Patent Description:
Ophthalmic surgery saves and improves the vision of tens of thousands of patients every year. However, given the sensitivity of vision to even small changes in the eye and the minute and delicate nature of many eye structures, ophthalmic surgery is difficult to perform and the reduction of even minor or uncommon surgical errors or modest improvements in accuracy of surgical techniques can make an enormous difference in the patient's vision after the surgery.

Ophthalmic surgery is surgery performed on the eye or any part of the eye. Ophthalmic surgery is regularly performed to repair retinal defects, repair eye muscles, remove cataracts or cancer, or to restore or improve vision. Refractive eye surgery, for example, is a type of ophthalmic surgery used to improve the refractive state of the eye for the purpose of decreasing or eliminating dependency on glasses or contact lenses. Refractive surgery procedures may include surgically remodeling the cornea and may be performed by lasers.

In refractive surgery and various other ophthalmic surgical procedures, ablation may be performed, which is the use of a laser to remove tissue. When performing ophthalmic surgery with lasers, an eye tracking system is often used to assist in centering the laser or otherwise controlling its position, monitoring the position of the eye, and maintaining the eye in an acceptable position throughout the procedure. Throughout an ophthalmic surgical procedure, the patient is positioned on a support.

<CIT> discloses a patient positioning system for use with a patient, which comprises an optical image sensor. The optical image sensor measures an optical image of a tissue structure of an eye of the patient. An image sensor support supports the image sensor. A patient support supports the patient. A linkage is coupled to the image sensor support with the patient support. A processor is coupled to the optical image sensor to determine a gradient of an illumination level of the optical tissue structure image. The processor is coupled to the linkage and configured to articulate the linkage so as to adjust a separation distance from the tissue structure to the image sensor in response to the gradient of the optical tissue structure image.

<CIT> discloses an eye tracking and positioning system for use with a refractive laser system including a camera interface, a computer, and a system for moving the patient relative to the laser beam. The computer includes a video frame grabber which extracts images of the eye from the camera, and is programmed to perform an eye tracking algorithm. The eye tracking algorithm calculates the exact center of the eye pupil, and compares the center with the desired location of the laser beam, as determined by a surgeon, with an image processing algorithm. If the relative location of the eye center and the laser beam fall outside a predetermined value, the patient chair, and thereby the patient, is repositioned relative to the laser beam, as opposed to the laser beam being repositioned relative to the patient. The repositioning counters the movement of the eye.

<CIT> discloses a method for determining an actual value of at least one system parameter or a deviation from a target value of at least one system parameter of a system for treating an eye by means of a treatment laser beam emitted by the system. A surface of a calibration body is ablated with at least one partial beam of the treatment laser beam with a predetermined ablation program. The surface ablated by the treatment laser beam is examined by means of aberrometry and/or profilometry, and the actual value of the system parameter or the deviation from the target value of the system parameter is determined based on the examination.

The present disclosure provides a system and a method for automated fine adjustment of an ophthalmic surgery support, wherein the automated fine adjustment method is performed during initialization of an eye tracking system or during equipment calibration.

According to an embodiment, a system is provided which includes a support, a control device operable to control a position of the support, an eye tracking system operable to detect a detectable position of an eye and generate data relating to the detectable position, a processing system comprising at least one programmed processing device, the processing system operable to receive data from the eve tracking system relating to the detectable position, determine a detectable position of the eye in relation to a center of a detection field of the eye tracking system, determine a direction and a distance the detectable position of the eye must be adjusted to be centered in relation to the center of the detection field of the eye tracking system, generate a control signal operable to adjust the position of the support so that the eye is centered in relation to the center of the detection field of the eye tracking system, and transmit the control signal to the control device to adjust the position of the support.

