Control components for robotic microsurgery procedures

Abstract

Apparatus and methods are described that include a control component unit (30) that includes X, Y, and Z linear rotational axes (52X, 52Y, 52Z) and pitch, roll, and yaw angular rotational axes (70, 72, 74). A control component tool (32) is coupled to the X, Y, and Z linear rotational axes (52X, 52Y, 52Z) and angular rotational axes (70, 72, 74) such that when an operator moves the control component tool along the linear X, Y, and Z directions, rotational motion about the linear rotational axes (52X, 52Y, 52Z) is generated, and when the operator moves the control component tool through roll, pitch, and yaw angular motion, rotational motion about each angular rotational axis (70, 72, 74) is generated. The control component tool is substantially balanced about the linear rotational axes (52X, 52Y, 52Z) and angular rotational axes (70, 72, 74). Other applications are also described.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 447,260 to Sohn, entitled "Control component for robotic microsurgical procedures," filed February 21, 2023, and incorporated herein by reference.

[0002] Some applications of the present invention relate generally to medical devices and methods, and more particularly to devices and methods for robotically performing microsurgical procedures. [Background technology]

[0003] Cataract surgery involves removing the eye's cloudy natural lens (known as a cataract) and replacing it with an intraocular lens. Such surgery typically involves several standard steps performed in succession.

[0004] In the first step, the patient's face around the eyes is disinfected (typically with an iodine solution) and then draped with sterile drapes so that only the eyes are exposed. Once disinfection and draping are complete, the eyes are anesthetized with a local anesthetic, typically administered in the form of liquid eye drops. The eyeball is then exposed using a lid speculum, which holds the upper and lower eyelids open. One or more incisions (typically two or three) are made in the cornea. The incision or incisions are usually made with a specialized blade called a keratome. At this stage, lidocaine is typically injected into the anterior chamber of the eye to further anesthetize the eye. This step is followed by a viscoelastic injection through the corneal incision or incisions. The viscoelastic injection is administered to stabilize the anterior chamber and help maintain intraocular pressure during the remainder of the procedure, as well as to expand the lens capsule.

[0005] The next step, also known as capsulorhexis, involves removing a portion of the anterior lens capsule. Various enhancement techniques have been developed to perform capsulorhexis, including laser-assisted capsulorhexis, zeptorhexis (which utilizes precision nanopulse technology), and marker-assisted capsulorhexis (which uses a predetermined marker to mark the cornea to indicate the desired size of the capsular opening).

[0006] Subsequently, in a step known as hydrodissection, a fluid wave is typically injected through the corneal incision to cut the outer cortical layer of the cataract. In the next step, known as hydrodelineation, the injection of a fluid wave separates the outer, soft nucleus of the lens from the inner, hard nucleus. The next step is phacoemulsification of the lens, a process known as phacoemulsification. The nucleus is first broken up using a chopper, and then the outer fragments of the lens are typically broken up and removed using a phacoemulsification probe. Aspiration is also typically performed using a separate tool during phacoemulsification. After phacoemulsification is complete, the remaining cortical (i.e., outer layer of the lens) material is aspirated from the capsule. To maintain fluid pressure in the anterior chamber during phacoemulsification and aspiration, a balanced salt solution is typically used instead of the aspirated fluid. Optionally, the capsule is polished, if necessary. An intraocular lens (IOL) is then inserted into the capsule. The IOL is typically foldable and is inserted in a folded configuration and then expanded within the capsule. At this stage, the viscoelastic material is typically removed using the same suction device previously used to aspirate fluid from the capsule. If necessary, the incision or incisions are sealed by increasing pressure within the bulbus oculi (i.e., globe of the eye), e.g., by pressing the inner tissue against the outer tissue of the incision to force the incision closed. Summary of the Invention

[0007] According to some applications of the present invention, a robotic system is configured for use in microsurgical procedures, such as intraocular surgery. Typically, when used in intraocular surgery, the robotic system includes, in addition to one or more robotic units (configured to hold tools), an imaging system, one or more displays, and a control component (e.g., a control component including a pair of control component units) through which one or more operators (e.g., medical professionals such as doctors and / or nurses) can control the robotic units. Typically, the robotic system includes one or more computer processors through which the components of the system and the operator(s) operatively interact with each other. The scope of this application includes mounting one or more robotic units in a variety of different positions relative to each other.

[0008] Typically, the movement of the robotic unit (and / or control of other aspects of the robotic system) is at least partially controlled by one or more operators (e.g., medical professionals such as doctors and / or nurses). For example, the operator may receive images of the patient's eye and the robotic unit and / or tools disposed therein via a display. Typically, such images are acquired by an imaging system. In some applications, the imaging system is a stereoscopic imaging device, and the display is a stereoscopic display. The operator typically performs steps of the procedure based on the received images. In some applications, the operator provides commands to the robotic unit via a control component. Typically, such commands include commands to control the position and / or orientation of tools disposed within the robotic unit and / or commands to control operations performed by the tools. For example, the commands may control a blade, a phacoemulsification tool (e.g., the operating mode and / or suction force of the phacoemulsification tool), a forceps, and / or an injector tool (e.g., which fluid (e.g., viscoelastic fluid, saline, etc.) to be injected and / or at what flow rate). Alternatively or additionally, the operator may input commands to control the imaging system (e.g., zoom, focus, and / or xy positioning of the imaging system). In some applications, the commands include, for example, controlling an intraocular lens manipulator tool, which manipulates the intraocular lens within the eye for precise positioning of the intraocular lens within the eye.

[0009] Typically, the control component includes one or more control component units configured to correspond to each robot unit of a robotic system. For example, the system may include a first and a second robot unit, and the control component may include a first and a second control component unit. In some applications, the control component unit includes each control component tool therein (to replicate the robot unit). Typically, a computer processor determines the XYZ position and orientation of the tip of the control component tool and drives the robot unit such that the tip of the actual tool being used to perform the procedure tracks the movement of the tip of the control component tool.

[0010] In some applications, the control component unit includes a position sensor to detect the XYZ position and three-dimensional orientation of the tip of the control component tool. The position sensor typically includes one or more rotary encoders and / or one or more inertial measurement units (typically including a three-axis accelerometer, a three-axis gyroscope, and / or a three-axis magnetometer). The inertial measurement units typically generate inertial measurement unit data related to the three-dimensional orientation of the control component tool. In some applications, a computer processor receives the rotary encoder data and / or the inertial measurement unit data and thereby determines the XYZ position and three-dimensional orientation of the tip of the control component tool.

[0011] In some applications, the control component unit is configured to provide force feedback to the user. To perform non-robotic anterior segment surgery, surgeons typically make one or more incisions in the patient's cornea, which are subsequently used as entry points for various surgical tools. Tools are inserted through the incisions and manipulated within the eye to achieve the surgical objective. During this manipulation, it is medically preferable for the tool not to press hard against the incision edges, lift upward, or push too far downward. Such movements can cause tears at the incision edges that widen the incision, potentially adversely affecting the surgical outcome. Ideally, surgeons manipulate the tool so that, at the tool's entry point into the incision, the tool rotates about the center of the incision and does not move laterally; such tool movement within the incision is herein described as maintaining a center of motion. In the case of robotic surgery as described herein, the above-described movement of the ophthalmic tool is described as maintaining a remote center of motion because the tool is typically controlled remotely (via the control component). In non-robotic surgery, manually maintaining the center of motion can be difficult, especially when the surgeon performing the current surgical action must focus on the tip of the tool. According to some applications of the present invention, force feedback is provided to assist an operator performing robotic-assisted ophthalmic surgery. This feedback is typically provided by a control component (described in more detail below) and typically assists the operator in maintaining a remote center of motion of the ophthalmic tool.

[0012] In some applications, the computer processor is configured to drive the control component unit to provide feedback (e.g., force feedback) to the operator indicative of the tool's entry position into the patient's eye within the incision. For example, as the tool is moved closer to the edge of the incision, resistance to movement of the control component arm may increase, and / or the control component arm may vibrate, and / or a different output may be generated. In some applications, the computer processor is configured to apply a force that resists operator-initiated movement of the control component tool that would deviate from the remote center of motion. In some applications, to provide the force feedback, the control component unit includes one or more motors, described in more detail below. In some applications, at least some of the motors are direct-drive motors (i.e., motors that do not transfer motion via gears), typically linear motors, e.g., linear voice coil motors.

[0013] Thus, according to some embodiments of the present invention there is provided an apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, the apparatus comprising: A control component unit, X, Y and Z linear rotational axes, and pitch, roll and yaw angular rotational axes; A control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, which is operated by an operator. When an operator moves the control component tool along the linear X, Y, and Z directions, rotational motion about the X, Y, and Z linear rotation axes is generated; a control component tool configured to be moved to generate rotational motion about each of the pitch, roll, and yaw rotation axes when an operator moves the control component tool through roll, pitch, and yaw angular motions; a control component unit including: An apparatus is provided in which the control component tool is substantially balanced about X, Y and Z rotational axes of linear motion, and pitch, roll and yaw rotational axes of angular motion.

[0014] In some embodiments, In four degrees of freedom, the control component tool is self-balancing and In the two degrees of freedom, the control component unit includes a counterweight that balances the weight of the control component and / or other components of the control component unit about the corresponding axis of rotation.

