MEDICAL INSTRUMENT WRIST WITH GRIP POSITION MEASUREMENT

Abstract

A medical device comprises a distal articulating member and a first jaw and a second jaw, each connected to the distal articulating member. A shaped fiber carrier is pivotally connected to the distal articulating member and defines a shaped fiber lumen. The medical device includes a shaped fiber with a distal end fixedly connected to the shaped fiber lumen. The shaped fiber carrier is indirectly connected to the first jaw and the second jaw, and movement of the shaped fiber carrier causes the shaped fiber to generate a signal related to the movement of the first and / or second jaw.

Description

Cross-Reference to Related ApplicationsThis application claims priority to U.S. Provisional Application No. 63 / 618,704, entitled "MEDICAL INSTRUMENT CRYSTALS WITH MEASUREMENT OF GRIP POSITION," filed January 8, 2024, which is incorporated herein by reference in its entirety.BackgroundThe embodiments described herein relate to medical devices and, more particularly, to instruments for minimally invasive surgery. More particularly, the embodiments described herein relate to medical devices that include wrist mechanisms and systems for measuring the grasp position of the medical device.Minimally invasive surgery (MIC) techniques employ tissue manipulation instruments that can be controlled either manually or via computer assisted teleoperation. Some MIC instruments include a therapeutic or diagnostic end effector (e.g., forceps, a cutting tool, or a cauterization tool) attached to a wrist mechanism at the distal end of an instrument shaft. During a MIC procedure, the end effector, wrist mechanism, and distal end of the shaft are inserted into a small incision or natural opening of the patient to position the end effector at a worksite in the patient's body. By means of the wrist mechanism, the orientation of the end effector with respect to the shaft can be varied in order to carry out the desired intervention at the work site. Wrist mechanisms typically provide certain Degree Of Freedom (DOF) for the movement of the end effector. For example, wrist mechanisms can alter the pitch and yaw orientation of the end effector with respect to the longitudinal axis of the shaft. A wrist may optionally provide a roll DOF for the end effector relative to the shaft, or a roll DOF for the end effector may be realized by rolling the shaft, the wrist and the end effector as a unit. An end effector may optionally have additional mechanical DOFs, such as a gripping or knife blade movement. In some cases, the mechanical wrist and end effector DOFs may be combined to provide different DOFs to control the end effector. For example, U.S. Pat. No. 5,792,135 (filed May 16, 1997) discloses a mechanism in which the mechanical DOFs of the wrist and end effector are combined to provide a DOF for yaw control of the end effector.To enable the desired movement of the distal wrist mechanism and end effector, the instruments may include cables that pass through the shaft of the instrument and connect the wrist mechanism to a mechanical structure configured to move the cables to operate the wrist mechanism and end effector. In teleoperated systems, the mechanical structure is typically motorized and connected to a computer processing system to provide a clinical user (e.g., a surgeon) with a user interface by which to control the instrument as a whole, as well as the components and functions of the instrument.In addition, the wrist mechanism generally provides certain degrees of freedom for the movement of the end effector. For example, in forceps or other grasping tools, the wrist can alter the pitch, yaw, and grasp orientation of the end effector with respect to the instrument shaft. Additional degrees of freedom could be realized via the wrist, but would require additional actuators (e.g., cables) in the wrist and the shaft. These additional elements compete for the limited space available for MIC applications given size constraints. The components required for operating other degrees of freedom, such as rolling the end effector or inserting and extracting by movement of the main tube, also compete for space on and / or in the shaft of the device.A conventional architecture for a wrist mechanism in a manipulator controlled medical device uses cables that are drawn in and out from a capstan in the proximal mechanical structure, thereby rotating the portion of the wrist mechanism that is connected to the capstan via the cables. For example, a wrist mechanism may be connected to three capstans - one for rotation about a pitch axis, a yaw axis, and a gripping axis. Each capstan can be controlled by two cables attached to the capstan such that one side dispenses the cable while the other side draws an equal length of cable. This architecture may require a total of six cables for three degrees of freedom, pulling from the wrist mechanism proximally along the length of the main shaft tube of the instrument to the proximal mechanical structure of the instrument. The efficient implementation of a wrist mechanism and proximal mechanical structure may be complicated because the cables must be