Surgical instrument with sensor alignment cable guide

Abstract

A control cable in a surgical instrument is continuously parallel to the longitudinal axis of the instrument to prevent a lateral force sensor in the instrument from sensing lateral forces from the cable. A surgical instrument includes an elongated hollow shaft having a longitudinal center axis. Multiple cables extend within the shaft. The force sensor includes a beam disposed within the shaft and one or more strain gauges disposed on the beam. A proximal anchor is disposed within the shaft and in contact with the proximal end of the beam. A distal anchor is at the distal end of the shaft and in contact with the distal end of the beam. A cable guide is disposed within the shaft to constrain portions of the multiple cables disposed along the sides of the beam to move parallel to the center axis, thereby preventing the moving cables from causing lateral forces on the beam.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 767,880, filed on November 15, 2018, the entire contents of which are incorporated herein by reference. Technical Field Background Art

[0003] Minimally invasive medical technologies aim to reduce the amount of tissue damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and harmful side effects. Teleoperated surgical systems using robotic assistance can be used to overcome the limitations of manual laparoscopic and open surgery. Advances in telepresence systems provide surgeons with a view inside the patient's body, increase the number of degrees of motion for surgical instruments, and the ability to coordinate surgical procedures over a long distance.

[0004] In manual minimally invasive surgery, the surgeon feels the interaction of the instrument with the patient via the long shaft, which eliminates tactile cues and masks force cues. In a teleoperated surgical system, natural force feedback is eliminated because the surgeon no longer directly manipulates the instrument. Instead, the end effector at the distal end of the long shaft is actuated by a control cable extending within the shaft.

[0005] Force sensors within the shaft can be used to measure clinical forces at the distal end of an instrument during a medical procedure due to the interaction between the end effector and patient tissue, suture material, etc. However, clinical force measurements may introduce errors due to extraneous forces imparted by the end effector control cable extending within the shaft. For example, such extraneous forces may be due to twisting of the cable as the shaft rolls about its longitudinal axis. Therefore, it is necessary to isolate the clinical forces from the extraneous mechanical control cable forces so that the clinical forces can be accurately measured. Summary of the invention

[0006] In one aspect, a surgical instrument is provided, comprising an elongated hollow shaft comprising a proximal end portion, a distal end portion, and a longitudinal shaft center axis extending between the proximal end portion and the distal end portion. A force sensor is located in the distal end portion of the shaft and is coaxial with the shaft center axis. The force sensor comprises a beam and one or more strain gauges on the beam. The beam comprises a proximal end and a distal end. A proximal anchor is located in the shaft and coupled to the proximal end of the beam. The proximal anchor comprises a first plurality of cable guide holes. The distal anchor is located in the shaft and coupled to the distal end of the beam. The distal anchor comprises a second plurality of cable guide holes longitudinally aligned with the first plurality of cable guide holes. A plurality of cables extend through the shaft, through the first plurality of cable guide holes, and through the second plurality of cable guide holes. As the shaft rolls around the shaft center axis, the first plurality of cable guide holes and the second plurality of cable guide holes constrain the plurality of cables to keep them parallel to the shaft center axis.

[0007] In another aspect, a surgical instrument is provided that includes an elongated hollow shaft having a longitudinal central axis and including an inner wall defining a central bore. A plurality of cables extend within the central bore. A force sensor includes a beam within the central bore and includes one or more strain gauges on the beam. A proximal anchor is in contact with the inner wall of the shaft within the central bore and with a proximal end portion of the beam. A distal anchor is in contact with a distal end portion of the beam within the central bore. A cable guide is within the central bore to constrain portions of the plurality of cables along the sides of the beam to move parallel to the central axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] When with Figure 1 Various aspects of the present disclosure may be best understood from the following detailed description when read together. It is emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the sizes of various features may be arbitrarily increased or decreased for clarity of discussion. In addition, the present disclosure may repeat reference numerals and / or letters in various examples. This repetition is for simplicity and clarity purposes and does not in itself express the relationship between the various embodiments and / or configurations discussed.

[0009] Figure 1 is an illustrative plan view of a minimally invasive teleoperated surgical system for performing minimally invasive diagnostic or surgical procedures on a patient lying on an operating table.

[0010] Figure 2 is a perspective view of the surgeon's console.

[0011] Figure 3 is a perspective view of a manipulator unit of a minimally invasive teleoperated surgical system.

[0012] Figure 4is a diagrammatic side top view of a surgical instrument coupled to an instrument holder.

[0013] Figure 5 is an illustrative top view of an elongated hollow shaft.

[0014] Figure 6 It is along Figure 5 An illustrative side cross-sectional view of the elongated hollow shaft along line 6-6 showing a force sensor disposed within.

[0015] Figure 7 It is along Figure 6 An illustrative proximal axial cross-sectional view of the elongated hollow shaft as shown at line 7-7, showing a proximal axial view of the proximal anchor.

[0016] Figure 8 It is along Figure 6 An illustrative distal axial view of the elongated hollow shaft is shown along line 8-8, which shows a distal axial view of the distal anchor.

[0017] Fig. 9 yes Figure 5 An illustrative side cross-sectional view of an elongated hollow shaft with a wall of the outer shaft cut away to show a cable extending longitudinally parallel to the longitudinal axis of the shaft.

[0018] Fig. 10A is a perspective view of the guide slot insert.

[0019] Fig. 10B is a perspective view of a distal end portion of an embodiment of a shaft with portions of the shaft wall removed to illustrate a cable and sensor beam disposed therein.

[0020] Fig.11A is an illustrative simplified longitudinal cross-sectional side view schematic drawing of a surgical instrument shaft in a neutral, resting position.