[0015] In some embodiments, the control component tool is self-balancing about two of the roll and yaw angular motion rotation axes and the X, Y, and Z linear motion rotation axes, and the control component includes first and second counterweights that balance the weight of the control component tool and / or other components of the control component unit, respectively, about the pitch angular motion rotation axis and one of the linear motion rotation axes.

[0016] In some embodiments, the first counterweight does not perfectly balance the weight of the control component tool about the pitch angular motion axis of rotation.

[0017] In some embodiments, the control component tool is configured to maintain its position and orientation in the absence of forces acting on the control component tool.

[0018] In some embodiments, the control component tool is configured to maintain its position and orientation in response to the operator letting go of the control component tool without applying any force to the control component tool.

[0019] In some embodiments, the control component unit includes one or more motors configured to drive movement of the control component tool and thereby provide force feedback to the operator.

[0020] In some embodiments, the one or more motors are configured to provide force feedback without having to overcome substantial inertial forces.

[0021] In some embodiments, the one or more motors include one or more direct drive motors.

[0022] In some embodiments, the one or more motors include one or more direct drive linear motors.

[0023] In some embodiments, the one or more motors include one or more direct drive linear voice coil motors.

[0024] According to some embodiments of the invention there is provided an apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, the apparatus comprising: A control component unit, a plurality of links connected to each other via a plurality of rotation axes; a control component unit including: a control component tool coupled to the link, the control component tool configured to be moved by an operator such that the link rotates about an axis of rotation when the operator moves the control component tool along linear X, Y, and Z directions; the plurality of links includes an X-direction link to provide X-direction linear motion; the plurality of rotational axes includes a Z rotational axis about which movement in the Z direction is effected; An arrangement is further provided in which the X-direction link is aligned with the Z-axis of rotation such that the X-direction link does not impart a torque about the Z-axis of rotation.

[0025] In some embodiments, the multiple rotational axes include a Y rotational axis about which movement in the Y direction is effected, the Y rotational axis being aligned with the Z rotational axis along the Z direction.

[0026] In some embodiments, the X-direction link includes a frame.

[0027] In some embodiments, the X-direction link is aligned with the Z rotational axis so that the X-direction link does not apply torque about the Z rotational axis.

[0028] In some embodiments, as the X-direction link moves, it remains aligned with the Z rotational axis and no compensating movement is required to balance the movement of the X-direction link.

[0029] In some embodiments, in four degrees of freedom the control component tool is self-balancing, and in two degrees of freedom the control component includes a counterweight that balances the weight of the control component and / or other components of the control component unit around the corresponding axis of rotation.

[0030] In some embodiments, the control component tool is configured to maintain its position and orientation in the absence of forces acting on the control component tool.

[0031] In some embodiments, the control component tool is configured to maintain its position and orientation in response to the operator letting go of the control component tool without applying any force to the control component tool.

[0032] In some embodiments, the control component unit includes one or more motors configured to drive movement of the control component tool and thereby provide force feedback to the operator.

[0033] In some embodiments, the one or more motors are configured to provide force feedback without having to overcome substantial inertial forces.

[0034] In some embodiments, the one or more motors include one or more direct drive motors.

[0035] In some embodiments, the one or more motors include one or more direct drive linear motors.

[0036] In some embodiments, the one or more motors include one or more direct drive linear voice coil motors.

[0037] According to some embodiments of the invention there is provided an apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, the apparatus comprising: A control component unit, X, Y and Z linear rotation axes and pitch, roll and yaw angular rotation axes; A control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, which is operated by an operator. When an operator moves the control component tool along the linear X, Y, and Z directions, rotational motion about the X, Y, and Z linear rotation axes is generated; a control component tool configured to be moved such that rotational motion about each of the pitch, roll and yaw rotation axes is generated when an operator moves the control component tool through the roll, pitch and yaw angular motions; a plurality of direct drive motors operatively coupled to each of the X, Y, and Z linear motion rotary axes; a control component unit including: 1. A computer processor comprising: moving the tip of the selected ophthalmic tool within the patient's eye in a manner consistent with the movement of the control component tool; and a computer processor configured to provide force feedback to an operator by driving the control component arms using a plurality of direct drive motors.

[0038] In some embodiments, the plurality of direct drive motors includes a plurality of linear motors.

[0039] In some embodiments, the plurality of linear motors comprises a plurality of linear voice coil motors.

[0040] In some embodiments, the direct drive motor is configured to avoid motor cogging.

[0041] In some embodiments, the direct drive motor is configured to provide a more accurate force feedback to the operator than the force feedback provided by a motor that jams.

[0042] According to some embodiments of the invention there is provided an apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, the apparatus comprising: A control component unit, X, Y and Z linear rotation axes and pitch, roll and yaw angular rotation axes; A control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, which is operated by an operator. When an operator moves the control component tool along the linear X, Y, and Z directions, rotational motion about the X, Y, and Z linear rotation axes is generated; a control component tool configured to be moved such that rotational motion about each of the pitch, roll and yaw rotation axes is generated when an operator moves the control component tool through the roll, pitch and yaw angular motions; X, Y, and Z motors operatively coupled to the X, Y, and Z linear motion rotary axes, respectively a control component unit including: 1. A computer processor comprising: moving the tip of the selected ophthalmic tool within the patient's eye in a manner consistent with the movement of the control component tool; and a computer processor configured to provide force feedback to an operator by driving the control component arms using X, Y, and Z motors; An apparatus is further provided in which a first end of the Y direction motor is aligned with the X rotation axis.

[0043] In some embodiments, the control component includes a frame, and the control component unit is configured such that when an operator moves the control component tool along a linear X direction, the frame rotates about an X linear motion rotation axis, and the Y direction motor is coupled to the frame to rotate with the frame.

[0044] In some embodiments, the Y motor does not exert a torque about the X axis of rotation when extending or retracting.

[0045] In some embodiments, the second end of the Y direction motor is offset from the Y axis of rotation so as to impart a torque about the Y axis of rotation when the Y direction motor extends or retracts.

[0046] In some embodiments, the second end of the Y direction motor is offset from the Y axis of rotation by 5 to 20 mm.

[0047] In some embodiments, the second end of the Y direction motor is offset from the Y axis of rotation by 5 to 20 mm.

[0048] In some embodiments, the second end of the Y direction motor is offset from the Y axis of rotation by 10 to 15 mm.

[0049] In some embodiments, the X, Y, and Z motors include direct drive motors.

[0050] In some embodiments, the direct drive motor includes a linear motor.

[0051] In some embodiments, the linear motor comprises a linear voice coil motor.

[0052] In some embodiments, the direct drive motor is configured to avoid motor cogging.

[0053] In some embodiments, the direct drive motor is configured to provide a more accurate force feedback to the operator than the force feedback provided by a motor that jams.

[0054] In some embodiments, the center of mass of the Y motor is substantially aligned with the X linear motion rotation axis.

[0055] In some embodiments, the Y-direction motor comprises a linear motor, and its center of mass is within 10 mm of the X-linear rotation axis when the Y-direction motor is fully extended or fully retracted.

[0056] In some embodiments, the Y-direction motor comprises a linear motor, and its center of mass is within 5 mm of the X-linear rotation axis when the Y-direction motor is fully extended or fully retracted.

[0057] According to some embodiments of the invention there is provided an apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, the apparatus comprising: A control component unit, X, Y and Z linear rotation axes and pitch, roll and yaw angular rotation axes; A control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, which is operated by an operator. When an operator moves the control component tool along the linear X, Y, and Z directions, rotational motion about the X, Y, and Z linear rotation axes is generated; a control component tool configured to be moved such that rotational motion about each of the pitch, roll and yaw rotation axes is generated when an operator moves the control component tool through the roll, pitch and yaw angular motions; at least one rotary encoder configured to detect rotational motion about a corresponding one of the axes of rotation; one or more wires extending from the rotary encoder; and a toroidal magnet disposed along a corresponding one of the axes of rotation a control component unit including: Further provided is a device in which one or more wires pass through a hole defined by a toroidal magnet.

[0058] In some embodiments, the control component unit comprises: a plurality of rotary encoders each configured to detect rotational motion about a corresponding one of the X, Y, and Z linear motion rotation axes, each having one or more wires extending therefrom; and toroidal magnets disposed along X, Y, and Z linear motion rotational axes, with one or more wires passing through holes defined by the toroidal magnets.

[0059] In some embodiments, the control component unit comprises: a plurality of rotary encoders, each configured to detect rotational motion about a corresponding one of the pitch, roll, and yaw angular motion rotation axes, and each having one or more wires extending therefrom; and a toroidal magnet disposed along an axis of rotation for pitch, roll, and yaw angular motion, with one or more wires passing through a hole defined by the toroidal magnet.

[0060] In some embodiments, the control component unit further comprises: a plurality of rotary encoders each configured to detect rotational motion about a corresponding one of the X, Y, and Z linear motion rotation axes, each having one or more wires extending therefrom; and toroidal magnets disposed along X, Y, and Z linear motion rotational axes, with one or more wires passing through holes defined by the toroidal magnets.

