Method and system for automated determination of patient eye level

Abstract

An ophthalmic surgical system includes a robotic arm disposed above a patient's eye. A positioning camera is disposed on the robotic arm and positioned to visualize the patient's eye. A processor is electrically coupled to the positioning camera. The processor is configured to receive an indication of a position of the robotic arm relative to a fixed reference, determine a focal distance between the positioning camera and the patient's eye, compare the focal distance to the position of the robotic arm, and determine a patient's eye level relative to the fixed reference.

Description

Technical Field

[0001] This disclosure generally relates to methods and systems for regulating intraocular pressure (“IOP”), and more specifically, but not in a limited manner, to methods and systems for automatically determining the level of a patient’s eye relative to a fixed reference. Background Technology

[0002] This section provides background information to help better understand the various aspects of this disclosure. It should be understood that the statements in this section of this document are to be interpreted in this context and are not an admission that they are prior art.

[0003] IOP (Intraocular Oscillation Point) is a crucial parameter during ophthalmic surgical interventions, including refractive surgery, lens replacement surgery, and retinal surgery. During these interventions, an irrigation fluid is typically introduced into the patient's eye. The flow rate and pressure of this fluid determine the resulting IOP. The flow rate and pressure of the irrigation fluid depend, at least in part, on the vertical position of the patient's eye (often referred to as "patient eye level"). Therefore, accurate determination of the patient's eye level is necessary to achieve the desired IOP. Current methods for measuring patient eye level involve the surgeon manually visualizing the patient's eye relative to indicators such as markers or lines on the surgical equipment. This method of determining patient eye level suffers from parallax errors and inefficiencies due to the surgical workflow. Summary of the Invention

[0004] Various aspects of this disclosure relate to an ophthalmic surgical system. The ophthalmic surgical system includes a robotic arm positioned above a patient's eye. A positioning camera is mounted on the robotic arm and positioned to visualize the patient's eye. A processor is electrically coupled to the positioning camera. The processor is configured to: receive indications of the position of the robotic arm relative to a fixed reference, determine the focal length between the positioning camera and the patient's eye, compare the focal length with the position of the robotic arm, and determine the level of the patient's eye relative to the fixed reference.

[0005] Various aspects of this disclosure relate to a surgical microscope. The surgical microscope includes a positioning camera positioned to visualize a patient's eye. An encoder is coupled to the positioning camera. The encoder is configured to determine the position of the positioning camera relative to a fixed reference. A processor is electrically coupled to the encoder and the positioning camera. The processor is configured to: receive an indication of the position of the positioning camera relative to the fixed reference, determine the focal length between the positioning camera and the patient's eye, compare the focal length with the position of a robotic arm, and determine the level of the patient's eye relative to the fixed reference.

[0006] Various aspects of this disclosure relate to a method for determining the level of a patient's eye. The method includes: focusing a positioning camera on the patient's eye; determining the position of the positioning camera relative to a fixed reference; determining the focal length between the positioning camera and the patient's eye; comparing the focal length with the position of the positioning camera relative to the fixed reference; and determining the level of the patient's eye.

[0007] This summary is provided to introduce a selection of concepts further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help limit the scope of the claimed subject matter. Attached Figure Description

[0008] This disclosure is best understood in conjunction with the accompanying drawings and the following detailed description. It should be emphasized that, in accordance with industry standard practice, the various features are not drawn to scale. In fact, for clarity of discussion, the dimensions of the various features may be arbitrarily increased or decreased.