carefully routed through the tool element, wrist mechanism, and proximal mechanical structure to maintain the stability of the wrist over the entire range of motion of the wrist mechanism and minimize the interactions (or coupling effects) of one axis of rotation to another. Moreover, for MIC applications, it is desirable to have a compact outer diameter of the instrument to minimize the size of the port required for insertion of the instrument into the patient. However, in more complex mechanisms, it may be a challenge to achieve the desired instrument diameter (e.g., 12 mm, 8 mm, 5 mm, or less) while providing the required mechanical degrees of freedom.Some wrist mechanisms are equipped with gripping tools or jaws and are part of a closed feedback system. In such an apparatus, the jaws can be used to grasp a patient's tissue. It may be desirable to know the speed and angular position of the jaws during use of the apparatus. However, it is difficult to incorporate sensors into the jaws to obtain accurate velocity and angular position data for each of the jaws in a wrist mechanism medical device and with a limited device diameter (e.g., a diameter of about 5 mm or less). For example, to obtain feedback on the speed and angular position / orientation of each individual movable jaw, each jaw must be directly connected to a sensor. The incorporation of multiple sensors into the jaws may require a larger instrument size to accommodate the routing of the sensors, which may be undesirable for a given port size and also results in higher cost and complexity. If only one distally located sensor is available due to size constraints and / or configuration of the jaws of the medical device, it may be difficult to provide the required sensor feedback to measure the position, velocity, and / or orientation of both jaws during use of the device.Therefore, there is a need for wrist mechanisms with improved sensor functions that can measure the position, velocity, and / or orientation of the jaws of the wrist mechanism while meeting the design requirements of the medical device.SummaryThis summary presents certain aspects of the embodiments described herein to provide a basic understanding. This summary is not a comprehensive overview of the subject matter, and is not intended to identify key or critical elements or to delineate the scope of the subject matter.In some embodiments, a medical device includes a distal joint member and a first jaw and a second jaw, each connected to the distal joint member. A forming fiber carrier is pivotally connected to the distal link and defines a forming fiber lumen. The medical device includes a forming fiber having a distal end fixedly connected to the forming fiber lumen. The forming fiber carrier is indirectly connected to the first jaw and the second jaw, and movement of the forming fiber carrier causes the forming fiber to generate a signal related to movement of the first and / or the second jaw.In some embodiments, the medical device includes an intermediate coupling mechanism coupled to the molded fiber carrier, and the molded fiber carrier is indirectly coupled to the first jaw and the second jaw via the intermediate coupling mechanism. In some embodiments, the intermediate coupling mechanism is a differential coupled between the first jaw and / or the second jaw and the forming fiber carrier, and the forming fiber carrier is indirectly coupled to the first jaw and the second jaw via the differential. In some embodiments, the intermediate coupling mechanism includes a cam mechanism to indirectly couple the molded fiber carrier to the first and / or second jaws. In some embodiments, the intermediate coupling mechanism includes a torsion spring to indirectly couple the molded fiber carrier to the first and / or second jaws.In some embodiments, the signal generated by the forming fiber comprises a signal associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw. In some embodiments, the forming fiber carrier is pivotally connected to the distal joint member about a first axis and the first jaw and the second jaw are each pivotally connected to the distal joint member about a second axis, the second axis being offset from the first axis. In some embodiments, the distal end of the forming fiber is located between the first axis and the second axis. In some embodiments, the molded fiber carrier is indirectly coupled to the first jaw and the second jaw such that an angular position of the molded fiber carrier relative to the second axis is associated with an average yaw angle of the first jaw and the second jaw.In some embodiments, the differential includes a housing, a first planetary gear, a second planetary gear, and a ring gear. The medical device also includes a transmission, a first sun gear, and a second sun gear. The first sun gear is fixedly connected to the first jaw and coupled to the housing. The second sun gear is fixedly connected to the second jaw and coupled to the housing. The ring gear is fixedly connected to the housing and coupled to the transmission, and the transmission is coupled to the molded fiber carrier. The housing is configured to rotate as the first and / or second