In additional embodiments, which may be combined with one another unless clearly exclusive: the support is a couch or a bed; a device for manual confirmation of an adjustment operable to input a confirmation is a switch, a key or a joystick; adjusting the position of the support so that the eye is centered in relation to the center of the detection field of the eye tracking system is performed automatically, without manual confirmation or automatically but only after manual confirmation; and adjusting the position of the support is performed during initialization of the eye tracking system, during surgery, during equipment calibration, during equipment calibration including automated fine adjustment of test targets, or during a docking procedure of a suction cone for a femtosecond laser surgery.

According to an embodiment, a method for automated fine adjustment of a support is provided, wherein the automated fine adjustment is performed during initialization of an eye tracking system or during equipment calibration. The method includes detecting a detectable position of an eye, generating data relating to the detectable position, processing data relating to the detectable position, determining a detectable position of the eye in relation to a center of a detection field of an eye tracking system, determining a direction and a distance the detectable position of the eye must be adjusted to be centered in relation to the center of the detection field of the eye tracking system, generating a control signal operable to adjust an ophthalmic surgery support so that the eye is centered in relation to the center of the detection field of the eye tracking system, and transmitting the control signal to a control device operable to adjust a position of the ophthalmic surgery support.

In additional embodiments, which may be combined with one another unless clearly exclusive: the support is a couch or a bed; adjusting a position of an ophthalmic surgery support so that the eye is centered in relation to the center of the detection field of the eye tracking system is performed automatically, without manual confirmation, or automatically but only after manual confirmation; and adjusting the position of the support is performed during initialization of the eye tracking system, during surgery, during equipment calibration, during equipment calibration including automated fine adjustment of test targets, or during a docking procedure of a suction cone for a femtosecond laser surgery.

The above systems may be used with the above methods and vice versa. In addition, any system described herein may be used with any method described herein and vice versa.

For a more complete understanding of the present invention and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, which are not to scale, in which like numerals refer to like features, and in which:.

In the following description, details are set forth by way of example to facilitate discussion of the disclosed subject matter. It should be apparent to a person of ordinary skill in the field, however, that the disclosed embodiments are exemplary and not exhaustive of all possible embodiments.

The present disclosure provides systems and methods for automated fine adjustment of a support used in ophthalmic surgery, wherein the automated fine adjustment method is performed during initialization of an eye tracking system or during equipment calibration.

During ophthalmic surgery, a patient is positioned on a support, for example, a couch or bed. An eye tracking system is used to determine the position of the eye, monitor the position of the eye, and assist in maintaining the eye in an acceptable position throughout the surgical procedure. Primary tracking operations are first used to determine the position of the eye to determine whether the eye is centered in relation to the detection field of the eye tracking system. Once centered, secondary tracking operations may be initialized to monitor the position of the eye throughout the duration of the procedure.

Before secondary tracking operations can be initialized to monitor the position of the eye throughout the procedure, the eye tracking system should first be centered. The eye tracking system may be centered in relation to any point of the eye, for example, the cornea or other structure of interest. If the eye is not centered prior to secondary eye tracking system initialization, this can cause interference that affects further tracking. Such interference may lead to undesirable offsets and rotations that can result in errors in ablation and other higher-order aberrations. The present disclosure provides systems and methods for automated fine adjustment of the support to center the eye in relation to the center of the detection field of the eye tracking system, wherein the automated fine adjustment method is performed during initialization of an eye tracking system or during equipment calibration.

To perform automated fine adjustment, the systems of the present disclosure provide a support, a control device to adjust the position of the support, an eye tracking system, and a processing system that receives data from the eye tracking system, determines a position of the eye in relation to a center of the detection field of the eye tracking system, generates a control signal for adjusting the position of the support so that the eye is centered in relation to the center of the detection field of the eye tracking system, and transmits the control signal to the control device to adjust the position of the support. Because any camera of an eye tracking system may be focused at any possible distance by adjusting or replacing optical elements of the camera, such as lenses, automated fine adjustment may be performed without the eye being first positioned at a threshold distance.

