused by the aspherical lens to form on the spectral lens 806 as a light spot. Since the spectral lens is designed to be reflected and / or scattered at a high level, the light returned from the spectral lens is in the form of a divergent cone 812, which, after traveling back through the aspherical lens, .

The position of the internal calibration target, as shown in Figures 1 and 2, is somewhere between the first lens 104/204 and the polarization beam splitter 174/274, so that a slightly diverging or converging The beam is equivalent to a beam coming from a point source before and after the object plane of the first lens 104/204. In other words, the internal calibration and / or reference target generation reference wavefront is equivalent to a converging or diverging wavefront emerging from the eye under test.

In one embodiment, the actual axial position of the spectral lens for the aspherical lens is designed such that the reference wavefront is made to resemble that of an aspherical lens. In another embodiment, the actual axial location of the spectral line is designed such that the reference wavefront produced is made to resemble that of a regular or near myopia.

Although aspherical lenses are used in this application, other types of lenses, including spherical lenses or cylindrical spherical lenses or spherical tapered spherical lenses, also produce reference wavefronts with any intended wavefront aberration for calibration and / or verification . In another embodiment, the position of the spectral lens for the aspherical lens can be made continuously variable so that the internally generated wavefront has a continuous variable diopter variable to allow complete calibration of the wavefront sensor in the designed diopter measurement range .

In another embodiment, the internal calibration target may be an exposed spectral member 836. In this case, when the condition on the stop position of the spectral member 836 is moved to the wavefront relay beam path, any part of the flat spectral surface intercepts the SLD beam and assumes that the topographical features of the spectral surface are substantially equal Thereby producing substantially the same reference wavefront. In this case, the emitted beam from the exposed member of the spectralon will be the diverging beam 838.

In another embodiment, the internal calibration and / or visual confirmation target includes a structure of exposed spectral material 866, aspherical lens 854 and spectral material 856, wherein spectral devices 866 and 856 It may be a single member. The mechanism for moving the internal calibration and / or confirmation target 852 into the wavefront beam path has two stops, of which the intermediate stops need not be very repetitive and the final magnetic stop position is highly repetitive. The intermediate stop position can be used to cause the exposed spectral member to intercept the SLD beam, and a highly repetitive stop position is used to position the aspheric lens and the spectral structure so that the aspheric lens can be positioned relative to the wavefront relay beam optical axis Centered and coaxial. In this way, two reference wavefronts 864, 868 are obtained, so that the system transfer function uses an internal calibration target to check whether it behaves as designed or needs to compensate for the misalignment of the wavefront relay optical system do.

Optical relaxation means, such as a neutral density filter and / or a polarizer, are included in the internal calibration and / or confirmation target, due to differences in the amount of light returned from the spectral lens relative to the amount of light returned from the actual eye, So that it becomes almost the same as that from the actual eye. Alternatively, the thickness of the spectral lens can be suitably selected so that the desired light amount can be converted and scattered or reflected, and the transmitted light can be absorbed by the light absorbing material (shown in FIG. 8).

One embodiment of the present invention is to interface the front end processing system 710 to the position sensing detector circuit 725, the SLD driver and the control circuit 715. This can be a quadrant detector / sensor, a side effect position sensing detector, a photodiode in a small, 2D arrangement, or the like, since the position sensor detector will be multiple channels side by side to have a sufficiently high temporal frequency response. In the case of a quadrant detector / sensor or a side effect position sensing detector, there are four signal channels in parallel. The front end processing system calculates the X, Y ratio scale based on the signal amplitudes from each of the four channels (A, B, C, D) as described below. In addition to the standard case, the front end processing system automatically adjusts the gain value of the SLD output and the variable gain amplifier (independently of each channel or the entire channel) according to the user's judgment, The output values of the final amplified A, B, C, and D for all sub-wavefront image spots sequentially sampled are optimized with the optimum signal to noise ratio. The optical signal returning from the patient's eyes changes according to the refracted state (myopia, timepieces, and primordial), and also changes according to the state of operation (water congestion, anhydrous congestion, half-congestion) and degree of glaucoma in the eye.

Figures 9a and 9b illustrate an embodiment of an electronic block diagram achieving the task of digital gain control and automatic SLD indexing through a servo mechanism to optimize the signal to noise ratio, Fig. 3 shows an embodiment in the form of Fig.

Referring to FIG. 9A, a microprocessor 901 is connected to a memory unit 905 having code and data stored therein. The microprocessor 901 is connected to the SLD 911 through an SLD driver and a control circuit having a digital-analog converter 915 and is connected to the MEMS scanner 921 through a MEMS scanner driving circuit having a digital- And is connected to the PSD 931 through a composite transimpedance amplifier 933, an analog-to-digital converter 935 and a variable gain digital amplifier 937.

In this example, the PSD is a quadrant detector with four channels leading to four final boosted digital outputs (A, B, C, D), and thus only one of each is shown in Figure 9a, but four complex transimpedances There are amplifiers, four analogue digital converters and four variable gain digital amplifiers.

This will be described with reference to FIG. 9B as described in U.S. Pat. No. 7,445,335. A sequential wavefront sensor is used for wavefront sampling and a PSD quad-detector 931 with four photoreactive areas A, B, C, D is used to determine the center of the sampled sub-wavefront image spot, And is used to indicate a local slope with respect to location. If the sub-wavefront is perpendicular to the sub-wavefront focusing lens in front of the quad detector 931, the image spot 934 on the quad-detector 931 will be centered, and the four photoreactive areas will be the same The same amount of light will be received as each region generating a signal having a strength. On the other hand, if the sub-wavefront deviates from normal incidence with an oblique angle (i. E., The upper right direction), then the image spot on the quad detector will be formed farther away from the center (as shown by image spot 938) Toward the side face).

The displacement (x, y) of the center point from the center (x = 0, y = 0) can be linearly approximated by the following equation.

(One)

The denominator (A + B + C + D) is used to normalize the measurement, so that the effect of the light source intensity variation (A, B, C, D) Can be erased. Equation (1) does not exactly calculate the local slope with respect to the center point position, but is a good approximation tool. In fact, there is a need to further correct for image spot position errors that may be introduced by some mathematical algorithms and equations that employ built-in algorithms.

10, in the start step 1002, the front end microprocessor 901 preferably initially sets the SLD to the output level as much as the eye safety document requirement allows. The gain of the variable gain digital amplifier 937 at this moment may be initially set to a value determined in the final session or at an intermediate value such as is generally selected.

The next step 1004 is to check the differential gain digital amplifier final outputs (A, B, C, D). If the amplified final output of the A, B, C, and D values is found to be within the desired signal strength range, then the range may be the same for each channel, and the processing flow is such that the gain of the variable- (Step 1006). If any or all of the final output is less than the desired signal strength range, the gain may be increased as shown in step 1008 and the final output is checked as shown by step 1010. If the final output is within the desired range, the gain can be set as shown by step 1012 at a slightly higher value than the current value to overcome the induced variation of the signal change causing the final output to re- have. If the final output is less than the desired signal strength range, then the gain does not reach its maximum value as shown to be checked by step 1014, increasing the gain per step 1008 and step 1010, The final output may be repeated until the final output falls within the range and the gain is set as shown in step 1012. [ According to one possible exceptional scenario, the final output is below the desired range when the gain is increased to its maximum value as shown by step 1014. In this case, the gain is set to the maximum value as shown in step 1016 and can be processed, but the end user is notified that the wavefront signal is too weak and the data will be invalid as shown in step 1018 A statement is sent to the end user.

On the other hand, if any of the final outputs of A, B, C, and D exceeds the desired signal strength range, the gain of the variable gain digital amplifier may be reduced as shown in step 1020, As shown by < / RTI > If all of the final output is within the desired range, the gain is shown by step 1024 at a value slightly below the current value to overcome the variation introduced by the signal change that may cause the final output to deviate from the desired range As shown in FIG. If any of the final outputs exceeds the desired signal strength range, the gain has not reached the minimum value as checked in step 1026, and the gain per step 1020 is reduced and the final output per step 1022 May be repeated until the gain is set as shown by step 1024 and the final output is within range.

