System and method for obtaining a lens capsule profile - Patent Application 20070122997

Abstract

The system includes a controller having at least one processor and at least one non-transitory tangible memory having instructions recorded thereon for executing a method for acquiring a profile of a lens capsule of an eye. The profile is represented by respective central planes and respective equatorial planes separated by respective transition points. The controller is configured to acquire imaging data of a portion of the lens capsule as viewed through the pupil of the eye. The imaging data is transformed into a calibrated reference coordinate system and fitted to the respective central planes of a predefined central region of the lens capsule. The profile is acquired based on a set of fitting parameters for the respective central planes and the equatorial planes. The respective central planes and the respective equatorial planes can be represented as an elliptical cone and an inclined parabola, respectively.

Description

[Technical Field]

[0001] The present disclosure relates to systems and methods for obtaining a profile of the lens capsule of an eye. [Background technology]

[0002] Humans have five basic senses: sight, hearing, smell, taste, and touch. Vision gives us the ability to visualize the world around us and connects us to our surroundings. Many people around the world have problems with the quality of their vision, requiring the use of ophthalmic lenses, such as intraocular lenses. Intraocular lenses can be implanted in the eye during cataract surgery to replace the clouded human lens. Having a profile of the eye's lens capsule before surgery can help with the selection of an intraocular lens. Summary of the Invention [Means for solving the problem]

[0003] Disclosed herein is a system having a controller with at least one processor and at least one non-transitory tangible memory having instructions recorded thereon for executing a method for acquiring a profile of a lens capsule of an eye. Execution of the instructions by the processor causes the controller to acquire imaging data of a portion of the lens capsule as seen through the pupil of the eye. The imaging data includes posterior and anterior data points and is transformed into a calibrated reference coordinate system having a first axis (X) and a second axis (Y). Also disclosed is a corresponding method for acquiring a profile of the lens capsule of an eye.

[0004] The profile is represented by respective central planes and respective equatorial planes separated by respective transition points. The controller is configured to fit the imaging data of the adjusted reference coordinate system to the respective central planes of the predefined central region of the lens capsule. The method includes obtaining transition coordinates as coordinate values ​​of the respective transition points in a positive X domain. The controller is configured to determine sets of fitting parameters for the respective central planes and the respective equatorial planes based on the transition coordinates and a plurality of constraints. The profile is obtained based on the sets of fitting parameters for the respective central planes and the respective equatorial planes.

[0005] The controller can be configured to select an intraocular lens based at least in part on a profile of the lens capsule. Transforming the imaging data into the adjusted reference coordinate system includes fitting the posterior and anterior data points to a first circle and a second circle, respectively, and determining intersections of the first and second circles. Transforming the imaging data into the adjusted reference coordinate system includes translating the posterior and anterior data points to be centered about respective centers of intersection and rotated such that the tilt angle of the rotation is zero.

[0006] The controller is configured to fit each midplane of the adjusted reference coordinate system to a respective conic equation of the conic surface, the controller is configured to determine a conic x-intercept as a coordinate on a first axis (X) where each conic equation intersects in a positive x-domain, and the transition coordinate is the product of the conic x-intercept and a predefined constant, the predefined constant being less than 1.

[0007] Each central plane includes a central anterior surface. The controller may be configured to represent the central anterior surface as an elliptical cone characterized by a first plurality of variables (Ka, Qa, Ra), the first plurality of variables (Ka, Qa, Ra) being obtained by fitting the imaging data to the central anterior surface of a predefined central region of the calibrated reference coordinate system. The central anterior surface Ca(x) may be defined as:

number

[0008] Each central plane comprises a central posterior surface. The controller may be configured to represent the central posterior surface as an elliptical cone characterized by a second plurality of parameters (Kp, Qp, Rp), the second plurality of parameters (Kp, Qp, Rp) being obtained by fitting the imaging data to the central posterior surface of a predefined central region of the calibrated reference coordinate system. The central posterior surface Cp(x) may be defined as:

number

[0009] The set of fitting parameters includes a first forward parameter (Ga), a second forward parameter (Pa), a first backward parameter (Gp), a second backward parameter (Pp), and the respective coordinates (Xe, Ye) of the vertices of the adjusted reference coordinate system. Each equatorial plane includes a front equatorial surface and a rear equatorial surface that meet at the vertex. The front equatorial surface and the rear equatorial surface are represented by respective tilted parabolic functions. The front equatorial surface is based in part on the first forward parameter (Ga), the second forward parameter (Pa), and the respective coordinates (Xe, Ye) of the vertices. The front equatorial surface Ea(x) can be defined as:

number

number

[0010] Each median surface includes a median-posterior surface and a median-anterior surface. Each equatorial surface includes an equatorial-anterior surface and an equatorial-posterior surface. The plurality of constraints includes a first equation corresponding to respective values ​​of the median-anterior surface and the equatorial-anterior surface in transition coordinates, and a second equation corresponding to respective values ​​of the median-posterior surface and the equatorial-posterior surface in transition coordinates.