[0009] Figure 1 It is a block diagram of an ophthalmic surgical system based on various aspects of this disclosure;

[0010] Figure 2 These are schematic diagrams of an ophthalmic surgical system in use, based on various aspects of this disclosure; and

[0011] Figure 3 This is a flowchart of the process for determining the level of a patient's eye, based on various aspects of this disclosure. Detailed Implementation

[0012] Various embodiments will now be described more fully with reference to the accompanying drawings. However, this disclosure can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0013] Figure 1 This is a block diagram of an ophthalmic surgical system 100. System 100 includes surgical instruments 102, a user interface 104, and a surgical microscope 106. In various embodiments, surgical instruments 102 may include any type of component or machine used in ophthalmic surgical interventions, including but not limited to handsets, pneumatic systems, laser sources, and illumination sources. Surgical instruments 102 may be used for ophthalmic surgical techniques, such as phacoemulsification, vitreoretinal surgery, laser refractive surgery, or any of a variety of other ophthalmic surgical methods known to those skilled in the art. In various embodiments, the user interface 104 includes any type of keyboard, switch, knob, pedal, button, pointing device, or other suitable component for receiving selections of surgical parameters from the user. The surgical microscope 106 may include any style of optical or electronic device or component assembly that provides the surgeon with a view of the patient's eye 112.

[0014] Surgical instrument 102 operates under the control of processor 108. Surgical instrument 102 also includes memory 110 capable of storing surgical parameter information. Processor 108 may be any microprocessor, microcontroller, programmable element, or other means or set of means for processing instructions for controlling surgical instrument 102. Processor 108 receives selections of parameters from user interface 104 and controls the operation of surgical parameters accordingly. Processor 108 also monitors surgical parameters during ophthalmic surgical interventions. Memory 110 may be any suitable form of volatile or non-volatile information storage device accessible by processor 108, including, for example, optical, electronic, or magnetic media.

[0015] Still referencing Figure 1 In various embodiments, the surgical system 100 includes a display device 120. The display device 120 includes any suitable optical or electronic components or a combination thereof capable of generating a visually perceptible display of surgical parameters on an image of the patient's eye 112. For example, the display device 120 may project light onto the surface of the patient's eye 112 to generate an image that is captured by the surgical microscope 106 along with the image of the eye 112. In other embodiments, the display device 120 may project a display into the optical path of the surgical microscope 106 to produce a display on the image of the eye 112. Such embodiments may allow the display to be focused or magnified along with the image of the eye 112. In other embodiments, the display and the image of the eye may be focused or sized independently. In yet another embodiment, the display device 120 may be incorporated into the eyepiece of the surgical microscope 106. The display device 120 may be configured to share and communicate with the processor 108 and / or memory 110 to allow adjustment of the surgical parameter display based on user-selected surgical parameters and real-time changes in those parameters during ophthalmic surgical interventions.

[0016] In some embodiments, data bus 114 (a serial bus in the illustrated embodiment) couples various components of the ophthalmic surgical system 100 together, enabling data communication between them. In typical embodiments, data bus 114 may include, for example, hardware, software embedded in a computer-readable medium, or any combination of coded logic (e.g., firmware) incorporated into or otherwise stored in hardware to couple the components of the ophthalmic surgical system 100 to each other. By way of example, and not limitation, data bus 114 may include an Accelerated Graphics Port (AGP) or other graphics bus, a Controller Area Network (CAN) bus, a Front Side Bus (FSB), HyperTransport (HT) Interconnect, Infinite Bandwidth Interconnect, Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or any other suitable bus, or a combination of two or more of these. In various embodiments, data bus 114 may include any number, type, or configuration of data buses 114 where appropriate.

[0017] Figure 2 This is a schematic diagram of an ophthalmic surgical system 100 in use. The ophthalmic surgical system 100 includes a positioning camera 204 mounted on a robotic arm 206. In various embodiments, the robotic arm 206 and the positioning camera 204 are located below a surgical microscope 106. In various embodiments, the positioning camera 204 is a three-dimensional camera; however, in other embodiments, other types of cameras may be used. A processor 108 is electrically coupled to the positioning camera 204 via a data bus 114. The robotic arm 206 is capable of movement, such as vertical translation, horizontal translation, angular movement, and rotational movement. In various embodiments, an encoder 207 (such as a linear encoder or angle encoder or other similar device) is used to transmit the vertical position of the robotic arm 206 relative to a fixed reference 216 to the processor 108. In various embodiments, the encoder 207 converts the position of at least one of the robotic arm 206 and the positioning camera 204 into an electrical signal that can be transmitted to the processor 108.

