CN116634960A - Surgical instrument with electropolished tungsten cable - Google Patents

Abstract

A surgical instrument includes one or more cables constructed from a separate tungsten wire having a polished surface. As a result, the rate of loss of instrument motion mass over time is significantly reduced, and thus the instrument service life is significantly increased.

Description

Surgical instrument with electropolished tungsten cable

Priority claim

The present application claims priority from U.S. patent application Ser. No. 63/145,270, filed 2/3/2021, and U.S. patent application Ser. No. 63/117,397, filed 11/23 2020, each of which is incorporated herein by reference in its entirety.

Background

Minimally invasive surgical techniques can reduce damage to tissue during diagnostic or surgical procedures, thereby reducing recovery time, discomfort, and unhealthy side effects for patients. A common form of minimally invasive surgery is endoscopy, while a common form of endoscope is laparoscopy, i.e., minimally invasive inspection and surgery within the abdominal cavity. In standard laparoscopic surgery, the patient's abdomen is inflated with gas and a cannula is passed through a small incision (about one-half inch or less) to provide an access port for surgical instruments. Other forms of minimally invasive surgery include thoracoscopy, arthroscopy, and similar "keyhole" surgery used to perform surgical procedures on the abdomen, chest, throat, rectum, joints, etc.

Teleoperated surgical systems ("tele-surgical systems") operating with computer assistance are known. These surgical systems are used for both minimally invasive surgery and "open" surgery where the incision is made large enough to allow the surgeon to access the surgical site directly. Examples of minimally invasive surgery and open surgery include the surgery listed above, as well as surgery using rigid and flexible shafts to teleoperate surgical instruments, such as neurosurgery, joint replacement surgery, vascular surgery, and the like.

Teleoperated surgical systems typically use interchangeable surgical instruments that include end effectors and are controlled by robotic manipulator technology commanded by a user. Some instrument types are designed for use in a variety of surgical procedures involving different patients, which require cleaning and sterilization between the individual procedures. The advantage of a multi-purpose instrument is that the cost of the instrument per surgical procedure is reduced. Mechanical and material constraints, such as cable wear and tear that naturally occur during normal use, limit the number of times these multipurpose instruments can be used. Accordingly, there is a need to reduce the wear and tear rate of the cable during normal use to increase the number of times the multi-purpose instrument can be used.

Disclosure of Invention

A surgical instrument includes one or more cables constructed from individual tungsten wires having polished surfaces. Surgical instruments having cables made from polished wires unexpectedly and surprisingly maintain motion quality over multiple use cycles, superior to instruments having cables with cold drawn (as-draw) wires (i.e., unpolished wires). The surgical instrument includes a shaft having a proximal end and a distal end. A movable end effector is coupled to the distal end of the shaft. A drive transmission structure (e.g., a capstan) is coupled to the proximal end of the shaft. A drive connector including one or more cables is coupled between the drive transmission structure and the end effector. At least one of the one or more cables includes a plurality of individual tungsten filaments. Each wire has a polished outer surface.

Cables within surgical instruments are often under tension to achieve high quality instrument motion. The polished wire does not have a sufficiently thick oxide layer such that wear of the oxide layer over time may result in a sufficient attenuation of the wire diameter and corresponding lengthening of the cable, resulting in increased relaxation and tension loss. Loss of tension over time may result in reduced quality of instrument motion. Thus, polishing of tungsten filaments results in a decrease in the rate of loss of tension over time, which results in a decrease in the rate of loss of motion quality over time.

Drawings

Aspects of the disclosure are best understood from the following detailed description when read with the accompanying drawing figures. It is emphasized that, in accordance with the standard practice of the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. Further, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Fig. 1 is a schematic plan view of an example minimally invasive teleoperational surgical system for performing a minimally invasive diagnostic or surgical procedure on a patient lying on an operating table.

Fig. 2 is a perspective view of an example user control unit.

Fig. 3 is a perspective view of an example manipulator unit of the minimally invasive teleoperated surgical system of fig. 1.

Fig. 4A is a schematic side view of an example surgical instrument.

Fig. 4B is a schematic functional schematic side view of the example surgical instrument of fig. 4A.

Fig. 4C is a schematic diagram showing some details of the example first drive connector of fig. 4B.

Fig. 5 is a schematic view of an alternative example surgical instrument.

Fig. 6 is a schematic perspective view illustrating a known cable.

Fig. 7 is a schematic cross-sectional view of a first example cable.

Fig. 8 is a schematic cross-sectional view of a second example cable.

Fig. 9 is a schematic cross-sectional view of a third example cable.

10A-10B are schematic partially cut-away perspective views of a pivotable wrist portion of a surgical instrument shown in two different positions with an articulatable jaw end effector mounted.

Fig. 11 is a schematic diagram showing a graph representing the experimental result of the first experiment.

FIG. 12 is a schematic, exemplary mechanical schematic of a corresponding axis or rotation of an instrument and its components to illustrate the moving mass of multiple degrees of freedom.

Fig. 13 is a schematic diagram showing a graph representing the experimental result of the second experiment.

Detailed Description

The inventors have unexpectedly and surprisingly found that surgical instruments using polished tungsten wire cables have an increased effective surgical instrument lifetime, which is measured in terms of the mass of the end effector's movement over time. The surgical instrument includes a plurality of movable components that degrade in use. Thus, for safety reasons, tele-surgical systems typically limit the number of times a surgical instrument can be used. For example, a device design may generally be tested to determine an expected average maximum life, and then a large safety margin is introduced to define a maximum usable life that is shorter than the expected average maximum life (e.g., the number of times the device may be used during normal operation, the amount of time the device may be used during operation, etc.).

One or more cables containing tungsten wires are typically incorporated into the surgical instrument, which is typically discarded after the instrument has reached its maximum useful life. During production, tungsten filaments used to construct surgical instrument cables are drawn at high temperatures, forming an oxide layer on the filaments.

Polishing wire refers to a tungsten wire from which an oxide layer (e.g., formed during high temperature production) is removed by a post-production process referred to herein as polishing. Post-production polishing techniques include electropolishing and chemical polishing. Electropolished tungsten filaments refer to tungsten filaments that have been electropolished to remove an oxide layer formed during high temperature production of the filament. Electro-polishing is an electrochemical technique for removing material from a metal workpiece. Chemical polishing of tungsten wires removes the oxide layer from the wire by using a chemical process in which one or more chemical baths or chemical chambers (which may be at elevated temperatures for more efficient processing) are used to create a chemical reaction (e.g., as part of a roll-to-roll (heel-to-heel) process) that strips the oxide layer from the exterior of the wire. Although some oxide may form on the tungsten wire during normal use after production (e.g., during cleaning of the instrument at elevated temperatures), the amount of oxide formed is much less than during production because the temperature during normal use is much lower than the oxidation promotion temperature during drawing of the tungsten wire.