[0011] The plurality of constraints includes a third equation corresponding to a first derivative of each of the central-front and equatorial-front surfaces in transition coordinates, a fourth equation corresponding to a first derivative of each of the central-posterior and equatorial-posterior surfaces in transition coordinates, a fifth equation corresponding to a second derivative of each of the central-posterior and equatorial-front surfaces in transition coordinates, and a sixth equation corresponding to a second derivative of each of the central-posterior and equatorial-posterior surfaces in transition coordinates.

[0012] Disclosed herein is a system including a controller having at least one processor and at least one non-transitory tangible memory having instructions recorded thereon for executing a method for obtaining a profile of a lens capsule of an eye. The profile is represented by respective central planes and respective equatorial planes separated by respective transition points. Execution of the instructions by the processor causes the controller to obtain a lens diameter and at least two variables from a set of variables, the set of variables including a lens thickness, a central anterior apex, and a central posterior apex. The transition coordinate is set as the product of the lens diameter and a predefined constant, the predefined constant being less than 0.5.

[0013] The controller is configured to obtain a first plurality of variables (Ka, Qa, Ra) and a pair of forward parameters (Ga, Pa) by simultaneously solving a first group of constraints based in part on the transition coordinates, and a second plurality of variables (Kp, Qp, Rp) and a pair of backward parameters (Gp, Pp) by simultaneously solving a second group of constraints based in part on the transition coordinates.

[0014] The controller is configured to obtain a profile based on the first plurality of variables (Ka, Qa, Ra), the pair of anterior parameters (Ga, Pa), the second plurality of variables (Kp, Qp, Rp), and the pair of posterior parameters (Gp, Pp), an update of the lens diameter is obtained based on the profile, and an update of the transition coordinate is obtained based on the update of the lens diameter.

[0015] If a difference between the transition coordinate updates and the transition coordinates is greater than a predefined threshold, the controller is configured to update a first plurality of variables (Ka, Qa, Ra) and a pair of forward parameters (Ga, Pa) by simultaneously solving a first group of constraints based in part on the transition coordinate updates. If a difference between the transition coordinate updates and the transition coordinates is greater than a predefined threshold, the controller is configured to update a second plurality of variables (Kp, Qp, Rp) and a pair of backward parameters (Gp, Pp) by simultaneously solving a second group of constraints based in part on the transition coordinate updates.

[0016] Each central surface includes a central-anterior surface and a central-posterior surface, and each equatorial surface includes an equatorial-anterior surface and an equatorial-posterior surface. The controller is configured to represent the central-anterior and central-posterior surfaces as respective elliptical cones characterized by a first plurality of variables (Ka, Qa, Ra) and a second plurality of variables (Kp, Qp, Rp). The controller is configured to represent the equatorial-anterior and equatorial-posterior surfaces as respective tilted parabolas characterized by a pair of anterior parameters (Ga, Pa) and a pair of posterior parameters (Gp, Pp).

[0017] The first group of constraints includes a first equation corresponding to the respective values ​​of the central front and the equatorial front in transition coordinates, a second equation corresponding to the respective first derivatives of the central front and the equatorial front in transition coordinates, a third equation corresponding to the respective second derivatives of the central front and the equatorial front in transition coordinates, and a fourth equation corresponding to the respective coordinates of the central front to the central front vertex.

[0018] The second group of constraints includes a fifth equation corresponding to the respective values ​​of the central posterior and equatorial posterior surfaces in transition coordinates, a sixth equation corresponding to the respective first derivatives of the central posterior and equatorial posterior surfaces in transition coordinates, a seventh equation corresponding to the respective second derivatives of the central posterior and equatorial posterior surfaces in transition coordinates, and an eighth equation corresponding to the respective coordinates of the central posterior surfaces to the central posterior vertex.