[0061] The present invention will be more fully understood from the following detailed description of the embodiments, taken in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0062] [Figure 1] FIG. 1 is a schematic diagram of a robotic system configured for use in microsurgical procedures, such as intraocular surgery, in accordance with some applications of the present invention. [Figure 2A-2B] 1A-1C are schematic diagrams of control component units according to some applications of the present invention; [Figure 3A-3C] 1 is a schematic diagram of portions of a control component unit, according to some applications of the present invention; [Figure 4A-4B] 10 is a schematic diagram of X and Y linear movement of a control component tool, in accordance with some applications of the present invention. [Figure 4C] 10 is a schematic diagram of a Y-direction motor of a control component unit, according to some applications of the present invention. [Figure 5A-5B] 10 is a schematic diagram of Z linear movement of a control component tool, according to some applications of the present invention. FIG. [Figures 6A-6B] 10 is a schematic diagram of a pitch angle movement of a control component tool, in accordance with some applications of the present invention; [Figures 7A-7B] 10 is a schematic diagram of the yaw motion of a control component tool, in accordance with some applications of the present invention; [Figure 8] 1 is a schematic diagram of a portion of a control component tool, in accordance with some applications of the present invention; [Figures 9A-9D] 1 is a schematic diagram of a control component unit according to some applications of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0063] Reference is now made to FIG. 1 , which is a schematic illustration of a robotic system 10 configured for use in microsurgical procedures, such as intraocular surgery, in accordance with some applications of the present invention. Typically, a robotic system 10 used in intraocular surgery includes one or more robotic units 20 (configured to hold a tool 21), as well as an imaging system 22, one or more displays 24, and control components 26 (e.g., control components including a pair of control component units 30, as shown in the expanded portion of FIG. 1 ), through which one or more operators 25 (e.g., medical professionals such as doctors and / or nurses) can control the robotic units 20. Typically, the robotic system 10 includes one or more computer processors 28 through which the components of the system and the operators 25 operatively interact with one another. The scope of this application includes mounting one or more robotic units in a variety of different positions relative to one another.

[0064] Typically, the movement of the robotic unit (and / or control of other aspects of the robotic system) is at least partially controlled by one or more operators 25 (e.g., medical professionals such as doctors and / or nurses). For example, the operator may receive images of the patient's eye and the robotic unit and / or tools disposed therein via display 24. Typically, such images are acquired by imaging system 22. In some applications, imaging system 22 is a stereoscopic imaging device, and display 24 is a stereoscopic display. The operator typically performs steps of the procedure based on the received images. In some applications, the operator provides commands to the robotic unit via control component 26. Typically, such commands include commands to control the position and / or orientation of tools disposed within the robotic unit and / or commands to control operations performed by the tools. For example, the commands may control a blade, a phacoemulsification tool (e.g., the operating mode and / or suction force of the phacoemulsification tool), a forceps, and / or an injector tool (e.g., which fluid (e.g., viscoelastic fluid, saline, etc.) to be injected and / or at what flow rate). Alternatively or additionally, the operator may input commands to control the imaging system (e.g., zoom, focus, and / or xy positioning of the imaging system). In some applications, the commands include, for example, controlling an intraocular lens manipulator tool, which manipulates the intraocular lens within the eye for precise positioning of the intraocular lens within the eye.

[0065] Typically, the control component 26 includes one or more control component units 30 configured to correspond to each robotic unit 20 of the robotic system. For example, as shown, the system may include first and second robotic units, and the control component may include first and second control component units 30, as shown. In some applications, the control component units include respective control component tools 32 therein (to replicate the robotic units), as shown in FIG. 1 . Typically, a computer processor determines the XYZ position and orientation of the tip 34 of the control component tool 32 and drives the robotic units such that the tip of the actual tool 21 being used to perform the procedure tracks the movement of the tip of the control component tool. In some cases, the tool 21 is referred to herein and in the claims as an “ophthalmic tool.” This term is used to distinguish the tool 21 from the control component tool 32 and should not be construed in any way to limit the type of tool that may be used as the tool 21. The term “ophthalmic tool” should be construed to include any one of the tools described herein and / or other types of tools that may occur to one of ordinary skill in the art upon reading this disclosure.

[0066] In some applications, the control component unit includes a position sensor to detect the XYZ position and three-dimensional orientation of the tip 34 of the control component tool 32. The position sensor typically includes one or more rotary encoders and / or one or more inertial measurement units (typically including a three-axis accelerometer, a three-axis gyroscope, and / or a three-axis magnetometer). The inertial measurement units typically generate inertial measurement unit data related to the three-dimensional orientation of the control component tool. In some applications, the computer processor 28 receives the rotary encoder data and / or the inertial measurement unit data and thereby determines the XYZ position and three-dimensional orientation of the tip 34 of the control component tool.

[0067] In some applications, the control component unit 30 is configured to provide force feedback to the user. To perform non-robotic anterior segment surgery, a surgeon typically makes one or more incisions in the patient's cornea, which are subsequently used as entry points for various surgical tools. Tools are inserted through the incisions and manipulated within the eye to achieve the surgical objective. During this manipulation, it is medically preferable for the tool not to apply strong pressure to the incision edges, lift upward, or depress excessively downward. Such movements can cause tears at the incision edges that widen the incision and can adversely affect the surgical outcome. Ideally, the surgeon manipulates the tool so that, at the tool's entry point into the incision, the tool rotates about the center of the incision and does not move laterally; such tool movement within the incision is herein described as maintaining a center of motion. In the case of robotic surgery as described herein, the above-described movement of the tool 21 is described as maintaining a remote center of motion because the tool is typically controlled remotely (via the control component unit 30). In non-robotic surgery, manually maintaining the center of motion can be difficult, especially when the surgeon performing the current surgical action must focus on the tip of the tool. According to some applications of the present invention, force feedback is provided to assist an operator performing robotic-assisted ophthalmic surgery. This feedback is typically provided by control component unit 30 (described in more detail below) and typically assists the operator in maintaining a remote center of motion of tool 21.

[0068] In some applications, the computer processor is configured to drive the control component unit to provide feedback to the operator indicative of the tool's entry position into the patient's eye within the incision. For example, as the tool is moved closer to the edge of the incision, resistance to movement of the control component arm may increase, and / or the control component arm may vibrate, and / or a different output may be generated. In some applications, the computer processor is configured to apply a force that resists operator-initiated movement of the control component tool 32 that would deviate from the remote center of motion. In some applications, to provide the force feedback, the control component unit includes one or more motors, described in more detail below. In some applications, at least some of the motors are direct-drive motors (i.e., motors that do not transfer motion via gears), typically linear motors, e.g., linear voice coil motors.

[0069] Reference is now made to FIGS. 2A and 2B, which are schematic illustrations of respective views of a control component unit 30 according to some applications of the present invention. In some applications, portions of the control component unit are housed within a housing 40. Typically, a control component tool 32 is disposed outside the housing for movement by an operator. For example, a shaft 42 may extend outside the housing 40, with the control component tool attached to the shaft. In some applications, the housing is shaped to define a surface 44 configured to support the palm and / or heel of an operator's hand while the operator manipulates the control component tool. As noted above, typically, a computer processor determines the XYZ position and orientation of the tip 34 of the control component tool 32 and drives the robotic unit such that the tip of the ophthalmic tool tracks the movement of the tip of the control component tool.

[0070] Reference is now made to Figures 3A, 3B, and 3C, which are schematic diagrams of portions of control component unit 30, according to some applications of the present invention. In some applications, the control component unit includes multiple links (at least some of which are typically configured as frames) that are coupled to one another via rotational axes. Typically, when an operator moves the control component tool along the X, Y, and Z linear directions, the links rotate about the corresponding rotational axes. For example, when the operator moves the control component tool along the X linear direction, frame 50 rotates about rotational axis 52X (shown in Figures 3B and 3C); when the operator moves the control component tool along the Y linear direction, link 54 rotates about rotational axis 52Y (shown in Figures 3C and 4C); and when the operator moves the control component tool along the Z linear direction, link 54 rotates about rotational axis 52Z (shown in Figure 3C).

[0071] It should be noted that the above description assumes that the link 54 is disposed perpendicular to the frame 50. In reality, during most use of the control component unit, the link 54 is disposed at an angle relative to the frame 50 (e.g., as shown in FIG. 4A ). In such a configuration, movement of the control component tool in the XY plane (or, more specifically, along the X or Y linear directions) typically results in rotation of the frame 50 about the axis of rotation 52X and rotation of the link 54 about the axis of rotation 52Y. For this reason, the use of the terms X, Y, and Z herein with respect to movement of parts of the control component unit should not be interpreted as strictly corresponding to movement along three linear axes that are perpendicular to one another. Rather, movement in the X and Y directions should be interpreted as relating to movement of the frame 50 or link 54 in the XY plane (not necessarily in directions perpendicular to one another), and movement in the Z direction should be interpreted as corresponding to movement of the link 54 in a direction perpendicular to the XY plane. Thus, rotation axis 52X and motor 56X are associated with movement of frame 50 in the XY plane (whether or not the movement is in the X direction as shown in the figure), rotation axis 52Y and motor 56Y are associated with movement of the link in the XY plane (whether or not the movement is in the Y direction as shown in the figure), and rotation axis 52Z and motor 56Z are associated with movement of link 54 perpendicular to the XY plane.