The inventors have observed that the cable formed from unpolished tungsten wire changes visual appearance and becomes more shiny as the surgical instrument accumulates over a period of use. When the cable is manipulated in a non-traditional manner (e.g., when "plucking" the cable like a guitar string), it is also observed that the natural frequency of the cable decreases as it becomes more shiny. These observations motivate the inventors to explore the effect of a surface oxide layer formed on tungsten wires on cable performance as well as on the performance of surgical instruments employing cables.

The inventors performed a comparative experiment in which 15 instruments were tested with cold drawn tungsten wires and 10 instruments were tested with polished tungsten wires. The mass of the instrument motion, which can be considered to be consistent and highly correlated with the motion of the instrument components for the commanded mechanical input, is experimentally measured. Experiments have shown that surprisingly tools using cables formed from polished tungsten filaments exhibit a longer lasting quality of movement over time than tools using cables formed from non-polished filaments.

The inventors presently believe that the surgical instrument lifecycle (which involves cleaning and disinfecting the surgical instrument after surgical use) may have an effect similar to the reduction of oxides present, creating a more shiny surface and reduced natural frequency observed by the inventors during unusual cable maneuvers. That is, the period of use may result in wear or loss of some of the oxide layer on each of the many wires forming the cable. The inventors believe that this loss of oxide layer results in a diameter taper of the individual filaments (differential wires). The cables within the surgical instrument are typically subjected to constant tension to achieve high quality instrument motion, so the inventors believe that the attenuation of the individual wire diameter over time results in the individual wires sliding relatively within the strands of the cable, which in turn results in lengthening of the cable. The inventors believe that increased cable length results in reduced cable tension, which accelerates the degradation of the instrument motion mass over time.

That is, the distal surgical instrument component may be precisely moved by using a cable under relatively high tension, rather than by using a cable having reduced tension. The reduced tension may result in slack which lengthens the cable and causes a small amount of cable stretch or displacement along the path of the cable. The reduced tension and the resulting relaxation can lead to a reduction in the moving mass. This is especially true for surgical instruments that use multiple cables (e.g., a first cable for controlling a first mechanical DOF (e.g., yaw or grip) and a second cable for controlling a second DOF (e.g., pitch)) to simultaneously control multiple end effector mechanical degrees of freedom. The inventors believe that cables constructed with polished tungsten wires are less susceptible to tension losses and, therefore, such cables contribute to a more sustained quality of instrument motion over time. The inventors believe that this surprising and unexpected result is due to the fact that for instruments having cables with polished tungsten wires, little or no oxide of the wires can wear out during the service life of the surgical instrument, and thus, less reduction in wire diameter, less wire slippage within the cable strand, and less cable tension loss within the instrument.

Teleoperated surgical system

Fig. 1 is a schematic plan view of an example minimally invasive teleoperational surgical system 10 for performing a minimally invasive diagnostic or therapeutic surgical procedure on a patient 12 lying on an operating table 14. The system includes a user control unit 16 for use by a surgeon 18 during a procedure. One or more assistants 20 may also participate in the procedure. Minimally invasive teleoperated surgical system 10 also includes one or more manipulator units 22 and an auxiliary unit computer processing subsystem 24. When the surgeon 18 views the surgical site through the user control unit 16, the manipulator unit 22 may manipulate the at least one surgical instrument 26 through a minimally invasive incision or natural body orifice in the body of the patient 12. An image of the surgical site may be obtained through an endoscope 28 (e.g., a stereoscopic endoscope, which may use manipulator unit 22 positions). The auxiliary unit 24 includes a computer processing subsystem, which may be centralized or distributed, that may be used to process images of the surgical site for subsequent display to the surgeon 18 via the user console 16. The auxiliary unit computer processing system 24 includes a logic unit (e.g., one or more processor circuits) and a memory storing instructions executed by the logic unit. In some embodiments, stereoscopic images may be captured, which allows for depth perception during a surgical procedure. The number of surgical instruments 26 that are used at one time typically depends on factors such as the diagnostic or therapeutic procedure and space constraints within the surgical site. If one or more of the surgical instruments 26 being used need to be replaced during the procedure, the assistant 20 may remove the surgical instrument 26 from the manipulator unit 22 and replace it with another surgical instrument 26 from the tray 30 in the operating room. The example auxiliary unit computer processing system 24 may be configured to process signals indicative of the forces applied at the surgical instrument. The example auxiliary unit computer processing system 24 may generate signals at the surgeon's console 16 indicative of haptic feedback corresponding to these applied forces. U.S. Pat. No. 6,424,885 Bl (filed 8.13 1999) is an example of a computer controlled system for a tele-surgical system, which is incorporated herein by reference.

Fig. 2 is a perspective view of an example user control unit 16. The example control unit 16 includes a viewer display 31, the viewer display 31 including a left eye display 32 and a right eye display 34 for presenting a coordinated stereoscopic view of the surgical site that achieves depth perception to the surgeon 18. The control unit 16 also includes one or more manual control inputs 36, 38 to receive large scale manual control movements. One or more surgical instruments 26 mounted for use on one or more corresponding manipulator units 22 are operatively coupled to move within a relatively small scale distance that matches the large scale manipulation of one or more manual control input devices 36, 38 by surgeon 18. For example, in the example system 10, the movement of the user (x, y, z) scales to the corresponding instrument movement by up to about 1:3, but the distal DOF is typically not scaled so that the pointing direction of the instrument matches the surgeon's hand, thereby remaining "intuitive". Thus, in the example system 10, for example, movement of the control input 36 or 38 by an amount on the order of approximately one inch may result in movement of the instrument by an amount on the order of approximately one third inch. In the example system, each control input device 36, 38 is operatively coupled to control a surgical instrument. For example, the first control input device 36 may be operably coupled to control a first surgical instrument and the second control input device 38 may be operably coupled to control a second surgical instrument. During the procedure, a plurality of different surgical instruments may be available at the instrument tray 30, for example, for mounting to the manipulator unit 22 for control by a user via the control unit 16. The control input devices 36, 38 may provide the same mechanical degrees of freedom (DOF) as the surgical instrument 26 with which they are associated to provide the surgeon 18 with telepresence or the perception that the respective control input devices 36 are operatively coupled to and integrated with the corresponding respective controlled surgical instrument 26 so that the surgeon has a strong feel of directly controlling the instrument 26. To this end, in the example system, position, force, and tactile feedback sensors (not shown) are used to transmit position, force, and tactile sensations from the surgical instrument 26 to the surgeon's hand through the control input devices 36, 38, subject to communication delay constraints. The signal (optionally an optical or electronic signal) modulated based on the force detected at the force sensor (not shown) at the instrument 26 may be processed by a processor at the auxiliary unit cart 24 to generate haptic feedback at the control input device 36 indicative of the detected force.