The systems and methods of the present disclosure provide the user many benefits. For instance, ophthalmic laser surgery implementing such systems and methods is more reliable because treatment errors due to improper eye alignment can be minimized and because automated adjustment is faster than manual adjustment. Automated fine adjustment systems can position the patient more accurately than manual adjustment because such systems can detect a target location more precisely than a user can. Automated adjustment is also more accurate and more precise because objective data for the eye is available, at least in the X-Y plane of the detectable range. The X-Y plane is defined as the plane roughly perpendicular to the apex of the cornea. A defined offset may be implemented to initiate eye tracking beginning from a defined position offset from the cornea or other specified starting position. Automated fine adjustment may also be used for equipment calibration, such as calibration using test targets, and in docking a suction cone for femtosecond laser ophthalmic surgery.

Referring now to the drawings, <FIG> is a schematic representation of elements of a system <NUM> for automated fine adjustment of an ophthalmic surgery support. System <NUM> includes support <NUM> connected to control device <NUM>, operable to adjust the position of the support, eye tracking system <NUM>, and processing system <NUM>. During ophthalmic surgery, a patient is placed on support <NUM>. Eye tracking system <NUM> includes at least one camera <NUM> operable to detect a detectable position of the eye <NUM> and generate data relating to the detectable position. The camera may include an autofocus feature. Eye tracking system <NUM> transmits data relating to the detectable position to processing system <NUM>. Processing system <NUM> processes the data relating to the detectable position to determine the position of the eye and whether the eye is centered in relation to the center of the detection field <NUM> of the eye tracking system. Any point of the eye may be specified as the point to be centered in relation to the center of the detection field. For instance, the center-point of the pupil <NUM> or any other structure of interest. Defined offsets may also be specified to cause tracking operations to be initialized from a defined offset in relation to the point of centering. System <NUM> further includes a device for manual confirmation of an adjustment <NUM> and display <NUM>. Device for manual confirmation <NUM> may be any device that can input a confirmation, for example, a button, switch, key or joystick. Device for manual confirmation <NUM> may also be a contactless device that can input a confirmation, for example, by voice recognition or gesture control.

Processing system <NUM> is connected to other system components, wirelessly or through a wired connection, which include eye tracking system <NUM> and control device <NUM>, and in certain embodiments, a device for manual confirmation of adjustment <NUM> and a display <NUM>. As shown in <FIG>, processing system <NUM> receives data from eye tracking system <NUM> relating to the detectable position of the eye, and processes the data to determine whether center-point of the pupil <NUM> is centered in relation to field of detection <NUM>. If the center-point of the pupil <NUM> is not centered in relation to field of detection <NUM>, processing system <NUM> determines the direction and distance support <NUM> must be adjusted for center-point of the pupil <NUM> to be centered. Processing system <NUM> generates and transmits a control signal for automated fine adjustment to control device <NUM>, in which the control signal indicates the direction and distance to adjust the support. System <NUM> is further configured to require manual confirmation of an adjustment to be input via device <NUM> before automated fine adjustment is performed. For example, the control device will not adjust the support until manual confirmation is input.

Processing system <NUM> also generates a pictorial representation based on data received relating to the detectable position of the eye. The pictorial representation is transmitted to display <NUM> to be presented as an image during ophthalmic surgery. The image may include, for example, the position of the eye <NUM>, the center of the pupil <NUM>, the field of detection <NUM> of eye tracking system <NUM>, and the center <NUM> of the field of detection <NUM>. The image may further include an indication of whether center of the pupil <NUM> is centered in relation to center <NUM> of field of detection <NUM>. To indicate whether center of the pupil <NUM> is centered, the image may include colored graphics, for example, green graphics to indicate the pupil is centered and orange graphics to indicate the pupil is not centered. Display <NUM> may further indicate whether automated fine adjustment is required to cause center of the pupil <NUM> to be centered. Since the system is configured to require manual adjustment, the image further includes an indication that an adjustment is pending manual confirmation, including the direction and distance determined for the adjustment.