jaws rotate relative to the other jaw, such that the direction of the average of the positions of the jaws changes (e.g., relative to the distal joint member) and the rotation of the housing causes rotation of the forming fiber carrier and the forming fiber. An orientation of the housing is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.In some embodiments, the rotational movement of the forming fiber carrier is limited by the differential. In some embodiments, the rotational movement of the forming fiber carrier is limited to + / - 45 degrees relative to a centerline of the forming fiber carrier. In some embodiments, the molded fiber carrier includes a transmission coupled to the differential.In some embodiments, the movement of the forming fiber carrier causes the forming fiber to generate a signal related to the movement of the distal joint member. In some embodiments, movement of the forming fiber carrier causes the forming fiber to generate a signal related to movement of a proximal joint.In some embodiments, a medical device includes a distal joint member and first and second jaws each connected to the distal joint member. A position sensor is connected to the distal joint member and a differential is coupled to the position sensor, the first jaw, and the second jaw. Movement of the first and / or second jaws relative to each other generates sensor movement of the position sensor via the differential, and the position sensor generates a signal associated with the sensor movement.In some embodiments, the signal generated by the position sensor is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw. In some embodiments, the position sensor is a molded fiber and the medical device includes a molded fiber carrier coupled to the differential. The forming fiber is at least partially placed in a lumen of the forming fiber carrier.In some embodiments, the differential includes a housing, a first planetary gear, a second planetary gear, and a ring gear. The medical device also includes a transmission, a first sun gear, and a second sun gear. The first sun gear is fixedly connected to the first jaw and coupled to the housing, the second sun gear is fixedly connected to the second jaw and coupled to the housing. The ring gear is fixedly connected to the housing and coupled to the transmission, and the transmission is coupled to the molded fiber carrier. The housing is configured to rotate as the first and / or second jaws rotate relative to the other jaw, such that a direction of the average of the positions of the jaws changes (e.g., relative to the distal joint member) and the rotation of the housing causes rotation of the position sensor. An orientation of the housing is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.In some embodiments, the position sensor generates a signal associated with the average of the first yaw angle of the first jaw and the second yaw angle of the second jaw depending on the orientation of the housing. In some embodiments, rotational movement of the position sensor is limited by the differential. In some embodiments, the rotational movement of the forming fiber carrier is limited to + / -45 degrees relative to a centerline of the forming fiber carrier. In some embodiments, the position sensor is indirectly coupled to the first jaw and the second jaw such that an angular position of the position sensor is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.In some embodiments, a medical device includes a distal joint member and a first jaw and a second jaw, each connected to the distal joint member. A forming fiber carrier is connected to the distal joint member and defines a forming fiber lumen. A forming fiber extends from a position proximal to the distal joint member to a distal end fixedly connected to the forming fiber lumen. The forming fiber is spaced from both the first and second jaws. The movement of the forming fiber carrier causes the forming fiber to generate a signal related to the movement of the first and / or second jaws.Other medical instruments, associated components, medical device systems, and / or methods according to the embodiments will be apparent to one skilled in the art upon review of the following drawings and detailed description. It is intended that all of these additional medical devices, associated components, medical device systems, and / or methods included in this specification fall within the scope of this disclosure.Brief Description of the DrawingsFIG. 