Fig. 3 is a perspective view of an example manipulator unit 22 of the minimally invasive teleoperated surgical system 10. The manipulator unit 22 comprises four manipulator support structures 72. Each manipulator support structure 72 includes an end-to-end pivotally mounted articulating support structure 73 and a pivotally mounted support beam 74. A respective surgical instrument bracket 75 including an actuator for controlling instrument movement is mounted at each support beam 74. Further, each manipulator support structure 72 may optionally include one or more set joints (e.g., unpowered and/or lockable joints) at the joints of the articulating support structure 73 and at the joints with the beams 74. The carriage 75 may be moved along the beam 74 to position the carriage 75 at different locations along the beam 74. Thus, the beams 74 may be used to position an attached surgical instrument carrier 75 relative to the patient 12 for surgery. Each surgical instrument 26 is detachably coupled to a bracket 75. More specifically, the mechanical adapter input interface 426 between each carriage 75 and each surgical instrument includes a drive input (not shown) driven by an actuator within the carriage 75 that is configured to couple rotational torque generated by the actuator to a drive element of the surgical instrument, which is generally described below. Although the manipulator unit 22 is shown as including four manipulator support structures 72, more or fewer manipulator support structures 72 may be used. Typically, at least one of the surgical instruments will include a vision system, typically including an endoscopic camera instrument for capturing video images and one or more video displays coupled to one of the brackets 75 for displaying the captured video images.

In one aspect, the carriage 75 houses a plurality of teleoperated actuators (not shown) that impart motion to the tension member (e.g., a cable drive member including a drive shaft and a capstan (not shown)) through the mechanical adapter interface 426, which in turn drives cable motion, which the surgical instrument 26 converts into various movements of the end effector portion of the surgical instrument 26. In some embodiments, a teleoperated actuator in the carriage 75 imparts motion to various components of the surgical instrument 26, such as wrist movement or jaw movement of the end effector.

The surgeon manipulates the control inputs 36, 38 to control the instrument end effector. Inputs ("input" commands) provided by a surgeon or other medical personnel to control input devices 36 or 38 are converted by actuation of one or more remote actuators by surgical instrument 26 into corresponding actions (corresponding "surgical instrument" responses). A flexible wire cable based force transmission mechanism or the like is used to transmit the motion of each of the remotely located teleoperated actuators to the corresponding instrument interface actuator output located at the instrument carrier 75. In some embodiments, the mechanical adapter interface 426 mechanically couples the instrument 26 to drive elements (e.g., a drive shaft and a capstan (not shown)) within the instrument carriage to control movement within the instrument 26, thereby driving cable movement that the surgical instrument 26 translates into various movements of an end effector on the surgical instrument 26.

Surgical instrument

The term "surgical instrument" is used herein to describe a medical device for insertion into a patient and for performing a therapeutic or diagnostic procedure. Surgical instruments typically include movable components that may include end effectors associated with one or more surgical tasks such as tissue grasping jaws, needle drivers, scissors, bipolar cautery, tissue stabilizers or retractors, clip appliers, stapling devices, imaging devices (e.g., endoscopes or ultrasound probes), and the like. Some surgical instruments for some embodiments further provide articulating support (sometimes referred to as a "wrist") for the end effector such that the position and orientation of the end effector can be manipulated with one or more mechanical DOFs relative to the shaft 410 of the instrument. In addition, many surgical end effectors include functional mechanical DOFs, such as open or closed jaws, or blades that translate along a path. Surgical instruments suitable for use in one or more embodiments of the present disclosure may have their end effectors (surgical instruments) controlled with one or more rods and/or flexible cables. In some examples, a rod, which may be in the form of a tube, may be combined with a cable to provide "push/pull" or "pull/pull" control of pulling, pushing, or combination of an end effector, wherein the cable provides a flexible segment as desired. A typical elongate shaft 410 for a surgical instrument is relatively small, for example 5 to 8 millimeters in diameter. The small scale of the mechanisms in surgical instruments creates unique mechanical conditions and construction problems for these mechanisms that are different from those found in similar mechanisms constructed at larger scales because the strength of the forces and materials do not scale at the same rate as the size of the mechanism. The rod and cable must fit within the elongate shaft and be able to control the end effector via the wrist joint. In some example instruments, the cable may be made from various metallic (e.g., tungsten or stainless steel) or polymeric (e.g., high molecular weight polyethylene) materials.

Fig. 4A is a schematic side perspective view of an example surgical instrument 26, the surgical instrument 26 including a shaft defining an internal bore and including a distal portion 410D and a proximal portion 410P. As used herein, the term "proximal" indicates a location closer to the manipulator support structure and further from the patient anatomy, while the term "distal" indicates a location further from the manipulator support structure and closer to the patient. The mechanical structure 422 is coupled to the proximal portion of the shaft 410. The mechanical structure 422 includes a drive assembly including a drive element (not shown) enclosed within the housing 425 for controlling movement of the movable member 428 and wrist 430 at the distal portion 410D of the shaft 410. Movable member 428 may include an end effector for performing therapeutic, diagnostic, or imaging surgical functions, or any combination of these functions. For example, movable component 428 may include any of a variety of end effectors, such as jaws, a needle driver, a cautery device, a cutting tool, an imaging device (e.g., an endoscope or ultrasound probe), or a combination device including a combination of two or more different instruments and imaging devices. The wrist 430 is coupled at the distal portion 410D of the shaft proximal to the movable member 428 to allow manipulation of the orientation of the movable member 428 relative to the elongate shaft 410. Various instrument wrist mechanism configurations are known, see, for example, U.S. Pat. No. 6,394,998 Bl (filing 9/17/1999), U.S. Pat. No. 6,817,974 B2 (filing 28/6/2002), U.S. Pat. No. 9,060,678 B2 (filing 13/6/2007), and U.S. Pat. No. 9,259,275 B2 (filing 11/12/2010), the disclosures of which are incorporated herein by reference. An adapter input interface 426 located between the carrier 75 and the mechanical structure 422 provides a mechanical drive interface between an actuator (not shown) within the carrier 75 and a drive element within the mechanical structure 422 for driving movement. The adapter input interface 426 transfers rotational torque driven by actuators provided by actuators in the carriage to drive elements in the mechanical structure 422 for controlling movement of the movable member 428 and the wrist joint 430.

Fig. 4B is a schematic functional schematic side view of the example surgical instrument 26 of fig. 4A, illustrating a schematic example range of functional motion of the movable member 428 and the wrist 430. The instrument hollow shaft 410 includes a longitudinal central axis 412 extending between a proximal portion 410P and a distal portion 410D. The movable member 428 is mounted for rotation about a first pin 434, the first pin 434 being mounted to the distal portion 410D of the shaft and extending perpendicular to the central axis 412. The wrist joint 430 is mounted for rotation about a second pin 436, the second pin 436 being mounted to the distal portion 410D of the shaft proximal to the first pin 434 and extending perpendicular to the central axis 412. The example shaft 410 is straight. However, alternative example instrument shafts are curved or articulating.