A processor <NUM> of processing system <NUM> may comprise, for example a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data. In some embodiments, processor <NUM> may interpret and/or execute program instructions and/or process data stored in memory <NUM>. Memory <NUM> may be configured in part or whole as application memory, system memory, or both. Memory <NUM> may include any system, device, or apparatus configured to hold and/or house one or more memory modules. Each memory module may include any system, device or apparatus configured to retain program instructions and/or data for a period of time (e.g., computer-readable media). The various servers, electronic devices, or other machines described may contain one or more similar such processors or memories for storing and executing program instructions for carrying out the functionality of the associated machine.

<FIG> is a digitally processed image <NUM> of a pupil <NUM> of an eye <NUM> that is off center in relation to the center of the detection field of eye tracking system <NUM>, and requires further adjustment to be centered. To assist in centering the pupil, the image shown in <FIG> presents a graphic indicating the valid range for centering <NUM>. The valid range for centering <NUM> may be visually represented by a square. The square may be colored to indicate that the eye is not yet centered, for example, an orange square. As shown in <FIG>, the square may also be illustrated with solid lines to indicate that the eye is not centered. In contrast, the square may be illustrated with dotted lines to indicate that the eye is centered, as shown in <FIG>. To assist in centering, the image further indicates X-axis <NUM> and Y-axis <NUM>, defined in relation to the x-y plane roughly perpendicular to the apex of the cornea. It is important to center the pupil with the center of the detection field of the eye tracking system <NUM> before initialization of further tracking operations because the accuracy of subsequent tracking operations relies upon the starting point being correctly centered. In <FIG>, center of the pupil <NUM> should be adjusted to be centered in relation to center of detection field <NUM>.

<FIG> is a digitally processed image <NUM> of a pupil <NUM> of an eye <NUM> that is centered in relation to the center of the detection field of the eye tracking system <NUM>, and does not require further adjustment to be centered. To assist in centering the pupil, the image shown in <FIG> presents a graphic indicating the valid range for centering <NUM>. The valid range for centering <NUM> may be visually represented by a square. The square may be colored to indicate that the eye is not yet centered, for example, a green square. As shown in <FIG>, the square may also be illustrated with dotted lines to indicate that the eye is centered. To assist in centering, the image further indicates X-axis <NUM> and Y-axis <NUM>, defined in relation to the x-y plane roughly perpendicular to the apex of the cornea. It is important to center the pupil with the center of the detection field of the eye tracking system <NUM> before initialization of further tracking operations because the accuracy of subsequent tracking operations relies upon the starting point being correctly centered. In <FIG>, center of the pupil <NUM> does not require further adjustment to be centered in relation to center of detection field <NUM>.

<FIG> is a digitally processed image <NUM> of a pupil <NUM> in a valid range for centering <NUM>, in relation to the center of the detection field of the eye tracking system; but, the image illustrates that the pupil could be positioned closer to the actual center of the detection field by implementing automated fine adjustment of the support. The valid range for centering <NUM> may be visually represented by a square. The square may be colored to indicate that the eye is centered. The square may also be illustrated with dotted lines to indicate that the eye is centered. In <FIG>, for example, the square is illustrated with dotted lines, indicating that the center of pupil <NUM> is within valid range for centering <NUM>. However, the center of pupil <NUM> is still not centered in relation to the center of the detection field of the eye tracking system <NUM>. To assist in centering, the image further indicates X-axis <NUM> and Y-axis <NUM>, defined in relation to the x-y plane roughly perpendicular to the apex of the cornea. Centering error <NUM> is shown in the top left corner of the valid range for centering <NUM>. Automated fine adjustment can be used to correct error <NUM> by adjusting pupil <NUM> in direction <NUM> until it reaches ideal position <NUM>.

