Controlling surgical instruments

Abstract

A control system for controlling manipulation of a surgical instrument in response to manipulation of a remote surgeon input device. The surgical instrument includes an end effector having a first end effector element and a second end effector element that are opposable and connected to an axis by an articulated connection. The control system receives commands from the surgeon input device to (i) change the orientation of the end effector, and (ii) open the first end effector element and the second end effector element relative to each other. In response to the command to change the orientation of the end effector, the control system determines an angle θ between a longitudinal axis of the articulated connection and the end effector. In response to the command to open the first end effector element and the second end effector element, the control system determines an opening angle θ between the first end effector element and the second end effector element. The control system compares θ with a maximum angle θmax between the longitudinal axis of the articulated connection and the end effector, and if θ>θmax, drives the first end effector element and the second end effector element to rotate so that (i) the angle between the longitudinal axis of the articulated connection and the end effector is θmax, and (ii) the opening angle between the first end effector element and the second end effector element is θmax.

Description

Background Art

[0001] The use of robots to assist and perform surgery is known. Figure 1 A typical surgical robotic system is shown. The surgical robot 100 consists of a base 102, an arm 104, and an instrument 106. The base supports the robot and may itself be rigidly attached to, for example, an operating room floor, an operating room ceiling, or a cart. The arm extends between the base and the instrument. The arm is articulated along its length by means of a plurality of flexible joints 108, which are used to position the surgical instrument in a desired position relative to the patient. The surgical instrument is attached to the distal end of the robotic arm. The surgical instrument penetrates the patient's body at a port in order to access the surgical site. At its distal end, the instrument includes an end effector 110 for performing a medical procedure. At Figure 1 , the end effector shown is a pair of jaws. The surgeon controls the surgical robot 100 via a remote surgeon console 112. The surgeon console includes one or more surgeon input devices 114. These can take the form of hand controllers or foot pedals. The surgeon console also includes a display 116.

[0002] The control system 118 connects the surgeon console 112 to the surgical robot 100. The control system receives inputs from the surgeon input devices and converts these inputs into control signals to move the joints of the robotic arm 104 and the end effector 110. The control system sends these control signals to the robot, where the corresponding joints are driven accordingly.

[0003] As is known, the jaws of the end effector are individually driven by cables. These cables can be used to drive the opening and closing of the jaws in order to grasp and release an object between them. The same cables can also be used to drive the deflection movement of the jaws in order to rotate the jaws in the same direction while the opening angle of the jaws remains constant. Since the same cables are used to drive both the opening / closing and deflection movements of the jaws, these operations are not independent. Therefore, the full opening / closing range of motion cannot be achieved within the full deflection range of motion, and vice versa.

[0004] Therefore, there is a need for a control system that better mediates the interdependence of the opening / closing and deflection motions of the end effector. Summary of the invention

[0005] According to one aspect of the present invention, a control system is provided for controlling the manipulation of a surgical instrument in response to manipulation of a remote surgeon input device, the surgical instrument comprising an end effector having a first end effector element and a second end effector element which are oppositely connected to an axis by an articulated connection, the control system being configured to: receive from the surgeon input device (i) a command to change the orientation of the end effector, and (ii) to open the first end effector element and the second end effector element relative to each other; in response to the command to change the orientation of the end effector, determine an angle θ between a longitudinal axis of the articulated connection and the end effector; in response to the command to open the first end effector element and the second end effector element, determine an opening angle θ between the first end effector element and the second end effector element; The maximum angle θ between the longitudinal axis of the articulated joint and the end effector is max compare; and if θ>θ max , driving the first end effector element and the second end effector element to rotate so that (i) the angle between the longitudinal axis of the articulated joint and the end effector is θ max , and (ii) the opening angle between the first end effector element and the second end effector element is

[0006] The control system can be configured such that if θ≤θ max , driving the first end effector element and the second end effector element to rotate so that (i) the angle between the longitudinal axis of the articulated joint and the end effector is θ, and (ii) the opening angle between the first end effector element and the second end effector element is

[0007] The angle θ may be between a longitudinal axis of the articulated coupling and an axis bisecting the end effector element.

[0008] θ max Can be and α max function, where α max is the maximum rotation from the longitudinal axis of the articulated linkage of the end effector element in the commanded rotational direction.

[0009] Optionally,

[0010] The control system may be configured to determine an opening angle between the first end effector element and the second end effector element by: In response to a command to open the first end effector element and the second end effector element, determining an opening angle ψ; comparing ψ to a maximum angle between the first end effector element and the second end effector element; to compare; and if The first end effector element and the second end effector element are driven to rotate so that the opening angle between the first end effector element and the second end effector element is

[0011] The control system may be configured such that, if Then the first end effector element and the second end effector element are driven to rotate so that the opening angle between the first end effector element and the second end effector element is

[0012] The command from the surgeon input device to change the orientation of the end effector may include rotation of at least a portion of the surgeon input device in its workspace.