[0072] Typically, as shown, Y rotational axis 52Y is aligned with Z rotational axis 52Z along the Z direction. Both Y and Z linear motion are typically provided via link 54. Note that in some applications, an additional support link 55 is disposed parallel to link 54 and rotates with it. In some applications, a rotary encoder is disposed along each of rotational axes 52X, 52Y, and 52Z (or a parallel rotational axis, e.g., the rotational axis of link 55). The rotary encoder detects rotation about each link's rotational axis and generates a signal in response. A computer processor derives the control component tool's motion along each linear direction from the signals generated by the rotary encoders. In some applications, at least one additional rotary encoder is disposed along each of rotational axes 52X, 52Y, and 52Z to provide system redundancy (e.g., so that if one of the rotary encoders fails, the other rotary encoder can be used).

[0073] Typically, the control component tool 32 is operator-movable and undergoes pitch, yaw, and roll angular rotation. The control component tool typically undergoes pitch angular rotation by rotating about a pitch rotation axis 70 (shown in FIG. 3A ) and yaw angular rotation by rotating the shaft 42 (to which the control component tool is attached) about its longitudinal axis 72 (which serves as the yaw rotation axis and is shown in FIG. 3A ). Typically, the control component tool undergoes roll angular rotation by rotating about its axis 74 (which serves as the roll rotation axis and is shown in FIG. 3A ). In some applications, an inertial measurement unit 76 is housed within the control component tool. Typically, the inertial measurement unit includes a three-axis accelerometer, a three-axis gyroscope, and / or a three-axis magnetometer. The inertial measurement unit typically generates inertial measurement unit data related to the three-dimensional orientation of the control component tool. Alternatively or additionally, the control component includes one or more rotary encoders for detecting the roll, pitch, and / or yaw orientation of the control component tool 32. Typically, the rotary encoders are disposed along the axes along which roll, pitch, and yaw angular rotations occur, respectively. In some applications, the control component includes an inertial measurement unit 76 for redundancy (e.g., so that the rotary encoders are used if the inertial measurement unit fails) in addition to one or more rotary encoders for detecting the roll, pitch, and / or yaw of the control component tool 32.

[0074] In some applications, the computer processor 28 receives rotary encoder data and inertial measurement unit data. Typically, the computer processor determines the XYZ position of the tip of the control component tool 32 based on the rotary encoder data, and determines the three-dimensional orientation (e.g., three Euler angles and / or another orientation representation) of the tip of the control component tool 32 based on the inertial measurement unit data or a combination of the rotary encoder data and the inertial measurement unit data. Thus, the computer processor is configured to determine the XYZ position and three-dimensional orientation of the tip of the control component tool based on a combination of the rotary encoder data and the inertial measurement unit data.

[0075] In some applications, the direct drive motors 56X, 56Y, 56Z (i.e., motors that do not transmit motion via gears) are typically linear motors (e.g., linear voice coil motors) and are associated with motion along each of the X, Y, and Z linear directions. As described above, in some applications, the computer processor is configured to drive the control component unit to provide force feedback to the operator indicative of the entry position of the ophthalmic tool within the incision into the patient's eye. In some applications, the motors are configured to drive linear tool movement to provide such force feedback. In some applications, the computer processor is configured to apply a force that resists operator-initiated movement of the control component tool 32 away from the remote center of motion. For example, in response to the operator moving the control component tool through a yaw rotation that would cause a corresponding movement of the ophthalmic tool away from the remote center of motion, the computer processor may move the control component tool linearly (via X, Y, and / or Z linear motion) such that the ophthalmic tool's remote center of motion is maintained. In some such applications, the force is applied by driving control component tools to move in X, Y, and Z linear directions via motors 56X, 56Y, 56Z.

[0076] As mentioned above, the robotic system 10 is typically used in procedures requiring delicate and precise movement of a surgical tool, such as ophthalmic procedures. Accordingly, the control component unit 30 is typically configured to allow movement of the control component tool without significant reaction forces (other than those intentionally applied by the operator via the motors 56X, 56Y, and 56Z) acting against that movement. In some applications, the control component tool includes a counterweight 58, which balances the weight of the control component tool relatively evenly about the pitch rotation axis 70. In some applications, the control component tool is not perfectly balanced about the pitch rotation axis 70 to give the surgeon a sense of the tool's weight (like a real surgical tool) and / or to reduce the overall mass of the control component tool. In some applications, the links 54 extend on either side of the Z rotation axis 52Z, and the control component tool and additional components are disposed on the links 54 (and / or parallel links 55) on a first side of the rotation axis 52Z. In some applications, a counterweight 62 is disposed on the link 54 on the opposite side of the rotational axis 52Z to balance the weight of the control component tools and additional components disposed on the first side. In some applications, the frame 50 (which functions as the link that provides linear motion in the X direction) is aligned with the Z rotational axis 52Z (shown in FIG. 3C ) so that the frame 50 does not impart torque about the Z rotational axis 52Z. Thus, the frame 50 does not need to be counterbalanced with respect to the Z rotational axis 52Z. In some applications, as the frame 50 moves (due to movement in the X direction), the frame remains aligned with the Z rotational axis 52Z and no compensating movement is required to balance the frame movement.

[0077] It should be noted that, according to the above description, the control component unit is typically balanced in all six degrees of freedom (three axial translations and three angular rotations). In some applications, as described, the control component unit utilizes counterweights to balance two degrees of freedom: axial movement in the Z direction and pitch angular movement. Counterweights are typically not required for balancing the remaining four degrees of freedom (i.e., X- and Y-axial movement, and roll and yaw angular movement) because the control component unit is designed such that the control component tool and / or other elements of the control component unit are self-balancing in these degrees of freedom. Because the control component unit is designed to be balanced in all six degrees of freedom (e.g., by self-balancing in four degrees of freedom and balancing provided by counterweights in the remaining two degrees of freedom), the control component tool tends to maintain its position and orientation when no forces are acting on the control component tool. Thus, typically, if an operator temporarily lets go of a control component tool (i.e., does not apply a force to the control component tool when letting go of the tool), the control component tool will maintain its position and orientation until the operator resumes control of the control component tool. Furthermore, typically, the control component tool provides relatively low inertial forces, such that force feedback can be provided to the operator with a relatively low level of force. That is, a motor configured to drive movement of the control component tool and thereby provide force feedback to the operator is configured to provide force feedback without having to substantially overcome inertial forces.

[0078] As noted above, direct drive motors (i.e., motors that do not transmit motion via gears) are typically used for the motors 56X, 56Y, and 56Z. In some applications, linear motors (typically linear voice coil motors) are used for the motors 56X, 56Y, and 56Z. In some applications, such motors are used for the motors 56X, 56Y, and 56Z to avoid motor cogging, which can impart resistance to the movement of the control component tool (and is common with rotary motors and / or motors that transmit motion via gears). Note that motor cogging can also lead to inaccuracies in the force feedback provided by the motor movement, which is typically avoided by using direct drive motors (typically linear motors, such as linear voice coil motors) for the motors 56X, 56Y, and 56Z. Alternatively, in some applications, motors that include gears in one or more of the motors 56X, 56Y, and 56Z are used.

[0079] Referring to FIG. 3C , as described above, in some applications, a rotary encoder is disposed along each of the rotational axes 52X, 52Y, and 52Z. The rotary encoder detects the rotation of each link about its axis and generates a signal accordingly. FIG. 3C shows a rotary encoder 64X for the X rotational axis 52X. Typically, a magnet 66X is disposed along the X rotational axis. In some applications, the magnet is toroidal, with its north and south poles on opposite sides of a line 68 that bisects the toroidal shape, as shown schematically in FIG. 3C . The rotary encoder 64X detects changes in the magnetic flux generated by the magnet 66X, thereby detecting rotation about the X rotational axis 52X. Typically, the magnet is toroidal, with an electrical wire (e.g., a wire extending from the rotary encoder 64X) passing through a hole 69 defined by the magnet. In this manner, the wire remains stationary as the magnet rotates, thereby preventing the wire from twisting. The inventors discovered that even if the magnet is toroidal, the magnetic flux generated by the magnet is strong enough to be detected by a rotary encoder. Note that while rotary encoder 64X for X axis of rotation 52X is shown in and described with reference to FIG. 3C, additional rotary encoders are typically similarly configured (e.g., using the toroidal magnets described). Similar configured rotary encoders (and toroidal magnets) are typically used to detect rotation about the Y, Z, yaw, pitch, and / or roll axes of rotation.

[0080] Reference is now made to FIGS. 4A and 4B, which are schematic illustrations of the X and Y linear movement of a control component tool according to some applications of the present invention. As noted above, typically, when an operator moves a control component tool in the XY plane, the links rotate about their respective rotational axes. For example, when an operator moves the control component tool along the X linear direction, frame 50 rotates about rotational axis 52X (as shown in FIGS. 3B and 3C), and when the operator moves the control component tool along the Y linear direction, link 54 rotates about rotational axis 52Y (as shown in FIG. 4C). Note that in some applications, an additional support link 55 is disposed parallel to link 54 and rotates together with link 54. Movement in the XY plane is illustrated in the transition from FIG. 4A to FIG. 4B, where FIG. 4A shows both frame 50 and link 54 in a contracted configuration and FIG. 4B shows both frame 50 and link 54 in an extended configuration. In some applications, rotary encoders are disposed along rotational axes 52X and 52Y. The rotary encoders detect the rotation of each link about its axis of rotation and generate signals accordingly. A computer processor derives the movement of the control component tool in the XY plane from the signals generated by the rotary encoders. In some applications, at least one additional rotary encoder is provided along each of the rotation axes 52X and 52Y to provide redundancy to the system (e.g., so that if one of the rotary encoders fails, the other rotary encoder is used).