The example proximal mechanical structure 422 includes one or more drive elements to transmit drive motion to the first drive connector 448 and the second drive connector 450, for example: a rotary disk capstan or various other axial rotary inputs; a rotary, rack or worm gear input; lever or gimbal inputs; linear drive elements such as slides, nuts on lead screws, elements coupled to fixed positions on cables, and other lateral translation inputs; pins and other axial translation inputs; a fluid pressure input; and the like. The drive elements of the example surgical instrument 26 of fig. 4B include a first rotatable cable drive capstan 444a and a second rotatable cable drive capstan 444B within the housing 425. Drive input discs 445a, 445b located within adapter interface 426 transmit torque forces provided by respective actuators 447a, 447b located within carrier 75 to drive rotational movement of respective first and second winches 444a, 444b. First drive connector 448 is coupled to impart rotational movement of movable component 428 about first pin 434 in parallel with rotational movement of first drive capstan 444 a. Second drive connector 450 is coupled to impart rotational movement of wrist 430 about second pin 436 in parallel with rotational movement of second drive capstan 444b. The first drive connector 448 and the second drive connector 450 each include one or more cables that are continuously under tension, as explained below. In the example surgical instrument 26, first drive capstan 444a is configured to continuously impart tension to one or more cables of first drive connector 448 prior to use. Likewise, second drive capstan 444b is configured to continuously impart tension to one or more cables of second drive connector 450 prior to use.

The example first drive connector 448 includes a first drive connector segment 448a and a second drive connector segment 446b. First drive connector segment 448a and second drive connector segment 448b each include a respective proximal cable portion that wraps around first drive capstan 444a such that when first capstan 444a is rotated in a first direction, the proximal cable portion of first drive segment 448a is paid out and the proximal cable portion of second drive segment 448b is paid out, and such that when first capstan 444a is rotated in a second direction, opposite the first direction, the proximal cable portion of first drive segment 448a is paid out and the proximal cable portion of second drive segment 448b is paid out. When the distal end of the instrument is in free space and not in a clamped state, during the spooling of the first drive segment 448a and the spooling of the second drive segment 448b, the first drive segment 446a exerts a force to move the movable member 428 in one direction about the first pin 434. Conversely, when the distal end of the instrument is in free space and not in a clamped state, during the spooling of the second drive segment 448b and the spooling of the first drive segment 448a, the second drive segment 448b applies a force to move the movable member 428 about the first pin 434 in a direction opposite to the direction of movement during the spooling of the first drive segment 448 a. The proximal cable portions of both the first and second drive connector segments 448a, 448b are under tension during spooling and paying of the proximal cable portion of the first drive connector segment 448a and during spooling and paying of the proximal cable portion of the second drive connector segment 448 b. When in a stationary state, where neither the wire is wound nor unwound, the first and second drive connector segments 448a, 448b are also under tension. However, it is noted that in some example instruments having jaws (e.g., when the instrument jaws are clamping tissue), the cables driving the jaws together are under tension, but the opposing cables opening the jaws are slack and have no tension.

In an alternative example surgical instrument (not shown), the first drive segment is coupled to a first capstan (not shown) and the second drive segment is coupled to a second capstan (not shown). In an alternative example surgical instrument, when the distal end of the alternative example instrument is in free space and not in a clamped state, the first drive segment applies a force to move the movable member in one direction during the reeling in of the first drive segment around the first capstan and the unreeling of the second drive segment around the second capstan. Conversely, when the distal end of the instrument is in free space and not in a clamped state, during the second drive segment spooling around the second capstan and the first drive segment spooling around the first capstan, the second drive segment applies a force to move the movable component around the first pin in a direction opposite to the direction of movement during spooling of the first drive segment.

The example second drive connector 450 includes a third drive connector segment 450a and a fourth drive connector segment 450b. Third drive connector segment 450a and fourth drive connector segment 450b each include a respective proximal cable portion wound about second drive capstan 444b such that when second capstan 444b is rotated in a first direction, the proximal cable portion of third drive segment 450a is paid out and the proximal cable portion of fourth drive segment 450b is paid out, and such that when second capstan 444b is rotated in a second direction opposite the first direction, the proximal cable portion of third drive segment 450a is paid out and the proximal cable portion of fourth drive segment 450b is paid out. When the distal end of the instrument is in free space and not in a clamped state, during retraction of the third drive segment 450a and deployment of the fourth drive segment 450b, the third drive segment 450a applies a force to move the wrist 430 in one direction. Conversely, when the distal end of the instrument is in free space and not in a clamped state, during retraction of the fourth drive segment 450b and deployment of the third drive segment 450a, the fourth drive segment 450b applies a force to move the wrist 430 about the second pin 436 in a direction opposite to the direction of movement during retraction of the third drive segment 450 a. The proximal cable portions of both the third drive connector segment 450a and the fourth drive connector segment 450b are under tension during spooling and payout of the proximal cable portion of the third drive connector segment 450a and during spooling and payout of the proximal cable portion of the fourth drive connector segment 450b. When in a stationary state, where neither take-up nor pay-off is performed, the third and fourth drive connector segments 450a, 450b are also in tension. However, as noted above, in some example instruments having jaws (e.g., when the instrument jaws are gripping tissue), the cable driving the jaws together is under tension, but the opposite cable opening the jaws is slack and has no tension.

In an alternative example surgical instrument (not shown), the third drive segment is coupled to a third capstan (not shown) and the fourth drive segment is coupled to a fourth capstan (not shown). In an alternative example surgical instrument, when the distal end of the alternative example instrument is in free space and not in a clamped state, the third drive segment applies a force to move the movable member in one direction during the reeling in of the third drive segment around the third capstan and the unreeling of the fourth drive segment around the fourth capstan. Conversely, when the distal end of the instrument is in free space and not in the clamped state, during the retraction of the fourth drive segment about the fourth capstan and the payout of the third drive segment about the fourth capstan, the fourth drive segment applies a force to move the movable member about the first pin in a direction opposite the direction of movement during the retraction of the third drive segment.