[0013] The surgeon input device may include a body and a trigger, and the command from the surgeon input device to open the first and second end effector elements relative to each other may include movement of the trigger relative to the body.

[0014] The command from the surgeon input device to open the first and second end effector elements relative to each other may include rotating the trigger away from the body.

[0015] At the end of the rotation, the angle between the trigger and the body can be Proportional.

[0016] The command from the surgeon input device to open the first and second end effector elements relative to each other may include linear translation of the trigger relative to the body.

[0017] The articulated coupling may include a first joint drivable by a first pair of drive elements, and a second joint drivable by a second pair of drive elements. The control system may be configured to drive the first end effector element and the second end effector element to rotate by commanding a first force to be applied to the first pair of drive elements so as to rotate the first end effector element around the first joint; and commanding a second force to be applied to the second pair of drive elements so as to rotate the second end effector element around the second joint.

[0018] The articulated coupling may further include a third joint drivable by a third pair of drive elements. The control system may be configured to: determine an angle Ω between the longitudinal axis of the shaft and the articulated coupling in response to a command to change the orientation of the end effector; and drive the end effector to rotate Ω about the third joint.

[0019] The control system may be configured to drive the end effector to rotate about the third joint by commanding application of a third force to the third pair of drive elements so as to rotate the end effector about the third joint.

[0020] The control system may be configured to: when driving the first end effector element and the second end effector element to rotate so that the angle between the longitudinal axis of the articulated joint and the end effector is θ max Thereafter, receiving from the surgeon input device another command to increase the opening angle between the first end effector element and the second end effector element relative to each other; in response to the another command: determining the opening angle between the first end effector element and the second end effector element Determine the angle θ between the longitudinal axis of the articulated joint and the end effector max ', where θ max 'yes and driving the first end effector element and the second end effector element to rotate, so that (i) the angle between the longitudinal axis of the articulated coupling and the end effector is θ max ', and (ii) the opening angle between the first end effector element and the second end effector element is

[0021] Optionally, where α max is the maximum rotation from the longitudinal axis of the articulated linkage of the end effector element in the commanded rotational direction.

[0022] Each of the first pair of drive elements and the second pair of drive elements may include a cable.

[0023] The first force, the second force and / or the third force may be a tensile force.

[0024] The opposable first and second end effector elements may be one of: a pair of jaws, a pair of scissors, and a needle driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will now be described by way of example with reference to the accompanying drawings. In the drawings:

[0026] Figure 1 A surgical robotic system for performing a surgical procedure is shown;

[0027] Figure 2a and 2b The distal end of an exemplary surgical instrument is shown;

[0028] Figure 3 An exemplary surgeon input device is shown;

[0029] Figure 4 The distal end of an exemplary surgical instrument is shown; and

[0030] Figure 5 is a flow chart of a method of controlling manipulation of a surgical instrument. DETAILED DESCRIPTION

[0031] The following describes controlling a surgical robotic instrument from a remote surgeon console. The instrument and console form Figure 1 Part of a surgical robotic system of the type shown.

[0032] The surgical instruments are supported by the robotic arm. The robotic arm itself is supported by a base. During surgery, the base is secured to a portion of the operating room, such as the floor, ceiling, cart, or patient bed. The robotic arm remains external to the patient at all times. The robotic arm includes a series of arm links interlaced with joints. These joints may be swivel joints. The end of the robotic arm distal to the base may be articulated relative to the base by movement of one or more joints. The surgical instruments are attached to a drive assembly at the distal end of the robotic arm. This attachment point is external to the patient.

[0033] The surgical instrument has an elongated profile with a shaft spanning between its proximal end and its distal end, the proximal end being attached to a robotic arm, the distal end being close to a surgical site in a patient's body. The proximal end of the surgical instrument and the instrument shaft can be rigid relative to each other and rigid relative to the distal end of the robotic arm when attached to the robotic arm. An incision is made into the patient's body, through which a port is inserted. The surgical instrument can penetrate the patient's body through the port to access the surgical site. Alternatively, the surgical instrument can penetrate the body through a natural cavity of the body to access the surgical site. At the proximal end of the instrument, the shaft is connected to an instrument interface. The instrument interface engages with a drive assembly at the distal end of the robotic arm. Specifically, individual instrument interface elements of the instrument interface engage individual drive assembly interface elements of the drive assembly. The instrument interface can be releasably engaged with the drive assembly. The instrument can be manually detached from the robotic arm without the need for any tools. This enables the instrument to be quickly detached from the drive assembly during operation and another instrument to be attached.