However, if it is checked in step 1026 that the gain has reached its minimum when at least one of the final outputs A, B, C, D exceeds the desired signal strength range. In this case, the gain is kept at the minimum value as shown in step 1028, and the SLD output is decreased as shown by step 1030. [ The final outputs A, B, C and D are checked in step 1032 after the SLD output has decreased and if the final outputs A, B, C and D are in the desired range, Is set as shown in step 1034 at a slightly lower level than the current level to overcome the variation caused in the signal change out of range. If at least one of the final outputs (A, B, C, D) exceeds the desired range and the SLD output does not reach 0 each time it checks step 1036, the SLD as shown in step 1030 The process of decreasing the output and checking the final outputs (A, B, C, D) as shown by step 1032 reaches the desired range and the SLD output is set as shown in step 1034 Can be repeated until. The only exception is that the SLD output reaches zero and at least one of the final outputs (A, B, C, D) exceeds the desired range. What this means is that there is a strong wave signal even though there is no SLD output. This can occur only when there is electronic interference or optical interference or crosstalk. The SLD output can be kept at zero as shown in step 1038 and a strong interfering signal is available to send a message to the end user that the data is invalid as shown in step 1040. [

In addition to the foregoing, optionally, the end user can manually control the gain and SLD output of the variable gain digital amplifier until the actual wavefront measurements are satisfactory.

The embodiment shown in Figs. 9A, 9B and 10 is for one of several possible methods to achieve the same purpose of improving the signal to noise ratio, which should be considered to represent such a concept. For example, at the beginning, it is never necessary to set the SLD output as much as possible for each eye safety condition. The SLD output is initially set to any level and adjusted with the amplifier gain until the final output (A, B, C, D) is in the desired range. The advantage of initially setting the SLD output to a relatively high level is that the signal ratio to the optical system, photonic domain, and noise is maximized prior to photoelectric conversion. However, this does not mean that other options do not work. In practice, the SLD output is initially set to zero and gradually increases with the adjustment of the amplifier gain until the final output (A, B, C, D) falls within the desired range. In this case, there is a corresponding change in sequence and flow details. These changes fall within the scope and spirit of the invention.

Another embodiment of the present invention uses a composite transimpedance amplifier to amplify the position signals of the sequential ocular and wavefront sensors. Figure 11 illustrates an example of a composite transimpedance amplifier that may be used to amplify a signal from any one quadrant (e.g., D1) of four quadrant photodiodes of a quadrant detector. The circuit is used in a position sensing detector circuit as shown in Fig. 9A. In a composite transimpedance amplifier, the current-to-voltage conversion ratio is determined by the value of the feedback resistor Rl (which may be, for example, 22 megohms) and is applied to resistor R2 to balance the input of op- ≪ / RTI > The decoupling capacitors C1 and C2 may be auxiliary capacitors of the resistors R1 and R2 or may be small capacitors added to the feedback loop. The durability and high frequency noise reduction of the transimpedance amplifier is determined by the resistance R3 of the feedback loop 1150, , The capacitor C3 and the op-amp U2A. In this circuit, + Vref becomes a positive reference voltage between ground and + Vcc. The output signal (output A) is proportional to R1, but the noise is proportional to the square root of R1, so that the noise-relative signal increases in proportion to the square root of R1 (because it is dominated by the ringing noise of R1 ).

Conventional high-bandwidth waved-surface sensors use standard transimpedance amplifiers rather than complex transimpedance amplifiers (see, for example, S. Avado et al., "2D High Bandwidth Hartmann Wavefront Sensor: Design Guidelines and Evaluation Tests ", Optical Engineering, 49 (6), 064403, June 2010). In addition, conventional wavefront sensors are not simply sequential but are parallel in one direction or the other. Also, although the same weakness is not encountered, the current sequential eye and the wavefront sensor are synchronized with the optical signal changes and pulsed. The described complex transimpedance amplifier applied to the amplification of optical signals in a sequential ophthalmic and wavefront sensor when combined in one direction or in another direction comprises the following configuration. (1) In order to improve the current-to-mating conversion accuracy, the selected feedback resistance value R1 that is substantially matched by the resistor R2 is very high. (2) The two decoupling capacitors (C1, C2) have very low capacitor values in order to reduce the noise contribution from the large resistance values (R1, R2) while maintaining the proper signal band position. (3) The low pass filter formed by R3, C3, U2A in the feedback loop substantially increases the stability and substantially reduces the high frequency noise of the transimpedance amplifier. (4) To achieve lock-in detection, the positive reference voltage (+ Vref) is locked in the DC signal phase-scaled appropriately for the drive signal of the SLD and the MEMS scanner, which is between ground and + Vcc. Also, in order to achieve an optimum signal to noise ratio, a quadrant sensor with minimum terminal capacitance is preferred, in order to avoid decentral conduction between any two of the four quadrants, good channel isolation between quadrants Is preferred.

In addition to the circuit described above, the optical signal converted to an analog current signal by the position sensing detector can be AC-coupled and amplified by a common transimpedance amplifier, which is otherwise unknown It is coupled with a standard lock-in detection circuit to recover a small signal. Fig. 12 shows an example of such a combination. The output signal from the transimpedance amplifier 1295 is mixed in the mixer 1296 with the output of the phase-locked loop 1297 (i.e., doubled) locked to the reference signal driving and pulsing SLD. The output of the mixer 1296 is passed through a low-pass filter 1298 to remove the summed frequency of the picked-up signal, and a time-constant low-pass filter is selected to reduce the uniform noise bandwith. The low pass filtered signal is further amplified by another amplifier 1299 for analog to digital conversion (AD conversion) where the signal path is further subtracted.

An alternative to the aforementioned lock-in detection is that the A / D conversion is activated just before the SLD is investigated to record the 'cancer' level and the A / D conversion is performed immediately before the SLD is investigated to record the ' . The difference is calculated to eliminate interference effects. Another embodiment is to operate the A / D conversion just before the SLD records or investigates the 'person' level, ignoring the cancer level when the interference effect is minimized.

In addition to the optical signal detection circuitry, the next critical electronic control element is a wavefront scanner / shifter. In one embodiment, the wavefront scanner / shifter is an electromagnetic MEMS (micro-electro-mechanical system) analog steering mirror driven by four D / A converters controlled by a microprocessor. In one embodiment, the two channels of the D / A converter are phase shifted by 90 degrees to the output sinusoid, while the other two channel output (X, Y) dc-offset voltages adjust the center of the wavefront sampled annular ring . The amplitude of the sinusoidal and cosine wavefronts can be varied by varying the amplitude of the wavefront sampled annular ring, which can be varied to accommodate various eye pupil diameters, as well as to carefully sample around one or more annular rings of the desired diameter wavefront within the military pupil region, Diameter. The slenderness ratio of the X, Y amplitude can be controlled to ensure that circular scanning is done when the mirror reflects the wavefront beam side.

Figures 13a-13f show how a wavefront synchronizes a MEMS scanner as sampled by multiple detectors arranged in a ring and the SLD pulses exhibit the same result.

13A, the MEMS 1312 is oriented such that the entire wavefront is shifted downward when the SLD pulse is initiated. In this case, the aperture 1332 samples a portion at the top of the circular wavefront section.

In Figure 13b, the wavefront is shifted down so that the aperture samples a portion from the right side of the circular wavefront section, in Figure 13c the wavefront is shifted upward, sampling a portion at the bottom of the circular wavefront section, , The wavefront is shifted to the right and a portion of the circular wavefront section is sampled from the left side.

FIG. 13E shows an equivalent structure for sequentially scanning the order of four pulses for each cycle to sample the wavefront section with four detectors arranged in a ring shape.

In another embodiment, the SLD may be synchronized with a MEMS scanner, and eight SLD pulses are initiated so that the eight sub-wavefronts are sampled at each MEMS scan rotation and each wavefront sampling annular ring rotation. SLD pulse initiation proceeds in time so that four odd or even pulses of the eight pulses are aligned on the X and Y axes of the MEMS scanner and the other four pulses are centered on the ring between the X and Y axes . 13F shows the result of the pattern of the MEMS scan rotation and the SLD start position thereon. The number of SLD pulses is not limited to 8 and may be any number, the SLD pulses need not be evenly spaced over time and need not be aligned with the X, Y axis of the MEMS scanner.

As an optional example, a portion of the wavefront to be sampled may be selected, for example, by varying the pulse number and / or the relative timing of the SLD initiation to the drive signal of the MEMS scanner, Shifting the wavefront sampling location along the sampling annular ring. Fig. 14 shows an example in which eight wavefront sampling positions are shifted by 15 degrees from that shown in Fig. 13F by slightly delaying the SLD pulses.