Fig. 4C is a schematic diagram illustrating some details of the example first drive connector 448 of fig. 4B. The first drive connector segment 448a includes a first cable 551, a first rigid element 556a, and a second cable 552. In the example first drive connector 448a, the first rigid element 556a includes a first hypotube. The first rigid element 556a is coupled to a distal portion of the first cable 551 and a proximal portion of the second cable 552. The proximal portion of first cable 551 is coupled to first capstan 444a. The distal portion of the second cable 552 is coupled to a movable member 428, the movable member 428 comprising a "tip" portion 470, the "tip" portion 470 being referenced in the following experimental section. The second drive connector segment 448b includes a third cable 553, a second rigid element 556b, and a fourth cable 554. In the example second drive connector 448b, the third rigid element 556b includes a second hypotube. The third rigid element 556b is coupled to a distal portion of the fourth cable 554 and a proximal portion of the third cable 553. A proximal portion of fourth cable 554 is coupled to first capstan 444a. A distal portion of the third cable 553 is coupled to the movable component 428. Proximal portions of the first cable 551 and the fourth cable 554 are wound around the first drive capstan 444a such that the first cable 551 pays out and the fourth cable 554 pays out when the first capstan 444a rotates in a first direction, and such that the first cable 551 pays out and the fourth cable 554 pays out when the first capstan 444a rotates in a second direction opposite the first direction. The example second drive connector 530 has a similar configuration including four cables and two hypotubes (not shown); for the sake of descriptive efficiency, the components of the second drive connector 530 corresponding to the components of the first drive connector 528 will not be described again.

Fig. 5 is a schematic view of an alternative example surgical instrument 426-1, the surgical instrument 426-1 including a movable member 428-1 that translates at a prismatic joint 462 (e.g., a pushrod, blade, stapler slider (sled), etc.). Double-headed arrow 464 represents the range of motion associated with a straight or curved translation constrained by the physical limits of joint 462. For descriptive efficiency, the example drive connectors 448a-1, 448b-1 and the example first capstan drive element 444A-1 of the alternative example surgical instrument 426-1 corresponding to the components of the surgical instrument 26 described above with reference to fig. 4A-4C will not be described.

Cable wire

A wire cable is a complex machine device that is complex. The cable generally comprises three components: filaments, strands and cores. An example surgical instrument 26 includes a cable formed of tungsten. It is well known that the advantageous properties of tungsten, doped tungsten and tungsten alloys include strength, high stiffness, high durability and temperature resistance. The wire strands are typically formed by helically winding a number of wires around a central wire. The outer strands are in turn helically wound around the core to form a complete cable.

Fig. 6 is a schematic perspective view of an example known cable 600, shown partially expanded, including a plurality of strands 602 helically wound around a strand core 603, and including a plurality of strands 604 helically wound around a cable core 606. The filaments of the example cable have a diameter, for example, in the range of 0.025 mm. The cable 600 includes a plurality of strands. The stranded wire 602 is shown partially deployed from the strand core wire 603, while the strand 604 is shown partially deployed from the cable core 606. The partially unwound strand 604 includes a plurality of outer filaments 602 that are helically wound around a strand core filament 603. The cable 600 includes a plurality of strands 604 wrapped around a core 606. In response to stresses that vary as cable 600 is pulled and flexed axially during operation, helically wound filaments 602 within strands 604 move slightly relative to one another. The strands 604 themselves also slide relative to each other to equalize more significant stresses within the cable 600. As the movement of the wire 602 and strand 604 occurs, the cable core 606 maintains the cable geometry and supports the strand 604 preventing them from collapsing or sliding out of position relative to each other when subjected to radial pressure. When the wire cable 600 is loaded, the helical arrangement (lay) of the strands 604 causes them to press inwardly toward the cable axis. The core 606 supports the pressure and prevents the strands 604 from rubbing and crushing. The core 606 also maintains the position of the strands 604 during bending.

An example cable for use within surgical instrument 26 includes a plurality of strands and a plurality of filaments arranged in a composite configuration. Fig. 7 is a schematic cross-sectional view of a first cable 700, the first cable 700 having four hundred seventeen (417) filaments 702 arranged in a 13x19-7x19-1x37 configuration. The first cable 700 includes thirteen outer strands 704, inner strands 708, and an inner core 710. The first cable has a wire diameter of about 0.015-0.025 mm. Fig. 8 is a schematic cross-sectional view of a second cable 800, the second cable 800 having two hundred and one (201) filaments 802 arranged in an 8x19-7x7 configuration. The second cable 800 includes eight outer strands 804 wound around a 7x7 core 814. The second cable 800 has a wire diameter of about 0.015-0.025 mm. Fig. 9 is a schematic cross-sectional view of a third cable 900, the third cable 900 having two hundred fifty-nine (259) filaments 902 arranged in a 7x37 configuration. The third cable 900 includes six outer strands 904 each having thirty-seven filaments. The third cable 900 includes a core region 906 having a single 1x37 strand. The third cable 900 has a wire diameter of about 0.015-0.025 mm.

Wrist portion

Fig. 10A-10B are schematic partially cut-away perspective views of a pivotable wrist portion 50 of a surgical instrument shown in two different positions, the pivotable wrist portion 50 mounting an articulatable jaw end effector. The surgical instrument includes a shaft on which the wrist portion is mounted. The wrist portion includes first, second and third pulley blocks 70, 66, 71, 74 to guide first, second and third cable segments 76, 78, 80 extending from within and around a shaft 82. Cables 76, 78, 80 are used in combination to cause wrist portion 50 to pivot about first axis 52, as indicated by arrow 54. The cables 76, 78, 80 are also used in combination to cause the end effector portion 56 of the wrist portion 50 to pivot about the second axis 58. End effector 56 includes jaws 60. It should be appreciated that tension is applied to cables 76, 78, 80 when cables 76, 78, 80 are used to pull wrist 50 between the pivoted positions and when they are used to pivot end effector 56. Further, it should be appreciated that the cables 76, 78, 80 follow a tortuous (i.e., a circuitous path with a sharp curve) path over several different sets of pulley guide surfaces, and that movement of the cables 76, 78, 80 along these paths imparts bending stresses to the cables. For example, it should be noted that cable 76 is wrapped partially around pulley 66 in a first direction, then wrapped partially around pulley 70 in a different direction, and then wrapped partially around pulley 56 in another direction perpendicular to the first direction of movement around pulley 66. Details of an embodiment of the wrist portion 50 of the surgical instrument are provided in U.S. patent No. 6,394,998 entitled "Surgical instruments for Use in Minimally Invasive Telesurgical Applications".

Instrument life

Surgical instruments have a limited useful life. Example surgical instruments have a useful life measured in terms of number of cleaning and sterilization ("CS") and number of surgical uses ("SU"). Cleaning and sanitizing typically involves scrubbing the distal end of the instrument with a hand and then immersing in an ultrasonic bath of an alkaline cleaning solution. The ultrasound bath is followed by autoclave sterilization up to 140 ℃. Surgical use varies depending on the type of instrument. For example, surgical needle drivers typically involve suturing and knot tying. Typical ranges of service life limitations for surgical instruments are ten surgical uses and at least ten cleaning and sterilization cycles.