[0034] At the distal end of the surgical instrument, the shaft is connected to an end effector by an articulated connection. The end effector participates in the surgical procedure at the surgical site. Figure 2aand 2b The distal end of an exemplary instrument is shown, which has a pair of jaws as an end effector 201. A shaft 202 is connected to the end effector 201 by an articulated connection 203. The articulated connection 203 includes several joints. These joints enable the attitude of the end effector to be changed relative to the direction of the instrument axis. Although Figure 2a and 2b Although not shown in FIG, the end effector may also include a joint. Figure 2a and 2b In the example of , the articulated connection 203 includes a pitch joint 204. The pitch joint 204 rotates about a pitch axis 205, which is perpendicular to the longitudinal axis 206 of the shaft 202. The pitch joint 204 allows the support 213 (described below) and therefore the end effector 201 to rotate about the pitch axis 205 relative to the shaft. Figure 2a and 2b In the example of , the articulated connection also includes a first deflection joint 207 and a second deflection joint 211. The first deflection joint 207 rotates around a first deflection axis 208. The second deflection joint 211 rotates around a second deflection axis 212. The deflection axes 208 and 212 are both perpendicular to the pitch axis 205. The deflection axes 208 and 212 can be parallel. The deflection axes 208 and 212 can be collinear. The articulated connection 203 includes a support body 213. At one end, the support body 213 is connected to the shaft 202 by the pitch joint 204. At the other end, the support body 213 is connected to the end effector 201 by the deflection joints 207 and 211. For ease of illustration, Figure 2a The support body is omitted so that other structures of the articulated connection can be more easily seen. The end effector 201 includes two end effector elements 209, 210. The end effector elements shown are opposing clamps. However, the end effector elements can be any type of opposing end effector elements, further examples of which are discussed later. The first deflection joint 207 is fixed to the first end effector element 209 and allows the first end effector element 209 to rotate relative to the support body 213 and the pitch joint 204 about the first deflection axis 208. The second deflection joint 211 is fixed to the second end effector element 210 and allows the second end effector element 210 to rotate relative to the support body 213 and the pitch joint 204 about the second deflection axis 212.

[0035] Figure 2a and 2bThe joint shown in is driven by a pair of drive elements. The drive elements are elongated. They are flexible transverse to the longitudinal span. They resist compression and tension along their longitudinal span. Each pair of drive elements is fixed to the corresponding instrument interface element of the instrument interface at the other end of the instrument shaft. Therefore, the robot arm transmits the driving force to the end effector in the following manner: the movement of the drive assembly interface element moves the instrument interface element, which moves the drive element, which moves one or more joints of the articulated portion and / or the end effector, thereby moving the end effector. The drive element can be a cable. The drive element can include several flexible parts and a rigid part. The flexible part engages parts of the instrument interface and the articulated connection, and the rigid part extends through all or part of the instrument shaft. For example, the flexible part can be a cable and the rigid part can be a spoke. Other rigid parts can be in the instrument interface or the articulated connection of the instrument. For example, the rack and pinion can be in the instrument interface or the articulated connection of the instrument.

[0036] Figure 2a and 2b A first pair of drive elements A1 , A2 is shown, which are constrained to move about a first yaw joint 207. The drive elements A1 , A2 drive a first end effector element 209 in rotation about a first yaw axis 208. Figure 2a and 2b A second pair of drive elements B1 , B2 is shown, which are constrained to move about a second deflection joint 211 . The drive elements B1 , B2 drive the second end effector element 210 in rotation about a second deflection axis 212 . Figure 2a and 2b Also shown is a third pair of drive elements C1, C2, which are constrained to move about a pitch joint 204. The drive elements C1, C2 drive the end effector 201 to rotate about a pitch axis 205. The end effector 201 can be rotated about the pitch axis 205 by applying tension to the drive elements C1 and / or C2. The pitch joint 204 and the yaw joints 207, 211 are driven independently by their respective drive elements.

[0037] The end effector elements 209 and 210 can be rotated independently. The end effector elements can be rotated in opposite rotational directions. For example, the end effector elements can be rotated toward each other in opposite rotational directions by applying tension to the drive elements A2 and B1. This closes the end effector elements together, which can be used to (i) grasp an object between the end effector elements, such as tissue or a needle or thread and / or (ii) cut an object between the end effector elements, such as tissue or thread. The end effector elements can be rotated away from each other in opposite rotational directions by applying tension to the drive elements A1 and B2. This opens the end effector elements, which can be used to (i) release an object that has been grasped between the end effector elements, and / or (ii) reopen a pair of scissors end effector elements ready for another cutting action. The two end effector elements can be rotated in the same rotational direction by applying tension to the drive elements A1, B1 or alternatively to A2 and B2. This deflects the end effector elements about the pivot axes 208 and 212. This can be used to enable the end effector to approach different parts of the surgical site. Alternatively, while one end effector element is held in place, the other end effector element may be rotated (in either rotational direction) by applying tension to only one of the drive elements A1, A2, B1, B2. Thus, both the grasping motion and the deflecting motion of the end effector are achieved by manipulating the same pair of drive elements: A1, A2 for the first end effector element 209 and B1, B2 for the second end effector element 210.