[0021] Fig. 11B yes Fig.11A An illustrative simplified perspective schematic drawing of a surgical instrument shaft showing an example cable passing through proximal and distal guide holes of a proximal anchor and a distal anchor.

[0022] Fig. 11C is an illustrative simplified perspective schematic drawing of a surgical instrument shaft showing the cable guide surface axis.

[0023] Fig. 12A is an illustrative simplified longitudinal cross-sectional side view of a surgical instrument shaft partially about a central axis of the shaft with an example control cable extending within the shaft rotating in an approximate partial helix about the central axis of the shaft.

[0024] Fig. 12Bis an illustrative simplified perspective schematic drawing showing an example control cable threaded through proximal and distal guide holes formed in proximal and distal anchors within a surgical instrument shaft.

[0025] Fig. 12C is an illustrative simplified perspective schematic drawing of a partially rotated surgical instrument shaft showing a cable guide surface axis extending parallel to the shaft center axis. DETAILED DESCRIPTION

[0026] Remotely operated surgical systems

[0027] Figure 1 1 is an illustrative plan view of a minimally invasive teleoperated surgical system 10 for performing minimally invasive diagnostic or therapeutic surgical procedures 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 the procedure. One or more assistants 20 may also participate in the procedure. The minimally invasive teleoperated surgical system 10 further includes one or more manipulator units 22 and an auxiliary unit 24. The manipulator unit 22 can manipulate at least one surgical instrument 26 through a minimally invasive incision in the body or a natural body orifice of the patient 12 while the surgeon 18 observes the surgical site through the user console 16. An image of the surgical site can be obtained through an endoscope 28 such as a stereo endoscope, and the endoscope can be positioned using the manipulator unit 22. A computer processor located on the auxiliary unit 24 can be used to process the image of the surgical site for subsequent display to the surgeon 18 through the user console 16. The computer processor may include a logic unit and a memory storing instructions executed by the logic unit. In some embodiments, a stereoscopic image can be captured, which allows the perception of depth during the surgical procedure. The number of surgical instruments 26 used at one time will generally depend on the diagnostic or therapeutic procedure and the space constraints within the operating site, as well as other factors. If it is necessary to replace one or more surgical instruments 26 being used during the procedure, the assistant 20 can 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 computer processor at the auxiliary unit 24 can be configured to process signals representing the forces applied at the surgical instrument. The example computer processor at the surgeon's console 16 can generate tactile feedback corresponding to these applied forces.

[0028] Figure 236 is a perspective view of the user console 16. The surgeon's console 16 includes an observer display 31, which includes a left eye display 32 and a right eye display 34, for presenting a depth-aware coordinated stereoscopic view of the surgical site to the surgeon 18. The user console 16 further includes one or more manually operated control input devices 36, 38 to receive larger-scale manual control movements. One or more slave surgical instruments 26 equipped for use at one or more corresponding manipulators of the manipulator unit 22 are moved at a relatively small-scale distance that matches the larger-scale manipulation of one or more master control inputs 36, 38 by the surgeon 18. The master control input devices 36, 38 can provide the same mechanical degrees of freedom as the surgical instruments 26 associated therewith to provide the surgeon 18 with a remote presentation, or a sense that the master control input device 36 is integrated with the slave surgical instruments 26, so that the surgeon has a keen sense of direct control of the instruments 26. To this end, subject to communication latency constraints, position, force, and tactile feedback sensors (not shown) may be employed to communicate position, force, and tactile sensations from surgical instrument 26 to the surgeon's hands via control input devices 36, 38. A signal (optionally optical or electronic) modulated based on the force detected at a force sensor (not shown) at instrument 26 may be processed by a processor at auxiliary unit cart 24 to generate tactile feedback at control input device 36 that is representative of the detected force.

[0029] Figure 37 is a perspective view of a manipulator unit 22 of an example minimally invasive teleoperated surgical system 10 according to some embodiments. The manipulator unit 22 includes four manipulator support structures 72. Each manipulator support structure 72 includes an articulated support structure 73 pivotally mounted end to end and a support spar 74 pivotally mounted. A corresponding surgical instrument bracket 75 (including a motor to control instrument movement) is mounted at each support spar 74. In addition, each manipulator support structure 72 may optionally include one or more equipment joints (e.g., unpowered and / or lockable) at the junction of the articulated support structure 73 and at the junction with the spar 74. The bracket 75 can be moved along the spar 74 to position the bracket 75 at different positions along the spar 74. Therefore, the spar 74 can be used to position the attached surgical instrument bracket 75 for surgical operation relative to the patient 12. Each surgical instrument 26 is removably connected to the bracket 75. Although the manipulator unit 22 is shown as including four manipulator support structures 72, more or fewer manipulator support structures 72 may be used. Generally speaking, at least one of the surgical instruments will include a vision system, which typically includes an endoscopic camera instrument for capturing video images and one or more video displays for displaying the captured video images, the one or more video displays coupled to one of the brackets 75.

[0030] In one aspect, carriage 75 houses a plurality of teleoperated actuators, such as motors (not shown), which impart motion to a tensioning member, such as a cable drive member, including a drive shaft and capstan (not shown), which in turn drives a cable to translate motion of surgical instrument 26 into various movements of an end effector portion of surgical instrument 26. In some embodiments, the teleoperated actuators in carriage 75 impart motion to various components of surgical instrument 26, such as, for example, end effector wrist movement or jaw movement.