Experiment-loss of motion in a single DOF

Fig. 11 is a schematic diagram showing a graph representing the experimental results of a first experiment involving pitch DOF motion loss versus normalized motion loss for an instrument having a cable with a cold drawn tungsten wire ("cold drawn wire") and an instrument having a cable with a polished tungsten wire ("Electropolished (EP) wire"). The solid curve represents the average experimental results for a population of instruments with cold drawn wire cables. The dashed curve represents the average experimental results for a population of tools with EP wire cables. The horizontal axis represents the usage period measured in terms of Cleaning and Sanitizing (CS) behavior and Simulated Surgical Usage (SSU) behavior. The vertical axis represents normalized motion loss in units of each degree. Normalization is achieved by dividing the experimental results by the average of the instruments in each instrument population when they are "new". The longitudinal axis provides a dimensionless measurement since the units of measurement cancel each other out.

The experiment of fig. 11 involves commanding the instrument to sweep back and forth through the pitching motion along the same path in opposite forward and reverse directions to each other. In the example instrument, the wrist 430 moves rotationally in a pitch motion about a longitudinal axis of the second pin 436 that corresponds to the first axis 52 shown in fig. 10A-10B. An angular error between commanded and measured wrist positions in the forward and reverse directions along the path is recorded. The path is rotated and the deviation is measured in terms of the degree (angle) of rotation of the wrist 430 about the second pin 436. A larger angular deviation between the commanded and measured forward and reverse movements along the path means that the loss of movement is increased. It should be appreciated that the loss of motion increases with the loss of cable tension.

During the experiment, the motion of instrument tip 470 was measured using a two-dimensional optical micrometer. The collimated laser beam was irradiated through a round window of 60 mm. The measurement of the position of the tip portion 470 of the instrument at a certain moment in time (e.g., the position of the tip of the movable member) is based on the shadow cast by the tip. Two-dimensional samples of the tip position are captured at a sufficiently fast rate to determine deviations from the commanded orientation.

The graph of fig. 11 shows that surgical instruments using EP wire cables better maintain the quality of instrument motion with increased life than instruments with cold drawn wire cables. For example, with reference to a period of use of zero (0) on the horizontal axis, the curves for both EP wire cable and cold drawn wire cable are new, and the normalized motion loss is one (1), which is the baseline motion quality for commanded forward and reverse motion as the instrument comes out of the manufacturing line. The deviation of the orientation error of the instrument with the EP wire cable is about one (1) with reference to the period of use ssu1+cs on the horizontal axis. However, the deviation in the orientation of the instrument with the cold drawn wire cable was about 1.25, which means that the loss of motion increased by about twenty-five percent (25%). With reference to the period of use ssu4+cs+cs on the horizontal axis, the deviation of the orientation error of the instrument with EP wire cable is about 1.05, which means that the loss of motion increases by about five percent (5%). However, the deviation in the orientation of the instrument with the cold drawn wire cable was about 1.3, which means that the loss of motion increased by about thirty percent (30%). With reference to the period of use ssu8+cs+cs on the horizontal axis, the deviation of the orientation error of the instrument with EP wire cable is about 1.15, which means that the loss of motion increases by about fifteen percent (15%). However, the deviation in the orientation of the instrument with the cold drawn wire cable was about 1.5, which means that the loss of motion increased by about fifty percent (50%). Thus, the experiments of fig. 11 show that the pitch DOF motion quality of an instrument with an EP wire cable is significantly better than the pitch DOF motion quality of an instrument with a cold drawn wire cable after several use cycles.

example-Multi-DOF instrument motion

Fig. 12 is a schematic, exemplary mechanical schematic of a corresponding axis or rotation of instrument 1200 and its components to illustrate moving masses in multiple degrees of freedom. The example instrument 1200 is a teleoperation commercialized by intuitive surgical corporation (Intuitive surgical, inc.)Representation of the distal portion of the surgical instrument, such as a large needle driver instrument. Fig. 12 illustrates a distal portion of an instrument 1200 including an instrument shaft 1202, a wrist linkage 1204, and first and second grasping jaws 1206a, 1206 b. The shaft axis S-S is defined along the length of the instrument shaft 1202. Wrist link 1204 is coupled to instrument shaft 1202 at a recoil wrist joint 1208 that rotates about pitch axis P-P. The wrist axis W-W is defined along the length of the wrist link 1204. The grasping jaws 1210a, 1210b are coaxially coupled to the wrist link 1204 at respective posterior roll jaw joints 1212a and 1212b, and each rotate about a yaw axis Y-Y. The gripping jaws 1210a, 1210b are closed at the clamping axis G. The center of motion R of the instrument 1200 is defined on the instrument shaft 1202 and represents the rotational position in space to be maintained stationary in space throughout the medical procedure, e.g., where the instrument shaft 1202 enters the patient's body wall.

The motion quality of the instrument 1200 may be considered higher when the instrument may be controlled to maintain a substantially fixed position of the center of motion R in space during complex instrument motions (e.g., in multiple degrees of freedom). Because components of instrument 1200 (e.g., cables) degrade with use, the ability to control the instrument to maintain a substantially fixed position of center of motion R in space during complex instrument movements in multiple degrees of freedom is reduced. In other words, as the instrument degrades, the mass of instrument motion decreases due to loss of precision in the movement of the instrument components. One cause of loss of movement accuracy is loss of cable tension. The inventors have found that an instrument with a polished wire cable experiences a slower rate of attenuation of the moving mass than an instrument with a cold drawn wire cable. The inventors believe that the reason why the motion quality of the instrument with a cable with polished filaments is more durable is that the polished filaments are drawn at a slower rate and therefore lose tension than a cable with cold drawn filaments.

During a medical procedure, a clinical user manipulates computer-aided remote control inputs 36, 38 to command movement of instrument 1200 and the various distal components of the instrument. One such motion is to roll the gripping jaws 1210a, 1210b about the clamping axis G, and it is understood that maintaining the spatial orientation and position of the clamping axis G during roll is important for effective instrument control and good clinical performance. Ideally, the shaft 1202 rotates about the axis S-S, the wrist link 1204 rotates about the axis W-W, and the gripping jaws 1210a, 1210b rotate together about the gripping axis G, all without changing the orientation and position of the gripping axis G or center of motion R.

Since the cable control wrist linkage 1204 moves simultaneously about the pitch axis P-P and the grip jaws 1210a, 1210b about the yaw axis Y-Y as the instrument shaft 1202 rolls about the axis S-S, effective cable control for each rotational degree of freedom is important to maintain the spatial orientation and position of the gripping axis G. As can be seen, as the joints 1208, 1212a, and 1212b rotate farther (e.g., grasp and move the suture needle) from a neutral position (e.g., straight and aligned with the shaft axis S-S), mechanical tolerances make it increasingly challenging to maintain the spatial position and orientation of the clamping axis G during instrument roll of the shaft 1202. The ability of the instrument to maintain as close as possible to the desired roll motion relative to the clamping axis G may be considered as an example of the moving mass of these instrument components.

