Multi-cable medical device

Abstract

The invention relates to a multi-cable medical device. A medical device includes pairs of cables each wound about an input spindle and connected to actuate a degree of freedom of a device shaft structure. The cables may be connected such that rotating the input spindle will actuate a respective degree of freedom. A first pulley in the instrument may receive a first cable from the input spindle and redirect the first cable toward the instrument shaft, and a second pulley may receive a second cable from the input spindle and redirect the second cable toward the instrument shaft. In one configuration, the first and second pulleys are mounted on the first and second horizontal planes, respectively, and the second pulley redirects the second cable through the first horizontal plane. Additionally or alternatively, the cables of one horizontal plane may intersect, while the cables of the other horizontal plane do not intersect.

Description

[0001] This application is a divisional application of Chinese patent application No. 202210249259.4 with the application date of June 22, 2017 and the name of “Multi-cable medical device”. The aforementioned application is a divisional application of Chinese patent application No. 201780054873.2 with the application date of June 22, 2017 and the name of “Multi-cable medical device”

[0002] Related Applications

[0003] This patent application claims the benefit of priority and filing date of U.S. Provisional Patent Application No. 62 / 362,431, filed on July 14, 2016, and entitled “MULTI-CABLE MEDICAL INSTRUMENT,” which is incorporated herein by reference in its entirety. Background Art

[0004] Robotically controlled instruments such as those used in minimally invasive medical procedures typically use a tool or end effector or other manipulating element at the distal end of an extended instrument rod. (As used herein, the terms "robotic" or "automatically" and the like include remotely operated or telerobotic aspects.) The instrument shaft and distal tool generally have a small diameter, typically less than 1 cm, to minimize the size of the incision or natural orifice required to insert the instrument. Therefore, the distal tool is typically remotely operated or actuated via a thin drive member (e.g., a tendon or rod) extending between the distal tool and a transmission (sometimes referred to as the rear end mechanism of the instrument). The rear end mechanism of a replaceable instrument is generally configured to be removably coupled to an actuator (e.g., a motor group) in a docking port of the robot. The robot can then control the actuator and apply force to the drive member through the rear end mechanism and apply force to the distal tool of the instrument through the drive member.

[0005] Medical devices with multiple degrees of freedom of motion often require many drive members, and the backend mechanisms that accommodate the transition from the layout of the robot's docking port to the layout of the drive members in the device shaft can be complex and difficult to assemble. Summary of the invention

[0006] According to one aspect of the present invention, a medical device can provide efficient routing of actuation cables and a relatively simple assembly process for complex medical devices.

[0007] A specific embodiment provides a medical device that includes a base frame, an input spindle mounted in the base frame, an upper cable and a lower cable wrapped around the input spindle, and an instrument shaft extending from the base frame and including a mechanical structure that provides multiple degrees of freedom of movement. The upper cable and the lower cable can be connected to the mechanical structure so that rotation of the input spindle actuates the corresponding degrees of freedom. The lower pulley can be mounted at a first horizontal plane to receive the lower cable from the input spindle and redirect the lower cable toward the instrument shaft. The upper pulley can be mounted at a second horizontal plane to receive the upper cable from the input spindle and redirect the upper cable through the first horizontal plane and toward the instrument shaft.

[0008] Another specific embodiment is a method for assembling a medical device. The method may include: installing a lower pulley on a first component of a chassis of the medical device; supplying a lower cable from an instrument shaft of the medical device through the lower pulley; attaching a second component of the chassis to the first component so that at least some portion of the lower cable is located between the lower pulley and the second component; installing an upper pulley in position so that the second component is located between the upper pulley and the lower pulley; and supplying an upper cable from the instrument shaft through the upper pulley.

[0009] Yet another specific embodiment is a medical device comprising an input spindle, lower cables respectively wound around the input spindles, upper cables respectively wound around the input spindles, and an instrument shaft extending from a base frame in which the input spindles are mounted. A mechanical structure on the instrument shaft has multiple degrees of freedom of motion, and the upper cables and the lower cables are connected to the structure so that the rotation of the input spindle respectively actuates the degrees of freedom. The lower cables or the upper cables can extend between the input spindle and the instrument shaft without crossing, and the paths of other upper cables or lower cables cross between the input spindle and the instrument shaft. The crossing in a group of cables can allow the upper cables and lower cables wound around the same input spindle to be more effectively oriented toward positions on opposite sides of the central axis of the instrument shaft, which can improve the mechanical efficiency of actuation of the mechanical structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Embodiments of medical systems employing removable instruments are shown.