[0031] The surgeon manipulates the master control input devices 36, 38 to control the instrument end effectors. Inputs provided by the surgeon or other medical personnel to the control input devices 36 or 38 ("master" commands) are converted by the surgical instrument 26 through one or more remote motors into corresponding actions (corresponding "slave" responses). A cable-based flexible cable force transfer mechanism or similar mechanism is used to transfer the motion of each of the remotely located teleoperated motors to the corresponding instrument interface actuator output located at the instrument bracket 75. In some embodiments, the mechanical adapter interface 76 mechanically couples the instrument 26 to the actuator 442 ( Figures 4 to 526) to control movement within the instrument 26. The surgical instrument 26 can be mechanically coupled to a first actuator (not shown) that can control a first movement of the surgical instrument, such as longitudinal (z-axis) rotation. The surgical instrument 26 can be mechanically coupled to a second actuator (not shown) that can control a second movement of the surgical instrument, such as planar two-dimensional (x, y) movement. The surgical instrument 26 can be mechanically coupled to a third actuator that can control a third movement of the surgical instrument, such as, for example, opening and closing of the jaws of an end effector.

[0032] Figure 4 is a diagrammatic side top view of surgical instrument 26 coupled to instrument bracket 75. As used herein, the term "proximal" refers to a direction closer to a manipulator arm, and the term "distal" refers to a direction farther from a manipulator wall.

[0033] The surgical instrument 26 includes an elongated hollow cylindrical tubular shaft 410 having a distal end portion 450 and a proximal end portion 456. The distal end portion 450 includes an end effector 454 for insertion into a patient's body cavity. The proximal end portion 456 is fixedly connected to a proximal instrument controller 440. The inner wall of the shaft defines a cylindrical hollow hole. The longitudinal center axis 411 of the shaft ("shaft center axis") is defined through the distal end portion 450 and the proximal end portion 450. The proximal instrument controller 440 includes a housing 441 (shown as transparent, indicated by dashed lines) enclosing a plurality of drive members 460, which may include one or more actuators (such as capstans and drive shafts) configured to couple a drive force imparted by one or more actuators 442 within the instrument bracket 75 to a cable 470 extending within the shaft 410 in parallel alignment with the shaft central axis 411. Co-pending U.S. Provisional Patent Application No. 62 / 767,895, filed on November 15, 2019, discloses drive members 460 according to some embodiments, the entire contents of which are expressly incorporated herein by this reference. The cable 470 extends within the shaft between the drive members and the end effector 454. The cable 470 is operably coupled so that movement of the cable can impart motion to the end effector 454, such as, for example, opening or closing of the jaws and causing rocking of the jaws and pitching of the wrist motion. The end effector 454 may include functional mechanical degrees of freedom, such as the jaws opening or closing, or the knife or wrist 452 translating along a path may move in the X direction and the Y direction. U.S. Pat. No. 6,394,998 shows an example of an end effector with multiple mechanical degrees of freedom. The distal portion 450 of the surgical instrument 26 may provide any of a variety of different types of end effectors 454, such as forceps, needle drivers, cautery devices, cutting tools, imaging devices (e.g., endoscopes or ultrasound probes), etc. Thus, an actuator 442 located near the proximal end portion 456 of the shaft 410 at the bracket 75 controls the movement of the end effector 454 at the distal end portion 450 of the shaft 410 by causing a drive member 460 within the housing 441 of the proximal instrument controller 440 to apply a control force on the cable 470, wherein the cable 470 extends within the shaft 410 parallel to the shaft axis 411 and between the drive member 460 and the end effector 454.

[0034] Instrument shaft with sensor alignment cable guide

[0035] Figure 5is an illustrative top view of the elongated hollow shaft 410. A clevis 502 depends distally from the distal end portion 450 of the shaft 410 for mounting an end effector (not shown) thereon. The end effector may typically include an additional clevis (not shown), often referred to as a distal clevis, to permit multiple degrees of motion. The clevis 502 includes opposing first and second arms 504, 506, with an axle 508 extending between the arms for mounting the end effector thereon. The clevis 502 illustrates one of the examples of various components that can be coupled to the distal end of the shaft 410, such as a wrist component, a therapeutic and diagnostic end effector component, an imaging component, etc.

[0036] Figure 6 It is along Figure 5 6-6 of the elongated hollow shaft 410, which shows a force sensor 602 disposed therein. The inner wall surface 412 of the shaft 410 defines a cylindrical hollow hole 413. The cable (not shown) extending within the shaft 410 is not shown so that the force sensor 602 can be more clearly shown. The force sensor 602 acts as a transducer, which includes an elongated beam 604 having a plurality of strain gauges 606 disposed thereon. The beam 604 is coaxially aligned with the longitudinal shaft center axis 411 and can have a variety of cross-sectional shapes (e.g., circular, rectangular, square, etc.). For example, the beam 604 can be formed of a material such as stainless steel, titanium, or a zirconium alloy. The strain gauge 606 is configured to generate one or more signals having a value representing the magnitude of the force applied to the beam 604 in a direction generally perpendicular to the shaft center axis 411. The proximal anchor 610 contacts the inner wall surface 412 of the shaft 410, and the proximal end portion of the beam 604 mechanically couples the proximal end portion of the beam 604 to the inner wall 412 portion of the shaft 410. The proximal anchor may be fixedly attached to the inner wall surface 412 of the shaft 410 (e.g., by interference or tight fit, glue, or welding). Similarly, the distal anchor 612 contacts the inner wall surface 412 of the shaft 410, and the distal end portion of the beam 604 mechanically couples the distal end portion of the beam 604 to the inner wall 412 portion of the shaft 410. The distal anchor 612 may be fixedly attached to the inner wall surface 412 of the shaft 410 (e.g., by interference or tight fit, glue, or welding). The U-clip 502 depends from the distal anchor 612.