[0081] Also, as noted above, in some applications, motors 56X, 56Y are disposed along the X and Y linear directions, respectively. Typically, each motor is a direct drive motor, e.g., a direct drive linear motor such as a linear voice coil motor. In some applications, the motors are configured to drive the tool to move in the XY plane to provide force feedback. In some applications, the computer processor is configured to apply a force that resists an operator's attempted movement of the control component tool 32 away from the remote center of motion. For example, in response to the operator moving the control component tool with a yaw or pitch angle rotation that would cause a corresponding movement of the ophthalmic tool away from the remote center of motion, the computer processor may move the control component tool linearly (via X, Y, and / or Z linear motion) so that the ophthalmic tool's remote center of motion is maintained. In some such applications, the force is applied by driving the control component tool to move in the XY plane via motors 56X, 56Y.

[0082] 4A and 4B, typically, X-direction motor 56X (or a linear extension therefrom) is coupled to frame 50 at location 78 offset from X rotational axis 52X. In some applications, location 78 is offset from X rotational axis 52X by 3 mm to 30 mm, e.g., 5 to 20 mm, e.g., 10 to 15 mm. Thus, when X-direction motor 56X extends or retracts, it applies a torque about the X rotational axis (which causes the control component tool to move in the X-Y plane). In some applications, motor 56X (or a linear extension therefrom) is coupled to frame 50 at location 78 located on extension 57 of frame 50 disposed within the frame's footprint, as shown in FIG. 3C.

[0083] Reference is now made to FIG. 4C, which is a schematic diagram of a Y-direction motor 56Y of a control component unit 30, according to some applications of the present invention. As shown in some applications, a first end of the Y-direction motor (or a linear extension therefrom) is aligned with the X rotational axis 52X. Typically, a second end of the Y-direction motor (or a linear extension therefrom) is coupled to link 54 at a location 80 that is offset from the Y rotational axis 52Y. In some applications, location 80 is offset from the Y rotational axis 52Y by 3 to 30 mm, e.g., 5 to 20 mm, e.g., 10 to 15 mm. Thus, when the Y-direction motor 56Y extends or retracts, it does not impart a torque about the X rotational axis 52X (requiring a compensating torque and / or movement in the X direction), but it does impart a torque about the Y rotational axis (which moves the control component tool in the X-Y plane). Typically, motor 56Y is coupled to frame 50 and configured to rotate with the frame 50. In this configuration, the motor does not impart a torque to the frame 50 as the frame 50 rotates.

[0084] Reference is now made to FIGS. 5A and 5B, which are schematic illustrations of Z-linear movement of a control component tool in accordance with some applications of the present invention. As noted above, typically, when an operator moves a control component tool along the Z-linear direction, link 54 rotates about Z-axis of rotation 52Z. Note that in some applications, an additional support link 55 is disposed parallel to link 54 and rotates with link 54. Movement along the Z-direction is illustrated in the transition from FIG. 5A to FIG. 5B, where FIG. 5A shows link 54 in a contracted (along the Z-direction) configuration and FIG. 5B shows link 54 in an expanded (along the Z-direction) configuration. In some applications, a rotary encoder is disposed along rotation axis 52Z (or a parallel rotation axis, e.g., a rotation axis passing through link 55). The rotary encoder detects rotation of link 54 about rotation axis 52Z and generates a corresponding signal. A computer processor derives the Z-direction movement of the control component tool from the signal generated by the rotary encoder. In some applications, at least one additional rotary encoder is disposed along the Z axis of rotation (or a parallel axis of rotation, e.g., a rotation axis passing through link 55) to provide redundancy to the system (e.g., so that if one rotary encoder fails, the other will be used).

[0085] Also, as noted above, in some applications, the motor 56Z is disposed along the Z linear direction. Typically, the motor is a direct drive motor, e.g., a direct drive linear motor such as a linear voice coil motor. In some applications, the motor is configured to drive the tool to move along the Z linear direction to provide force feedback. In some applications, the computer processor is configured to apply a force that resists an operator's attempted movement of the control component tool 32 away from the remote center of motion. For example, in response to the operator moving the control component tool through a yaw or pitch rotation that would cause a corresponding movement of the ophthalmic tool away from the remote center of motion, the computer processor may move the control component tool linearly (via X, Y, and / or Z linear motion) so that the ophthalmic tool's remote center of motion is maintained. In some such applications, the force is applied by driving the control component tool to move in the Z linear direction via the motor 56Z. As shown, the motor is coupled to the link 54 at a location 82 that is offset from the Z axis of rotation 52Z. In some applications, location 82 is offset from Z axis of rotation 52Z by 3 mm to 30 mm, e.g., 5 to 20 mm, e.g., 10 to 15 mm. Thus, when Z direction motor 56Z extends or retracts, it applies a torque about the Z axis of rotation (which causes the control component tool to move along the Z direction).

[0086] Reference is now made to Figures 6A and 6B, which are schematic illustrations of pitch angular motion of a control component tool 32, in accordance with some applications of the present invention. Reference is also made to Figures 7A and 7B, which are schematic illustrations of yaw angular motion of a control component tool, in accordance with some applications of the present invention. As noted above, a control component tool typically undergoes pitch angular rotation by rotating about a pitch rotation axis 70. This is shown in the transition from Figure 6A to Figure 6B, with the pitch rotation indicated by arrow 90. More typically, the tool undergoes yaw angular rotation by rotating a shaft 42 (to which the control component tool is attached) about its own axis 72 (which serves as the yaw rotation axis). This is shown in the transition from Figure 7A to Figure 7B, with the shaft rotation indicated by arrow 92.

[0087] Reference is now made to Figure 8, which is a schematic illustration of a portion of a control component tool, in accordance with some applications of the present invention. As noted above, the control component tool typically undergoes roll angle rotation by rotating about its axis 74, as indicated by arrow 94.

[0088] As noted above, with reference to the angular rotations shown schematically in FIGS. 6A through 8 , in some applications, an inertial measurement unit 76 is housed within the control component tool. Typically, the inertial measurement unit includes a three-axis accelerometer, a three-axis gyroscope, and / or a three-axis magnetometer. The inertial measurement unit typically generates inertial measurement unit data related to the three-dimensional orientation of the control component tool. Alternatively or additionally, the control component includes one or more rotary encoders for detecting the roll, pitch, and / or yaw orientation of the control component tool 32. Typically, the rotary encoders are disposed along the axes along which the roll, pitch, and yaw angular rotations occur, respectively. In some applications, the control component includes an inertial measurement unit 76 for redundancy (e.g., so that the rotary encoders are used if the inertial measurement unit fails) in addition to one or more rotary encoders for detecting the roll, pitch, and / or yaw of the control component tool 32.

[0089] As noted above, in some applications, an operator provides commands to the robotic unit via the control component 26. Typically, such commands include commands controlling operations performed by a tool. For example, the commands may control a blade, a phacoemulsification tool (e.g., the operating mode and / or suction power of the phacoemulsification tool), a forceps, and / or an injector tool (e.g., which fluid (e.g., a viscoelastic fluid, saline, etc.) to inject and / or at what flow rate). Alternatively or additionally, the operator may input commands to control an imaging system (e.g., the zoom, focus, and / or x-y positioning of the imaging system). In some applications, the commands include, for example, controlling an intraocular lens manipulator tool, which manipulates an intraocular lens within the eye for precise positioning of the intraocular lens within the eye. In some applications, the control component tool (and / or another portion of the control component unit) includes one or more components configured to receive such input from an operator. For example, as shown in FIG. 8, the control component tool may include a roller wheel 96. Alternatively or additionally, the control component tool may include different types of components, such as buttons, configured to receive such input from an operator.

[0090] Reference is now made to Figures 9A, 9B, 9C, and 9D, which are schematic illustrations of control component unit 30 according to some applications of the present invention. Figures 9A and 9B show perspective views, Figure 9C shows a side view, and Figure 9D shows a top view, respectively, of the control component unit. The structure and function of control component unit 30 shown in Figures 9A-9B is generally similar to control component unit 30 shown in Figures 2A-8, except for the differences described below.

[0091] The control component unit 30 shown in Figures 9A-9B is generally similar in some respects to the control component unit 30 shown in Figures 2A-8. The control component unit generally includes a frame 50 that rotates about a first axis of rotation 52X and a link 54 that rotates about a second axis of rotation 52Y and a third axis of rotation 52Z. Typically, an operator moves the control component tool along the X, Y, and Z linear directions, causing the link to rotate about the corresponding axis of rotation. For example, when the operator moves the control component tool along the X linear direction, the frame 50 rotates about axis of rotation 52X; when the operator moves the control component tool along the Y linear direction, the link 54 rotates about axis of rotation 52Y (shown in Figures 3C and 4C); and when the operator moves the control component tool along the Z linear direction, the link 54 rotates about axis of rotation 52Z (shown in Figure 3C).