In another alternative example, if the wavefront is sampled at an offset angle of 0 degrees on the first frame, sampled at an angle of 15 degrees in the second frame, sampled at an angle of 30 degrees on the third frame, and repeating this pattern, It is possible to sample the wavefront with an increased spatial resolution when the data from the wavefront is collected and processed. Figure 15 shows this pattern. A gradual increase between frames at the initial start time of the SLD can be performed in a desired manner with substantial timing accuracy to achieve any desired spatial resolution along any annular wavefront sampling ring. In addition, it is possible to sample different annular rings of different diameters by combining variations in the amplitude of the driving signals of the sinusoidal and co-sinusoidal curves of the MEMS scanner. In this way, sequential sampling of the entire wavefront can be achieved with the desired spatial resolution at the radial and angular magnitudes of the polar coordinate system. This is an example of a variety of possible sequential wavefront scanning / sampling designs. For example, a similar approach can be applied in the case of raster scanning.

9B, the known standard ratio scale equation, in relation to interpolating the center positions of the sequentially sequentially sampled sub-wavefront image spots on the position sensing device / detector PSD, And the old XY axis is aligned and oriented on that of the MEMS scanner, although they are not absolutely required, they have the same X, Y axis. For example, in the case of a quadrant detector, the ratio scale X, Y values of sequentially sampled sub-wavefront image spots may be expressed as follows based on the signal strengths from each of the four quadrants (A, B, C, D) .

X = (A + B C D) / (A + B + C + D)

Y = (A + D B C) / (A + B + C + D)

In general, such a ratio scale value of X, Y does not directly give a very accurate transverse displacement or center position because, for example, the response of a quadrant detector is a function of the gap distance and the size of the image spot is local Local deviations / convergences of the average slope and the sampled sub-wavefront, and the sub-wave surface sampled aperture shape and size. One embodiment of the present invention is to modify this relationship or equation so that the sampled sub-wavefront tilt can be determined more accurately.

In one embodiment, the relationship between the ratio scale measurement result and the actual center displacement is determined theoretically and / or experimentally, and the expression related to the ratio scale is modified to more accurately reflect the center position. Figure 16 shows an example of the theoretically determined relationship between the position and the ratio scale estimate, which is the actual center displacement along the X, Y axis.

Due to this nonlinearity, the anticipation of the effect can be applied to the original equation, which appears as a modified relationship between the ratio scale (X, Y) and the actual center position (X ', Y'). Below is an example of this inverse relationship.

Here, PrimeA and PrimeB are constants.

The relationships or equations shown above are exemplary and are not intended to limit the various approaches that can be used to achieve the same purpose. Indeed, the above correction is for the center position of the sampled sub-wavefront of any intensity profile when the image spot is displaced along the X, Y axis. If the image spot is displaced in the X, Y direction, further correction is required, especially if high precision measurement is required. In one embodiment, a substantially determined relationship of the form of the data matrix between the quadrant detector reported ratio scale and the actual center position (X ', Y') to be expressed in relation to (X, Y) , The inverse relationship can be set to transform each (X, Y) data point into a new (X ', Y') data point at the center.

17 is an exemplary block diagram illustrating how calibration is performed to derive a modified relationship and to be made to be a more accurate wavefront aberration measurement. In step 1705, the wavefront can be generated from the wave model using a variety of means from a wavefront manipulator, such as a deformable mirror, which produces different wavefronts, such as with different diffraction and convergence or with different wavefront aberrations have. In a second step 1710, the actual center position (X ', Y') of the differently sampled sub-wavefronts is determined experimentally to obtain the relationship between (X ', Y') and (X, Y) (X, Y). However, a diopter value is obtained for the calibrated wavefront tilt and hence the center data point location. In a third step 1715, the measurements are made with real eyes, and the obtained relationship can be used to determine the sampled sub-wavefront from the center position and hence the real eye. In a fourth step 1720, the determined center position or slope of the sampled sub-wavefront can be used to determine wavefront aberration or refractive errors of the actual eye.

The first and second calibration related steps may be performed once for each formed wavefront sensor system and the third and fourth steps may be repeated for a plurality of actual eye measurements as in one case. However, this does not mean that the calibration step is performed only once. In practice, it is desirable to repeat the calibration step periodically.

In one embodiment of the invention, the calibration step or partial calibration step may be repeated as often as desired by the manufacturer or end user using an internal calibration target driven by a microprocessor as shown in Figure 9A. For example, the internal calibration target may be temporarily moved to the optical wavefront relay beam path each time, and the system may be configured such that each actual eye measurement is automatically or manually performed as desired by the end user, do. The internal calibration need not provide all the data points to a level that can be provided by a more universal calibration. Instead, the internal calibration target needs to provide several data points. With these data points, it can be empirically verified whether the optical alignment of the wavefront sensor is intact or if environmental factors such as temperature changes and / or mechanical impacts interfere with the optical alignment of the wavefront sensor. Thus, it can be verified whether a completely new universal calibration needs to be performed or whether a slight minor software-based calibration is sufficient for accurate real eye measurement. Optionally, the measured reference wavefront aberration using the internal calibration target allows to grasp the inherent optical system aberration of the wavefront sensor optical system, and the actual eye wavefront aberration eliminates the optical system wavefront aberration derived from the measured total wavefront aberration ≪ / RTI >

In another embodiment of the present invention, the calibration target (internal or external) may determine an offset angle between the SLD start pulse and the MEMS mirror scanning position between the initial time delay or sub-wavefront sampling position and the MEMS mirror scanning position along any wave- . The same calibration step may be used to determine if the SLD start time is sufficiently accurate for the MEMS scan mirror position and any differences from any desired precision, and electronic hardware based calibration or pure software based calibration may be performed at SLD start time or MEMS scanning Can be performed to fine tune the drive signal.

In another embodiment of the present invention, if the calibration (internal or external) detects that the optical alignment is off, or if the eye is not located at the optimal position but the wavefront measurement can be done by software calibration , Such a software-based adjustment may be performed for supply to the misalignment as described with reference to FIG.

In another embodiment of the invention, if eight sub-wavefronts are sampled around the annular ring of the wavefront generated from the calibration target or the actual eye, for example, the PSD yellowing shift or the patient's eyes X '(i), Y' i, i)), where i = 0, 1, 2, ..., 7, and (X ', Y The translation of the Cartesian coordinates is done so that the eight data points are given by the new Cartesian coordinates Xtr, Ytr and represented by the set of data points Xtr (i), Ytr (i), where i = 0, 1, 2, ..., 7, and the cluster center of the center data point is aligned at the new origin (Xtr = 0, Ytr = 0). In this manner, any effect induced in the shape of the entire prism wavefront tilt to appear, for example, from the misalignment between the sub-wavefront sampling aperture and the position sensing detector / device, is filtered out of the measured wavefront. As a result, the remainder of the data processing can be used to identify refractive errors and / or high aberrations of the wavefront.

The sequential wavefront sampling has the inherent advantage that it can relate to sampling on the annular ring for each individually sampled displacement of the subpopulated center position.

As described above, the displacement of the center of the sampled wavefront portion is determined using the rate scales X, Y calculated from the output signal produced by the PSD. The position of this output value forms a position pattern that can be analyzed by a front end or posterior end electronic processing system that determines the ophthalmic characteristics of the subject's eye. The formation and analysis of this pattern is shown in Figure 9c. In Figure 9c, the displacement is depicted as being displayed or monitored. However, in other embodiments, such displacements are handled by the algorithms run as software by the front end processing system and are not necessarily visible to the user.

9C shows a number of representative examples of sequential shifts of the corresponding center positions when displayed as a 2D data point pattern on a monitor, an associated image spot position on a quadrant detector behind a subfluorescent focus lens, a plane wavefront, defocus, astigmatism, do. Instead of the figure, a number of shifted wavefronts are sampled and projected as different sub-wavefronts onto the same sub-wavefront focus lens and quad detector, and are equivalent to those described above with reference to Figures 13a-e, The wavefronts are shown around the same annular ring, so that multiple quad-detectors are shown around the same annular ring to indicate the case of scanning different portions of the wavefront for a single sub-wavefront focus lens and a single quad detector.

Consider starting to scan around the wavefront yellow ring from the upper sub-wavefront and moving clockwise with respect to the second sub-wavefront as shown by the arrow 9009 on the right-hand side. 9C, all of the sub-wavefronts (e.g., 9002) form an image spot 9003 at the center of the quad-detector 9004 so that the monitor 9006, when the wavefront is a planar wave 9001, The center locus 9005 on the xy coordinate system always exists at the origin of the xy coordinate system.