[0037] Figure 7 It is along Figure 6 7-7 of the illustrative proximal axial view of the elongated hollow shaft 410, which shows a proximal axial cross-sectional view of the proximal anchor 610. Figure 6 and Figure 7, the proximal anchor 610 includes a proximal annular portion 702 defining an example central opening 705, the example central opening 705 being dimensioned to securely receive the proximal end portion of the beam 604 therein. More specifically, the central opening 705 is defined by a lip 706 in the proximal transverse annular portion 702. As shown, the example lip 706 has a shape of a superimposed cross and a circle, such that the central opening 705 has a cross section with a relatively small circle superimposed on a relatively large cross. The outer perimeter of the proximal transverse annular portion 702 is dimensioned and configured to fit closely within the shaft 410, such that the proximal annular portion 702 imparts forces received at the outer wall surface 415 of the shaft 410 to the proximal end portion of the beam 604, and vice versa. The proximal annular portion 702 includes a proximal cable guide portion 708 represented by a dashed line. The example proximal cable guide portion 708 defines a proximal first plurality of cable guide holes 704 in the surface of the proximal annular portion 702. In the example shaft 410, the proximal first plurality of cable guide holes 704 are arranged in a first pattern. The proximal first plurality of cable guide holes 704 are sized to be a sliding channel through which control cables (not shown) pass. The first cable and the second cable are configured to control the end effector in three degrees of freedom.

[0038] Figure 8 It is along Figure 6 8-8 of the elongated hollow shaft 410, showing a distal axial view of the distal anchor 612. Figure 6 and Figure 8 , the distal anchor 612 includes a distal transverse annular portion 802 defining a central portion indicated by dashed line 805, the opposite sides of which are affixed to the distal end portion (not shown) of the beam. The outer perimeter of the distal transverse annular surface portion 802 is sized and configured to fit tightly within the shaft 410. The distal annular portion 802 includes a distal cable guide portion 808 indicated by dashed line. The example distal cable guide portion 808 defines a distal second plurality of cable guide holes 804 in the surface of the distal annular portion 802. In the example shaft 410, the distal second plurality of cable guide holes 804 are arranged in a second pattern. The distal cable guide holes are sized to be sliding passages through which control cables (not shown) pass.

[0039] The proximal cable guide portion 708 and the distal cable guide portion 808 operate together to guide the cable parallel to the shaft center axis 411. As shown in the drawing, the proximal first plurality of cable guide holes 704 are arranged in a first pattern, the distal second plurality of cable guide holes 804 are arranged in a second cable guide hole pattern, and the first pattern matches the second pattern. The proximal guide portion 708 is aligned with the distal guide portion 808 such that the first pattern including the proximal first plurality of cable guide holes 704 is longitudinally aligned with the second pattern including the distal second plurality of cable guide holes 804. Each proximal cable guide hole 704 is aligned with the corresponding distal cable guide hole 804 such that the cable guide surface axis 1150 (see FIG. 1150 ) passing through the centers of the corresponding aligned proximal holes 704 and distal holes 804 is longitudinally aligned with the distal holes 804. Fig. 11C ) is aligned parallel to the shaft center axis 411. The proximal cable guide portion 708 and the distal cable guide portion 808 cooperate together to maintain the cable aligned parallel to a portion of the shaft center axis 411 where the sensor beam 604 extends. Fig. 9 yes Figure 5 An illustrative side cross-sectional view of an elongated hollow shaft 410 of FIG. 4, wherein the wall of the outer shaft is cut away to show a cable 460 extending longitudinally parallel to the shaft axis 411. For example, the cable 460 can branch in different directions at the distal end portion of the shaft, such as for routing to be actuated by different actuators. Also, the cable can branch in different directions at the distal end portion of the shaft, such as for routing to different components of the end effector. The above-mentioned U.S. Patent No. 6,394,998 shows an example of a cable branching in a complex tortuous path at the end effector. Each proximal cable guide hole 704 of the proximal cable guide portion 708 of the proximal anchor 610 is longitudinally aligned with the corresponding distal cable guide hole 804 of the distal cable guide portion 808 of the distal anchor 612 to guide the cable 470 extending between a pair of aligned guide holes to extend parallel to the longitudinal center axis 411 of the shaft 410, which is also the longitudinal axis of the sensor beam 604. In some example shafts, the cable 460 is formed of a flexible rope construction made of stainless steel, tungsten, polyethylene fiber, or ultra-high molecular weight polyethylene (UHMWPE). In some example shafts, in a portion of the shaft where the cable is not required to bend, an elongated solid tube formed of a stainless steel alloy or similar material may be inserted and coupled at either end with a flexible cable segment extending through the proximal and distal end portions of the shaft along an associated routing path.