1 is a plan view of a minimally invasive teleoperated medical system used to perform a medical procedure such as surgery, according to an embodiment. FIG. 2 is a perspective view of a user console of the minimally invasive teleoperated surgical system shown in FIG. 1. FIG. 3 is a perspective view of an optional accessory of the minimally invasive teleoperated surgical system shown in FIG. 1. FIG. 4 is a perspective view of a manipulator unit, including a plurality of instruments, of the minimally invasive teleoperated surgical system shown in FIG. 1. FIG. 5 is a schematic plan view of a distal end portion of a medical device according to an embodiment. FIG. 6 is a schematic plan view of the distal end portion of a medical device according to another embodiment. FIG. 7 is a side view of a medical device according to an embodiment in which the wrist is in a straight configuration. FIG. 8 is a plan view of a distal end portion of the medical device of FIG. 7 in which the wrist is in a straight configuration. FIG. 9 is a perspective view of the distal end portion of the medical device of FIG. 7 in which the wrist is in an inclined configuration (i.e., a distal joint member is twisted relative to a proximal joint member of the medical device). FIG. 10 is a perspective view of the distal end portion of the medical device of FIG. 7 with a distal member twisted relative to a proximal member and selected components removed for illustrative purposes. FIG. 11 is a perspective view of a connector of the medical device of FIG. 7. FIG. 12 is a top perspective cross-sectional view of the distal end portion of the medical device of FIG. 7, with the distal member and proximal member in a straight configuration, with the jaws in a closed configuration, with selected components removed for illustration purposes. FIG. 13 is a partial cross-sectional perspective view of the distal end portion of the medical device of FIG. 7, with the distal member rotated relative to the proximal member, the jaws closed, and selected components removed for illustrative purposes. FIG. 14 is a partial perspective view of the distal end portion of the medical device of FIG. 7, wherein the distal and proximal jaws are in a straight configuration, the jaws are in an open position, and selected components have been removed for illustrative purposes. FIG. 15 is a partial perspective view of the distal end portion of the medical device of FIG. 7 showing another side of the medical device with the distal member and proximal member in a straight configuration and selected components removed for illustrative purposes. FIG. 16 is a partial cross-sectional view of the distal end of the medical device of FIG. 15 showing another side of the medical device with the distal member and proximal member in a straight configuration and selected components removed for illustrative purposes. FIG. 17 is a perspective view of the medical device of FIG. 7 with the distal member rotated relative to the proximal member and selected components removed for illustrative purposes. FIG. 18 is a perspective view of the medical device of FIG. 7 with the distal member rotated relative to the proximal member and selected components removed for illustrative purposes and showing a different side of the medical device than in FIG. 17. FIG. 19 is a partially exploded perspective view of the medical device of FIG. 18. FIG. 20 is a partially exploded perspective view of the medical device of FIG. 18 showing a different side of the medical device than in FIG. 19. FIG. 21 is an exploded, more detailed drawing of the medical device of FIG. 18 showing the planet gears of the differential. FIGS. 22A-22C are each another perspective view of the differential of the medical device of FIG. 7. FIG. 23 is a side view of a distal end part of a medical device according to another embodiment. FIG. 24 is a perspective view of the distal end portion of the medical device of FIG. 23, with one of the tool members and cables removed for illustrative purposes. FIG. 25 is a side view of a portion of the distal end portion of the medical device of FIG. 23, with selected components removed for illustrative purposes. FIG. 26 is an exploded perspective view of a portion of the distal end portion of the medical device of FIG. 23. FIG. 27 is an exploded perspective view of a portion of the distal end portion of the medical device of FIG. 23, illustrating a side opposite to that shown in FIG. 26. FIGS. 28A-28C each show the distal end portion of the medical device of FIG. 23, with the tool members oriented in various positions relative to each other and / or the distal member. FIGS. 29A-29E are each a side view of the distal end portion of the medical device of FIG. 23, with a portion of one of the tool members removed for illustrative purposes, and the tool members each shown in a different position relative to one another and / or to the distal member. FIG. 30 is a perspective view of a distal end part of a medical device according to another embodiment. FIG. 31 is a perspective view of the distal end portion of the medical device of FIG. 30, with one of the tool members and cables removed for illustrative purposes. FIG. 32 is a side view of a portion of the distal end portion of the medical device of FIG. 30, with selected components removed for illustrative purposes. FIG. 33 is a side view of the distal end portion of the medical device of FIG. 32, with one of the torsion springs removed for illustrative purposes and a portion of a molded fiber sensor seen. FIG. 34 is an exploded perspective view of a portion of the distal end portion of the medical device of FIG. 30. FIG. 35 is another exploded perspective view of a portion of the distal end portion of the medical device of FIG. 30. FIG. 36A is a perspective view of the molded fiber carrier and the intermediate coupling mechanism of the medical device