[0019] The above and other features and advantages of the present disclosure will become readily apparent from the following detailed description of the best mode for carrying out the disclosure, when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram of a system for obtaining a profile of the lens capsule of an eye, including a controller. [Figure 2] FIG. 2 is a schematic flow chart of a method executable by the controller of FIG. 1 according to a first embodiment. [Figure 3] FIG. 3 is an example of a schematic fragment of a cross-sectional image of an eye, the image having data points posterior and anterior to the lens capsule. [Figure 4] FIG. 4 is a schematic diagram of the rear and front data points of FIG. 3 in the original reference coordinate system. [Figure 5] FIG. 5 is a schematic diagram of the rear and front data points of FIG. 4 after transformation into a rectified reference coordinate system. [Figure 6]FIG. 6 is a schematic illustration of the capsular bag profile obtained by the system of FIG. 1 in a calibrated reference frame. [Figure 7] FIG. 7 is a schematic diagram of the capsule profile shown in FIG. 6 in the original reference coordinate system. [Figure 8] FIG. 8 is a schematic flow chart of a method executable by the controller of FIG. 1 according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Referring to the drawings, in which like reference numbers refer to like components, Figure 1 schematically illustrates a system 10 for obtaining a profile of the lens capsule of an eye. With reference to Figure 1, system 10 includes a controller C having at least one processor 12 and at least one memory 14 (or non-transitory tangible computer-readable storage medium) having instructions recorded thereon for performing one or more methods. Methods 100 and 300 are shown and described below with reference to Figures 2 and 8, respectively.

[0022] Referring to FIG. 1 , system 10 may include a user interface 16 for collecting user data from one or more clinical facilities or electronic medical record units. System 10 may include a data management unit 18 for storing and / or facilitating the transfer of user data and other functions. Various components of system 10 may be configured to communicate over a short-range network 20 and / or a long-range network 22. Referring to FIG. 1 , controller C may communicate with a remote server 24 and / or a cloud unit 26, which may include one or more servers hosted on the Internet for storing, managing, and processing data. Cloud unit 26 may be a private or public information source maintained by an organization such as, for example, a research institute, a company, a university, and / or a hospital.

[0023] 1, the short-range network 20 may be a bus implemented in various ways, such as a serial communication bus in the form of a local area network. The local area network may include, but is not limited to, a Controller Area Network (CAN), a Controller Area Network with Flexible Data Rate (CAN-FD), Ethernet, Bluetooth, Wi-Fi, and other data connection topologies. The long-range network 22 may be a wireless local area network (LAN) that links multiple devices in a wirelessly distributed manner, a wireless metropolitan area network (MAN) that connects several wireless LANs, or a wireless wide area network (WAN) that covers a large geographic area such as a nearby city or town. Other types of connections may also be employed.

[0024] The controller C may be configured to receive and transmit wireless communications with the remote server 24 via a mobile application 28 shown in FIG. 1. The mobile application 28 may communicate with the controller C over a short-range network 20 to access data at the controller C. In one example, the mobile application 28 is physically connected (e.g., wired) to the controller C. In another example, the mobile application 28 is embedded in the controller C. Circuits and components for the remote server 24 and mobile application 28 ("app") available to those skilled in the art may be employed.

[0025] 1 , the user interface 16 and / or the controller C may be configured to communicate with an imaging device 30, which may be an optical coherence tomography machine. The imaging device 30 may also be an ultrasound machine, a magnetic resonance imaging machine, or other imaging device available to those skilled in the art. Additionally, the user interface 16 and / or the controller C may communicate with a profile output module 32 and a lens selection module 34 to select an intraocular lens 36, as described below.

[0026] Referring to Figure 3, an exemplary image of eye E is shown. As described below, with reference to Figure 3, controller C is configured to acquire imaging data of portion 140 of lens capsule 142 as seen through pupil 144 of eye E. Lens capsule 142 has lens thickness 146 and lens diameter 148. Also shown in Figure 3 are cornea 152 and iris 154. It is understood that Figure 3 is not to scale.

[0027] Referring now to FIG. 2 , a flowchart of method 100 is shown. Method 100 need not be applied in the particular order described herein, and some blocks may be omitted. In block 102 of FIG. 2 , method 100 includes acquiring imaging data of a portion 140 of a lens capsule 142 visible through a pupil 144 of an eye E. Method 100 uses the surface portion 140 visible through the dilated pupil 144 to enable prediction of the overall shape of the lens capsule 142, including portions of the shape obscured by the iris 154. The imaging data may be acquired by ultrasound biomicroscopy, optical coherence tomography, magnetic resonance imaging, or other imaging techniques available to those skilled in the art. The imaging data may be obtained from a single image or multiple images. The imaging data may be acquired from an imaging device 30.

[0028] Referring to Figure 3, the imaging data includes posterior data points 160 (at posterior side P) and anterior data points 170 (at anterior side A). The posterior data points 160 and anterior data points 170 are shown plotted in Figure 4 (referred to herein as the original reference coordinate system 150) in units of pixels along a horizontal axis Q and a vertical axis R. The image shown in Figure 4 (posterior side P is above anterior side A) is vertically flipped compared to Figure 3 (anterior side A is above posterior side P) because in Figure 3 the coordinate values ​​of the vertical axis R progress downward.