[0040] Fig. 10A is a perspective view of the guide slot insert 1002 . Fig. 10B is a perspective view of a distal end portion of an embodiment of the shaft 1040 with portions of the shaft wall removed to illustrate the cable 460 and sensor beam 604 disposed therein. Fig. 10A, the guide slot insert 1002 includes an outer engagement surface 1004, and includes a first proximal guide slot surface 1006, a second proximal guide slot surface 1008, and a third proximal guide slot surface 1010 defining corresponding first guide slots 1012, second guide slots 1014, and third guide slots 1016, each of the first guide slots 1012, second guide slots 1014, and third guide slots 1016 is sized to allow a single one of the cables 460 to pass through a sliding channel therethrough. Reference Fig. 10B , the proximal anchor 1050 defines a first aperture area and a second aperture area 1052, each aperture area having a complementary engagement surface (not shown) that is contoured to mate with the outer engagement surface 1004 of the first and second instances of the guide slot insert 1002. As shown, the guide slot inserts 1002 are each inserted into a corresponding aperture area 1052 such that the guide slots 1012, 1014, 1016 of each guide slot insert 1002 at the proximal anchor 1050 are longitudinally aligned with the corresponding distal guide holes 1062 at the distal anchor 1060. In this manner, the cable 460 extending between the proximal guide slots and the corresponding distal guide holes extends parallel to the longitudinal center axis 1041 of the shaft 1040. Each of the proximal cable guide slots 1012, 1014, 1016 defined by the proximal anchor 1050 is longitudinally aligned with a corresponding distal cable guide hole 1062 of the distal cable guide portion 808 of the distal anchor 1060 to guide the cable 460 extending between the aligned proximal guide cable slot distal guide hole pair to extend parallel to the longitudinal center axis 1041 of the shaft 1040, wherein the longitudinal center axis 1041 of the shaft 1040 is also the longitudinal axis of the sensor beam 604. Each corresponding portion of the cable 460 extends parallel to the center axis 1041 between the corresponding proximal slot surface and the corresponding corresponding distal guide hole. More specifically, as shown in FIG. Fig. 10B As shown, in some optional embodiments, the guide groove surface and the surface of the aperture area 1052 cooperate to define a single proximal guide hole 1082 for a corresponding single cable 460. These proximal guide holes 1082 are longitudinally aligned with the corresponding distal guide holes 1062. In other optional embodiments, the shaft wall portion 1044 of the shaft 1040 can cover the outer proximal guide groove surface 1006, 1010, so that the guide groove surface and the portion of the shaft wall inner surface cooperate to define the proximal guide hole 1082 aligned with the corresponding distal guide hole 1062. The advantage of such an embodiment is that the need to form a closed void in the proximal anchor 1050 is eliminated, thereby reducing manufacturing complexity and cost. And it should be appreciated that in some optional embodiments, one or more guide groove inserts similar to the guide groove insert 1002 can be used in the distal anchor component instead of forming a plurality of discrete cable guide holes in the distal anchor component.

[0041] Usage Examples

[0042] By ensuring that the control cable remains parallel to the force sensor beam at all shaft roll orientations about the shaft center axis, forces on the cable that actuate the distal end member of the instrument do not affect lateral forces on the force sensor beam when the instrument is in use. In this manner, the lateral forces on the sensor beam sensed by the force sensing elements on the sensor beam are effectively limited to clinical forces associated with the distal end member of the instrument interacting with tissue and objects at the surgical site. As a result, the force sensors on the force sensor beam can accurately sense these clinical forces and, in turn, transmit the sensed clinical forces to a computer processor, which in turn outputs the sensed forces as an accurate tactile representation of the clinical forces at the distal end of the instrument to the hands of a surgeon operating the user input device via the user input device.

[0043] Fig.11A is an illustrative simplified cross-sectional side view schematic drawing of a surgical instrument shaft 410 in a neutral rest position with an example control cable 460 extending within the shaft parallel to the shaft's central axis 411. The neutral rest position is a position within the shaft 410 where the control cable 460 is not twisted, such as midway between two rotational ranges of motion limits of the shaft 410. Fig. 11B is in Fig.11A An illustrative simplified perspective schematic drawing of a surgical instrument shaft 410 in a neutral, stationary position showing an example cable 460 passing within the hollow shaft 410 through a proximal guide hole 704 in a proximal guide portion 704 of a proximal anchor 610 and through a distal guide hole 804 in a distal cable guide portion 804 of a distal lateral surface portion 503. Fig. 11C 1 is an illustrative simplified perspective schematic drawing of surgical instrument shaft 410 in a neutral orientation showing cable guide surface axis 1150 extending parallel to shaft center axis 411 between the center of proximal guide hole 704 defined in proximal guide surface 1102 and the center of distal guide hole 804 defined in distal guide surface 1202. Thus, hole 704 and hole 804 are a pair of longitudinally aligned holes, and proximal guide surface 1102 and distal guide surface 1202 are a pair of longitudinally aligned guide surfaces. For example, in Figure 8 , the distal transverse annular portion 802 provides the distal transverse surface portion 503. However, in an alternative example (not shown), the distal end portion of the sensor beam 604 is tapered and extends within a complementary tapered opening of the U-shaped clamp, and the distal end portion of the sensor beam 604 is secured to the distal end portion of the shaft 410. Thus, the U-shaped clamp 502 secures the beam 604 within the shaft 410. Thus, for example, in the alternative example, the U-shaped clamp 502 provides the distal transverse surface portion 503.

[0044] Fig. 12A is an illustrative simplified longitudinal cross-sectional side view of a surgical instrument shaft 410 partially rotated (approximately half a turn) about a central axis 411 of the shaft, with an example control cable 460 extending within the shaft rotating about the central axis 411 of the shaft 410 in approximately a partial helix. Fig. 12B An example cable 460 is shown in FIG. Fig. 11B An illustrative simplified perspective schematic drawing of the proximal and distal guide holes 704, 804 formed in the proximal anchor 610 and in the distal lateral surface 503 within the hollow shaft 410 is depicted. Fig. 12C is an illustrative simplified perspective schematic drawing of surgical instrument shaft 410 when partially rotated showing cable guide surface axis 1150 extending parallel to shaft center axis 411 .

[0045] Since the alignment of the cable 460 is fixed as it exits the proximal instrument control 440 portion of the instrument, the cable will twist within the shaft 410 as the shaft 410 rotates about the central shaft axis 411 relative to the proximal instrument control 440. However, as shown, the guide holes in the proximal and distal anchors that longitudinally support the force sensor beam maintain longitudinal alignment and will prevent the cable from twisting within the force sensor beam portion of the instrument shaft.