[0011] Figure 2A and Figure 2B Side and top views of example embodiments of a medical device are shown.

[0012] Figure 3 Cable routing in an example implementation of a backend mechanism of a medical device is shown.

[0013] Figure 4 is a cross-sectional view showing cable routing relative to a chassis and other structures in an example embodiment of a backend mechanism of a medical device.

[0014] Figure 5 is an expanded view of an embodiment of a medical device including a backend mechanism having a multi-piece chassis.

[0015] Fig. 6A , Figure 6B and Figure 6C Shown is a pulley structure created during an assembly process for a back end mechanism that guides cables between an instrument shaft of a medical instrument and a set of input spindles around which the cables are wound.

[0016] Fig.6D A cross section of a portion of an exemplary embodiment of a backend mechanism is shown, and illustrates how various components of the chassis may cooperate proximate the pulley to prevent the cable from derailing.

[0017] The drawings show examples for explanation purposes rather than the invention itself. The use of the same reference numerals in different drawings indicates similar or identical items. DETAILED DESCRIPTION

[0018] The back-end mechanism of a robotically controlled medical device guides cables from multiple input spindles to the instrument axis of the device and uses routing that allows simple assembly using a small number of components. The cables and associated pulleys in the device can be grouped specifically according to the horizontal plane or height relative to the instrument axis, and the lower cables can be fitted to the pulleys installed in the lower chassis component, and then the next higher chassis component and the pulleys for the upper cables are attached to the lower chassis component. The two-stage system is particularly effective in a self-counteracting system, in which each input spindle has a pair of two associated cables that are wound around the input spindle at different heights in opposite directions so that as the spindle rotates, one cable is wound in one direction and the other cable is unwound in the opposite direction. The cable routing leaves room for other components of the back end of the medical device, for example, to allow control or actuation of the instrument axis rollers, clamping drives, electrical connectors and latching mechanisms that attach the back-end mechanism to the robot. Cable routing may also position cables that are paired relative to one another in the instrument shaft so that the paired cables can effectively actuate opposite directions of motion of the instrument's degrees of freedom.

[0019] Figure 1 An example of a medical system 100 using a replaceable medical device 110 is shown. The system 100 (e.g., a da The surgical system 100 may particularly employ a plurality of surgical instruments 110, each of which is removably mounted in a docking port 120 on a manipulator arm 130 of a robot 140. A sterile barrier (not shown) including a drape and adapter for the instrument 110 may be between the instrument 110 and the robot 140, such that the robot 140 including the manipulator arm 130 and the docking port 120 is outside the sterile environment for the patient. Thus, the robot 140 may not need to be sterilized between medical procedures. Instead, the instrument 110, which may be used in a sterile environment and may contact the patient, is compact and removable, such that the instrument 110 may be sterilized or replaced between medical procedures performed using the system 100.

[0020] The instruments 110 may vary in structure and purpose, but may still be interchangeable, such that an instrument 110 mounted in a docking port 120 of a robot 140 may be selected for a particular medical procedure or altered during a medical procedure to provide a desired clinical function. Each instrument 110 generally includes an end effector or distal tool 112, an instrument shaft 114, and a backend mechanism 116. The distal tool 112 may have different designs to achieve many different functions. For example, the distal tools 112 for different instruments 110 may have many different shapes or sizes, and may include forceps, graspers, scalpels, scissors, cautery tools, or needle drivers, to name just a few possibilities, and instruments 110 with different distal tools 112 may be mounted on different arms 130 of a robot 140 and may work together at the same working site. An endoscopic camera (e.g., a stereo camera) may also be mounted on the arm to provide visual information, particularly images, of the working site in which the distal tool 112 of the instrument 110 may operate.

[0021] The docking port 120 may include an actuator (e.g., a drive motor) that provides mechanical power for actuating mechanical structures in the instrument 110, a drive coupler that connects the actuator to an input of the instrument 110, and a system for establishing and maintaining a sterile barrier between the instrument 110 and the rest of the medical system 100. The docking port 120 may additionally include an electrical interface to provide power to the instrument 110 or to communicate with the instrument 110, such as identifying the type of instrument 110 in the docking port 120, accessing parameters of the instrument 110, or receiving information from sensors in the instrument 110. For example, the electrical interface may transmit measurements to the robot 140, such as measurements of the position, orientation, or posture of the distal tool 112 and instrument shaft 114 of the instrument 110. A computer system, which may be connected to or part of the robot 140 and connected to a user interface device (not shown), may receive measurements from the instrument 110 and user commands from a surgeon or other medical personnel, and may execute software that controls the drive motors in the arm 130 and docking port 120 as needed to operate the instrument 110 in accordance with the user commands.