[0018] During the procedure, the positioning camera 204 is positioned above the patient's eye 112. The encoder 207 transmits the position (h) of the robotic arm 206 relative to a fixed reference 216 to the processor 108. In various embodiments, the fixed reference 116 may be, for example, the operating room floor; however, in other embodiments, any fixed reference point can be used. The positioning camera 204 attempts to focus on the patient's eye 112. The processor 108 determines the focal length (z) between the positioning camera 204 and the eye 112. By comparing the focal length (z) with the position (h) of the positioning camera 204 relative to the fixed reference 216, the processor 108 determines the patient's eye level relative to the fixed reference 216. For example, in the specific case where the fixed reference 216 is the operating room floor, the difference between the height (h) of the positioning camera 204 above the operating room floor and the focal length (z) can determine the patient's eye level. In various embodiments, the patient's eye level is determined prior to ophthalmic surgical intervention and is used to maintain the desired IOP setpoint. In other embodiments, processor 108 continuously determines the focal length (z) of positioning camera 204 and continuously determines the patient's eye level. Continuously determining the patient's eye level helps adjust IOP due to patient repositioning, for example, during ophthalmic surgical intervention.

[0019] Figure 3 This is a flowchart of a process 300 for determining a patient's eye level. Method 300 begins at step 302. At step 304, the positioning camera 204 is oriented above the patient's eye 112. At step 306, the encoder 207 transmits the position (h) of the positioning camera 204 relative to a fixed reference 216 to the processor 108. At step 308, the positioning camera 204 is focused on the patient's eye 112. At step 310, the focal length (z) of the positioning camera 204 is transmitted to the processor 108. At step 312, the processor 108 compares the focal length (z) with the position (h) of the positioning camera 204 and determines the patient's eye level. At step 314, the patient's eye level is displayed to the operator via a display device 120. At step 316, the operator uses the patient's eye level to determine the IOP setpoint. Method 300 ends at step 318. However, in various embodiments, process 300 may periodically or continuously monitor the patient's eye level in an effort to ensure proper adjustment of the IOP during ophthalmic surgical intervention. In such embodiments, process 300 does not end at step 318, but returns from step 316 to step 308.

[0020] Depending on the implementation, certain actions, events, or functions of any algorithm described herein may be performed in a different order, and may be added, combined, or omitted entirely (e.g., not all described actions or events are necessary for algorithmic practice). Furthermore, in some embodiments, actions or events may be performed concurrently, for example, through multithreading, interrupt handling, or multiple processors or processor cores or other parallel architectures, rather than sequentially. Although some computer-implemented tasks are described as being performed by a specific entity, other embodiments in which these tasks are performed by different entities are also possible.

[0021] For the purposes of this application, the term "computer-readable storage medium" encompasses one or more tangible computer-readable storage media having a structure. By way of example, and not limitation, a computer-readable storage medium may, where appropriate, include semiconductor-based or other integrated circuits (ICs) (e.g., field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs)), hard disks, HDDs, hybrid hard disk drives (HHDs), optical disks, optical disk drives (ODDs), magneto-optical disks, magneto-optical drives, floppy disks, floppy disk drives (FDDs), magnetic tape, holographic storage media, solid-state drives (SSDs), RAM drives, secure digital cards, secure digital drives, flash memory cards, flash memory drives, or any other suitable tangible computer-readable storage media or combinations thereof.

[0022] As will be understood by those skilled in the art, the term “substantially” is defined as meaning that is, but not necessarily entirely, the specified content (and includes the specified content; for example, substantially 90 degrees includes 90 degrees, and substantially parallel includes parallel). In any disclosed embodiment, the terms “substantially,” “approximately,” “roughly,” and “about” may be replaced with “[percentage]” of the specified content.

[0023] The conditional language used herein, such as “may,” “possibly,” “can,” “for example,” etc., unless explicitly stated otherwise or otherwise understood in the context in which they are used, is generally intended to convey that certain embodiments include certain features, elements, and / or states, while other embodiments do not. Therefore, such conditional language is not intended in general to imply that features, elements, and / or states are required by any means necessary in one or more embodiments, or that one or more embodiments must include logic for determining whether such features, elements, and / or states are included in or will be implemented in any particular embodiment, with or without author input or prompting.