[0038] Any type of instrument having opposable end effector elements is relevant to the following description. A first exemplary type is a cutting instrument, where the end effector elements engage to cut tissue or another object between the end effector elements. A second exemplary type is a grasping instrument, where the end effector elements engage to grasp tissue or another object between the end effector elements.

[0039] The surgeon console includes one or more surgeon input devices. Each surgeon input device enables the surgeon to provide control inputs to the control system. For example, the surgeon input device may be a hand controller, a foot controller such as a pedal, a touch sensitive input to be controlled by a finger or another part of the body, a voice control input device, an eye control input device, or a gesture control input device. The surgeon input devices may provide a number of inputs that the surgeon may individually manipulate.

[0040] Figure 3An exemplary hand controller 300 is shown. The hand controller is connected to the surgeon's console, for example, by a gimbal (not shown). This enables the hand controller to move with three translational degrees of freedom relative to the surgeon's console. The hand controller shown is intended to be grasped by the right hand. A mirrored hand controller can be grasped by the left hand. The hand controller includes a body 301 suitable for grasping by a hand. The hand controller may include additional inputs, such as buttons, switches, levers, slide inputs, or capacitive sensor inputs, such as a track pad 303. Figure 3 The manual controller of the embodiment includes a trigger 302. The trigger 302 is movable relative to the body 301. In the manual controller shown, the trigger 302 is rotatable relative to the body 301. Alternatively or in addition, the trigger can be linearly translated relative to the body 301. The manual controller may include two triggers, each trigger for independently controlling a single different one of the end effector elements 209, 210.

[0041] The surgeon can rotate the trigger 302 relative to the body 301 of the manual controller to command the end effector elements 209, 210 of the instrument to close in a grasping / closing motion or to open in a releasing / opening motion. For example, the surgeon can rotate the trigger 302 toward the body 301 of the manual controller to command a grasping / closing motion. The surgeon can rotate the trigger 302 away from the body 301 of the manual controller to command a releasing / opening motion. The surgeon can rotate the body of the manual controller in the manual controller workspace to command an orientation change of the end effector element.

[0042] The control system connects the surgeon's console to the surgical robot. The control system includes a processor and a memory. The memory stores software code that can be executed by the processor in a non-transitory manner so that the processor controls the surgeon's console and the robotic arms and instruments in the manner described herein. The control system receives input from the surgeon's input device and converts it into control signals to move the joints of the robotic arm and / or the joints of the articulated joints and / or the joints of the end effector. The control system sends these control signals to the robotic arm, where the corresponding joints are driven accordingly. In response to the manipulation of the surgeon's input device, the manipulation of the surgical instruments is thereby controlled by the control system.

[0043] When the control system controls an instrument having opposed end effector elements, upon detecting opening movement of a manual control, the control system responds by commanding the application of forces to drive elements of the end effector elements to rotate the end effector elements away from each other in opposite rotational directions. Figure 2a and 2b , the control system responds to detecting the opening motion by commanding the application of force to A1 and force to B2 to cause the end effector element to deploy.

[0044] Upon detecting a second movement of the manual controller in the manual controller workspace, the control system may respond by commanding any one or combination of: (i) joints of the surgical robot arm, (ii) joints of the articulated connector 203 of the surgical instrument, and (iii) joints of the end effector. The commanded articulation causes the posture of the end effector to change as directed by the second movement. For example, the second movement may be a rotation of the body 301 of the manual controller. As another example, the second movement may be manipulating another input on the manual controller, such as moving another trigger. The movement may be a rotation of another trigger relative to the body of the manual controller. Alternatively or in addition, the other trigger may translate linearly relative to the body 301.