[0046] To simplify the explanation and drawing, FIG. 11A to FIG. 11B and in FIG. 12A to FIG. 12B Only a single example control cable 460 is shown in FIG. 4 , although it will be appreciated that in actual embodiments, multiple cables extend within the hollow shaft 410. Furthermore, in order to better illustrate the external forces exerted on the example cable 460, FIG. 12A to FIG. 12B The rotation of the shaft and the corresponding helical rotation of the cable shown in FIG. 1 are exaggerated beyond what would normally occur in practice.

[0047] The proximal end portion of the example cable 460 is secured to the example drive member 462 within the proximal instrument controller 440 disposed at the proximal end portion of the shaft 456. The distal end portion of the cable 460 is secured to the end effector 454 at the distal end portion of the shaft 450. Note that the example cable 460 may follow a tortuous path within the end effector 454 (such as that of U.S. Pat. No. 6,394,998). FIG. 11A to FIG. 11B ), for example, which may include: an interface with one or more pulleys or other mechanical control structures to facilitate three-degree-of-freedom movement of the end effector.

[0048] The force sensor 602 is disposed within the shaft 410 aligned with the shaft central axis 411. In some embodiments, the sensor 602 includes a beam 604 having a strain gauge 606 thereon. The beam 604 has a proximal end portion and a distal end portion affixed to respective proximal anchors 610 and distal transverse surfaces 503. The proximal anchor 610 is affixed to the inner wall of the shaft 410 at a first axial position of the shaft. In some embodiments, the proximal anchor 610 includes a first planar surface 702 aligned perpendicular to the shaft central axis 411 and the first planar surface 702 includes a proximal guide surface 1102 defining a proximal guide hole 704. Similarly, in some embodiments, the distal transverse surface 503 includes a second planar surface aligned perpendicular to the shaft central axis 411 and the second planar surface includes a distal guide surface 1202 defining a distal guide hole 804. The example cable 460 passes through the proximal guide hole 704 and the distal guide hole 804. The proximal guide surface 1102 and the distal guide surface 1202 define the proximal guide hole 704 and the distal guide hole 804 that are sized to permit the cable 460 to slide therein.

[0049] Regardless of whether the axis 410 is in Fig. 11B The static positioning is still Fig. 12B In the rotational orientation of the beam 604, the proximal guide surface 1102 and the distal guide surface 1202 are longitudinally aligned to guide the portion of the cable 460 extending between the proximal guide surface 1102 and the distal guide surface 1202 along the side of the beam 604 to align parallel to the shaft center axis 411 and parallel to the beam. More specifically, the proximal guide surface 702 and the distal guide surface 802 define a proximal hole 704 and a distal hole 804 that are wide enough to permit sliding passage of the example cable 460 and are narrow enough so that the guide surfaces 1102 and the guide surfaces 1202 about the holes 704 and the holes 804 cause the cable 460 to align parallel to the shaft center axis 411 when the shaft is set in a neutral orientation and when the shaft is set in a rotational orientation. In some embodiments, the proximal guide surface 1102 and the distal guide surface 1202 cooperate with the wall of the shaft 410 or the U-shaped clamp 502 to provide the guide hole 704 and the guide hole 804.

[0050] During a medical procedure, a surgeon may manipulate the master control input devices 36, 38 to provide input commands to control the movement of a slave end effector 454 at the distal end 450 of the shaft 410. Movement of the end effector 454 may cause it to physically contact patient tissue 1250, for example, for clinical purposes such as cutting, suturing, probing, or cauterizing the contacted tissue. It will be appreciated that different types of end effectors may be provided, for example, for these different purposes. During contact of the end effector 454 with the patient tissue 1250, the end effector may apply an end effector force FE applied to the tissue 1250, and in reaction, the tissue may exert a corresponding tissue force F on the end effector 454 T . End effector force F E and the corresponding organizational strength F T Each includes a force component perpendicular to the shaft central axis 411, and each may include a force component parallel to the shaft central axis 411. FIG. 11A to FIG. 11B and FIG. 12A to FIG. 12B An example reference coordinate system is provided in . The z-axis is shown aligned parallel to the longitudinal axis. The (x, y) plane is shown aligned perpendicular to the longitudinal axis.

[0051] Specifically, for example, organizational strength F T The plane component F perpendicular to the shaft center axis 411 T(x，y) and the z-direction component F parallel to the shaft center axis 411 Tz .

[0052]

[0053] The vertical tissue force component F applied at the end effector 454 T(x，y) A corresponding vertical bending force F may be induced at the portion of the shaft 410 where the sensor 602 is disposed. B(x，y) The vertical bending force may cause a portion of the axis 410 along the side of the sensor 602 to deflect or cause bending. The proximal anchor 610 and the distal guide cross member 503 mechanically couple the vertical bending force to the sensor 602, thereby causing the strain gauge 606 mounted on the sensor beam 604 to generate one or more signals representing the magnitude of the bending force. The strain gauge may be configured to couple the vertical mechanical bending force F B(x，y) into an electrical or optical signal having a signal value representing the magnitude of the perpendicular bending force in the coupling. Note that the parallel organization force component F Tz The magnitude of may be determined by one or more separate sensors disposed at the proximal end portion 450 of the shaft 410 at the instrument controller 440 .

[0054] It will be appreciated that although the shaft 410 can rotate about the shaft central axis 411, for example due to the rolling degree of freedom (DOF) of the wrist, during a medical procedure, the proximally located instrument controller 440 is generally maintained in a fixed position relative to the patient tissue 1250. The end effector 454 is fixedly secured at the clevis 502, which is fixedly secured to the distal anchor, so that the end effector 454 rotates in unison with the shaft 410 via rotation of the proximal anchor and the beam. Thus, the end effector 454 and the shaft rotate together about the shaft central axis 411, while the instrument controller 440 does not rotate.