[0092] As noted above, the above description assumes that link 54 is disposed perpendicular to frame 50. In reality, during most use of the control component unit, link 54 is disposed at an angle relative to frame 50 (e.g., as shown in FIG. 4A ). In such a configuration, movement of the control component tool in the XY plane (and along the X or Y linear directions) typically results in rotation of frame 50 about rotational axis 52X and rotation of link 54 about rotational axis 52Y. For this reason, the use of the terms X, Y, and Z herein in connection with movement of parts of the control component unit should not be interpreted as strictly corresponding to movement along three mutually perpendicular linear axes. Rather, movement in the X and Y directions should be interpreted as relating to movement of frame 50 or link 54 in the XY plane (not necessarily in directions perpendicular to one another), and movement in the Z direction should be interpreted as corresponding to movement of link 54 in a direction perpendicular to the XY plane. Thus, rotation axis 52X and motor 56X are associated with movement of frame 50 in the XY plane (whether or not the movement is in the X direction as shown in the figure), rotation axis 52Y and motor 56Y are associated with movement of the link in the XY plane (whether or not the movement is in the Y direction as shown in the figure), and rotation axis 52Z and motor 56Z are associated with movement of link 54 perpendicular to the XY plane.

[0093] Typically, as shown, Y rotation axis 52Y is aligned with Z rotation axis 52Z along the Z direction. Furthermore, both Y and Z linear motion are typically provided via link 54. Note that in some applications, an additional support link 55 is disposed parallel to link 54 and rotates with it. In some applications, link 54 and / or link 55 are comprised of two or more portions fixed to one another. For example, as shown in FIG. 9A , links 54 and 55 each include a first portion disposed to the left of Z rotation axis 52Z and a second portion disposed to the right of Z rotation axis 52Z. In some applications, a rotary encoder is disposed along each of rotation axes 52X, 52Y, and 52Z (or a parallel rotation axis, such as the rotation axis of link 55). The rotary encoder detects rotation of each link about its rotation axis and generates a signal in response. A computer processor derives the control component tool's motion along each linear direction from the signals generated by the rotary encoders. In some applications, at least one additional rotary encoder is disposed along each of the rotational axes 52X, 52Y, and 52Z to provide redundancy to the system (e.g., so that if one of the rotary encoders fails, the other rotary encoder is used).

[0094] As described with reference to the control component unit 30 shown in FIGS. 2A through 8 , the control component tool 32 is typically operator-movable and undergoes pitch, yaw, and roll angular rotation. The control component tool typically undergoes pitch angular rotation by rotating about a pitch rotation axis 70, and yaw angular rotation by rotating the shaft 42 (to which the control component tool is attached) about its own axis 72 (which serves as the yaw rotation axis). The control component tool typically undergoes roll angular rotation by rotating about its own axis 74 (which serves as the roll rotation axis). In some applications, an inertial measurement unit 76 is housed within the control component tool. Typically, the inertial measurement unit includes a three-axis accelerometer, a three-axis gyroscope, and / or a three-axis magnetometer. The inertial measurement unit typically generates inertial measurement unit data related to the three-dimensional orientation of the control component tool. Alternatively or additionally, the control component includes one or more rotational encoders for detecting the roll, pitch, and / or yaw orientation of the control component tool 32. Typically, the rotational encoders are disposed along the axes along which the roll, pitch, and yaw rotations occur, respectively. In some applications, the control component includes an inertial measurement unit 76 for redundancy (e.g., so that the rotary encoders are used if the inertial measurement unit fails) in addition to one or more rotary encoders for detecting the roll, pitch, and / or yaw of the control component tool 32.

[0095] 2A-8, the computer processor 28 typically receives rotary encoder data and inertial measurement unit data. Typically, the computer processor determines the XYZ position of the tip of the control component tool 32 based on the rotary encoder data, and determines the three-dimensional orientation (e.g., three Euler angles and / or another orientation representation) of the tip of the control component tool 32 based on the inertial measurement unit data, or a combination of the rotary encoder data and the inertial measurement unit data. Thus, the computer processor is configured to determine the XYZ position and three-dimensional orientation of the tip of the control component tool based on a combination of the rotary encoder data and the inertial measurement unit data.

[0096] As described with reference to the control component unit 30 shown in FIGS. 2A through 8 , typically the direct drive motors 56X, 56Y, 56Z (i.e., motors that do not transmit motion via gears) are typically linear motors (e.g., linear voice coil motors) and are associated with motion along the X, Y, and Z linear directions. As noted above, in some applications, a computer processor is configured to drive the control component unit to provide force feedback to the operator indicative of the entry position of the ophthalmic tool within the incision into the patient's eye. In some applications, the motors are configured to drive linear tool movement to provide such force feedback. In some applications, the computer processor is configured to apply a force resisting operator-initiated movement of the control component tool 32 away from the remote center of motion. For example, in response to the operator moving the control component tool through a yaw rotation that would cause a corresponding movement of the ophthalmic tool away from the remote center of motion, the computer processor may move the control component tool linearly (via X, Y, and / or X linear motion) such that the ophthalmic tool's remote center of motion is maintained. In some such applications, the force is applied by driving control component tools to move in X, Y, and Z linear directions via motors 56X, 56Y, 56Z.

[0097] As mentioned above, the robotic system 10 is typically used in procedures requiring delicate and precise movement of a surgical tool, such as ophthalmic procedures. Accordingly, the control component unit 30 is typically configured to allow movement of the control component tool without significant reaction forces (other than those intentionally applied by the operator via the motors 56X, 56Y, and 56Z) acting against that movement. In some applications, the control component tool includes a counterweight 58, which balances the weight of the control component tool relatively evenly about the pitch rotation axis 70. In some applications, the control component tool is not perfectly balanced about the pitch rotation axis 70 to give the surgeon a sense of the tool's weight (like a real surgical tool) and / or to reduce the overall mass of the control component tool. In some applications, the links 54 extend on either side of the Z rotation axis 52Z, and the control component tool and additional components are disposed on the links 54 (and / or parallel links 55) on a first side of the rotation axis 52Z. In some applications, a motor 56Z disposed along the Z linear direction is disposed on a link 54 on the opposite side of the rotation axis 52Z to balance the weight of the control component tool and additional components disposed on the first side. In some such applications, the control component unit does not include an additional counterweight for this purpose (unlike the control component units shown in FIGS. 2A-8, which include a dedicated counterweight 62 for this purpose). Alternatively, the control component unit includes a counterweight for this purpose in addition to the motor 56Z.

[0098] In some applications, frame 50 (which functions as a link to provide linear motion in the X direction) includes two curved arms, and motor 56Y (and optionally its extension 56YE) passes along a straight line between the two curved arms. In some applications, the end of frame 50 adjacent Z rotation axis 52Z is ​​aligned with Z rotation axis 52Z (as shown in FIG. 9A ), and frame 50 does not apply torque about Z rotation axis 52Z. Therefore, frame 50 does not need to be counterbalanced with respect to Z rotation axis 52Z. In some applications, as frame 50 moves (due to movement in the X direction), the frame remains aligned with Z rotation axis 52Z, and no compensating movement is required to balance the frame movement.

[0099] It should be noted that, according to the above description, the control component unit is typically balanced in all six degrees of freedom (three axial translations and three angular rotations). In some applications, as described, the control component unit utilizes a counterweight to balance two degrees of freedom: axial motion in the Z direction and pitch angular motion. (In the embodiment shown in FIGS. 9A-9D , motor 56Z functions as a counterweight in the axial motion in the Z direction.) Counterweights are typically not required for balancing the remaining four degrees of freedom (i.e., X- and Y-axial motions, and roll and yaw angular motions) because the control component unit is designed such that the control component tool and / or other elements of the control component unit are self-balancing in these degrees of freedom. Because the control component unit is designed to be balanced in all six degrees of freedom (e.g., by self-balancing in four degrees of freedom and balancing provided by counterweights in the remaining two degrees of freedom), the control component tool tends to maintain its position and orientation when no forces are acting on the control component tool. Thus, typically, if an operator temporarily lets go of a control component tool (i.e., does not apply a force to the control component tool when letting go of the tool), the control component tool will maintain its position and orientation until the operator resumes control of the control component tool. Furthermore, typically, the control component tool provides relatively low inertial forces, such that force feedback can be provided to the operator with a relatively low level of force. That is, a motor configured to drive movement of the control component tool and thereby provide force feedback to the operator is configured to provide force feedback without having to substantially overcome inertial forces.

[0100] In addition to the above differences, the structure and function of the control component unit 30 shown in FIGS. 9A-9B differs from the structure and function of the control component unit 30 shown in FIGS. 2A-8 in the following ways.