FIG. 12 illustrates the distal component of instrument 1200 in which the clamping axis G is displaced in orientation and position relative to the axis S-S of the instrument shaft by rotation of the wrist joint 1208 about the pitch axis P-P and rotation of the jaw joints 1212a, 1212b about the yaw axis Y-Y. In order to rotate the grasping jaws 1210a, 1210b about the clamping axis G while maintaining the instrument shaft 1202 through the center of motion R, the wrist link 1204 must rotate about its longitudinal axis W-W and at the same time the wrist axis W-W will sweep along the surface of an imaginary cone (not shown) having an apex at the yaw axis Y-Y between the jaw joints 1212a, 1212 b. Also, the instrument shaft 1202 must rotate about its longitudinal axis S-S and at the same time the axis S-S will sweep along the surface of an imaginary cone (not shown) with the apex at the center of motion R. (the instrument shaft 1202 may translate through the center of motion R as desired). However, as mechanical degradation of instrument components (e.g., cables) occurs over time, the complex interaction between the various cable-controlled mechanical DOFs will cause deviations in motion of the wrist linkage 1204 and the gripping jaws 1210a, 1210b about their associated axes such that the gripping axis G will no longer remain spatially stable, both in orientation and in position. During a commanded rolling movement of the gripping jaws 1210a, 1210b about the gripping axis G, the amount of deviation of the gripping axis G from its ideal stable position over time can be considered as an indication of the degradation of the moving mass over time. For example, the gripping axis G may begin to sweep along an irregular cone surface (not shown) that translates in space, and such sweeping motion may become irregular and jerky. Eventually, the moving mass will drop to the point where the instrument becomes unsatisfactory for clinical use and must be replaced. The motion quality may be measured by observing the path followed by one or more instrument components. In the example instrument 1200, a smooth tapered path indicates high quality motion, while an irregular or jerky tapered path indicates lower quality motion.

Experiment-loss of motion in multiple DOF

Fig. 13 is a schematic diagram showing a graph representing the experimental results of a second experiment involving a multi-DOF moving mass boundary volume (binding volume) around the instrument tip of an instrument with a cold drawn wire cable and a tool with an EP wire cable compared to normalized motion losses. The solid curve represents the experimental results for an instrument with a cold drawn wire cable. The dashed curve represents the experimental results for an instrument with an EP wire cable.

The experiment of fig. 13 involves commanding an instrument (e.g., the example instrument 1200 of fig. 12) to move through a complex 6DOF, during which the instrument tip portion will be maintained in a fixed position. Example 6DOF motion is "needle-a-needle", which is the motion that some instruments perform during a suturing task during a surgical procedure. The purpose during the suturing task is to guide a curved needle in a curved path similar to that of the needle between a target entry point and an exit point in tissue. This motion is similar to maintaining the instrument tip 470 in a substantially fixed position in space as the instrument tip 470 rotates about the axis G while other components of the instrument move in three dimensions.

The longitudinal axis in fig. 13 indicates the normalized boundary volume traversed by the tip during 6DOF motion. During 6DOF movement, two orthogonal two-dimensional vision systems are used to measure the movement of tip 470. Based on these measurements, the bounding volume encompasses the movement of the tip during the 6DOF movement. The larger the bounding volume, the more the position of the tip 470 changes during 6DOF movement. The larger bounding volume means more motion loss. It should be appreciated that the loss of motion increases with the loss of cable tension.

The graph of fig. 13 shows that surgical instruments using EP wire cables better maintain the quality of instrument motion with increased life than instruments with cold drawn wire cables. For example, with reference to a period of use of zero (0) on the horizontal axis, the curves for both EP wire cable and cold drawn wire cable are new, and the normalized motion loss is one (1), which is the baseline for the motion of the tip portion 470. The normalized boundary volume of the instrument with EP wire cable is about one (1) with reference to the period of use ssu1+cs on the horizontal axis. However, the normalized bounding volume of the tool with the cold drawn wire cable is about 1.75, which means that the average bounding volume is increased by about 75% over the average volume of the "new" instrument. With reference to the period of use ssu4+cs+cs on the horizontal axis, the normalized bounding box volume of the instrument with EP wire cable is about 1.1, which means that the average bounding volume is increased by about 10% over the average volume of the "new" instrument. However, the normalized boundary volume of the instrument with cold drawn wire cable is about 1.5, which means that the average boundary volume is increased by about 50% over the average volume of the "new" instrument. With reference to the period of use ssu8+cs+cs on the horizontal axis, the normalized bounding volume of the instrument with EP wire cable is about 1.2, which means that the average bounding volume is increased by about 20% over the average volume of the "new" instrument. However, the normalized bounding volume of the tool with the cold drawn wire cable is about 1.75, which means that the average bounding volume is increased by about 75% over the average volume of the "new" instrument. Thus, the experiment of fig. 13 also shows that the motion quality of the instrument with EP wire cable after several use cycles is significantly better than the motion quality of the instrument with cold drawn wire cable.

The above description is presented to enable any person skilled in the art to create and use a surgical instrument having a cable comprising a polished tungsten wire and a corresponding cable comprising a polished tungsten wire. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. In the preceding description, numerous details are set forth for the purpose of explanation. However, it will be appreciated by one of ordinary skill in the art that embodiments in the disclosure may be practiced without such specific details. In other instances, well-known processes have been shown in block diagram form in order not to obscure the description of the invention in unnecessary detail. The same reference numbers may be used to identify different views of the same or like items in different drawings. Thus, the foregoing description and drawings of examples according to the invention are merely illustrative of the principles of the invention. It will therefore be appreciated that various modifications may be made to the embodiments by those skilled in the art without departing from the scope of the invention, which is defined in the appended claims.

Claims (30)

1. A surgical instrument, comprising:

a shaft including a proximal end and a distal end;

a movable member coupled to the distal end of the shaft;

a mechanical structure coupled to the proximal end of the shaft,

the mechanical structure includes a drive element; and

a drive connector coupled between the drive element and the movable member, the drive connector comprising one or more cables,

at least one of the one or more cables comprises a plurality of individual filaments, each filament of the plurality of individual filaments comprising tungsten, and

each wire of the plurality of individual wires has a polished outer surface.

2. The surgical instrument of claim 1, wherein:

the cable includes a plurality of strands; and is also provided with

One or more strands of the plurality of strands include the plurality of individual filaments.

3. The surgical instrument of claim 1, wherein:

the cable includes a core strand and a plurality of outer strands surrounding the core strand; and is also provided with

The core strand includes the plurality of individual filaments.