[0055] More specifically, rotation of the shaft 410 about the shaft central axis 411 causes a corresponding helical-like rotation of the proximal first portion 460-1 of the example cable disposed between the proximal anchor 610 and the proximal end portion of the shaft 456. Importantly, however, the FIG. 11A to FIG. 11B Drawing and FIG. 12A to FIG. 12B As shown in comparison of the drawings, despite rotation of the shaft 410 and despite corresponding twisting of the example 460 cable, the proximal guide surface 1102 and the distal guide surface 1202 cooperate to guide the distal second portion 460-2 of the example cable 460 extending therebetween and along the edge of the sensor beam 604 into alignment parallel to the shaft center axis 411.

[0056] exist FIG. 11A to FIG. 11B and FIG. 12A to FIG. 12B The example of the proximal drive member 460 can be used to apply the cable force F C is applied to the example cable 460 to effect movement of the distally mounted end effector 454. The cable force may include a statically tensioned cable force F CS and dynamic clinical cable force F CD The sum of .

[0057] F C =F CS +F CD (2)

[0058] In some embodiments, the example cable 460 may be typically provided with a static cable force F CS Pre-tensioning. During a surgical procedure, in response to surgeon commands at the master input devices 36, 38, an additional dynamic clinical force F may be applied to the cable. CD , to achieve the movement of the cable and the corresponding movement of the end effector 454. Typically, the static pretension cable force F CS The magnitude is significantly smaller than the dynamic clinical cable force F CD For example, in some embodiments, the static cable force F CS Typically of magnitude in the range of about 2-5 lbf, the dynamic cable force F CDTypically, the magnitude is in the range of about 20-30 lbf. In addition, the magnitude of the cable force is typically significantly greater than the vertical tissue force F T(x，y) and the corresponding bending force F B For example, in some embodiments, the vertical tissue force F T(x，y) And the corresponding bending force is typically of magnitude in the range of about 0-5 lbf.

[0059] exist FIG. 11A to FIG. 11B In the neutral static position shown, the total cable force F C The cable force is applied in the z direction parallel to the shaft center axis, and as a result, the cable force has no vertical (x, y) plane component to be applied to the sensor 602. Therefore, in the neutral static position, the cable force does not affect the sensor 602's response to the vertical bending force F B measurement because the cable force is directed entirely parallel to the shaft center axis 411 in the z direction.

[0060] exist FIG. 12A to FIG. 12B In the rotational positioning shown, the cable force F Cz The first axial component of the cable force F is applied to the first proximal portion 460-1 of the example cable 460 in a direction parallel to the shaft center axis 411 and in the z direction. In addition, in the rotational positioning, in the vertical (x, y) plane, the cable force F C(x，y) The planar second component of is applied to the proximal anchor 610 in a direction perpendicular to the shaft center axis 411 .

[0061] F C =F Cz +F C(x，y) (3)

[0062] In the absence of guide 1102 and matching 1202, the cable force F C(x，y) The second component of the plane of the force F is applied to the distal anchor 612, which is coupled to the clinical vertical bending force F B Therefore, in the example rotation positioning, the cable force F C(x，y) The second component of the plane of the force has the potential to impart a cable-related force to the sensor 602, which may introduce error into the force generated by the vertical tissue force component F T(x，y) The vertical bending force F B measurement.

[0063] Advantageously, however, the first guide surface 1102 and the second guide surface 1202 align the sensor 602 with the cable force F by causing the second distal portion 460 - 2 of the example cable 460 to align parallel to the shaft center axis 411 . C(x，y)The second distal portion 460-2 of the example cable 460 runs along the side of the sensor beam 602 to isolate the error-causing plane perpendicular components. The second distal portion 460-2 of the cable 460 is caused to align parallel to the shaft center axis 411 to ensure that all cable forces at the second distal portion 460-2 of the cable 460 are z-directed forces aligned parallel to the shaft center axis 411. In other words, the cable forces at the second distal portion 460-2 of the cable 460 have no (x, y) plane components perpendicular to the shaft center axis 411. Therefore, the cable forces applied at the second distal portion 460-2 of the cable 460 do not interfere with the sensor 602's response to the vertical tissue force F B measurement.

[0064] Example embodiments have been described in the drawings in which force sensing features are incorporated into the distal end of a surgical instrument shaft. In other optional embodiments, components other than force sensing functions may be used if design requirements specify that the instrument control cable should be parallel to the components between the proximal control unit of the instrument and the distal actuator of the instrument. Similarly, in still other optional embodiments, the aspects described herein are applied to the middle or proximal end portion of the instrument shaft so that the control cable that operates the distal end feature of the instrument is continuously parallel to the components disposed in the middle or proximal end portion of the shaft.

[0065] The above description is presented to enable any person skilled in the art to create and use a surgical instrument with a cable guide to align a control cable extending within an instrument shaft in parallel with a sensor beam disposed within the shaft to prevent vertical cable forces from being imparted to the sensor. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. In the foregoing description, a large number of details are set forth for the purpose of illustration. However, one of ordinary skill in the art will appreciate that the embodiments of the present disclosure may be practiced without using these specific details. In other instances, well-known processes are shown in block diagram form to avoid obscuring the description of the invention with unnecessary details. The same drawings may be used to represent different views of the same or similar items in different drawings. Therefore, the foregoing description and drawings according to embodiments of the present invention are merely illustrative of the principles of the invention. Therefore, it will be understood that various modifications may be made to the embodiments by those skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims

1. A surgical instrument, comprising: a force sensor comprising a beam and one or more strain gauges on an outer surface of the beam, The beam further includes a proximal end and a distal end, and a central axis of the beam defined by the proximal end and the distal end of the beam; a proximal anchor coupled to the proximal end of the beam, the proximal anchor defining a bore; a distal anchor coupled to the distal end of the beam, the distal anchor defining a bore, and the bore in the distal anchor being aligned with the bore in the proximal anchor; an end effector component distal to the distal anchor and coupled to the distal end of the beam; as well as a cable coupled to impart movement to the end effector member; wherein the cable extends through the bore of the proximal anchor and through the bore of the distal anchor and is thereby constrained to extend outside of the outer surface of the beam and parallel to the central axis of the beam.