[0022] Figure 2A and Figure 2B An example implementation of a medical device 110 is shown. Figure 2A Specifically shown is a perspective view of an embodiment having a tool 112 at the distal end of an instrument shaft 114 and showing the instrument shaft 114 extending from a backend mechanism 116. In the illustrated embodiment, the distal tool 112 and the instrument shaft 114 have six degrees of freedom of motion relative to the backend mechanism 116. In particular, the six degrees of freedom correspond to: pitch and yaw rotation of the distal portion of the tool 112 about two respective vertical axes 201 and 202 associated with a first joint mechanism 211 (also referred to as "first joint 211"); pitch and yaw rotation or motion of the jaws 213 relative to two respective vertical axes 203 and 204 associated with a second joint mechanism 212 (also referred to as "second joint 212"; joints 211, 212 are sometimes referred to as "wrists"); opening or closing motion 205 of the jaws 213 for "grasp" actuation; "roll" rotation of the instrument shaft 114 about its central length axis 206. Other instruments may have more, fewer, or different degrees of freedom of motion.

[0023] Backend mechanism 116 such as Figure 2BSix input spindles 221-226 are shown having engagement features shaped and positioned to engage actuators, such as drive motors, in the docking port of the robot. Typically, each input spindle 221-226 can be coupled to actuate a different degree of freedom of motion of the instrument so that the robot can identify and use the correct one or more actuators to rotate the one or more spindles that exercise the desired degree of freedom of motion. The assignment of the corresponding degrees of freedom to the input spindles 221-226 must be known to the robot, but can be defined in other ways by any standard or convention. In an exemplary embodiment, the input spindle 226 can be coupled to a rolling mechanism that is connected to the proximal end of the instrument shaft 114 so as to rotate the instrument shaft 114 about its length axis 206 when the input spindle 226 is rotated. The input spindles 221-225 can be coupled to a drive member (not shown), such as a cable or rod extending through the instrument shaft 114 to the distal tool 112, so that an actuator in the robot can rotate the input spindles 221-225 to control the distal mechanism including the joints 211 and 212 and the jaw 213. More specifically, in an exemplary embodiment, rotation of the input spindle 221 can control rotation or actuation of the distal portion of the tool 112 about the axis 201. Rotation of the input spindle 222 can control rotation about the axis 202. Rotation of the input spindle 223 can control rotation about the axis 203 for yaw actuation of the jaw 213, and rotation of the input spindle 224 can control rotation about the axis 204 for pitch actuation of the jaw 213. In some embodiments, rotation of the input spindles 221-226 can correspond to a motion that is different from or more complex than a simple rotation of the structure about an axis. For example, input spindle 225 may be coupled to jaws 213 via a push-pull rod to actuate clamping with jaws 213. Also, in certain embodiments, a mechanism in tool 112 may couple a proximal portion of joint 212 to a distal portion of joint 211 for parallelogram motion, while the distal portion of joint 212 may move independently.

[0024] Figure 3 Shows Figure 2A and Figure 2B 1 and 2. Selected elements of an embodiment of a back end mechanism 116 of the present invention are shown, and in particular the routing of cables in the back end mechanism 116 that pass through the instrument shaft 114 and connect to the joints 211 and 212 is shown. The term "cable" is used in a broad sense herein to include any tendon-like structure. In particular, a length of cable in a medical device can include segments of different materials or different characteristics. The cable can include, for example, twisted segments where flexibility in the cable is desired (e.g., where the cable is wrapped around a spindle, capstan, or pulley) and can include more rigid segments (e.g., tubes or rods) to limit stretching where less bending of the cable is desired. Figure 3Not shown are elements of the back end mechanism 116, which may be used to actuate degrees of freedom associated with the rotation of the instrument shaft 114 or for opening and closing of the jaws 213. Commonly filed U.S. Patent Application No. 62 / 362,340 (filed on July 14, 2016) entitled “GEARED ROLL DRIVE FOR MEDICAL INSTRUMENT” and U.S. Patent Application No. 62 / 362,365 (filed on July 14, 2016) entitled “GEARED GRIP ACTUATION FOR MEDICAL INSTRUMENTS” disclose various aspects of specific embodiments of such mechanisms, and the entire contents of which are incorporated herein by reference.