[0029] In block 104 of Figure 2, the method 100 includes transforming the rear data points 160 and the front data points 170 from the original reference coordinate system 150 (shown in Figure 4) to an adjusted reference coordinate system 200 (shown in Figures 5 and 6). First, referring to Figure 4, the rear data points 160 are fitted to the equation of a first circle 162 on the rear side P. The front data points 170 are fitted to the equation of a second circle 172 on the front side A. The first circle 162 and the second circle 172 intersect at intersection points 180, 182 shown in Figure 4.

[0030] Second, referring to FIG. 4, controller C is configured to determine a center 184 between intersection points 180, 182. The coordinate transformed point (of adjusted reference coordinate system 200 of FIG. 5) is obtained by centering rear data point 160 and front data point 170 around center 184 and rotating the center coordinates by an angle opposite to tilt angle 188 so that the resulting tilt angle 188 is zero. Tilt angle 188 can be obtained as the arctangent of the ratio of the increase in each vertical coordinate value between intersection points 180, 182 divided by the increase in each horizontal coordinate value. Adjusted reference coordinate system 200 is shown in FIGS. 5-6 and has an X-axis and a Y-axis.

[0031] In block 106 of FIG. 2, and with reference to FIG. 5, the controller C is configured to fit the posterior data points 160 and the anterior data points 170 of the adjusted reference coordinate system 200 to respective central planes 210 (see FIG. 5) within a predefined central region 205 of the lens capsule 142. In one example, the predefined central region 205 is in the range of 3-7 mm. In one example, the predefined central region 205 is approximately 5 mm, corresponding to an average-sized open pupil. The predefined central region 205 can be correlated to the opening diameter of the pupil 144 of a particular patient.

[0032] In the illustrated embodiment, each central surface 210 is an elliptical cone. Each central surface 210 may be another type of conical surface. It is understood that the shape of each central surface 210 may vary. Referring to FIG. 5 , trace 202 and trace 212 show extrapolations of each central surface 210 at the posterior side P and the anterior side A, respectively. Each central surface 210 is extrapolated to determine a positive cone intersection 220 and a negative cone intersection 222. The controller is configured to determine a cone x-intercept 224 as the coordinate on the x-axis where each cone equation intersects in the positive x-domain. In other words, the cone x-intercept 224 is the x-coordinate of the positive cone intersection 220.

[0033] 6-7, profile L is represented by a respective central plane 210 and a respective equatorial plane 240. Each equatorial plane 240 includes a posterior equatorial surface 252 and an anterior equatorial surface 262. The anterior central surface 260 is adjacent to the anterior equatorial surface 262 on both sides. The posterior central surface 250 is adjacent to the posterior equatorial surface 252 on both sides. Referring to FIG. 6, profile L of the lens capsule 142 is symmetric about the X-axis at X=0.

[0034] In block 108 of FIG. 2, the controller C is configured to obtain the transition coordinate Xt (see FIG. 6), which is the coordinate value of each transition point 274 in the positive X domain. In other words, the transition coordinate Xt is the positive coordinate on the X-axis of each transition point 274. Referring to FIG. 6, each transition point 274 in the positive X domain and the negative X domain (corresponding to the coordinate -Xt) are equidistant from the line X = 0. The transition coordinate Xt is set as the product of the conical x-section 224 (Xi) and a predefined constant F, such that Xt = F * Xi. The predefined constant F is less than 1. In one example, the predefined constant F is within the range of 0.5 to 0.9. In one example, the predefined constant F is set to 0.7.

[0035] Referring to FIG. 6, the central rear surface 250 and the central front surface 260 can be generated from the equation of the conical equation over the range -Xt < x < Xt, where Xt is the transition coordinate. In the example shown, the central front surface 260 is represented as an elliptical cone characterized by a first plurality of variables (Ka, Qa, Ra). The central front surface 260, i.e., Ca(x), is defined as follows:

Equation

[0036] The central rear surface 250 is represented as an elliptical cone characterized by a second plurality of variables (Kp, Qp, Rp). The central rear surface 250, i.e., Cp(x), is defined as follows:

Equation

[0037] 6-7, the post-equatorial surface 252 and the front-equatorial surface 262 can be represented by respective tilted parabolic functions. The front-equatorial surface 262 and the post-equatorial surface 252 intersect at a vertex 270 in the positive X domain and another vertex 272 in the negative X domain.

[0038] 2, the method 100 includes determining a set of fitting parameters for each midplane 210 and each equatorial plane 240. The set of fitting parameters includes a first anterior parameter (Ga), a second anterior parameter (Pa), a first posterior parameter (Gp), a second posterior parameter (Pp), and respective coordinates (Xe, Ye) of the vertices 270 in the positive X domain of the adjusted reference coordinate system 200.