[0045] Thus, the control system may respond to detecting a second movement (e.g., rotation) of the body of the manual controller at least in part by commanding the application of a force to the drive element of the end effector element to rotate the end effector element. Figure 2a and 2b , the control system may command the application of force to A2 and B2 to deflect the end effector elements 209 and 210 in a clockwise direction. The control system may command the application of force to A1 and B1 to deflect the end effector elements 209 and 210 in a counterclockwise direction. The control system may command the application of the same force to both A1 and B1 (or A2 and B2). If the end effector elements are mated, and the drive elements of these end effector elements are mated, then for a configuration in which the end effector elements are not fully closed and apply force to each other, the same force is applied to A1 and B1 (or A2 and B2) to deflect the two end effector elements in unison. The control system may also respond to the detection of a second movement (e.g., rotation) of the body of the manual controller by commanding the application of a force to one of C1 and C2 to rotate the pitch joint 204. The control system may also respond to the detection of a second movement (e.g., rotation) of the body of the manual controller by commanding the application of torque to one or more joints around the robot arm.

[0046] The same drive elements A1 , A2 and B1 , B2 are used to drive the end effector elements in rotation to open and close the end effector elements relative to each other and to deflect the end effector. Therefore, the opening / closing and deflecting operations are not independently driven.

[0047] refer to Figure 4 Each end effector element 209, 210 is capable of rotating about the axis of the joint 207, 211 to which it is connected relative to the longitudinal axis 401 of the articulated joint 203. The longitudinal axis 402 of the end effector element farthest from the longitudinal axis 401 of the articulated joint 203 is at Figure 4203 as being separated from the longitudinal axis 401 of the articulated joint 203 by an angle α. The longitudinal axis 403 of the end effector element closest to the longitudinal axis 401 of the articulated joint 203 is at Figure 4 401 as being separated from the longitudinal axis 401 of the articulated joint 203 by an angle β. In other words, the angle between the longitudinal axes 402 and 403 of the end effector elements is

[0048] Each end effector element is limited in the extent to which it can rotate about the axis of the joint to which it is connected. The maximum rotation angle between the longitudinal axis 402 of the farthest end effector and the longitudinal axis 401 of the articulated joint 203 is α max For example, α max Can be in the range of 60° to 90°. max Can be in the range of 65° to 80°. max It can be 70°. max Depending on the instrument, the end effector element can be opened to an extended angle Then as Figure 4 As the end effector element deflects, the opening angle is initially maintained. However, once the distal end effector element 210 is max If the surgeon input device continues to command a deflection action, and the control system continues to drive the instrument accordingly, the end effector element 210 remains stationary, but the other end effector element 209 continues to deflect, i.e., continues to rotate clockwise. begins to decrease, so the end effector element begins to close even though the surgeon input device is still commanding the end effector element to remain open.

[0049] exist Figure 4 , the end effector is shown as having been deflected in a clockwise direction relative to the longitudinal axis 401 of the articulated joint. Thus, the end effector element 210 is farthest from the longitudinal axis 401 of the articulated joint. The maximum rotation angle between the axes 402 and 401 is α max When the end effector is deflected in a counterclockwise direction relative to the longitudinal axis 401 of the articulated joint, the end effector element 209 is farthest from the longitudinal axis 401 of the articulated joint. In this case, the maximum rotation angle between the axes 401 and 403 is α max For one end effector element rotating clockwise and the other end effector element rotating counterclockwise, the maximum rotation angle α maxcan be the same. This may be the case for symmetrical instruments. For other instruments, for one end effector element rotating clockwise and the other end effector element rotating counterclockwise, the maximum rotation angle α max It can be different. For example, this may be the case for an asymmetric instrument. For some asymmetric instruments, the end effector element may have a range of motion that is limited to only one side of the longitudinal axis 401 of the articulated connection. In this case, the same end effector element is always farthest from the longitudinal axis 401 of the articulated connection.

[0050] The end effector elements may also be limited in how far they can rotate away from each other. For example, the opening angle may be limited to It may be device dependent. For example, It can be in the range of 40° to 90°. It can be in the range of 45° to 75°.

[0051] Figure 5 A method implemented by a control system to limit the deflection motion of an end effector in order to preferentially maintain an opening angle of the end effector element is shown.

[0052] exist Figure 5 At step 501 , the control system receives commands from a surgeon input device to (i) change the orientation of an end effector, and (ii) open end effector elements relative to each other.

[0053] As described above, the command from the surgeon input device to change the orientation of the end effector can be a rotation of the surgeon input device in its workspace. The surgeon input device can be connected to the surgeon console by an articulated link, optionally including a universal joint assembly. A position sensor can be included on each movable joint of the articulated link. The control system receives a sensed position of each joint of the articulated link. Based on the known order, mass and length of the links and joints in the articulated link and the received sensed positions, the control system determines the change in orientation of the surgeon input device. Based on the change in orientation of the surgeon input device, the control system determines the commanded change in orientation of the end effector.