[0025] As described above, the input spindles 221, 222, 223 and 224 are used to actuate the degrees of freedom associated with the respective axes 201, 202, 203 and 204, and each input spindle 221, 222, 223 and 224 includes a pair of capstans around which a pair of drive cables are wound. Figure 3 As shown, the upper capstan 231A and the lower capstan 231B may be fixed to the axle of the input spindle 221, so that the two capstans 231A and 231B rotate with the rotation of the input spindle 221. (The terms "upper" and "lower" are used here to distinguish horizontal planes, and may only be used on the instrument axis 114 such as Figure 3 ) The cable 241A is wound around the capstan 231A in one direction (e.g., clockwise or counterclockwise), and the cable 241B is wound around the capstan 231B in the opposite direction (e.g., counterclockwise or clockwise). The cable 241A extends from the upper capstan 231A to the upper pulley 251, which guides the cable 241A toward the instrument axis 114. Similarly, the cable 241B extends from the lower capstan 231B to the lower pulley 261, which guides the cable 241B toward the instrument axis 114. Cables 241A and 241B extend from respective pulleys 251 and 261 through guide 280 into instrument shaft 114 and connect through instrument shaft 114 to actuated joint mechanism 211 such that pulling on cable 241A or 242B will rotate the distal portion of mechanism 211 (and the distal portion of tool 112) about axis 201. The position of pulleys 251 and 261 and the shape of guide 280 can position cables 241A and 241B on opposite sides of a center or length axis 206 of instrument shaft 114, which can allow cable 241A to effectively drive movement of mechanism 211 about axis 201 in one direction or to some extent, and also allow cable 241B to effectively drive movement of mechanism 211 about axis 201 in the opposite direction or to some extent.

[0026] Each input spindle 222, 223 or 224 similarly includes an axle passing through a pair of capstans 232A and 232B, 233A and 233B, or 234A and 234B, around which a pair of cables 242A and 242B, 243A and 243B, or 244A and 244B are wound in opposite directions, and the cables 242A, 242B, 243A, 243B, 244A and 244B pass through respective pulleys 252, 262, 253, 263, 254 and 264 and through guide 280 and instrument shaft 114. In an exemplary embodiment, cables 242A and 242B are connected to joint mechanism 211, and cables 243A, 243B, 244A and 244B are connected to joint mechanism 212.

[0027] Each pair of cables 242A and 242B, 243A and 243B, and 244A and 244B as described above includes one cable wound in one direction (e.g., clockwise) around the input spindle 221, 222, 223, or 224 and another cable wound in another direction (e.g., counterclockwise) around the input spindle 221, 222, 223, or 224, such that rotation of the input spindle 221, 222, 223, or 224 pulls one cable while releasing the other cable. Thus, the instrument 110 can employ self-opposing actuation, wherein each pair of cables 241A and 241B, 242A and 242B, 243A and 243B, or 244A and 244B controls a corresponding degree of freedom of motion of the instrument, such as rotation about axis 201, 202, 203, or 204. Non-opposing cable actuation (e.g., one cable per spindle) can be used in some embodiments.

[0028] In the system shown, mechanisms 211 and 212 are wrists or joints, each of which provides two degrees of freedom of motion. Many other mechanisms can provide one or more degrees of freedom of motion, and can be connected so that one or more pairs of cables can respectively actuate one or more degrees of freedom. For example, the actuated mechanism can include a mechanical linkage with a connecting rod that can rotate around a pivot, and a pair of cables can be connected so that the connecting rod rotates in opposite directions relative to the pivot. Alternatively, the actuated mechanism can be any structure that can be moved / actuated in opposite directions, such as a linkage, a sliding member, or a flexible member. For each pair of cables, pulling a cable can drive the actuation of the corresponding degree of freedom in one direction or to some extent, and pulling another cable in the pair of cables can drive the actuation of the corresponding degree of freedom in the opposite direction or to some extent.