[0039] The equatorial posterior surface 252 (see FIGS. 6 and 7) is based in part on the first posterior parameter (Gp), the second posterior parameter (Pp), and the respective coordinates (Xe, Ye) of the vertex 270 in the positive X domain. The equatorial posterior surface 252, or Ep(x), is defined as follows:

number

number

[0040] The set of fitting parameters is based on the transition coordinate Xt and a number of constraints. The number of constraints includes a first, second, third, fourth, fifth, and sixth equation. In the example shown, there are six fitting parameters and six constraint equations. The six constraint equations can be numerically solved using, for example, the MATLAB function fsolve, which employs a trust region algorithm. Other numerical algorithms available to those skilled in the art may also be employed.

[0041] The first equation corresponds to the respective values ​​of the central front surface 260 and the equatorial front surface 262 at the transition coordinate Xt as follows: Ca(Xt) = Ea(Xt). The second equation corresponds to the respective values ​​of the central back surface 250 and the equatorial back surface 252 at the transition coordinate Xt as follows: Cp(Xt) = Ep(Xt).

[0042] The third equation corresponds to the first derivative of each of the central front 260 and the equatorial front 262 in the transition coordinate Xt as follows:

number

number

number

number

[0043] In block 112 of FIG. 2, the controller C is configured to acquire a profile L based on the set of fitting parameters (acquired in block 110) applied to each medial plane 210 and each equatorial plane 240. FIG. 6 shows the profile L after the set of fitting parameters have been acquired. Additionally, in block 112, the profile L may be realigned to the original reference coordinate system 150 shown in FIG. 4. FIG. 7 is a schematic diagram of the profile L after the opposite transformation of block 104, including decentration and retilt. To provide visualization to the clinician, the profile L in the original reference coordinate system 150 may be superimposed on the image of the eye E in FIG. 3.

[0044] Also in block 112, the controller C can be configured to select the intraocular lens 36 based at least in part on the profile L of the lens capsule 142. Obtaining the correct shape L of the lens capsule optimizes the selection of the power of the intraocular lens 36. This effect is enhanced if the intraocular lens 36 is an accommodating lens that can change its shape in response to an external force. In other words, the intraocular lens 36 can respond differently to the same accommodation change mediated by the ciliary muscle depending on the geometric dimensions and shape of the lens capsule 142.

[0045] Referring now to FIG. 8, a flowchart of a method 300 that can be executed by the controller C of FIG. 1 is shown. The method 300 does not need to be applied in the particular order described herein, and some blocks may be omitted. In block 302 of FIG. 8, the controller C is configured to obtain the lens diameter 148 (see FIG. 3) and at least two variables from a set of variables. The set of variables includes the lens thickness 146 (see FIG. 3), the central anterior apex 264 (see FIG. 6), and the central posterior apex 254 (see FIG. 6), respectively, along the Y-axis. The set of variables can be obtained from the imaging device 30 of FIG. 1 or from other sources. The method 300 enables prediction of the overall shape of the lens capsule 142 using a small number of parameters.

[0046] 7, a method 300 includes representing a profile L in a respective midplane 210 and a respective equatorial plane 240 of a calibrated reference coordinate system 200, as shown in FIG. 6. Each midplane 210 includes a mid-anterior surface 260 and a mid-posterior surface 250, each represented as an elliptical cone characterized by a first plurality of variables (Ka, Qa, Ra) and a second plurality of variables (Kp, Qp, Rp). Each equatorial plane 240 includes an equatorial-anterior surface 262 and an equatorial-posterior surface 252, each represented as an inclined parabola characterized by a pair of anterior parameters (Ga, Pa) and a pair of posterior parameters (Gp, Pp).

[0047] In block 304 of FIG. 8, the controller C is configured to set a transition coordinate Xt (see FIG. 6) as the product of the lens diameter 148 (LD) and a predefined constant J, such that Xt=J*LD. The predefined constant J is less than 0.5. In one example, the predefined constant J is 0.35. The transition coordinate Xt can also be obtained as the product of the X-coordinate (Xe) of each of the vertices 270 in the positive X domain and the predefined constant J, such that Xt=J*(2*Xe). The lens diameter 148 (LD) can be set as twice the value of the X-coordinate (Xe) of each of the vertices 270, such as LD=2*Xe.

[0048] In block 306 of Figure 8, the controller C is configured to obtain a first plurality of variables (Ka, Qa, Ra) and a pair of forward parameters (Ga, Pa) by simultaneously solving a first group of constraints based in part on the transition coordinate Xt. The first group of constraints includes four equations that can be solved numerically, for example, using the MATLAB function fsolve. Because there are five unknowns and four equations, the Levenberg-Marquardt method can be used. Other numerical algorithms available to those skilled in the art may also be employed.