[0024] While the detailed description above has shown, described, and pointed out novel features applicable to various embodiments, it should be understood that various omissions, substitutions, and changes can be made to the form and details of the illustrated apparatus without departing from the spirit of this disclosure. As will be appreciated, the methods described herein can be implemented in forms that do not provide all the features and benefits set forth herein, as some features may be used or practiced separately from other features. The scope of protection is defined by the appended claims, not by the foregoing description. All variations within the equivalent meaning and scope of the claims should be included within their scope.

Claims

1. An ophthalmic surgical system, comprising: A robotic arm positioned above the patient's eyes; A positioning camera is mounted on the robotic arm and positioned to visualize the patient's eyes; A processor, electrically coupled to the positioning camera, is configured to: Receive an indication of the position of the robotic arm relative to a fixed reference; Determine the focal length between the positioning camera and the patient's eye; The patient's eye level relative to the fixed reference is determined by comparing the focal length with the position of the robotic arm; and The intraocular pressure set point is determined based on the patient's eye level.

2. The ophthalmic surgical system as described in claim 1, wherein, The fixed reference point is the operating room floor.

3. The ophthalmic surgical system as described in claim 2, wherein, The position of the robotic arm relative to the fixed reference is the height of the robotic arm above the floor of the operating room.

4. The ophthalmic surgical system as described in claim 2, wherein, The patient's eye level relative to the fixed reference is the height of the patient's eyes above the floor.

5. The ophthalmic surgical system as described in claim 1, wherein, The positioning camera is a three-dimensional camera.

6. The ophthalmic surgical system of claim 1, further comprising an encoder coupled to the robotic arm, the encoder being configured to determine the position of the robotic arm relative to the fixed reference.

7. The ophthalmic surgical system of claim 6, wherein, The encoder is electrically coupled to the processor.

8. The ophthalmic surgical system of claim 7, wherein, The encoder is at least one of a linear encoder and an angle encoder.

9. A surgical microscope, comprising: A positioning camera, which is positioned to visualize the patient's eyes; An encoder coupled to the positioning camera, the encoder being configured to determine the position of the positioning camera relative to a fixed reference; A processor, electrically coupled to the encoder and the positioning camera, is configured to: Receive an indication of the position of the positioning camera relative to the fixed reference; Determine the focal length between the positioning camera and the patient's eye; The patient's eye level relative to the fixed reference is determined by comparing the focal length with the position of the positioning camera; and The intraocular pressure set point is determined based on the patient's eye level.

10. The surgical microscope as claimed in claim 9, wherein, The fixed reference point is the operating room floor.

11. The surgical microscope as claimed in claim 10, wherein, The position of the positioning camera relative to the fixed reference is the height of the positioning camera above the floor of the operating room.

12. The surgical microscope as claimed in claim 11, wherein, The patient's eye level relative to the fixed reference is the height of the patient's eyes above the floor.

13. The surgical microscope as described in claim 9, wherein, The positioning camera is a three-dimensional camera.

14. The surgical microscope as claimed in claim 9, wherein, The encoder is at least one of a linear encoder and an angle encoder.

15. A method for determining the eye level of a patient, the method comprising: Make the positioning camera focus on the patient's eye; Determine the position of the positioning camera relative to a fixed reference; Determine the focal length between the positioning camera and the patient's eye; The patient's eye level is determined by comparing the focal length with the position of the positioning camera relative to the fixed reference; and The intraocular pressure set point is determined based on the patient's eye level.

16. The method of claim 15, wherein, Determining the position of the positioning camera relative to the fixed reference includes determining the height of the positioning camera above the operating room floor.

17. The method of claim 16, wherein, The patient's eye level is the height of the patient's eyes above the floor of the operating room.

18. The method of claim 15, wherein, The determination of the focal length is performed continuously.

19. The method of claim 18, wherein, Continuously determining the focal length helps in adjusting the intraocular pressure setpoint during ophthalmic surgical interventions.

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