[0029] The wiring of the cables 241A, 242A, 243A and 244A uses upper pulleys 251, 252, 253 and 254 to receive the cables 241A, 242A, 243A and 244A from the upper capstans 231A, 232A, 233A and 234A, and uses lower pulleys 261, 262, 263 and 264 to receive the cables 241B, 242B, 243B and 244B from the corresponding lower capstans 231B, 232B, 233B and 234B. The upper pulleys 251, 252, 253 and 254 can all be positioned at about the same common height, while the lower pulleys 261, 262, 263 and 264 can all be positioned at another common height different from the common height of the upper pulleys 251, 252, 253 and 254. This allows the pulley to be captured in a stack of blocks or chassis components as described further below.

[0030] The arrangement of the upper pulleys 251, 252, 253 and 254 and the lower pulleys 261, 262, 263 and 264 can also be simplified by pairing the pulleys to spin independently on a common axle. Using pulleys with a common axle can allow for faster assembly because multiple pulleys can be added to the structure by attaching a single axle. Figure 3 In an embodiment, the input spindles 221, 222, 223, and 224 are arranged in a rectangular array, for example, in rows and columns, and the cable paths from the input spindles in the same row to positions above the instrument axis 114 are substantially parallel. Therefore, the pulleys 251 and 253 that guide the cables 241A and 243A extending from the input spindles 221 and 223 at the same height and in substantially the same direction can be mounted on a common axle 271. Similarly, the upper pulleys 252 and 254 that guide the cables 242A and 244A emerging from the input spindles 222 and 224 at substantially the same height and direction can be mounted on a common axle 272. The lower pulleys 262 and 264 that guide the cables 242B and 244B emerging from the input spindles 222 and 224 at substantially the same height and direction can be mounted on another common axle ( Figure 3 The lower pulleys 261 and 263 that guide the cables 241B and 243B emerging from the input spindles 222 and 224 in substantially the same path and direction may be mounted on another common axle 274.

[0031] The pulley axles 271-274 can also be angled relative to the central axis 206 of the instrument shaft 114 based on the exit direction of the cables from the input spindles 221-224. For example, the axle 271 can be rotated about a first axis (e.g., an axis parallel to the axles of the input spindles 221-224) to minimize the fleet angle of the cables 241A and 243A from the input spindles 221 and 223 at the pulleys 251 and 253. The axle 271 can be rotated about a second axis (e.g., an axis generally parallel to the portion of the cables 241A and 243A between the pulleys 251 and 253 and the capstans 231A and 233A) so that the portion of the cables 241A and 243A between the pulleys 251 and 253 and the guide 280 converges toward the guide 280 and the instrument shaft 114. The angling of the axles 271 to 274 can reduce the average deflection angle for the cables to enter and exit from the upper and lower pulleys, thereby reducing friction and wear.

[0032] The axles 271 to 274 can be further positioned relative to the input spindles 221 to 224 and the instrument shaft 114 to minimize the wrap angle across the sliding surface on the pulley. The position of the pulley can be further refined based on the desired cable path leaving the guide 280. In particular, the redirection of any cable passing through the guide 280 should only cause friction on the elastic surface (e.g., metal portion) of the guide 280 and not cause friction on the softer surface (e.g., plastic portion) of the guide 280. The wrap angle across the guide 280 should also be small so that any cable friction and sawing effect on the guide 280 is very small. The cable path should further be relatively oriented (direct) so that the length of the twisted cable does not negatively affect the overall stiffness of the drive train between the corresponding input spindle and the actuation mechanism. Typically, the twisted segments of the cable are easier to stretch than the rigid hypotube segments used in some embodiments.