When the input wavefront is diverged as shown at 9011, the center of the image spot 9013 of each sub-wavefront 9012 is shifted radially outward from the wavefront center by the same amount deviating from the center of the quad- And as a result the locus 9015 on the monitor 9016 becomes a clockwise circle as indicated by the arrow 9018 starting from the upper position 9017. On the other hand, if the input wavefront converges as shown at 9021, the center of the image spot 9023 of each sub-wavefront 9022 is positioned radially inward relative to the center of the wavefront with the same amount deviating from the center of the quad detector 9024 do. As a result, the center locus 9025 on the monitor 9026 is circular but starts from the bottom position 9027 and clockwise as indicated by the arrow 9028. If a sinusoidal change is detected for the X-axis center position and the y-axis center position, the change indicates that the input wavefront changes from the diverging beam to the converging beam or its surroundings. Further, the starting point of the center locus can be used as a reference indicating whether or not the input wavefront diverges or converges.

Referring to FIG. 9C, when the input wavefront is astigmatism, the wavefront diverges in the vertical direction as shown by 9031a and converges in the horizontal direction as shown by 9031b. As a result, the center position of the vertical sub-wave surface 9033a is arranged radially outward with respect to the center of the input wave front, and the center position of the horizontal sub-wave surface 9033b is arranged radially inward with respect to the center of the input wave front. As a result, the center locus 9035 on the monitor 9036 is moved in the counterclockwise direction indicated by the arrow 9038 starting from the upper position 9037, and the center locus rotation is again reversed.

It is not difficult to understand whether the input wavefront is astigmatism or converging on the subdividing plane as a whole or on the whole, and the rotation of the center locus will be clockwise (not reversed), but in astigmatism, The trajectory of the astigmatism becomes an ellipse rather than a circle because the sub-wavefront along one axis of astigmatism becomes more divergent or convergent than that along the other axis.

In the case of the more general astigmatic wavefront, the central trajectory is rotated in a reverse direction with a circular or elliptical trajectory, or the central trajectory is rotated in a general clockwise direction, although the trajectory becomes elliptical. The axis of the ellipse lies in a radial direction with respect to the center, with the center representing the astigmatism axis. In this case, the four sub-wavefronts around the yellow ring are not sufficient to accurately determine the astigmatic axis and more sub-wavefronts (8, 16, 32 instead of 4).

In summary, in the case of converging spherical wavefront divergent wavefronts from the human eye, the sequentially sampled sub-wavefronts around the annular ring of the eye pupil will appear as sequential center data points located around the circle, Depending on whether the wavefront is divergent or convergent, it is formed at different positions. In other words, for example, in the case of divergence, if any data point (for example i = 0) is in any position (e.g. Xtr (0), Ytr (0)) = (0, 0.5) If expected, it is expected that for the same spherical radius but converging wavefront with different sign, the same data point will be placed in the opposite position (for example (Xtr (0), Ytr (0)) = (0, -0.5) On the other hand, if the original wavefront has spherical and cylindrical elements, then the center data points will track ellipses, which can be normal rotation ellipses, straight lines, unusual or reverse ovals, abnormal or counter-rotating circles. U.S. Patent No. 7445335 and U.S. Patent No. 8100530, all of which are incorporated herein by reference.

One embodiment of the present invention uses the positive and negative values of the main and minor axes to describe the center data point as an even ellipse. For example, a full divergence wavefront is defined as having a positive major axis and minor axis, and a statically converging wavefront is defined as producing a negative major axis and minor axis.

18 shows a graph of a sequential ellipse using a trigonometric function, where U (t) = a · cos (t), V (t) = b · sin Is the radius of the source circle. Where a> b> 0, a and b are positive values, and the ellipse rotates counterclockwise. Thus, the elliptic points represent the sequentially calculated center displacements of the entire divergent wavefront with divergent and cylindrical oblique angular error elements with different degrees of divergence in the horizontal and vertical directions. If a = b, the ellipse shows the same divergent spherical wavefront in the horizontal and vertical directions. If the value of t0 is 0 < t0 < / 2, the point (U (t0), V (t0)) is placed in the first quadrant of the U-V cartesian coordinate system.

In the embodiment of FIG. 18 and FIGS. 19, 20 and 21, it can be assumed that the catheter coordinate axes U and V are aligned with the quadrant detector axes x and y, and the astigmatism axes follow the x and y axes Can be assumed. Therefore, the ellipses shown in Figs. 18 to 21 are vertically oriented in the horizontal direction.

If both the main and minor axes are negative values, they can be expressed as a, -b. 19, the corresponding sequential ellipses are U (t) = -a cos (t), V (t) = -b sin b is expressed as a negative value. As a result, the ellipse rotates counterclockwise. It can be seen that the convergence shows a totally converging wavefront with different spherical and cylindrical refractive error elements in horizontal and vertical directions. If a = b, it represents a spherical wave front which accepts the same convergence in both horizontal and vertical directions. The point U (t0), V (t0)) is placed in the third quadrant of the U-V Cartesian coordinate on the opposite side with respect to the origin of the coordinate system as compared to Fig. 18, if t0 is 0 &lt; t0 &lt;

If the main axis is a positive value and the minor axis is a negative value, then these can be expressed as a, -b. 20, a corresponding sequential ellipse is U (t) = a · cos (t), V (t) = -b · sin (t), a> b> 0, , and -b is expressed as a negative value. As a result, the ellipse starts from the fourth quadrant and rotates clockwise. It can be seen that the divergence shows horizontal diffuse wavefronts and vertical convergence wavefronts with different spherical and cylindrical refractive error elements in horizontal and vertical directions. If a = b, it represents a cylindrical wavefront with horizontal diffusivity and vertical convergence equal, diverging horizontally and converging vertically. If the value of t0 is 0 < t0 < / 2, the point (U (t0), V (t0)) is placed in the fourth quadrant of the U-V Cartesian coordinate.

If the main axis is a negative value and the minor axis is a positive value, then these can be expressed as a, b. 21, the corresponding sequential ellipses are U (t) = -a cos (t), V (t) = b sin (t), a> b> 0, And b is a positive value. As a result, the ellipse is rotated clockwise starting from the second quadrant. It can be seen that the horizontal convergence and the vertical divergence have spherical and cylindrical buckling error elements that converge horizontally and diverge vertically. If a = b, it exhibits a cylindrical wavefront with horizontal convergence and vertical divergence equal, converging horizontally and diverging vertically. The point U (t0), V (t0)) is placed in the second quadrant of the U-V Cartesian coordinate on the opposite side with respect to the origin of the coordinate system as compared to Fig. 20 if the value of t0 is 0 < t0 <

The axis of the positive and the axis of the negative are given to the divergent wavefront, which is arbitrary and can be reversed if it can be distinguished. The positive direction of the axis can be changed. For example, the U axis can point to the upper side instead of the right side, and the V axis can point to the right side instead of the upper side. In this case, as shown in Fig. 22, the sequential center data points expected from the diverging spherical wavefront sampled in the plane indicated by the dashed line become clockwise circles, indicating the data point position and polarity indicated by numerals and arrows in Fig. do. The sequential rotation direction can be changed in comparison with Fig. 18 due to the different polarity of the axes. Similarly, in the same case, the expected sequential center data points from the converging spherical wavefront sampled in the plane represented by the dashed line shown in Fig. 23 become clockwise circles, resulting in a number Data point location and polarity. When the sampled wavefront is changed from diverging to converging, a numerically assigned data point from the original position in Fig. 22 can be replaced with the opposite position in Fig.

One embodiment of the present invention uses calibration (internal or external) to determine the initial offset angle of the data point vector with respect to the Xtr axis or the Ytr axis. Another embodiment of the present invention rotates the catheter coordinate system (Xtr, Ytr) to another Cartesian coordinate system (U, V) by the offset angle, wherein at least one of the calibration center data points, for example, i = 0 And the data points (U (0), V (0)) are aligned on the U, V axis of the new catheter coordinate system UV. In this way, the measured sub-wavefront gradient is expressed as (U (i), V (i)), i = 0, 1, 2, ..., 7, Aligned and averaged to an ellipse if present on the associated ellipse, the ellipse parameter being connected to the spherical and cylindrical diopter values of the sampled wavefront, and the major axis and minor axis directions being associated with the cylindrical axis of the sampled wavefront.

Figure 24 shows the Cartesian coordinate translational and rotational motion further translated into a U-V coordinate system of eight sequential sampled center data points translated from the original X-Y coordinate system to a translational Xtr-Ytr and fitted to a sequential ellipse. In the total divergent wavefront and the illustrated coordinate axis selection, the sequential rotation direction is clockwise. In this example, the centers of eight sequentially obtained data points are determined first, and the X-Y coordinate system is translated to the Xtr-Ytr coordinate system, where the origin of the Xtr-Ytr coordinate system is the eight sequentially obtained data points. The principal and minor axes of the fitted ellipses (corresponding axial polarity have already been described) are obtained by digital data processing, and the coordinate system rotation is obtained by interpolating the principal axes or minor axes of the fitted ellipse in the U coordinate system of the UV coordinate system having the same origin as the Xtr- V axis. In this embodiment, the first data point (point 0) is already aligned on the U axis or positioned on the axis. In a more general case this may not be the case. However, if the alignment of the first data point (point 0) with the U axis is helpful for data processing, the start time of the SLD for the drive signal of the MEMS scanner can be adjusted to enable such alignment, Phase delay can be used to simplify data processing.