[0049] The first equation corresponds to the respective values ​​of the central front 260 and the equatorial front 262 at the transition coordinate Xt: Ca(Xt)=Ea(Xt). The second equation corresponds to the respective first derivatives of the central front 260 and the equatorial front 262 at the transition coordinate Xt:

number

number

[0050] In block 308 of FIG. 8, the controller C is configured to obtain a second plurality of variables (Kp, Qp, Rp) and a pair of backward parameters (Gp, Pp) by simultaneously solving a second group of constraints based in part on the transition coordinate Xt. The second group of constraints includes four equations (equations 5 to 8) that can be solved numerically using, for example, the MATLAB function fsolve. Because there are five unknowns and four equations, the Levenberg-Marquardt method can be used. Other numerical algorithms available to those skilled in the art may also be employed.

[0051] The fifth equation corresponds to the respective values ​​of the central aft surface 250 and the equatorial aft surface 252 at the transition coordinate Xt as follows: Cp(Xt)=Ep(Xt). The sixth equation corresponds to the respective first derivatives of the central aft surface 250 and the equatorial aft surface 252 at the transition coordinate Xt as follows:

number

number

[0052] The output of block 306 can be used to obtain the central front 260 and the equatorial front 262. The central front 260, Ca(x), is defined as follows:

number

number

[0053] The output of block 308 may be used to obtain the central posterior plane 250 and the equatorial posterior plane 252. The central posterior plane 250, or Cp(x), is defined as follows:

number

number

[0054] 8, the controller C is configured to obtain a profile L based on the first plurality of variables (Ka, Qa, Ra), the pair of anterior parameters (Ga, Pa), the second plurality of variables (Kp, Qp, Rp), and the pair of posterior parameters (Gp, Pp). The controller C is configured to obtain an updated value of the lens diameter 148 based on the profile L, and to obtain an updated value of the transition coordinate Xt based on the updated value of the lens diameter 148.

[0055] 8, the controller C is configured to determine whether a difference between the transition coordinate update and the transition coordinate is less than a predefined threshold, in other words, whether the transition coordinate update and the transition coordinate converge within the predefined threshold. If so, the method 300 ends. The controller C may be configured to select an intraocular lens 36 based at least in part on the profile L of the lens capsule 142.

[0056] Otherwise, as shown by line 313, method 300 loops back to block 306, where controller C is configured to update a first plurality of variables (Ka, Qa, Ra) and a pair of forward parameters (Ga, Pa) by simultaneously solving a first group of constraints based in part on the updated values ​​of the transition coordinates. Additionally, controller C is configured to update a second plurality of variables (Kp, Qp, Rp) and a pair of backward parameters (Gp, Pp) by simultaneously solving a second group of constraints based in part on the updated values ​​of the transition coordinates.

[0057] In summary, system 10 (through implementation of methods 100 and / or 300) requires a relatively small number of parameters while enabling prediction of the profile L of capsule 142 with a relatively high degree of accuracy. System 10 uses separate parameter values ​​for the anterior side A and the posterior side P of capsule 142, and thus captures physiological asymmetries in the shape of capsule 142, which may cause one side to be flatter compared to the other.

[0058] The controller C of FIG. 1 includes computer-readable media (also referred to as processor-readable media), including non-transitory (e.g., tangible) media that participate in providing data (e.g., instructions) that can be read by a computer (e.g., by a computer processor). Such media may take many forms, including, but not limited to, non-volatile and volatile media. Non-volatile media may include, for example, optical or magnetic disks and other persistent memory. Volatile media may include, for example, dynamic random access memory (DRAM), which may constitute primary storage. Such instructions may be transmitted over one or more transmission media, including coaxial cables, copper wire, and optical fiber, including the wires that comprise a system bus coupled to the computer's processor. Some forms of computer-readable media include, for example, floppy disks, flexible disks, hard disks, magnetic tape, or other magnetic media; CD-ROMs, DVDs, or other optical media; punch cards, paper tape, or other physical media with patterns of holes; RAM, PROMs, EPROMs, Flash EEPROMs, or other memory chips or cartridges; or other computer-readable media.

[0059] The lookup tables, databases, data repositories, or other data stores described herein may include various types of mechanisms for storing, accessing, and retrieving various types of data, including a hierarchical database, a set of files in a file system, a proprietary application database, a relational database management system (RDBMS), etc. Each such data store may be contained within a computing device employing a computer operating system such as those described above, or may be accessed over a network in one or more of a variety of ways. The file system may be accessible from the computer operating system and may include files stored in various formats. The RDBMS may employ a Structured Query Language (SQL) in addition to a language for creating, saving, editing, and executing stored procedures, such as the PL / SQL language described above.

[0060] While the detailed description and drawings or figures support and explain the present disclosure, the scope of the present disclosure is defined solely by the claims. While the best mode and some alternative embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for carrying out the disclosure defined in the appended claims. Furthermore, the features of the embodiments shown in the drawings or described herein should not necessarily be understood as independent embodiments. Rather, each of the characteristics described in one of the example embodiments can be combined with one or more other desirable characteristics from other embodiments, resulting in other embodiments not described in words or with reference to the drawings. Accordingly, such other embodiments are encompassed within the regulated framework of the appended claims.