[0033] The spacing between the input spindles 221-224 can be significantly larger than the diameter of the instrument shaft 114 in which the cables need to be oriented. Therefore, the paths of the cables need to converge between the input spindles 221-225 and the instrument shaft 114. The cables should also not rub against each other or any other structure in the backend mechanism 116. To avoid cable interference, the winding direction of the cables 241A, 241B, 242A, 242B, 243A, 243B, 244A and 244B around the input spindles in the illustrated embodiment is selected so that the cables in one horizontal plane (e.g., the lower cables 241B, 242B, 243B and 244B) emerge from the interior of the array of input spindles 221-224, and the cables in the other horizontal planes (e.g., the upper cables 241A, 242A, 243A and 244A) emerge from the outer edge of the array of input spindles. The lower cables 241B, 242B, 243B, and 244B emerging from the interior of the region of the input spindle array can converge directly toward the instrument axis 114 at a relatively small angle without interfering with each other or rubbing against other structures (such as, the input spindle 223 or 224). The upper cables 241A, 242A, 243A, and 244A emerging from the outer edges of the input spindles 221 to 224 have a cross-path, which increases the angle of convergence. In particular, the upper cables 241A and 243A emerging from the input spindles 221 and 223 cross over the upper cables 242A and 244A emerging from the input spindles 222 and 224. For the cross-mode, the upper pulleys 251 and 253 in the same horizontal group as the upper pulleys 252 and 254, while having a generally common height, can be staggered in height (e.g., so that the cables 241A and 243A can cross over the cables 242A and 244A without rubbing). The larger angle of convergence provided by the cross pattern allows cables 241A and 242A to pass from the outer edges of input spindles 221 and 222 through the gap between input spindles 223 and 224. The cross pattern also allows pulleys 251 and 253 receiving cables 241A and 243A to be farther away from pulleys 252 and 254 receiving cables 242A and 244A than pulleys 261 and 263 are farther away from pulleys 262 and 264. The wider spacing of the upper pulleys 251 to 254 allows cables 241A to 244A to be guided toward instrument shaft 114 without interference from lower pulleys 261 to 264 or cables 241B to 244B. Crossing the cables of one horizontal plane in this manner also allows cables wrapped around the same input spindle to be positioned and thus paired for oppositely actuating the same degree of freedom in instrument shaft 114, which can allow for efficient connection of the cable pairs to the actuation mechanism.

[0034] Figure 3The cable routing in the embodiment of can provide several advantages. In particular, the difference in the horizontal separation of the upper pulleys 251 to 254 and the horizontal separation of the lower pulleys 261 to 264 can allow the upper pulleys 251 to 254 to be vertically positioned closer to the lower pulleys 261 to 264, for example, with a vertical separation that is smaller than the diameter of the pulleys 251 to 254 and 261 to 264. Moreover, the upper pulleys 251 to 254 and the lower pulleys 261 to 264 can be at the same distance from the nearest input spindles 223 and 224. Since one set of pulleys does not need to be closer to the input spindle, all pulleys can be at a longer distance from the input spindle, which can minimize the splay of the actuation cables. The cross-cable pattern can further reduce the space required to accommodate the desired splay. The cable routing can position the pulleys so that the cables do not rub against each other or on the adjacent input spindles, and no additional intermediate idler wheels are required.

[0035] Figure 4 A cross-sectional view of the internal structure in an example embodiment of the back end mechanism 116 is shown. As shown, the back end mechanism 116 can include a chassis 500 having a central support structure 410 extending between the rows of input spindles 221, 222, 223, and 224. The routing of the cables 241A to 244A or 241B to 244B allows the chassis 500 to be strengthened using the central support structure 410 without interfering with the cables 241A to 244A or 241B to 244B. The cable routing also allows the cables 241A to 244A or 241B to 244B to converge sufficiently to pass between the input spindles 225 and 226, through an opening in the linkage 420 for actuating the jaws 213, and through an opening in the linkage 430 for actuating rotation about the instrument shaft axis 206. This configuration of having the support structure 410 at the center of the back end mechanism 116 opens access from around the perimeter of the chassis 500 to the input spindles 221, 222, 223, and 224, for example, to attach and wind the cables 241A-244A or 241B-244B around the capstans 231A-234A and 231B-234B and tighten the capstan clamping screws during assembly of the back end mechanism 116. Once the input spindles 221, 222, 223, and 224 are installed in the chassis 500 and the capstans 231A-234A and 231B-234B are wound and clamped, the space around the input spindles 221, 222, 223, and 224 can be used for other structures, such as the structure 440, to lock the back end mechanism to the docking port on the robot.

[0036] Figure 5An expanded view of some components in an embodiment of a medical device having a multi-piece chassis 500 for a backend mechanism 116 is shown. The chassis 500 includes components 510, 520, 530, 540, 550, and 560 that can snap together during assembly. During assembly, the proximal end of the instrument shaft 114 can be inserted into a bearing system in the chassis component 510, at which point cables (e.g., cables 241A to 244A and 241B to 244B) attached to the distal tools of the instrument extend from the instrument shaft 114. The cables can then be fed through the desired locations in the guide 280, and the chassis component 520 can be attached to the chassis component 510 so that the guide 280 is captured between the chassis components 510 and 520. All or part of the clamping or rolling gears or mechanisms coupled to the input spindles 225 or 226 may also be assembled on the chassis components 510 and 520 before the chassis components 510 and 520 are snapped together and may be held in place by the chassis components 510 and 520. The upper portion of the chassis component 520 also includes the central support structure 410, which is described above and includes a feature 524 shaped to hold the lower capstan 231B to 234B to be mounted on the input spindles 221 to 224.