[0054] The command from the surgeon input device to open the end effector elements relative to each other may be a rotation of the trigger away from the body of the surgeon input device. Alternatively, the command from the surgeon input device to open the end effector elements relative to each other may be a linear translation of the trigger relative to the body. For example, Figure 3The manual controller 300 may include a position sensor that senses the rotational (or linear) position of the trigger 302 relative to the body 301 of the manual controller. The control system receives the sensed rotational (or linear) position of the trigger from the position sensor.

[0055] At step 502 , in response to a command to change the orientation of an end effector, the control system determines an angle between a longitudinal axis of an articulated linkage and the end effector. Figure 4 θ is shown between the longitudinal axis 401 of the articulated joint and the axis 404 bisecting the end effector element. Figure 4 , bisecting axis 404 is such that (i) axes 402, 403, and 404 all intersect at some point, and (ii) the angle between axes 402 and 404 is equal to the angle between axes 403 and 404. Axes 402, 403, and 404 intersect where they meet yaw axes 207 and 212.

[0056] Angle θ is the angle that determines the effect of the orientation change commanded by the surgeon input device. Angle θ may be proportional to the angle through which the surgeon input device is rotated in its workspace. In the case where the orientation change is commanded by motion of a portion of the surgeon input device, such as another trigger, angle θ may be proportional to the angle through which the portion of the surgeon input device is rotated or the distance that the portion of the surgeon input device has been linearly translated.

[0057] At step 503, the control system compares θ and θ max For comparison. max is the maximum value of θ. In other words, θ max θ is the maximum angle between the longitudinal axis 401 of the articulated joint and the end effector. max The opening angle of the end effector element can be adjusted Alternatively or additionally, θ max The maximum rotation angle α of the farthest end effector element can be max For example,

[0058]

[0059] The control system determines whether θ>θ max If θ≤θ max , the end effector element is controlled to rotate so that the angle θ between the longitudinal axis 401 of the articulated connection and the end effector does not cause the opening angle of the end effector element to start closing. Therefore, if θ≤θ max, then at step 504, the control system drives the first end effector element and the second end effector element to rotate so that the angle between the longitudinal axis 401 of the articulated connection and the end effector is θ. For example, the angle between the longitudinal axis 401 of the articulated connection and the bisecting axis 404 is θ.

[0060] If at step 503, the control system determines that θ>θ max , then the end effector element is controlled to rotate so that the angle between the longitudinal axis 401 of the articulated connection and the end effector is θ so that the opening angle of the end effector element begins to close. Therefore, in fact, at step 505, the control system drives the first end effector element and the second end effector element to rotate so that the angle between the longitudinal axis 401 of the articulated connection and the end effector is θ max For example, the angle between the longitudinal axis 401 of the articulated connection and the bisecting axis 404 is θ max .

[0061] At the same time, the control system determines the opening angle between the first end effector element and the second end effector element. At step 506, in response to the command to open the end effector elements, the control system determines an opening angle ψ between the first end effector element and the second end effector element. Specifically, ψ is the angle between the longitudinal axis of the first end effector element 402 and the longitudinal axis of the second end effector element 403. Angle ψ is the angle that determines the opening angle between the end effector elements to achieve the command by the surgeon input device. Once the trigger has been moved to execute the command of step 501, the angle ψ can be proportional to the rotational position of the trigger relative to the surgeon input device body.

[0062] At step 507, the control system combines ψ with The control system determines whether if Then, at step 508, the control system drives the first end effector element and the second end effector element to rotate so that the angle between the longitudinal axes 402 and 403 of the end effector elements is

[0063] If at step 507, the control system determines At step 509, the control system drives the first end effector element and the second end effector element to rotate so that the angle between the longitudinal axes 402 and 403 of the end effector elements is

[0064] exist Figure 5In FIG. 5 , steps 504, 505, 508 and 509 are all included in the dashed line step 510. This is to indicate that Figure 5 Those steps of steps 504, 505, 508, and 509 that are implemented in a given iteration of the control method of are implemented in coordination. For example, if the answer to both steps 503 and 507 is no, then steps 504 and 508 are performed in coordination. If the answer to both steps 503 and 507 is "yes," then steps 505 and 509 are performed in coordination. If the answer to step 503 is "no," and the answer to step 507 is "yes," then steps 504 and 509 are performed in coordination. If the answer to step 503 is "yes," and the answer to step 507 is "no," then steps 505 and 508 are performed in coordination.

[0065] Coordinated execution means that the control system determines to apply force to the first pair of drive elements A1, A2 and to apply force to the second pair of drive elements B1, B2 so that (i) the end effector is driven to θ or θ max , and (ii) the opening angle is driven to (Right now, or ).