[0101] In some applications, as shown in FIGS. 9A-9B , the motor 56Y is disposed in the XY plane such that its center of mass is substantially aligned with the X axis of rotation 52X when the motor 56Y is extended or retracted. Typically, this prevents movement of the motor 56Y from applying a torque in the Z direction to the link 54 as the motor 56Y extends and retracts. Note that the center of mass of the motor moves slightly as the motor extends and retracts. Typically, the motor is positioned such that the center of mass of the motor is aligned with the X axis of rotation 52X in at least one position in the fully extended and fully retracted states. Further, typically, the center of mass of the motor is aligned with the X axis of rotation 52X when the motor is in its central position relative to the fully extended and fully retracted states. In some applications, the center of mass of the motor is within 10 mm, e.g., within 5 mm, of the X axis of rotation 52X when the motor is fully extended or fully retracted. 2A-8, it should be noted that motor 56Y is coupled to frame 50 and is configured to rotate with frame 50. As such, the motor does not apply torque to frame 50 as frame 50 rotates.

[0102] In some applications, frame 50 includes an angled extension 50E to which motor 56X (and optionally its extension 56XE) is coupled. Motor 56X rotates frame 50 about axis 52X when motor 56X (or its extension) pushes or pulls angled extension 50E. Typically, inclusion of angled extension 50E in a control component unit reduces the size of the control component unit (and the overall footprint of the control component) compared to when motor 56X (or its extension 56XE) is coupled to a non-angled continuation of frame 50 on the opposite side of axis 52X from the main portion of frame 50. In some applications, motor 56X pushes or pulls non-angled extension 57 disposed within the frame footprint, as shown in FIG. 3B , for example, causing motor 56X (or its extension) to rotate frame 50 about axis 52X.

[0103] Similarly, in some applications, the link 54 includes an angled extension 54E to which a motor 56Y (and, optionally, an extension 56YE thereof) is coupled. The motor 56Y rotates the link 54 about the axis 52Y by the motor (or its extension) pushing or pulling on the angled extension 54E. Typically, the inclusion of the angled extension 54E in the control component unit reduces the size of the control component unit (and the overall footprint of the control component) compared to when the motor 56Y (or its extension 56YE) is coupled to a non-angled continuation of the link 54 on the opposite side of the axis 52Y from the main portion of the link 54. In some applications, the motor 56Y pushes or pulls the link 54 at a location 80 offset from the Y axis of rotation 52Y, as shown in FIG. 4C , for example, causing the motor (or its extension) to rotate the frame 50 about the axis 52Y.

[0104] In some applications, the longitudinal axis 72 of the shaft 42 (which serves as the yaw rotation axis) is aligned with the ends of the links 54 and 55. This is in contrast to the embodiment shown in Figures 2A-8, in which the shaft 42 is supported in extensions from the links 54 and 56. Aligning the longitudinal axis 72 of the shaft 42 with the ends of the parallel links 54 and 55 typically reduces the size of the control component unit (and the overall footprint of the control components) compared to when the shaft 42 is supported in extensions from the links 54 and 56.

[0105] Although some applications of the present invention have been described in connection with cataract surgery, the scope of this application includes applying the devices and methods described herein, mutatis mutandis, to other medical procedures. In particular, the devices and methods described herein for other medical procedures may be applied to other microsurgical procedures performed using microsurgical techniques, such as general surgery, orthopedic surgery, gynecological surgery, ENT surgery, neurosurgery, oral and maxillofacial surgery, plastic surgery, podiatric surgery, vascular surgery, and / or pediatric surgery. In some such applications, the imaging system includes one or more microscopic imaging units.

[0106] It should be noted that the scope of this application includes, mutatis mutandis, the application of the devices and methods described herein to intraocular procedures other than cataract surgery. Such procedures may include collagen crosslinking, endothelial keratoplasty (e.g., DSEK, DMEK, and / or PDEK), DSO (Descemet's membrane stripping without grafting), laser-assisted corneal transplantation, corneal transplantation, LASIK / PRK, SMILE, pterygium, ocular surface cancer treatment, secondary IOL placement (suture, transconjunctival, etc.), iris repair, IOL repositioning, IOL exchange, lamellar keratectomy, minimally invasive glaucoma surgery (MIGS), limbal stem cell transplantation, astigmatic keratectomy, limbal relaxing incision (LRI), amniotic membrane transplantation (AMT), glaucoma surgery (e.g., trub, tube, minimally invasive glaucoma surgery), automated lamellar keratoplasty (ALK), anterior vitrectomy, and / or pars plana anterior vitrectomy.

[0107] The applications of the invention described herein may take the form of a computer program product accessible from a computer-usable or computer-readable medium (e.g., a non-transitory computer-readable medium) that provides program code for use by or in connection with a computer or any instruction execution system, such as computer processor 28. For purposes of this description, a computer-usable or computer-readable medium may be any apparatus that can contain, store, transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. The medium may be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or propagation medium. Typically, the computer-usable or computer-readable medium is a non-transitory computer-usable or computer-readable medium.

[0108] Examples of computer-readable media include semiconductor or solid state memory, magnetic tape, removable computer diskettes, random access memory (RAM), read-only memory (ROM), rigid magnetic disks, and optical disks, current examples of which include compact disk read-only memory (CD-ROM), compact disk read / write (CD-R / W), DVD, and USB drives.

[0109] A data processing system suitable for storing and / or executing program code includes at least one processor (e.g., computer processor 28) coupled directly or indirectly to memory elements via a system bus. The memory elements may include local memory utilized during the actual execution of the program code, mass storage devices, and cache memory that provides temporary storage of at least some of the program code to reduce the number of times the code must be retrieved from mass storage devices during execution. The system is capable of reading instructions of the present invention on a program storage device and performing the method of an embodiment of the present invention in accordance with these instructions.

[0110] Coupling a network adapter to a processor enables the processor to be coupled to other processors or remote printers or storage devices through intervening private or public networks. Modems, cable modems, and Ethernet cards are just a few examples of currently available types of network adapters.

[0111] Computer program code for carrying out operations of the present invention can be written in any combination of one or more programming languages, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as the C programming language or similar programming languages.

[0112] It will be understood that the algorithms described herein can be embodied by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, when executed by the processor of the computer (e.g., computer processor 28) or other programmable data processing apparatus, produce means for performing the functions / acts specified in the algorithms described herein. These computer program instructions can also be stored on a computer-readable medium (e.g., a non-transitory computer-readable medium) to direct the computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored on the computer-readable medium can produce an article of manufacture including instruction means for performing the functions / acts specified in the algorithms. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to perform a series of operational steps on the computer or other programmable data processing apparatus to produce a computer-implemented process, such that the instructions, when executed on the computer or other programmable data processing apparatus, provide the process for performing the functions / acts specified in the algorithms described herein.

[0113] Computer processor 28 is typically a hardware device that is programmed with computer program instructions to create a special-purpose computer. For example, when programmed to execute the algorithms described with reference to the figures, computer processor 28 typically acts as a special-purpose robotics system computer processor. Typically, the operations described herein as being performed by computer processor 28 change the physical state of a memory, which is an actual physical item, having a different magnetic polarity, charge, etc., depending on the memory technology being used. In some applications, the operations described herein as being performed by a computer processor are performed by multiple computer processors in combination with each other.

[0114] It will be appreciated by those skilled in the art that the present invention is not limited to what has been specifically shown and described above, and the scope of the present invention includes both combinations and subcombinations of the various features described above, as well as variations and modifications that would occur to one skilled in the art upon reading the foregoing description and that are not present in the prior art.

Claims

1. 1. An apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, said apparatus comprising: A control component unit, X, Y and Z linear motion rotation axes, and pitch, roll and yaw angular motion rotation axes; a control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, the control component tool being configured by an operator; when the operator moves the control component tool along linear X, Y, and Z directions, rotational motion is generated about X, Y, and Z linear motion rotation axes; a control component tool configured to be moved to generate rotational motion about each of pitch, roll, and yaw angular motion rotation axes when the operator moves the control component tool through roll, pitch, and yaw angular motions. a control component unit comprising: An apparatus in which the control component tool is substantially balanced about the X, Y and Z linear motion rotational axes and the pitch, roll and yaw angular motion rotational axes.

2. the control component tool is self-balancing in four degrees of freedom; 2. The apparatus of claim 1, wherein the control component unit comprises a counterweight that balances the weight of the control component and / or other components of the control component unit around corresponding axes of rotation in two degrees of freedom.

3. 3. The apparatus of claim 2, wherein the control component tool is self-balancing about two of the roll and yaw angular motion rotation axes and the X, Y, and Z linear motion rotation axes, and the control component comprises first and second counterweights that balance the weight of the control component tool and / or other components of the control component unit, respectively, about the pitch angular motion rotation axis and one of the linear motion rotation axes.

4. The apparatus of claim 3 , wherein the first counterweight does not perfectly balance the weight of the control component tool about the pitch angular motion axis of rotation.

5. The apparatus of claim 1 , wherein the control component tool is configured to maintain its position and orientation in the absence of forces acting on the control component tool.

6. 6. The apparatus of claim 5, wherein the control component tool is configured to maintain its position and orientation in response to the operator letting go of the control component tool without applying any force to the control component tool.

7. The apparatus of claim 1 , wherein the control component unit comprises one or more motors configured to drive movement of the control component tool to provide force feedback to the operator.

8. The apparatus of claim 7 , wherein the one or more motors are configured to provide the force feedback substantially without having to overcome inertial forces.