The example of a wavefront sampling described in this application for an annular ring, coordinate system transformation and related data processing has the advantage that the spherical-cylindrical diopter value is analytically determined as a function of the (U (i), V (i) And in this case, the data processing is simple and can be done very quickly. In other words, the data point (U (i), V (i)) is becomes aligned to facilitate the ellipse in the standard position (centered at the origin, the main axis along U axis), U (t) = a cos (t), V ( t) = b sin (t), where a and b denote the major and minor axes, respectively, and have a positive or negative value.

This algorithm makes it possible to measure the eye wavefront in real time with high precision in a large dynamic range. When the U and V axes are rotated to fit the ellipse to the standard position, the direction of the ellipse indicates the astigmatism axis. Also, the sum of a and b represents the relative sum of divergent and converging astigmatic components, and the direction of rotation helps to identify which components are divergent and which components converge. As a result, a real-time dose of the surgical correction procedure can be performed. In particular, real-time wavefront measurement results can be used to orient, align, and guide surgery for limbal relaxation incision (LRI), and / or astigmatic keratotomy (AK) and IOL (ophthalmic lens) rotation.

Fig. 25 is a special case of Fig. 24 showing eight coordinate data points on the coordinate system rotation transformation and the UV coordinate system, where the left hand side corresponds to a spherical wavefront with divergent spherical waves having the same positive major axis and minor axis, And corresponds to a converging spherical wavefront having negative major axis and minor axis. By converging from diverging, the numbered data points from the original position to the opposite position can be replaced when the sampling wavefront changes.

When there are superimposed astigmatism components on the spherical component, a number of center data point trajectory scenarios are generated according to the degree of astigmatism wavefront inclination compared to spherical wavefront inclinations as described in commonly assigned U.S. Patents 7445335 and 8100530 . By transforming the catheter coordinate system as described above, the center data point is traced to the origin of the UV coordinate system with one of the data points aligned to the U or V axis but with different elliptical shapes and orientations can do. All shapes of the pattern include a normal rotating ellipse having a positive major axis and a positive minor axis, and a straight line having a positive or negative major axis or a positive or negative minor axis, a negative major axis and a positive minor axis or positive minor axis An unsteady or counter-rotating ellipse having a minor axis, a positive major axis and negative minor axis, or a negative major axis and a positive minor axis.

It is possible to distinguish three different circular trajectory patterns (a spherical circle that emits, a spherical circle that converges, and an inverse circle of astigmatism) from each other in the case of a circular trajectory because the axial polarity Because the wavefront samples are determined by the order in which they are collected. In practice, the astigmatic reversal circle is effectively coupled to the ellipse because one axis (major axis or minor axis) has a different sign and polarity than the other axis (minor axis or major axis). The direction of the ellipse, or a straight or reverse rotation circle, can be determined from the major axis or minor axis direction and lies at an angle of 0 to 180 degrees as accepted by the optician or ophthalmologist. The assignment of the main axis and / or minor axis is arbitrary so that the absolute length of the main axis need not be longer than the length of the minor axis. This provision only has the meaning of facilitating the calculation of the refractive error associated with the wavefront from the eye.

In addition to sampling the wavefronts around one annular ring, multi-centered rings of wavefronts or multiple annular rings of different diameters can be sampled. By doing so, a 2D wavefront map is obtained and displayed to the end user. By changing the sampling size of the annular ring of the wavefront sensor dynamically, it is possible to confirm the condition of the anhydrous state of the object through the whole corneal time system.

In another embodiment, the MEMS scanning mirror can be operated to sample the sub-wavefront in a concentric ring or spiral pattern of varying radii, through which a high order of aberration can be detected. Zernike decomposition can be performed to extract wavefront aberration coefficients including high order aberrations such as trefoil, coma, and spherical aberration. For example, a coma can be determined by detecting a lateral shift of the wavefront as the scan radius increases or decreases. The number of samples per annular ring is uniformly divided by three and the trefoils can be detected when the scan radius increases or decreases when the dots form an inverted triangular pattern.

Effective spacing between any two wavefront sampling points can be controlled by controlling the drive signal amplitude and SLD start time of the MEMS scan mirror. If the aperture is electrically variable in addition to reducing the size of the sub-wavefront sampling aperture by the front end processing system, high spatial precision / resolution sampling of the wavefront can precisely control the SLD start time, reduce the SLD pulse width, This is achieved by increasing the precision in the control of the scan mirror amplitude or position. In this regard, the MEMS scan mirror operates in a closed loop servo mode by feeding back the MEMS mirror scan angle monitor signal to an electronic control system and / or microprocessor that controls the scan angle drive signal to achieve better scan angle control accuracy do. On the other hand, more advantageous can be achieved by increasing the sub-wavefront sampling aperture or by increasing the pulse width of the SLD. Thus, another embodiment of the present invention uses an electronic device that controls the wavefront shifter / scanner and the SLD to achieve higher precision / resolution in spatial wavefront sampling or more averaging in spatial wavefront sampling. Spatial wavefront sampling with high precision / resolution is required for high order aberration measurements, and more averaged spatial wavefront sampling is needed to measure wavefront refraction errors for cylindrical axis or astigmatic axis and spherical and cylindrical diopter values.

The catheter coordinate system translational and rotational motion described above is one of many various coordinate system transformations that can be employed to facilitate computation of refraction errors and wavefront aberrations. For example, non-catecentric coordinate systems such as polar or non-vertical axis-based coordinate transformations may be used. Thus, the range of concepts using coordinate system transformations to facilitate wavefront aberration and refractive error calculations should not be limited to the catheter coordinate system. This conversion is also possible between the catheter coordinate system and the polar coordinate system.

In practice, the wavefront from the patient's eye may have a higher order aberration in addition to spherical and cylindrical refractive errors. However, in most vision correction procedures, such as glaucoma refractive surgery, only spherical and cylindrical refractive errors are corrected. Thus, with a request for averaging, the best spherical and cylindrical corrected diopter values and cylinder axis angles can be found and processed. The present invention is particularly suitable for this application by associating and averaging the center locus to one or more ellipses for one or more annular rings with the principal axis and minor axis polarity considered when linking the center data points to the ellipse, The resultant solution given in relation to the cylindrical axis with the value already includes averaging the effect of the higher order aberrations. Algorithm and data processing, on the other hand, tells the end user how high a level aberrations are in the wavefront by calculating how closely the center data points are linked to the ellipse to the end user.

Fig. 26 is a process flow diagram of one embodiment when decoating spherical and cylindrical diopter values and cylindrical axis angles. Fig. (2605) moving the internal calibration target to the wavefront relay path to calibrate the system and obtain an offset angle, obtaining (2610) a relationship between the SLD pulse delay and offset angle values, determining an internal calibration target from the wavefront relay beam path The step of calibrating including the step of moving 2615 may be performed once for any number of real-time eye measurements, such as once for each eye measurement, as once, or once for any number of times as previously described.

Once the offset angle information is obtained, there is an optional step 2620 that alters or adjusts the offset angle obtained by varying the initial phase of the sine and cosine drive signals sent to the SLD pulse delay or MEMS scan mirror. For example, with a spherical reference wavefront, the offset angle can be adjusted such that one of the center data points is aligned on the X or Y axis, in which case there is no need to perform additional coordinate system rotation transformation. This reduces the burden on data processing.

At the next step 2625, the center data point position is calculated from the ratio accumulation (X, Y) values, modified center position values (X ', Y' Can be calculated as the center position value (Xtr, Ytr). The next step 2630 involves the coordinate system rotation transformation from (Xtr, Ytr) to (U, V) so that if the SLD pulse delay is to be controlled for the MEMS mirror scan, one of the center data points is the Xtr axis or Ytr It is already on the axis.

In the next step 2635, which determines whether the wavefront is spherical, all or part of the center data point vector for a different (Xtr = 0, Ytr = 0) or (U = 0, V = 0) ) Can be compared with each other. For example, when all vector integrations or standard deviations of lengths are less than a predetermined reference value (e.g., a value less than a corresponding 0.25D cylinder), the wavefront can be treated as spherical. Alternatively, the vector sums of some or all of the data point vectors may be compared, and the sum may be substantially the same and the difference may be less than the predetermined reference value so that the wavefront may be determined to be spherical.