<FIG> is a flow chart of a method <NUM> for performing automated fine adjustment of an ophthalmic surgery support. The method claimed relates to automated fine adjustment being performed during initialization of an eye tracking system or during equipment calibration, only. All other method steps do not relate to the method claimed, but are disclosed for explanatory reasons, only. At step <NUM>, an input is received by a processor with a memory, wherein the input indicates a position of an eye. At step <NUM>, the position of the eye is evaluated to determine if the eye is centered in relation to the center of the detection field of the eye tracking system. If the eye is centered in relation to the center of the detection field of the eye tracking system, then at <NUM>, the automated fine adjustment process terminates. If the eye is not centered in relation to the center of the detection field of the eye tracking system, then at <NUM>, the direction and distance the eye must be adjusted to be centered in relation to the center of the detection field of the eye tracking system may be determined.

At step <NUM>, a control signal is generated for automated fine adjustment, the control signal indicating the distance and direction the eye may be adjusted to be centered in relation to the center of the detection field of the eye tracking system. At step <NUM>, whether manual confirmation is required to perform automated fine adjustment is determined. If manual confirmation is not required, then at <NUM>, automated fine adjustment may be performed automatically, without manual confirmation. If manual confirmation is required, then at <NUM>, whether manual confirmation has been input may be determined. If manual confirmation has been input, then at <NUM>, automated fine adjustment may be performed automatically, without manual confirmation. But, if manual confirmation has not yet been input, then at <NUM>, the control signal generated may be kept on standby and automated fine adjustment will not be performed until manual confirmation is input. At step <NUM>, the control signal generated may be kept on standby prior to or after being transmitted to the control device of the support.

The patient may be positioned within a detection range of the eye tracking system before any steps of the method are performed, and a warning may be generated if the patient is not within the detection range at the beginning of performance of the method or if the patient moves out of the detection range during performance of the method.

Method <NUM> may be implemented using the system of <FIG>, or any other suitable system. The preferred initialization point for such methods and the order of their steps may depend on the implementation chosen. Some steps may be optionally omitted, repeated, or combined. Some steps of such methods may be executed in parallel with other steps. In certain embodiments, the methods may be implemented partially or fully in software embodied in computer-readable media.

For the purposes of this disclosure, computer-readable media may include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Computer-readable media may include, without limitation, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such wires, optical fibers, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing.

Claim 1:
A system (<NUM>) for automated fine adjustment of an ophthalmic surgery support (<NUM>) comprising:
a support (<NUM>);
a control device (<NUM>) operable to control a position of the support (<NUM>);
an eye tracking system (<NUM>; <NUM>) operable to detect a detectable position of an eye (<NUM>) and generate data relating to the detectable position;
a display (<NUM>);
a device (<NUM>) for manual confirmation of an adjustment, the device operable to input a confirmation; and
a processing system (<NUM>) comprising at least one programmed processing device, the processing system (<NUM>) operable to:
receive data from the eye tracking system (<NUM>; <NUM>) relating to the detectable position;
determine a detectable position of the eye (<NUM>) in relation to a center of a detection field (<NUM>) of the eye tracking system (<NUM>; <NUM>);
determine a direction and a distance the detectable position of the eye (<NUM>) must be adjusted to be centered in relation to the center of the detection field (<NUM>) of the eye tracking system (<NUM>; <NUM>);
generate a control signal operable to adjust the position of the support (<NUM>) so that the detectable position of the eye (<NUM>) is centered in relation to the center of the detection field (<NUM>) of the eye tracking system (<NUM>; <NUM>); and
transmit the control signal to the control device (<NUM>) to adjust the position of the support (<NUM>),
characterised in that
the processing system (<NUM>) is configured to generate a pictorial representation based on the received data and to transmit the pictorial representation to the display (<NUM>) to be presented as an image, the image including the direction and the distance determined for the adjustment and an indication that the adjustment is pending manual confirmation, and
wherein adjusting the position of the support so that the eye (<NUM>) is centered in relation to the center of the detection field (<NUM>) of the eye tracking system (<NUM>; <NUM>) is performed automatically, but only after manual confirmation.