9. The apparatus of claim 7 , wherein the one or more motors include one or more direct drive motors.

10. The apparatus of claim 9 , wherein the one or more motors include one or more direct drive linear motors.

11. The apparatus of claim 10 , wherein the one or more motors include one or more direct drive linear voice coil motors.

12. 1. An apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, said apparatus comprising: A control component unit, a plurality of links connected to each other via a plurality of rotation axes; a control component tool coupled to the link configured to be moved by an operator such that the link rotates about the axis of rotation when the operator moves the control component tool along linear X, Y, and Z directions; a control component unit comprising: the plurality of links includes an X-direction link to which an X-direction linear motion is provided; the plurality of rotational axes includes a Z rotational axis about which the Z-direction movement is effected; The apparatus wherein the X-direction link is aligned with the Z-axis of rotation such that the X-direction link does not impart a torque about the Z-axis of rotation.

13. 13. The apparatus of claim 12, wherein the plurality of rotational axes includes a Y rotational axis about which the Y-directional motion is effected, the Y rotational axis being aligned with the Z rotational axis along the Z direction.

14. The apparatus of claim 12 , wherein the X-directional link comprises a frame.

15. The apparatus of claim 12 , wherein the X-direction link is aligned with the Z-axis of rotation such that the X-direction link does not impart a torque about the Z-axis of rotation.

16. 13. The apparatus of claim 12, wherein the X-direction link remains aligned with the Z rotational axis when the X-direction link undergoes movement, and no compensating movement is required to balance the movement of the X-direction link.

17. 13. The apparatus of claim 12, wherein the control component tool is self-balancing in four degrees of freedom and wherein the control component is provided with a counterweight in two degrees of freedom that balances the weight of the control component and / or other components of the control component unit around a corresponding axis of rotation.

18. 18. Apparatus according to any one of claims 12 to 17, wherein the control component tool is configured to maintain its position and orientation in the absence of forces acting on the control component tool.

19. 20. The apparatus of claim 18, wherein the control component tool is configured to maintain its position and orientation in response to the operator letting go of the control component tool without applying any force to the control component tool.

20. 18. The apparatus of any one of claims 12 to 17, wherein the control component unit comprises one or more motors configured to drive movement of the control component tool to provide force feedback to the operator.

21. 21. The apparatus of claim 20, wherein the one or more motors are configured to provide the force feedback substantially without having to overcome inertial forces.

22. 21. The apparatus of claim 20, wherein the one or more motors include one or more direct drive motors.

23. 23. The apparatus of claim 22, wherein the one or more motors include one or more direct drive linear motors.

24. 24. The apparatus of claim 23, wherein the one or more motors comprise one or more direct drive linear voice coil motors.

25. 1. An apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, said apparatus comprising: A control component unit, X, Y and Z linear motion rotation axes, and pitch, roll and yaw angular motion rotation axes; a control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, the control component tool being configured by an operator; when the operator moves the control component tool along linear X, Y, and Z directions, rotational motion is generated about X, Y, and Z linear motion rotation axes; a control component tool configured to be moved to generate rotational motion about each of pitch, roll and yaw rotation axes when the operator moves the control component tool through roll, pitch and yaw angular motions; a plurality of direct drive motors operatively coupled to each of the X, Y, and Z linear motion rotation axes; a control component unit comprising:

1. A computer processor comprising: moving the tip of the selected ophthalmic tool within the patient's eye in a manner consistent with the movement of the control component tool; a computer processor configured to provide force feedback to the operator by driving the control component arm using the plurality of direct drive motors; A device comprising:

26. 26. The apparatus of claim 25, wherein the plurality of direct drive motors comprises a plurality of linear motors.

27. 27. The apparatus of claim 26, wherein the plurality of linear motors comprises a plurality of linear voice coil motors.

28. 26. The apparatus of claim 25, wherein the direct drive motor is configured to avoid motor cogging.

29. 30. The apparatus of claim 28, wherein the direct drive motor is configured to provide more accurate force feedback to the operator than force feedback provided by a motor that experiences motor jamming.

30. 1. An apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, said apparatus comprising: A control component unit, X, Y and Z linear motion rotation axes and pitch, roll and yaw angular motion rotation axes; a control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, the control component tool being configured by an operator; when the operator moves the control component tool along linear X, Y, and Z directions, rotational motion is generated about X, Y, and Z linear motion rotation axes; a control component tool configured to be moved to generate rotational motion about each of pitch, roll and yaw rotation axes when the operator moves the control component tool through roll, pitch and yaw angular motions; X, Y, and Z motors operatively coupled to the X, Y, and Z linear motion rotation axes, respectively a control component unit comprising:

1. A computer processor comprising: moving the tip of the selected ophthalmic tool within the patient's eye in a manner consistent with the movement of the control component tool; a computer processor configured to provide force feedback to the operator by driving the control component arms using the X, Y, and Z motors; Equipped with The apparatus wherein a first end of the Y motor is aligned with the X axis of rotation.

31. 31. The apparatus of claim 30, wherein the control component includes a frame, and the control component unit is configured such that when the operator moves the control component tool along the linear X direction, the frame rotates about the X linear motion rotation axis, and the Y direction motor is coupled to the frame to rotate with the frame.

32. 31. The apparatus of claim 30, wherein the Y motor exerts no torque about the X axis of rotation when extending or retracting.

33. 33. The apparatus of any one of claims 30 to 32, wherein a second end of the Y direction motor is offset from the Y axis of rotation so as to impart a torque about the Y axis of rotation when the Y direction motor extends or retracts.

34. 34. The apparatus of claim 33, wherein the second end of the Y motor is offset from the Y axis of rotation by 5 to 20 mm.

35. 35. The apparatus of claim 34, wherein the second end of the Y motor is offset from the Y axis of rotation by 5 to 20 mm.

36. 36. The apparatus of claim 35, wherein the second end of the Y motor is offset from the Y axis of rotation by 10 to 15 mm.

37. 33. The apparatus of any one of claims 30 to 32, wherein the X, Y, and Z motors comprise direct drive motors.

38. 38. The apparatus of claim 37, wherein the direct drive motor comprises a linear motor.

39. 39. The apparatus of claim 38, wherein the linear motor comprises a linear voice coil motor.

40. 38. The apparatus of claim 37, wherein the direct drive motor is configured to avoid motor cogging.

41. 41. The apparatus of claim 40, wherein the direct drive motor is configured to provide more accurate force feedback to the operator than force feedback provided by a motor that experiences motor jamming.

42. 33. The apparatus of any one of claims 30 to 32, wherein the center of mass of the Y motor is substantially aligned with the X linear motion axis of rotation.

43. 43. The apparatus of claim 42, wherein the Y direction motor comprises a linear motor, and wherein the center of mass of the Y direction motor is within 10 mm of the X linear motion axis of rotation when the Y direction motor is fully extended or fully retracted.

44. 44. The apparatus of claim 43, wherein the Y direction motor comprises a linear motor, and wherein the center of mass of the Y direction motor is within 5 mm of the X linear motion axis of rotation when the Y direction motor is fully extended or fully retracted.

45. 1. An apparatus for use with a robotic unit configured to perform a procedure on a part of a patient's body using one or more tools, said apparatus comprising: A control component unit, X, Y and Z linear motion rotation axes and pitch, roll and yaw angular motion rotation axes; a control component tool coupled to the X, Y, and Z linear motion rotational axes and the pitch, roll, and yaw angular motion rotational axes, the control component tool being configured by an operator; when the operator moves the control component tool along linear X, Y, and Z directions, rotational motion is generated about X, Y, and Z linear motion rotation axes; a control component tool configured to be moved to generate rotational motion about each of pitch, roll and yaw rotation axes when the operator moves the control component tool through roll, pitch and yaw angular motions; at least one rotary encoder configured to detect rotational movement about a corresponding one of said axes of rotation; one or more wires extending from the rotary encoder; and a toroidal magnet disposed along said corresponding one of said rotation axes; a control component unit comprising: Equipped with The one or more wires pass through a hole defined by the toroidal magnet.

46. The control component unit: a plurality of rotary encoders each configured to detect rotational motion about a corresponding one of the X, Y, and Z linear motion rotation axes, each having one or more wires extending therefrom; 46. ​​The apparatus of claim 45, further comprising: toroidal magnets disposed along the X, Y, and Z linear motion rotational axes, wherein the one or more wires pass through holes defined by the toroidal magnets.

47. The control component unit: a plurality of rotary encoders, each configured to detect rotational motion about a corresponding one of the pitch, roll, and yaw angular motion rotation axes, each having one or more wires extending therefrom; 46. ​​The apparatus of claim 45, further comprising: a toroidal magnet disposed along the pitch, roll, and yaw angular motion rotational axis, wherein the one or more wires pass through a hole defined by the toroidal magnet.

48. The control component unit further comprises: a plurality of rotary encoders each configured to detect rotational motion about a corresponding one of the X, Y, and Z linear motion rotation axes, each having one or more wires extending therefrom; 48. The apparatus of claim 47, further comprising: toroidal magnets disposed along the X, Y, and Z linear motion rotational axes, wherein the one or more wires pass through holes defined by the toroidal magnets.

Images