In the case of a spherical wavefront, a data point may be associated with an ellipse in addition to calculating a substantially equivalent principal axis length and minor axis length as a subsequent step 2640, as shown in Fig. 26, The major axis and minor axis lengths can be averaged according to the sign and polarity of the main and minor axes, the average positive or negative spherical diopter value output. The relationship between the diopter value and the major axis or minor axis length can be obtained or obtained during the universal calibration step as described above.

An optional subsequent step 2645 represents a spherical diopter value quantitatively computed as a numerical value and / or a spherical diopter value computed qualitatively as a circle, wherein the circle diameter or radius represents an absolute spherical diopter value, Color, or line pattern for a circle.

On the other hand, if the wavefront is not spherical, it can be expected that astigmatic components are present. In a subsequent step 2650, the data points may be associated with the ellipse, and the principal axis length and minor axis length with polarity may be calculated if the value is positive or negative and if the elliptical angle is the major axis angle or the minor axis angle. By calculating the elliptical angles, major axis and minor axis length, it is possible to calculate the spherical and cylindrical diopter values using the experimentally obtained calibration relationship or reference table. It is desirable that there is only a unique method for any ellipse in which the diopter value is constant with respect to the principal axis length and minor axis length (including polarity or sign information). As in the case of spherical wavefronts, the optional subsequent step 2655 qualitatively represents the spherical and cylindrical diopter values and numbers as a set of numbers qualitatively as cylindrical axes and / or circles and straight lines, wherein the circle diameter represents the spherical diopter value , The straight line length indicates the cylindrical diopter value, and the linear angle, which is long, thin, dashed, or an arrow, indicates the cylindrical axis angle. Alternatively, the qualitative indicia may be in the form of an ellipse, wherein the major axis and minor axis lengths denote spherical diopter values, and the difference between the major axis and minor axis lengths (taking into account the polarity) represents the cylindrical diopter value and the direction angle of the ellipse represents the cylindrical axis angle . The sign of the spherical and cylindrical diopter values can be shown, for example, using different line patterns or different colors for the circle and straight line representations or for the elliptic representations. One embodiment of the invention allows the user to select a circle and a straight line or an ellipse to indicate the refractive error of the patient's eye.

There are many other ways to qualitatively indicate refraction errors. The foregoing qualitative indications are merely illustrative, not universal. For example, such an indication may be an ellipse whose principal axis is proportional to one independent cylindrical diopter value and whose minor axis is proportional to another independent vertical cylindrical diopter value. Also, the axis angle represents one cylinder, and the other circle angle may be the original angle or the angle shifted by 90 degrees. The cylinder axis angle may be the main axis angle or the minor axis angle depending on whether the end user prefers a positive or negative cylindrical condition That is because it is. Optionally, the indicia can be two vertical straight lengths of one vertical length proportional to one independent vertical vertical cylindrical diopter value and one linear length proportional to one independent cylindrical dioptric value.

As described above, one embodiment of the present invention is for overlapping on a real-time video image of a patient's eye, of a wavefront measurement in a qualitative or quantitative manner. The displayed ellipse or straight line will depend on the direction of the medical staff relative to the patient's eye (excellent or temporary), and if it is temporary, the patient's eye will be displayed on the right or left side. In glaucoma surgery, the axis of the cylinder in glaucoma surgery is aligned to the abrupt axis of the cornea, so that medical personnel are preferred to undergo LRI (soft tissue dissection) based on the indicated axial direction.

The real-time eye image may be processed with a pattern recognition algorithm to determine the axis of the implanted toric IOL associated with the iris representation, such as secret or to achieve registration of the eye with respect to the patient's lying position or vertical position. In addition, the real-time image can also be used to register a particular lens (natural or artificial) for alignment and / or to record an optical signal (e.g., from a wavefront and / or OLCI / OCT measurement) Can be used to confirm the comparison.

Conversion from the elliptical major axis and minor axis length associated with the diopter value can be done in a variety of ways depending on the end user's preference. As is known to those of ordinary skill in the art, there are three ways of representing the same refractive error condition. The first one is represented as two independent vertical cylinders, the second one as spherical and positive cylinders, and the third one as spherical and negative cylinders. In addition, these indications are for conditions or actual wavefronts. Associated ellipses actually provide two independent vertical cylindrical diopter values directly. With regard to the conversion from one indication to another, this is known to the ordinarily skilled artisan. It should be emphasized that one embodiment of the present invention utilizes positive and negative values representing the major and minor axes of the associated ellipses and uses two independent and vertical cylindrical diopters The calibration method that associates the spindle length with the minor axis length is used for the value.

Opticians, ophthalmologists, and ophthalmologists use a variety of methods to present the same wavefront to the cornea or pupil plane of the patient's eye. For example, it is common for opticians to favor the display of conditions, which is a lens used to remove curved wavefronts to make them flat or flat, and the ophthalmologist has a spherical and cylindrical diopter value, I prefer a direct indication of what is to be a wavefront at. Optical engineers, on the other hand, use a wavefront map that uses a Zernike polynomial coefficient without a diopter value, or a 2D error of the actual wavefront from a perfectly flat or planar wavefront. The embodiment of the present invention is for the mutual conversion between different displays that can be done by the end user since the algorithm is installed in the device for this transformation, which depends on the choice of the format for this display.

In connection with further enhancing the signal to noise ratio and improving measurement accuracy and / or accuracy, the association of an ellipse or a circle with a straight line is determined by one frame (or set) of data points or multiple frames (or sets) Lt; / RTI &gt; Alternatively, the obtained spherical and cylindrical diopter values and cylindrical axis angles are averaged through multiple captures. For example, the average can be easily achieved by adding a given number of spheres and cylindrical diopter values of multiple measurements, respectively, and dividing the number given. Similarly, the cylindrical angle can be averaged even though it may be more related because of a wrap-around problem of close to 0 degrees while reporting an angle of 0 to 180 degrees. As one approach, we can use trigonometric functions to solve this wrap-around problem.

The front end processing system as shown in Fig. 7 controls an internal fixed target in addition to other LEDs. However, the internal fixed target need not be limited to one LED and need not be limited to a single image such as a back-lit hot air balloon. Instead, the internal fixed target may be a micro-display combined with an eye receiving portion that enables an optical element, such as a focus variable lens. The patient's eye is fixed in different directions by illuminating different pixels of the micro-display, so that peripheral vision field information such as a wavefront map of the 2D array can be obtained. In addition, the patient &apos; s eyes may be fixed at different distances which allow measurement of the reception range or amplitude. The fixed micro-display target may also be controlled to be turned on or off with various speeds and duty cycles, and the micro-display may be colored so that the stationary target brightens the pattern or spot and varies the color.

As described above, one embodiment of the present invention is to track eyes. Figure 27 shows an exemplary process flow diagram of an eye tracking algorithm. The related step may include estimating (2705) the position of the eye cavity using eye pupil location information from other means such as detecting real-time eye pupil or iris image or specular reflection from corneal apex by scanning the SLD beam in two dimensions; Adjusting (2710) the SLD beam scanner to track eye movement; Shifting the DC driving component of the wavefront scanner / shifter relative to the SLD beam adjustment to compensate for the movement of the eye pupil so that the same intended portion of the wavefront from the eye is always sampled irrespective of eye movement, Step 2720 of calibrating the measurement of the wavefront aberration. The real-time image camera provides a visual estimate of the center of the iris or the center of the corneal limbus. By relating the position of the SLD beam (X, Y) to the field of view, the SLD can be oriented to the same position on the cornea. For wavefront sensing, this position is slightly off axis or in this case slightly shifted from the vertex of the cornea, and the specular reflection of the SLD beam does not directly return to the position sensing detector / device of the wavefront sensor. The center of the limbus or the center of the iris can be used as a reference point for orienting the SLD beam.