[0037] The assembly process may then connect chassis component 530 to chassis component 520. Chassis components 530 and 520 are separated to allow for assembly of linkage 420, which is coupled to input spindle 525 and used for grip actuation in the exemplary embodiment.

[0038] The chassis member 530 has an upper portion that is shaped to hold axles 273 and 274 for lower pulleys that guide and redirect the actuation cables toward the instrument axis. Fig. 6A As shown, lower pulleys 263 and 261 on axle 273 may be mounted in grooves formed in chassis member 530. Similarly, lower pulleys 262 and 264 on axle 274 are mounted in another set of grooves in chassis member 530. Lower cables 241B, 242B, 243B, and 244B extending from instrument shaft 114 may be seated in grooves on corresponding lower pulleys 261, 262, 263, and 264 and passed through openings in chassis member 530 such that the proximal ends of lower cables 241B, 242B, 243B, and 244B are proximate feature 524 where input spindles 221-224 will reside.

[0039] Next, the assembly process may connect the chassis component 540 to the chassis component 530, such as Figure 6BAs shown. The chassis components 530 and 540 can be shaped to provide a tight fit between the chassis components 540 and the pulleys 261 to 264 so that the cables 241B, 242B, 243B and 244B are not easily derailed. The upper pulleys 251 and 253 on the axle 272 and the upper pulleys 252 and 254 on the axle 271 can be installed in the groove formed by the combination of the chassis components 530 and 540. The groove in which the axle 271 is assembled can be on a slightly different horizontal plane than the groove in which the axle 272 is assembled so that the upper cables can cross as described above. The upper cables 241A, 242A, 243A and 244A can be placed on the corresponding upper pulleys 251, 252, 253 and 254 and pass through the opening in the chassis 500 so that the proximal ends of the upper cables 241A, 242A, 243A and 244A are also close to the feature 524. The chassis component 550 is as follows Figure 6C It is shown connected to the bottom frame members 530 and 540, and can be shaped to provide a close fit with the upper pulleys 251-254 so that the upper cables 241A, 242A, 243A and 244A are not easily derailed. Fig.6D In particular, a cross-sectional view is shown illustrating how chassis member 550 may fit tightly to pulley 251 when mounted on members 530 and 540 such that a gap 545 between chassis member 550 and pulley 251 is narrower than the thickness of cable 241A on pulley 251. As a result, cable 241A fits into the groove in pulley 251 and does not slip through gap 545.

[0040] Return to Figure 5, chassis component 560 snaps onto or otherwise connects to one or more of chassis components 520, 530, and 550. The top of chassis component 560 is shaped to fit the docking port of the robot and includes features 564 that are shaped and positioned to hold engagement features of the input spindles 221 to 224 of the instrument. When chassis component 560 is attached to the assembly including components 510, 520, 530, 540, and 550, chassis 500 can capture the input spindles 221 to 224 between features 564 on chassis component 560 and features 524 on chassis component 520. Each input spindle can include an axle and a pair of capstans, such as upper capstans 231A to 234A and lower capstans 231B to 234B, which are initially free to rotate relative to each other. The loose proximal end of the actuation cable near feature 524 can be attached to a corresponding one of capstans 231A to 234A or 231B to 234B. Each capstan can then be independently rotated to wind the attached cable in the desired direction and remove slack and provide the desired pre-tension in the attached cable. Once both cables wrapped around the input spindle have the desired cable tension, the capstan can be clamped or locked in place on the axle of the input spindle, such as by tightening a clamping screw. Such as including Figure 4 Other structures of the release handle of structure 440 can be wrapped around the outside of the actuation structure and cable and can be installed after the assembly of the input spindle and the routing of the cable. Commonly filed U.S. Patent Application No. 62 / 362,454 (filed on July 14, 2016) entitled "INSTRUMENTRELEASE" describes in more detail structures such as a release handle including structure 440, and its entire contents are incorporated herein by reference.