of FIG. 30. FIG. 36B is an exploded perspective view of the molded fiber carrier and the intermediate coupling mechanism of FIG. 36A. FIG. 37 is a side view of the distal end portion of the medical device of FIG. 30, with a portion of one of the tool elements removed for illustrative purposes and showing a molded fiber vector. Fig. 38 is a schematic diagram conceptually showing how a molded fiber carrier is balanced by an intermediate coupling mechanism having opposing springs. FIG. 39 is a flow chart showing a method of assembling a medical device with a molded fiber sensor. FIG. 40 is a schematic illustration of a controller for use with a minimally invasive teleoperated surgical system, according to an embodiment. FIG. 41 is a flow diagram illustrating a method for generating an adjusted output signal from a molded fiber sensor according to an embodiment. FIG. 42 is a flow diagram illustrating a method for calibrating a molded fiber sensor of a medical instrument according to an embodiment.Detailed DescriptionThe embodiments described herein can be advantageously used in a variety of grasping, cutting and manipulation procedures in connection with minimally invasive surgery. In some embodiments, an end effector of a medical device (e.g., an instrument) may move relative to a power transmission mechanism of the instrument in multiple mechanical DOFs. The medical devices described herein may include, for example, one or more mechanical DOFs in the end effector itself, e.g., two jaws each rotating relative to a clevis (2 DOFs including a "grip" DOF when the jaws rotate in opposite directions to each other upon closure) and a distal clevis rotating relative to a proximal clevis (a DOF).In some embodiments, the medical devices of the present application allow distal end movement in three degrees of freedom (e.g., about a pitch, yaw, and gripping axis) using only four tension members (e.g., cables, straps, or the like), thereby reducing the total number of tension members required for articulation, reducing the space required in the shaft and wrist mechanism for laying the tension members, reducing the overall cost, and allowing further miniaturization of the wrist mechanism and shaft assemblies to promote MIC procedures. As described herein, in some embodiments, a medical device includes a wrist assembly that includes a proximal joint member coupled to a distal joint member that is connected to an end effector. The distal member may rotate relative to the proximal member along an arcuate contact surface of the distal and proximal members.The medical devices described herein may include an end effector in the form of grasping tools or jaws at a distal end of the medical device that may be used to grasp tissue of a patient, grasp a needle (e.g., suture), or perform other operations. The end effector may be connected to a wrist and the wrist may be connected to an instrument shaft, which may be rigid or flexible with respect to its material. In various embodiments, the medical device may have a maximum diameter of about 5 mm, in other embodiments a maximum diameter between 4-6 mm, and in yet other embodiments a maximum diameter of about 8-12 mm.The end effector and wrist mechanism may be part of a closed loop feedback system for the medical device. Sensors embedded in the medical device may be integrated into a closed loop to reduce hysteresis of the medical device and improve positional accuracy for articulation of the medical device. In various embodiments, the medical device may include one or more position or orientation sensors, such as one or more shape fibers or shape fiber bundles (e.g., one or more optical fibers or fiber bundles with fiber Bragg gratings) to provide information about the position, orientation and / or velocity of joints and / or links of the medical device (e.g., the end effector, joints of the wrist mechanism, links of the wrist mechanism, and / or joints and links of the shaft of the medical device). Such sensors may also provide information about the position and / or orientation of the medical device relative to the anatomy of the patient (e.g., position and / or orientation of the medical device relative to organs, cavities and / or lumens through which the medical device may be passed) as well as information about the position and / or orientation of the anatomy of the patient itself (e.g., position or orientation of organs, flexible lumens, movable soft tissue, etc.).For position and / or orientation feedback of a minimally invasive medical device having a two jaw end effector, it is desirable to have sensor information indicative of the position and / or orientation of both jaws. However, the integration of shaped fibers into both jaws of a medical device having one or more wrist mechanisms and a limited device diameter (e.g., a diameter of about 5 mm or less) presents a challenge. In some embodiments, the minimum bending radius of a forming fiber in the medical device may be constrained to prevent breakage of the forming fiber during articulation of the device. In some embodiments, the minimum bend radius may be in the range of 4-5 mm, for example. This can lead to problems in