[0066] In response to a command to change the orientation of the end effector, the control system can also determine the angle Ω between the longitudinal axis 206 of the shaft 202 and the longitudinal axis 401 of the articulated connection 203. The angles θ and Ω are determined to collectively achieve the orientation change commanded by the surgeon's input device. For example, the combined angle θ+Ω can be proportional to the angle through which the surgeon's input device has been rotated in its workspace. In this case, at step 510, the control system drives the third pair of drive elements C1, C2 so as to rotate the support body 213 and therefore the end effector 201 about the pitch axis 205 by the angle Ω.

[0067] After the end effector element and / or support body has been driven to the angle described with reference to step 510, the control loop may repeat. In other words, another command to change the orientation of the end effector and open the end effector element may be received by the control system at step 501. In this case, the above method repeats. Alternatively, at step 511, the control system may receive another command to increase the opening angle between the end effector elements. For example, the trigger of the surgeon input device may have been rotated farthest away from the body of the surgeon input device. No command to change the orientation of the end effector is received from the surgeon input device. If at step 510, the end effector has been driven to θ max , then the farthest end effector element 210 is already in a position that can be opened at the current opening angle The maximum rotation angle α maintained at max .

[0068] In response to another command in step 511, at step 512, the control system determines is the opening angle between the first end effector element and the second end effector element. Determine to achieve the opening angle between the end effector elements commanded by the surgeon input device at step 511. Once the trigger has been moved to execute the command of step 511, the angle Can be proportional to the rotational position of the trigger relative to the body of the surgeon input device.

[0069] Then, at step 513, the control system determines θ max '. θ max ' is the distance between the longitudinal axis of the hinged connection and the opening angle The maximum angle between the end effectors that can be maintained. θ max ' can be the opening angle of the end effector element Alternatively or additionally, θ max ' can be the maximum rotation angle α of the farthest end effector element max For example,

[0070]

[0071] Then, at step 514, the control system drives the end effector element to rotate so that (i) the angle between the longitudinal axis of the articulated joint and the end effector is θ max ', and (ii) the opening angle between the first end effector element and the second end effector element is Therefore, in practice, the distal-most end-effector element 210 maintains its rotational position at α max , and drives the closest end effector element 209 to rotate toward the longitudinal axis of the articulated connection 401 to achieve the desired opening angle

[0072] As a numerical example, consider α max =70°. At step 508, the end effector element is driven to an opening angle of Therefore, using Equation 1, θ max =45°. At step 510, the end effector is driven to θ max = 45°. Thus, each end effector element is at 20° and 70° of the longitudinal axis 401 of the articulated joint. At step 511, the control system receives a command from the surgeon input device to open the end effector element to The opening angle of max = 70°, using equation 2, θmax = 40°. Thus, each end effector element is at 10° and 70° of the longitudinal axis 401 of the articulated joint.

[0073] therefore, Figure 5 The control method prevents the opening angle of the end effector element from increasing when the surgeon inputs a command to increase the deflection movement of the end effector. Maintain the opening angle of the end effector element Priority is given to maximizing the angle by which each individual end effector element can rotate from the longitudinal axis 401 of the articulated linkage.

[0074] Figure 5 The steps shown in the control method are steps related to the problem dealt with in this article. Figure 5 Many other steps are performed during the control method. These other steps are Figure 5 Not shown in FIG.

[0075] The end effector may take any suitable form. For example, the end effector may be a pair of curved scissors, an electrosurgical instrument, such as a pair of monopolar scissors, a needle holder, a pair of clamps, or an open grasper.

[0076] The robots described herein can be used for purposes other than surgery. For example, the port can be an inspection port in a manufactured item such as a car engine, and the robot can control a viewing tool to view the inside of the engine.

[0077] Applicants hereby independently disclose each individual feature described herein and any combination of two or more such features, as long as these features or combinations can be implemented based on the present specification as a whole according to the common knowledge of those skilled in the art, regardless of whether these features or combinations of features solve any problem disclosed herein, and do not limit the scope of the claims. Applicants point out that various aspects of the present invention may consist of any such single feature or combination of features. In view of the above description, it is obvious to those skilled in the art that various modifications can be made within the scope of the present invention.

Claims

1. A control system for controlling manipulation of a surgical instrument in response to manipulation of a remote surgeon input device, the surgical instrument comprising an end effector having first and second opposable end effector elements connected to a shaft by an articulated connection, the control system being configured to: receiving a command from the surgeon input device to (i) change the orientation of the end effector, and (ii) open the first end effector element and the second end effector element relative to each other; determining an angle θ between a longitudinal axis of the articulated linkage and the end effector in response to a command to change the orientation of the end effector; determining an opening angle φ between the first end effector element and the second end effector element in response to a command to open the first end effector element and the second end effector element; The maximum angle θ between the longitudinal axis of the articulated joint and the end effector is max For comparison, θ max is φ and α max Function, α max is the maximum rotation angle between the longitudinal axis of the articulated coupling and the one of the first end effector element and the second end effector element that is farthest from the longitudinal axis of the articulated coupling; as well as If θ > θ max , driving the first end effector element and the second end effector element to rotate so that (i) the angle between the longitudinal axis of the articulated joint and the end effector is θ max , and (ii) an opening angle between the first end effector element and the second end effector element is φ.