A unique feature of the algorithm described in this application is the step of offsetting the DC driving component of the wavefront scanner / shifter in proportion to the SLD beam adjustment. This is a meaningful step because this step ensures that the same part of the wavefront from the eye (the same annular ring of the wavefront) is sampled. Without this step, when the eye moves in the lateral direction, other parts of the wavefront from the eye will be sampled, which will cause significant wavefront measurement errors. The last step in calibrating the wavefront aberration measurement is optional because, as a compensation that can be provided by the wavefront scanner / shifter relative to the SLD beam adjustment, the result for the wavefront measurement is the sampled portion of the wavefront, There will be other known aberration elements and / or prism inclination and / or added astigmatism for the whole. It has been shown that the refraction error decoding algorithm automatically averages the aberration to grasp the compromised spherical and cylindrical shapes and filter the prism tilt through the coordinate system translational motion. In this refraction error measurement, there is no further need for prism tilt correction. The coordinate system displacement is an indication of the prism inclination of the wave front from the eye and other known aberrations and / or prism inclination and / or additional astigmatism caused by eye tracking for complete wavefront measurement, which should include prism inclination Should be removed, so the last calibration step is still needed.

Another embodiment of the present invention is to select the diameter of the wavefront sampled annular ring through which the slope sensitivity of the response curve as a function of the annular ring diameter while the wavefront sampling is performed only in the eye pupil region is determined by a higher measurement sensitivity and / Lt; / RTI &gt; In general, over the de-installer values of different wavefront aberrations, such as spheres, cylinders, and trefoils, spherical diopter values require the greatest coverage range because it varies a lot between different eyes, This is because when the eye is removed (ie, the eye is uncensored), it changes a lot during glaucoma surgery. On the other hand, when the glaucoma surgery is completed or nearly finished with an implanted IOL (intraocular lens), the wavefront from the eye should be as close to planar as the half-cone eye should be close in time. In a typical auto-refractive measurement, the wavefront from the 3 mm diameter central region of the eye pupil is typically sampled. Thus, the wavefront sensor can be used with an effective wavefront sampling annular ring area (e.g., 0.1D) covering a sufficient diopter measurement resolution (e.g., 0.1D) and a sufficient decoverer coverage range (e.g., -30D to + 30D) Lt; / RTI &gt; On the other hand, a high sensitivity and / E is used to identify the time gaze at the wavefront measurement resolution, so that the pupil size is close enough to the end of the glaucoma refractive surgery, as long as the pupil size is large enough to more accurately measure the refractive error or wavefront of the half- For example, a 5mm diameter flared sampling annular ring can be extended.

Figure 28 illustrates an embodiment of a flow diagram of an algorithm that can implement this concept. Using eye pupil information obtained from the real-time eye image to estimate the eye pupil size (2805); Using eye pupil size information to determine a maximum diameter of the wavefront sampling annular ring (2810); And increasing (2815) the maximum diameter of the yellow ring to the maximum diameter determined by step (2810) for half-pixel stagnation to achieve better diopter resolution. This "zoom-in" feature allows the user to select or automate. In addition, a PSD ratio scale output can be used to adaptively adjust the annular ring diameter for optimal diopter resolution and dynamic range coverage.

One feature of the present invention is to combine real-time eye images with and without pattern recognition algorithms as wavefront measurement data to detect the presence of eyebrows / eyelashes, irises, facial skin, surgical tools, Moving the eye away from the range. By doing so, the "name" or "cancer" data is excluded and the SLD is smartly turned on or off to reduce exposure time, where the exposure time allows the high SLD power source to be delivered to the eye, thereby increasing the noise- . Figure 29 illustrates an exemplary process flow diagram illustrating this concept. (2905) using a wavefront sensor signal to distract the eye from the real-time eye image and / or the desired location and / or range or to detect the presence of an unintended object in the wavefront relay beam path; Discarding "name" or "cancer" wavefront data as error 2910; Turning off the SLD when the wavefront data is in error 2915, and optionally 2920 notifying the end user when the wavefront data is erroneous or invalid.

Another embodiment of the present invention is to provide an optical system that allows an increase in the optical power within the safety constraint that can be introduced into the eye that can increase the optical signal ratio relative to the noise, performs averaging, / RTI &gt; Also, the SLD beam divergence / convergence and SLD beam spot size on the retina is dynamically adjusted using, for example, an axially movable lens or a focusing variable lens or a variable lens, wherein the SLD spot size on the retina is a more constant And to enable calibrated measurements. On the other hand, the SLD beam spot size and shape on the retina may be monitored using the same real time eye image sensor, for example, by adjusting different image sensors or focuses contributing solely to monitoring the SLD beam spot on the retina of the eye have. With this feedback and installation of the closed loop servo electronics system, the static or scanned pattern of SLD spots on the retina can be removed.

Another embodiment of the present invention is directed to a different scanner that scans a surgical laser beam for performing refractive correction of the eye such as a LRI (limb salvation incision) or another free space beam combiner that can use the same SLD beam scanner Or as a surgical light source to be combined with an SLD beam installed through the same optical fiber. The same laser or different lasers can be used to "guide" and "mark" the medical staff "laying" on the eye so that they can see the laser mark through the surgical microscope.

Another embodiment of the present invention is to measure the eye distance while the eye plane is being measured and to calibrate the measurement of the wave plane from the eye when the eye distance is changed. Information on the eye distance from the wavefront sensor module is particularly important for glaucoma refractive surgery because when the natural lens of the eye is removed, that is, the eyes become aphakic and the wavefront from the eye is severely diverged, The small axial motion of the eye with respect to the module results in a relatively large change in refractive error or wavefront aberration measurements. How the correction to the wavefront is performed when the eye is moved in the lateral direction from the designed position has already been described. Similar corrections are made when the eye moves in the axial direction from its design position. By thus correcting in the axial direction, a low optical coherence interferometer (LOCI) or an optical coherence tomograph (OCT) can be included in the wavefront sensor module and is used to measure the axial distance of the eye. Alternatively, a simpler technique using optical triangulation to measure the distance of the eye may be employed. LOCI and OCT are favored in that they can make biometric / anatomical eye measurements in addition to the distance of the eye. Such measurements are particularly valuable for eye refractive surgery while showing a valid lens (natural or artificial) position, if the lens has a tilt, anterior chamber depth, thickness of the cornea, lens thickness and eye length. Through lateral scanning, which can be achieved by OCT systems, the cornea and / or eye lens (natural or artificial) refractive power sources can be derived cooperatively or independently, especially in the case of anhydrous eyes.

Yet another embodiment combines two or more of the measurement results obtained by the LOCI / OCT and eye image cameras, wavefront sensors for other purposes. In one embodiment, the combined information detects optical scattering and / or opacity in the media of the ocular system, such as the presence of glaucomatous opacity and the presence of optical bubbles in the eye It can be used after the natural eye lens is broken by the femtosecond laser. The combined information can be used to calculate IOL conditions for real-time target refraction in the operating room (OR) immediately before or after the IOL is performed, to detect anomalous state of the eye, to identify refractions, and to determine effective lens positions Can be used to find out. The combined information can also be used to determine alignment of the patient's head and can be used to make a determination if the patient's eye is perpendicular to the optical axis of the wavefront sensor module. Combined information can also be used to alert the healthcare provider if dry eyes need to be detected and needed to be moisturized. The combined information may also include, for example, whether the targeted eye refraction has reached the end of the surgery or whether the multi-focal IOL is properly centered without significant tilting or when the toric IOL is implanted, rotated about the calibration axis The patient may be personalized and displayed by the medical staff so as to notify the medical staff of only the desired information such as the pre-operative eye refraction error, the IOL condition in the anhydrous state, and the last point indicator. The display may show an integrated data display or a secret display.

The combined information can additionally be used to determine whether the eye is well aligned or not, which direction the patient &apos; s eye should be moved in, or directional guidance on the display to tell the clinician in which direction the microscope should be moved for good alignment . This information can be used to determine whether the eyelids are closed or optical bubbles are present, whether the refracted / broken eye lens material remains within the eye sphere that will affect the results of the wavefront measurement, And the like.

2, the sub-wavefront focus lens 220 may be controlled by an electronic system. Such a lens may be a variable focus lens or an axially movable lens or a variable mirror. The purpose of this lens operation is to dynamically adjust the focal distance in an open route or closed control loop such that the image / light spot size formed by the sub-focal focus lens is subject to local divergence or convergence of the sequentially sampled sub- Can be controlled. This is especially true when wavefront sampling is done around the annular ring. For example, in order to achieve good response slope sensitivity to good wavefront tilt with accuracy and / or precision, the image spot may include a PSD (quadrant detector or lateral effect location sensing Detector). &Lt; / RTI &gt; Optionally, the image spots of the sampled sub-wavefronts that form on a PSD (quadrant detector or side effect position sensing detector) can be controlled to any desired magnitude. For example, one choice for spot size is for one quadrant of the quadrant detector, as is known to those of ordinary skill in the art. Another possible choice is a size that produces a high sensitivity and a large dynamic response range, which is compromised. Another option is the image spot size, which is twice the gap size of the quadrant detector. The different image spot sizes may change dynamically according to the average local convergence or divergence of sequentially sequentially sampled sub-wavefronts.