Claims

1. 1. A system comprising: a controller having at least one processor and at least one non-transitory tangible memory having instructions recorded thereon for executing a method for obtaining a profile of a lens capsule of an eye; Including, the profiles are represented by respective median planes and respective equatorial planes separated by respective transition points; Execution of the instructions by the processor causes the controller to: acquiring imaging data of a portion of the lens capsule as seen through a pupil of the eye, the imaging data including posterior data points and anterior data points; transforming the imaging data into a calibrated reference coordinate system having a first axis (X) and a second axis (Y); fitting the imaging data to the respective central planes of the predefined central regions of the adjusted reference coordinate system; Obtaining transition coordinates as coordinate values ​​of each transition point in the positive X domain; determining a set of fitting parameters for the respective median planes and the respective equatorial planes based on the transition coordinates and a plurality of constraints; obtaining the profile based on the set of fitting parameters of the respective median planes and the respective equatorial planes; the controller is configured to optimize intraocular lens selection; the intraocular lens is an accommodative lens that can change its shape in response to an external force; the set of fitting parameters includes a first forward parameter (Ga), a second forward parameter (Pa), a first backward parameter (Gp), a second backward parameter (Pp), and respective coordinates (Xe, Ye) of vertices of the adjusted reference coordinate system; each of the equatorial planes includes a front equatorial plane and a rear equatorial plane that intersect at the vertex; system.

2. the controller is configured to select an intraocular lens based at least in part on the profile of the lens capsule. The system of claim 1 .

3. Transforming the imaging data into the adjusted reference coordinate system includes: fitting the rearward data points and the forward data points to a first circle and a second circle, respectively, and determining an intersection point of the first circle and the second circle; translating the rear data points and the front data points so as to rotate about the centers of the respective intersection points such that the tilt angle of the rotation is zero; The system of claim 1 , comprising:

4. the controller is configured to fit the respective central planes of the adjusted reference coordinate system to respective conic equations of conical surfaces; the controller is configured to determine a cone x-intercept as the coordinate on the first axis (X) where the respective cone equation intersects in a positive x-domain, the transition coordinate being the product of the cone x-intercept and a predefined constant, the predefined constant being less than 1; The system of claim 1 .

5. each said central surface includes a central front surface; the controller is configured to represent the central front surface as an elliptical cone characterized by a first plurality of variables (Ka, Qa, Ra), the first plurality of variables (Ka, Qa, Ra) being obtained by fitting the imaging data to the central front surface of the predefined central region of the adjusted reference coordinate system; The central front surface (Ca(x)) is [Equation 1] is defined as The system of claim 1 .

6. each said central surface includes a central aft surface; the controller is configured to represent the central posterior surface as an elliptical cone characterized by a second plurality of variables (Kp, Qp, Rp), the second plurality of variables (Kp, Qp, Rp) being obtained by fitting the imaging data to the central posterior surface of the predefined central region of the adjusted reference coordinate system; The central posterior surface (Cp(x)) is [Equation 2] is defined as The system of claim 1 .

7. the front equatorial surface and the rear equatorial surface are represented by respective tilted parabolic functions; The equatorial front surface is based in part on the first anterior parameter (Ga), the second anterior parameter (Pa), and the respective coordinates (Xe, Ye) of the vertices, and the equatorial front surface (Ea(x)) is [Equation 3] is defined as The system of claim 1 .

8. The equatorial posterior surface is based in part on the first posterior parameter (Gp), the second posterior parameter (Pp), and the respective coordinates (Xe, Ye) of the vertices, and the equatorial posterior surface (Ep(x)) is [Equation 4] is defined as The system of claim 7.

9. each of the central surfaces includes a central rear surface and a central front surface; each of the equatorial planes includes a front equatorial plane and a rear equatorial plane; the plurality of constraints include a first equation corresponding to respective values ​​of the central-front surface and the equatorial-front surface in the transition coordinates, and a second equation corresponding to the respective values ​​of the central-posterior surface and the equatorial-posterior surface in the transition coordinates; The system of claim 1 .