2. The surgical instrument of claim 1, wherein: The proximal anchor includes a guide surface; The distal anchor includes a guide surface; and The guide surface of the proximal anchor defines the bore of the proximal anchor, and the guide surface of the distal anchor defines the bore of the distal anchor.

3. The surgical instrument of claim 1, wherein: The surgical instrument further comprises a shaft; and The proximal end of the beam is coupled to the shaft.

4. The surgical instrument of claim 1, wherein: The surgical instrument further includes a shaft and a drive member; The shaft includes a proximal end portion and a distal end portion; the drive member being located proximal to the proximal end of the shaft; the proximal end of the beam coupled to the distal end portion of the shaft; and The cable extends from the drive member to the end effector component.

5. The surgical instrument of claim 1, wherein: The surgical instrument further includes a guide slot insert; The guide slot insert includes a guide slot; The proximal anchor includes a guide hole; and The cable extends through the guide slot and the guide hole of the proximal anchor.

6. The surgical instrument of claim 1, wherein: The surgical instrument further includes a shaft and a guide slot insert inserted into the shaft; The shaft includes an inner surface; The guide slot insert includes a guide slot; The proximal anchor includes a guide hole defined by the guide slot and the inner surface of the shaft; and The cable extends through the guide hole of the proximal anchor.

7. The surgical instrument of claim 1, wherein: The proximal anchor includes an opening; The distal anchor includes an opening; The proximal end of the beam is inserted into the opening of the proximal anchor; and The distal end of the beam is inserted into the opening of the distal anchor.

8. The surgical instrument of claim 1, wherein: The proximal anchor includes a planar guide surface; and The planar guide surface is perpendicular to the central axis of the beam.

9. The surgical instrument of claim 1, wherein: The cable is pre-tensioned.

10. The surgical instrument of claim 3, wherein: The proximal anchor is arranged to rotate in unison with the shaft; and The distal anchor is arranged to rotate in unison with the shaft.

11. The surgical instrument of claim 1 , wherein: the cable is a first cable, the hole of the proximal anchor is a first hole of the proximal anchor, and the hole of the distal anchor is a first hole of the distal anchor, The surgical instrument further includes a second cable; The proximal anchor includes a guide surface; The distal anchor includes a guide surface; the guide surface of the proximal anchor defines the first and second holes of the proximal anchor, and the first and second holes of the proximal anchor are arranged in a pattern; the guide surface of the distal anchor defines the first hole of the distal anchor and the second hole of the distal anchor, and the first hole and the second hole of the distal anchor are arranged in the pattern; and The second cable extends through the second hole of the proximal anchor and the second hole of the distal anchor so as to be constrained to extend outside of the outer surface of the beam and parallel to the central axis of the beam.

12. The surgical instrument of claim 11, wherein: The first cable and the second cable are each pre-tensioned.

13. The surgical instrument of claim 11, further comprising: a shaft comprising a proximal end portion and a distal end portion; a first drive member disposed at the proximal end portion of the shaft and coupled to a proximal end portion of the first cable; a second drive member disposed at the proximal end portion of the shaft and coupled to a proximal end portion of the second cable; and An end effector is disposed at the distal end portion of the shaft and coupled to the distal end portions of the first cable and the second cable.

14. The surgical instrument of claim 11, wherein: The surgical instrument further includes a proximal guide slot insert coupled to the proximal anchor; The proximal guide slot insert includes a first guide slot and a second guide slot; The first guide slot is aligned with the first hole of the proximal anchor, and the second guide slot is aligned with the second hole of the proximal anchor; and The cable extends through the first guide slot, and the second cable extends through the second guide slot.

15. A surgical instrument comprising: a force sensor comprising a beam and one or more strain gauges on an outer surface of the beam, the beam comprising a proximal end and a distal end, and a central axis of the beam being defined between the proximal end and the distal end of the beam; a proximal anchor coupled to the proximal end of the beam, the proximal anchor comprising a first plurality of guide holes; a distal anchor coupled to the distal end of the beam, the distal anchor including a second plurality of guide holes aligned with the first plurality of guide holes; and Multiple cables, Each cable of the plurality of cables extends through a corresponding unique guide hole of the first plurality of guide holes and a corresponding unique guide hole of the second plurality of guide holes, and Each of the plurality of cables is constrained by the corresponding unique guide hole in the first plurality of guide holes and the corresponding unique guide hole in the second plurality of guide holes to extend outside the outer surface of the beam and spaced apart from the outer surface of the beam and remain parallel to the central axis of the beam.

16. The surgical instrument of claim 15, wherein: The surgical instrument further includes a shaft, a plurality of drive members, and an end effector; The shaft includes a proximal end portion and a distal end portion; the plurality of drive members being proximal to the proximal end portion of the shaft; The end effector is distal to the distal anchor; each of the plurality of cables being coupled to a respective unique drive member of the plurality of drive members; and Each cable of the plurality of cables is coupled to the end effector.

17. The surgical instrument of claim 15, wherein: The surgical instrument further includes a shaft; The shaft includes a proximal end portion and a distal end portion, wherein a longitudinal shaft central axis extends between the proximal end portion and the distal end portion; the force sensor being at least partially located within the distal end portion of the shaft; and The central axis of the force sensor is coaxial with the shaft central axis.

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