By offsetting the defocus of the wavefront by DC offset or by dynamically compensating the wavefront, the image spot is always made to be at or near the center of the quadrant detector. In this manner, the image spot of each sampled sub-wavefront must be able to be locked and nulled in size and position to ensure that the highest sensitivity is achieved. The drive signals for the wavefront compensation or defocus offset device, the wavefront shifter and the sub-wavefront focus lens can be used to accurately determine the wavefront tilt of each sampled sub-wavefront.

The apparatus described in this application can accomplish a number of additional tasks depending on the structure of the host computer processing the wavefront data, the eye image data, the eye distance data, the low coherence interferometry data, and the like. For example, the host computer may be able to obtain scales such as refractive errors, display quantitative or qualitative scales on the display, and allow the physician to select the manner in which any quantitative or qualitative scales are displayed . With regard to how the wavefront measurement is displayed, the end user is able to select an indefinite point indication, such as a wavefront aberration versus reflex condition and / or a positive cylindrical and / or cylindrical view, and /

The host computer is configured to allow the medical staff to rotate or rotate the real-time image / video of the patient's eye in a desired direction. In addition, the clinician can view the results of the low coherence interferometry measurements by panning images, wavefront measurement results, and even surgery or subsequent requests.

Most importantly, the present invention guides the practitioner to titrate the visual acuity correction process in real time to optimize the result of the visual acuity process. For example, guide the physician to adjust the position of the IOL in the eye until the measurement of the center, tilt, and circumferential angular orientation positions confirms the optimal placement of the IOL. It also guides the medical staff to rotate the toric eye lens (IOL) implanted to correct / neutralize astigmatism. In addition, the present invention guides the medical team to perform a limb / corneal incision or a lenticular laser (Flexi) in the substrate to correct and neutralize astigmatism.

The apparatus described in this application is used to indicate whether the implanted multi-focal IOL has a desired focus range in addition to optimizing its position. The device of the present invention can be used to determine if an implanted AIOL (accommodating IOL) provides a desired coverage range.

On the display, a real-time guide is provided on how the vision correction process proceeds to facilitate removal of the remaining aberrations, identify the results, document the values, and sense aberrations. The displayed real-time information is automatically digitized by the medical staff or the vision corrector to "zoom in" or "zoom out" warning whether the vision correction process is going in the right direction or in the wrong direction. When an arbitrary level of calibration is reached, the displayed information is highlighted in terms of font size, intensity, style, or color, for example, to verify internally that it has reached a refracted endpoint target, such as an on-time viewing.

In addition to visual feedback, spoken feedback can also be used independently or with visual feedback. For example, the audio information may be provided with or without video / graphics information showing in which direction the IOL should be moved for proper alignment or in which direction the toric lens should be rotated to correct / neutralize the astigmatism . The real time audio signal can be generated to indicate the type of refraction error, the sum of errors, and the change in error. The pitch, tone, and size of the real-time audio signal are changed to indicate the enhancement or erroneous correction that is applied during the vision correction process. The specific pitch of the real-time audio signal can be generated to confirm that there is an error with respect to the cylinder with a tone representing the sum of the cylindrical errors.

One of the most important applications of the present invention is to assist in glaucoma surgery to determine whether the pre-operative IOL power is correct or not, in a state of anxiety in the eyes of the patient. Real-time anechoic wavefront measurement (preferably with eye biometry as provided by the built-in low coherence interferometry) accurately determines the required IOL power and pre-selected pre-selected IOL power is used, For those who do not have this constant result, it is possible to confirm whether or not it is right for the patient of the recovery corneal refraction process.

Another important application of the present invention is to monitor and store changes in corneal shape and other eye biomechanical parameters during the entire session of glaucoma surgery while the wavefront from the patient's eye is being measured. These changes can be measured prior to, during, and after glaucoma surgery in the operating room OR, and can be measured by corneal metrology and pachymetry as a result of various factors that cause changes in the wavefront from the patient's eye, And may be a change in corneal shape and thickness as measured by depth, lens position, and thickness. For example, these factors may be caused by local anesthesia, eyebrow examination, incision / wound formed on the cornea, anterior chamber filling material, intraocular pressure, water / solution supply to the cornea, wound closure, Includes effects of wavefront changes from glaucoma surgery medical staff.

Data on changes in the biome / anatomy parameters of the eye can be used to compensate for the effects caused by various factors. Wavefront results after treatment of the incision / wound may be expected and may be used to set any desired objective eye refraction for glaucoma surgery. Biomaterial / anatomic parameters of corneal shape and other eyes just before and after surgery were built-in OCT and eye camera. And may be measured using an external corneal profilometer / corneal meter attached to an operating microscope or attached to the apparatus described herein. Immediately after surgery, measurements are made in the operating room before or after local anesthesia is applied, when the eyebrows are in a properly lying position before and after the eyebrows are open. At the time of surgery, the anterior chamber was filled with an arbitrary gel (OVC, ophthalmic viscous surgical device) before the corneal incision, the glaucoma lens was removed and the intraocular lens was implanted, It is done in the operating room before the suture is sutured. Immediately after surgery, measurements are taken either in the operating room or immediately after the clinician treats the incisions / wounds before the eyebrows are removed, when the patient is in the immediate lying position, and after the eyebrows have been removed.

Thus, data obtained by changes in corneal morphology or other biological / anatomical parameters of the eye are combined with ocular wavefront measurement data or stored in a database. Other measurements may be made after the incision / wound has fully healed after a few weeks or months after surgery and changes or differences in intra-ocular surface, corneal shape, and / or eye biochemical parameters may be collected. A nominal database is created and processed to determine the target refraction immediately after the glaucoma surgery that needs to be set to ensure that the desired visual acuity outcome is finally achieved after the wound is fully healed. In this way, all effects including aberrations caused by medical personnel, such as astigmatism, for example, represented by a particular personal corneal incision habit can be considered.

The wavefront sensor disclosed in this application can be combined with a wide variety of other ophthalmic instruments in a wide range. For example, the wavefront sensor may be mounted to a femtosecond laser or excimer laser for alignment and / or guidance for LASIK or eye lens fractures or "incision " or for closed loop removal of eye tissue. The real-time eye image, OLCI / OCT data, and wavefront data may be combined to indicate whether optical bubbles are present in the eye lens or the anterior chamber before and after eye surgery and during surgery. Alternatively, the wavefront sensor may be mounted or fitted to a slit lamp biomicroscope.

The present invention may be mounted or coupled to an adaptive optical system. Variable mirror or liquid crystal based transmissive wavefront compensators can be used to manipulate real time wavefronts to partially or fully compensate for wavefront errors partially or totally.

In addition, the wavefront sensor described in this invention can be combined with other types of intraocular pressure (IOP) measuring means. In one embodiment, it may be used directly to detect IOP by measuring eye wavefront changes as a function of the patient's heart rate. The sensor can be used directly to calibrate the IOP.

These embodiments may be used to guide an optical system, a spectacle and / or an eyeglass, an IOL, or an incision / processing device to create an optical system. Such embodiments can be applied to microscopy and / or molecular analysis of cells or other metrology equipment. The present invention can be used in lens processing, spectacle confirmation, micro-physiology, and the like.

While various embodiments have been described as illustrative of the present invention, those skilled in the art will be able to dedicate many other modifications as may be made to such teachings.

104/204: first lens
116/216: Second lens
140/240: Third lens
142/242: fourth lens
118/218: Wavefront Sampling Aperture

Claims (6)

A light source 172 for outputting a light beam for irradiating the target eye;
A first beam deflecting member (180) intercepting the light beam and directing the light beam toward the target eye; And
And a controller (410) connected to the light source, the beam deforming member, and controlling the beam deforming member to compensate for lateral movement of the target eye. The method according to claim 1,
An image detector 162 for outputting an image of the target eye; And
Further comprising a controller coupled to the image detector and configured to process the image to determine a lateral motion of the subject eye. 3. The method of claim 2,
Wherein the control unit controls the first beam deformation member to track a lateral motion of the target eye. The method according to claim 1,
Wherein the light source is a high-brightness diode. The method according to claim 1,
Wherein the beam deforming member is a micro-electro-mechanical system (MEMS) reflector. The method according to claim 1,
A second beam deflecting member (182) for receiving the light beam and directing the light beam toward the target eye; Further comprising:
Wherein the control unit controls the second beam deflecting member to scan the light beam around a small portion of the retina of the subject's eye so as to disperse the optical energy in a larger area.

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