10. The plurality of constraints are: a third equation fitting the first derivative of each of the central front and the equatorial front in the transition coordinates; a fourth equation fitting the respective first derivatives of the central posterior surface and the equatorial posterior surface in the transition coordinate; The system of claim 9 , comprising:

11. The plurality of constraints are: a fifth equation fitting the second derivative of each of the central front and the equatorial front in the transition coordinates; a sixth equation fitting the respective second derivatives of the central posterior surface and the equatorial posterior surface in the transition coordinate; The system of claim 9 , comprising:

12. 1. A system comprising: a controller having at least one processor and at least one non-transitory tangible memory having instructions recorded thereon for executing a method for obtaining a profile of a lens capsule of an eye; Including, the profiles are represented by respective median planes and respective equatorial planes separated by respective transition points; Execution of the instructions by the processor causes the controller to: obtaining a lens diameter and at least two variables from a set of variables including lens thickness, a central anterior apex, and a central posterior apex; setting a transition coordinate as the product of said lens diameter and a predefined constant, the predefined constant being less than 0.5; simultaneously solving a first group of constraints based in part on the transition coordinates to obtain a first plurality of variables (Ka, Qa, Ra) and a pair of forward parameters (Ga, Pa); simultaneously solving a second group of constraints based in part on the transition coordinates to obtain a second plurality of variables (Kp, Qp, Rp) and a pair of backward parameters (Gp, Pp); system.

13. each said medial surface including a central-anterior surface and a central-posterior surface, and each said equatorial surface including an equatorial-anterior surface and an equatorial-posterior surface; the controller is configured to represent the central-front surface and the central-rear surface as respective elliptical cones characterized by the first plurality of variables (Ka, Qa, Ra) and the second plurality of variables (Kp, Qp, Rp), respectively; the controller is configured to represent the equatorial-front surface and the equatorial-rear surface as respective tilted parabolas characterized by the pair of anterior parameters (Ga, Pa) and the pair of posterior parameters (Gp, Pp), respectively; The system of claim 12.

14. the controller is configured to select an intraocular lens based at least in part on the profile of the lens capsule. The system of claim 13.

15. The first group of constraints is a first equation corresponding to the respective values ​​of the central front and the equatorial front in the transition coordinates; a second equation fitting the first derivative of each of the central front and the equatorial front in the transition coordinates; a third equation fitting the second derivative of each of the central front and the equatorial front in the transition coordinates; a fourth equation that aligns each coordinate of the central front surface with the central front vertex; The system of claim 13 , comprising:

16. The second group of constraints is: a fifth equation corresponding to the respective values ​​of the central posterior surface and the equatorial posterior surface in the transition coordinate; a sixth equation corresponding to the first derivative of each of the central posterior surface and the equatorial posterior surface in the transition coordinate; a seventh equation fitting the second derivatives of the central posterior surface and the equatorial posterior surface in the transition coordinate; an eighth equation that aligns each coordinate of the central posterior surface with the central posterior vertex; The system of claim 13 , comprising:

17. The controller obtaining the profile based on the first plurality of variables (Ka, Qa, Ra), the pair of forward parameters (Ga, Pa), the second plurality of variables (Kp, Qp, Rp), and the pair of backward parameters (Gp, Pp); obtaining an updated value of the lens diameter based on the profile; and obtaining an updated value of the transition coordinate based on the updated value of the lens diameter. updating the first plurality of variables (Ka, Qa, Ra) and the pair of forward parameters (Ga, Pa) by simultaneously solving the first group of constraints based in part on the updated transition coordinates if a difference between the updated transition coordinates and the transition coordinates is greater than a predefined threshold; updating the second plurality of variables (Kp, Qp, Rp) and the pair of backward parameters (Gp, Pp) by simultaneously solving the second group of constraints based in part on the updated transition coordinates if the difference between the updated transition coordinates and the transition coordinates is greater than the predefined threshold; The system of claim 13 configured to:

18. 1. A method for obtaining a profile of a lens capsule of an eye using a controller having at least one processor and at least one non-transitory tangible memory, comprising: acquiring imaging data of a portion of the lens capsule as seen through a pupil of the eye, the imaging data including posterior data points and anterior data points; transforming, via the controller, the imaging data into a calibrated reference coordinate system having a first axis (X) and a second axis (Y), wherein the profile of the lens capsule is represented by respective medial planes and respective equatorial planes separated by respective transition points in the calibrated reference coordinate system; fitting the imaging data to the respective central planes of a predefined central region of the adjusted reference coordinate system via the controller; obtaining, via the controller, transition coordinates as coordinate values ​​of the respective transition points in a positive X domain; determining, via the controller, sets of fitting parameters for the respective median planes and the respective equatorial planes based on the transition coordinates and a plurality of constraints; obtaining, via the controller, the profiles based on the sets of fitting parameters for the respective median planes and the respective equatorial planes; Including, the controller is configured to optimize intraocular lens selection; the intraocular lens is an accommodative lens that can change its shape in response to an external force; the set of fitting parameters includes a first forward parameter (Ga), a second forward parameter (Pa), a first backward parameter (Gp), a second backward parameter (Pp), and respective coordinates (Xe, Ye) of vertices of the adjusted reference coordinate system; each of the equatorial planes includes a front equatorial plane and a rear equatorial plane that intersect at the vertex; method.

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