guiding a molded fiber through the jaws and wrist mechanism of a reduced diameter minimally invasive medical device that can move in the degrees of freedom pitch and / or yaw. Moreover, the molding fiber may be provided with a straight portion at the distal end of the molding fiber to correctly transmit and reflect optical signals to thereby determine position and orientation. In some embodiments, the straight portion may be at least 3 mm long, for example. This can lead to problems in minimizing the length of the end effector and the minimum throwing arm required for articulation of the end effector.The embodiments described herein overcome the challenges of providing position, velocity, and / or orientation sensor feedback for minimally invasive medical devices with pitch and yaw articulation. Due to size constraints, constraints on the placement and / or configuration of the jaws and wrist of the medical device, the devices described herein may include a sensor / sensor bundle positioned at the distal end of the medical device, the sensor spaced from the jaws of the medical device. For example, the sensor / sensor bundle may determine information about the position, velocity, and / or orientation of the jaws via an indirect coupling with the jaws via one or more intervening elements (e.g., without the sensor / sensor bundle being directly embedded in the jaws). In some embodiments, only a single sensor / sensor bundle is attached to the distal end of the medical device. The position sensor and mechanisms described herein may be used to detect the average position and speed of the two jaws during use of the medical device without being directly connected to the jaws. In some embodiments, a gear differential is used to determine the average angular velocity and position of the jaws. Alternatively, a cam mechanism may be coupled to the jaws and used to determine the average angular velocity and position of the jaws.More specifically, in some embodiments, a molded fiber carrier is pivotally connected in a distal link and is coupled to a gear differential located between the two jaws of the medical device. Each jaw is fixedly connected to a respective sun gear which is coupled to a respective one of two planetary gears of the differential. The planet gears are located in a differential housing and are likewise interlocked with one another. On the outside of the transmission housing there is an integrated ring gear which is connected via a transmission to the distal molded fiber carrier. The molded fiber carrier has a molded fiber lumen in which the molded fiber extends to a distal end of the lumen. The molded fiber carrier and the molded fiber are therefore not directly connected to one of the two jaws, but are coupled to the jaws via the differential.As the average position of the jaws changes, the differential housing is rotated accordingly, which in turn moves the forming fiber carrier and the forming fiber therein. In addition to this information about the position of the jaws, the forming fiber can also provide the orientation of the distal joint member (e.g., relative to the proximal joint member) as well as the position and velocity of the proximal joint member, joints of any and all of the flexible instrument parts through which the forming fiber can pass (e.g., a flexible instrument shaft). In this way, the embodiments described herein enable a single molded fiber sensor or sensor bundle to provide information about various aspects of the distal end of the medical device, including the position of the jaw. The embodiments described here enable an efficient, compact design of the end effector. In some embodiments, the tension members that actuate the jaws are guided along an outer portion of the jaws, and the differentials described may be packaged in the jaw bodies for a compact shape. In some alternative embodiments, the transmission connecting the differential to the distal form fiber carrier could be replaced with cables. In further alternative embodiments, instead of a differential, a cam mechanism may be integrated with or coupled to the jaws and used to determine the average angular velocity and position of the jaws.The jaw position measurement is determined by the position sensor (e.g., the forming fiber) bending relative to the mean or difference between the two jaws. In the case of a forming fiber, the use of a differential limits the motion of the forming fiber to allow the limitation of the bending radius of the forming fiber and a straight portion at the distal tip of the forming fiber. This also allows the use of a single forming fiber or bundle of forming fibers to determine the position of two jaws. Alternatively, the differential may be used with other types of position sensors.As used herein, the term "distal" refers to the direction toward a worksite and the term "proximal" refers to a direction away from the worksite. For example, the end of a medical device closest to the target tissue would be the distal end of the medical device and the end opposite the distal end would be the proximal end of the medical device.Moreover, certain words chosen to describe one or more embodiments and optional