[0041] Compared with the complexity of the device, Figure 5 and FIG. 6A to FIG. 6D The illustrated instrument assembly and cable routing process may be relatively simple. In particular, achieving the desired cable routing does not require simultaneously passing the cables through and around a complex sequence of structures from which the cables may slip. Instead, assembly may be performed in a series of simple steps with the cables in a secure configuration after each step. Furthermore, the shape of the chassis provides good access to the input spindle for cable connection.

[0042] Although specific embodiments have been disclosed, these embodiments are merely examples and should not be considered limiting. Various adaptations and feature combinations of the disclosed embodiments are within the scope of the appended claims. For example, although embodiments using a rotating spindle have been described, other means of controlling cable movement may be used. These means include, for example, sliding tabs, levers, universal joints, and the like.

Claims

1. A medical device comprising: Multiple input spindles; a plurality of first cables, each first cable being wound around a corresponding input spindle of the plurality of input spindles; a plurality of second cables, each second cable being wound around a corresponding input spindle of the plurality of input spindles; a chassis in which the plurality of input spindles are mounted; an instrument shaft including a first end and a second end, the instrument shaft extending from the chassis at the first end; a mechanical structure coupled to the second end of the instrument shaft, the mechanical structure having a plurality of degrees of freedom of motion, the plurality of first cables and the plurality of second cables being connected to the mechanical structure such that rotation of the plurality of input spindles actuates the degrees of freedom; a plurality of first pulleys mounted at a first level on the chassis, the plurality of first pulleys receiving the plurality of first cables from the plurality of input spindles and redirecting the plurality of first cables toward the instrument axis; as well as A plurality of second pulleys are mounted on the chassis at a second level different from the first level, the plurality of second pulleys receiving the second cables from the plurality of input spindles and redirecting the second cables through the first level and toward the instrument axis.

2. The apparatus of claim 1, wherein the chassis comprises: a first member on which the plurality of first pulleys are mounted; as well as The second component is installed above the first component so that the plurality of first pulleys are located between the first component and the second component, and the second component is located between the plurality of first pulleys and the plurality of second pulleys.

3. An apparatus according to claim 1 or claim 2, wherein: The plurality of first cables extend between the plurality of input spindles and the plurality of first pulleys without crossing; and A first group of the second plurality of cables and a second group of the second plurality of cables cross between the plurality of input spindles and the plurality of second pulleys.

4. The apparatus of claim 3, wherein: For each individual one of the plurality of input spindles, the first cable and the second cable wrapped around the individual input spindle are oriented toward locations on opposite sides of a central axis of the instrument shaft.

5. The apparatus of claim 3, wherein: The plurality of input spindles are arranged in an array; each first cable of the plurality of first cables is wound around a corresponding input spindle in a direction such that a path of the first cable from the corresponding input spindle to the plurality of first pulleys occurs within the array; as well as Each second cable of the plurality of second cables is wound around a corresponding input spindle in a direction such that a path of the second cable from the corresponding input spindle to the plurality of second pulleys emerges from a perimeter of the array.

6. The apparatus of claim 1 or claim 2, wherein: For each respective input spindle of the plurality of input spindles, the first cable is wound around the respective input spindle in a first direction, and the second cable is wound around the respective input spindle in a second direction opposite to the first direction.

7. A method for assembling a medical device, comprising: Mounting a plurality of first pulleys on a first component of a chassis of the medical device; feeding a plurality of first cables from an instrument shaft of the medical instrument through the plurality of first pulleys; attaching a second member of the chassis to the first member such that at least a portion of the plurality of first cables is located between the plurality of first pulleys and the second member; mounting a plurality of second pulleys in position on the chassis such that the second member is located between the plurality of second pulleys and the plurality of first pulleys; and A second plurality of cables are fed from the instrument shaft through the second plurality of pulleys.

8. The method according to claim 7, wherein: A gap between the second member and the plurality of first pulleys is narrower than a width of the plurality of first cables.

9. The method according to claim 7, further comprising: A third member of the chassis is attached to the first member and the second member such that at least a portion of the second plurality of cables is located between the second plurality of pulleys and the third member.

10. The method according to claim 7 or claim 8 or claim 9, further comprising: winding a first cable of the plurality of first cables around a lower portion of the input spindle; as well as A second cable of the plurality of second cables is wound around an upper portion of the input spindle, wherein the second cable and the first cable are wound around the input spindle in opposite directions.

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