2. The control system according to claim 1, wherein the control system is configured such that if θ ≤ θ max , driving the first end effector element and the second end effector element to rotate so that (i) the angle between the longitudinal axis of the articulated joint and the end effector is θ, and (ii) the opening angle between the first end effector element and the second end effector element is φ.

3. A control system according to claim 1 or 2, wherein the angle θ is between a longitudinal axis of the articulated joint and an axis bisecting the first end effector element and the second end effector element.

4. The control system according to claim 1 or 2, wherein θ max = α max -φ / 2.

5. The control system according to claim 1 or 2, wherein the control system is configured to determine an opening angle φ between the first end effector element and the second end effector element by: determining an opening angle ψ in response to a command to open the first end effector element and the second end effector element; = ψ and the maximum angle φ between the first end effector element and the second end effector element max Make comparisons; as well as If ψ > φ max , driving the first end effector element and the second end effector element to rotate so that the opening angle φ between the first end effector element and the second end effector element = φ max .

6. The control system according to claim 5, wherein the control system is configured such that if ψ ≤ ​​φ max , then the first end effector element and the second end effector element are driven to rotate so that an opening angle φ = ψ between the first end effector element and the second end effector element.

7. A control system according to claim 1 or 2, wherein the command from the surgeon input device to change the orientation of the end effector includes a rotation of at least a portion of the surgeon input device in a working space of the surgeon input device.

8. A control system according to claim 1 or 2, wherein the surgeon input device includes a body and a trigger, and wherein a command from the surgeon input device to open the first end effector element and the second end effector element relative to each other includes movement of the trigger relative to the body.

9. The control system of claim 8, wherein the command from the surgeon input device to open the first and second end effector elements relative to each other comprises rotation of the trigger away from the body.

10. The control system of claim 9, wherein the angle between the trigger and the body is proportional to φ.

11. The control system of claim 8, wherein the command from the surgeon input device to open the first and second end effector elements relative to each other comprises a linear translation of the trigger relative to the body.

12. The control system of claim 1 or 2, wherein the articulated joint comprises a first joint drivable by a first pair of drive elements, and a second joint drivable by a second pair of drive elements, and wherein the control system is configured to drive the first end effector element and the second end effector element to rotate by: commanding application of a first force to the first pair of drive elements to rotate the first end effector element about the first joint; and A second force is commanded to be applied to the second pair of drive elements to rotate the second end effector element about the second joint.

13. A control system according to claim 1 or 2, wherein the articulated connection further comprises a third joint drivable by a third pair of drive elements, and wherein the control system is configured to: In response to the command to change the orientation of the end effector, determining an angle Ω between a longitudinal axis of the shaft and the articulated coupling; and The end effector is driven to rotate about the third joint by Ω.

14. The control system of claim 13, wherein the control system is configured to drive the end effector to rotate about the third joint by commanding application of a third force to the third pair of drive elements so as to rotate the end effector about the third joint.

15. The control system according to claim 1 or 2, wherein the control system is configured to: When the first end effector element and the second end effector element are driven to rotate so that the angle between the longitudinal axis of the articulated joint and the end effector is θ max thereafter, receiving another command from the surgeon input device to increase an opening angle between the first end effector element and the second end effector element relative to each other; In response to the other command: determining an opening angle φ' between the first end effector element and the second end effector element; Determine the angle θ between the longitudinal axis of the articulated joint and the end effector max ', where θ max ' is a function of φ'; and The first end effector element and the second end effector element are driven to rotate so that (i) the angle between the longitudinal axis of the articulated joint and the end effector is θ max ', and (ii) an opening angle between the first end effector element and the second end effector element is φ'.

16. The control system of claim 15, wherein θ max ' = α max - φ' / 2, where α max is the maximum rotation from the longitudinal axis of the articulated joint of the end effector in the commanded rotational direction.

17. The control system of claim 12, wherein each of the first pair of drive elements and the second pair of drive elements comprises a cable.

18. The control system of claim 12, wherein the first force and / or the second force is a tensile force.

19. The control system of claim 1 or 2, wherein the opposable first and second end effector elements are one of: a pair of jaws, a pair of scissors, and a needle driver.

20. The control system of claim 14, wherein the third force is a tensile force.

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