4. The surgical instrument of claim 1, wherein:

the cable includes a core strand and a plurality of outer strands surrounding the core strand; and is also provided with

One or more strands of the plurality of strands include the plurality of individual filaments.

5. The surgical instrument of claim 1, wherein:

the cable includes a core strand and a plurality of outer strands surrounding the core strand; and is also provided with

The core strand and the plurality of outer strands include the plurality of individual filaments.

6. The surgical instrument of any one of claims 1, wherein:

each filament of the plurality of individual filaments consists essentially of tungsten, doped tungsten, or a tungsten alloy.

7. The surgical instrument of any one of claims 1-6, wherein:

each wire of the plurality of individual wires has a diameter in the range of 0.015-0.175 mm.

8. The surgical instrument of any one of claims 1-6, wherein:

each wire of the plurality of individual wires has a diameter of less than 0.175 mm.

9. The surgical instrument of any one of claims 1-6, wherein:

the cable has a diameter in the range of 0.3-2.0 mm.

10. The surgical instrument of any one of claims 1-6, wherein:

the cable has a diameter of less than 2.0 mm.

11. The surgical instrument of any one of claims 1-6, wherein:

The drive connector comprises a hypotube;

the hypotube includes a proximal end; and is also provided with

The cable is coupled between the proximal end of the hypotube and the drive element.

12. The surgical instrument of any one of claims 1-6, wherein:

the drive connector comprises a hypotube;

the hypotube includes a distal end; and is also provided with

The cable is coupled between the distal end of the hypotube and the movable member.

13. The surgical instrument of any one of claims 1-6, wherein:

the drive connector includes a first hypotube and a second hypotube, the first hypotube including a proximal end and a distal end, and the second hypotube including a proximal end and a distal end;

the one or more cables include a first cable, a second cable, a third cable, and a fourth cable;

the first cable is coupled between the drive element and the proximal end of the first hypotube;

the second cable is coupled between the distal end of the first hypotube and the movable member;

the third cable is coupled between the drive element and the proximal end of the second hypotube; and is also provided with

The fourth cable is coupled between the distal end of the second hypotube and the movable member.

14. The surgical instrument of any one of claims 1-6, wherein:

the drive connector includes a first hypotube and a second hypotube, the first hypotube including a proximal end and a distal end, and the second hypotube including a proximal end and a distal end;

the one or more cables include a first cable, a second cable, and a third cable;

the first cable is coupled between the drive element and the proximal end of the first hypotube;

the second cable is coupled between the distal end of the first hypotube and the distal end of the second hypotube;

the movable member is coupled to the second cable between the distal end of the first hypotube and the distal end of the second hypotube; and is also provided with

The third cable is coupled between the drive element and the proximal end of the second hypotube.

15. The surgical instrument of any one of claims 1-6, wherein:

the drive connector includes a first hypotube and a second hypotube, the first hypotube including a proximal end and a distal end, and the second hypotube including a proximal end and a distal end;

the one or more cables include a first cable, a second cable, a third cable, and a fourth cable;

The mechanical structure includes a second drive element;

the first cable is coupled between the drive element and the proximal end of the first hypotube;

the second cable is coupled between the distal end of the first hypotube and the movable member;

the third cable is coupled between the second drive element and the proximal end of the second hypotube; and is also provided with

The fourth cable is coupled between the distal end of the second hypotube and the movable member.

16. The surgical instrument of any one of claims 1-6, wherein:

the drive connector includes a first hypotube and a second hypotube, the first hypotube including a proximal end and a distal end, and the second hypotube including a proximal end and a distal end;

the one or more cables include a first cable, a second cable, and a third cable;

the mechanical structure includes a second drive element;

the first cable is coupled between the drive element and the proximal end of the first hypotube;

the second cable is coupled between the distal end of the first hypotube and the distal end of the second hypotube;

the movable member is coupled to the second cable between the distal end of the first hypotube and the distal end of the second hypotube; and is also provided with

The third cable is coupled between the second drive element and the proximal end of the second hypotube.

17. The surgical instrument of any one of claims 1-6, wherein:

the drive element comprises a rotary drive element.

18. The surgical instrument of any one of claims 1-6, wherein:

the drive element comprises a linear drive element.

19. The surgical instrument of any one of claims 1-6, wherein:

the mechanical structure includes a teleoperated manipulator drive input; and is also provided with

The teleoperated manipulator drive input is coupled to the drive element.

20. The surgical instrument of any one of claims 1-6, wherein:

the surgical instrument further comprises a pulley;

the pulley has a diameter of less than 5 mm; and is also provided with

The cable is wound at least partially around the pulley.

21. The surgical instrument of any one of claims 1-6, wherein:

the surgical instrument includes a first pulley and a second pulley adjacent to the first pulley;

the cable is wound at least partially around the first pulley in a first winding direction; and is also provided with

The cable is wound at least partially around the second pulley in a second winding direction opposite the first winding direction.

22. The surgical instrument of any one of claims 1-6, wherein:

during a first state of the drive connector, the drive connector is stationary;

during a second state of the drive connector, the drive connector is urged by the drive element to translate in a first direction; and is also provided with

During the first and second states of the drive connector, the one or more cables are under tension.

23. The surgical instrument of claim 22, wherein:

the first and second states of the drive connector exist under conditions where the cable has been subjected to ten or more surgical, cleaning and autoclave sterilization cycles.

24. The surgical instrument of claim 22, wherein:

the first and second states of the drive connector exist under conditions where the cable has been subjected to twenty or more surgical, cleaning and autoclave sterilization cycles.

25. The surgical instrument of any one of claims 1-6, wherein:

during a first state of the drive connector, the drive connector is stationary;

During a second state of the drive connector, the drive connector is urged by the drive element to translate in a first direction;

during a third state of the drive connector, the drive connector is urged by the drive element to translate in a second direction opposite the first direction; and is also provided with

The one or more cables are under tension during the first, second, and third states of the drive connector.

26. The surgical instrument of claim 25, wherein:

the first, second, and third states of the drive connector exist after the cable has been subjected to ten or more surgical, cleaning, and autoclave sterilization cycles.

27. The surgical instrument of claim 25, wherein:

the first, second, and third states of the drive connector exist after the cable has been subjected to twenty or more surgical, cleaning, and autoclave sterilization cycles.

28. The surgical instrument of any one of claims 1-6, wherein:

the surgical instrument includes an end effector; and is also provided with

The end effector includes the movable member.

29. The surgical instrument of claim 28, wherein:

the end effector includes a needle driver.

30. The surgical instrument of any one of claims 1-6, wherein:

the surgical instrument includes a mechanical wrist structure and an end effector;

the wrist structure is coupled between the distal end of the shaft and the end effector; and is also provided with

The robot arm structure includes the movable member.