elements or features are not intended to limit the disclosure. For example, spatially relative terms such as "below," "below," "below," "above," "above," "proximal," "distal," and the like, may be used to describe the relationship of one element or feature to another element or feature, as depicted in the figures. These spatially relative terms are intended to encompass different positions (i.e., translation arrangements) and orientations (i.e., rotational arrangements) of a device in use or operation in addition to the position and orientation depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "below" other elements or features would then be "above" or "above" the other elements or features. The term "below" can thus encompass positions and alignments from above and below. A device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the descriptions of movements along (translation) and about (rotation) different axes include different spatial positions and orientations. The combination of position and orientation of a body defines the posture.Likewise, geometric terms such as "parallel," "perpendicular," "round," or "square" are not intended to require absolute mathematical precision unless the context dictates otherwise. Rather, such geometric terms allow for deviations due to manufacturing or corresponding functions. For example, when an element is described as being "round" or "generally round", a component that is not exactly circular (e.g., one that is slightly elongated or a versatile polygon) is still encompassed by this description.Moreover, the singular forms "a" and "the" also include the plural forms unless the context clearly indicates otherwise. The terms "comprises," "includes," "has," and the like, specify the presence of particular features, steps, operations, elements, components, etc., but do not preclude the presence and / or addition of one or more other features, steps, operations, elements, components, or groups.Unless otherwise indicated, the terms apparatus, medical device, medical instrument, and variants thereof may be used interchangeably.Aspects of this disclosure will be described with reference to a teleoperated surgical system. An example of the architecture of such a teleoperated surgical system is the surgical system da Vinci® which is marketed by Intuitive Surgical, Inc. of Sunnyvale, California. Examples of such surgical systems are the surgical system da Vinci Xi® (model IS4000), the surgical system da Vinci X® (model IS4200) and the surgical system da Vinci Si® (model IS3000). However, those skilled in the art will understand that the inventive aspects disclosed herein may be embodied and implemented in various ways, including computer-assisted, non-computer-assisted, and hybrid combinations of manual and computer-assisted embodiments and implementations. Implementations on the surgical systems of da Vinci® (e.g., model IS 4000, model IS 3000, model IS 2000, model IS 1200, model SP 1099) are presented merely as examples and are not to be considered as limiting the scope of the inventive aspects disclosed herein. The inventive aspects may be embodied and implemented in relatively smaller hand-held hand-held hand-operated devices that are not mechanically anchored in a global frame of reference as well as relatively large systems with additional mechanical support anchored in a global frame of reference.FIG. 1 is a top view of a teleoperative surgical system 1000 operating at least partially with computer assistance (a "teleoperative system"). Both the telesurgical system 1000 and its components are considered medical devices. The telesurgical system 1000 is a minimally invasive robotic surgical system (MIRS) used to perform a minimally invasive diagnostic or surgical procedure on a patient P lying on an operating table 1010. The system may have any number of components, such as a user control unit 1100, which is used by a surgeon or other skilled clinician S during the procedure. The MIRS system 1000 may further include a manipulator unit 1200 (colloquially "surgical robot") and an optional accessory unit 1150. The manipulator unit 1200 may include one or more arm assemblies 1300 connected to removable surgical instruments 1400. The manipulator unit 1200 may move at least one removably coupled instrument 1400 through a minimally invasive incision in the body or in the natural body opening of the patient P while the surgeon S views the surgical site and controls the movement of the instrument / instruments 1400 via the control unit 1100. An image of the operation area is captured by an endoscope (not shown), e.g., a monoscopic or stereoscopic endoscope, that can be controlled by the manipulator unit 1200 to orient the endoscope. The accessory unit 1150 may be used to process the images of the surgical site for subsequent display to the surgeon S via the user control unit 1100. The number of instruments 1400 used simultaneously generally depends, among other things, on the diagnostic or surgical method and the spatial conditions in the operating room. When it is necessary to change one or more of the instruments 1400 used during an intervention, an assistant removes the instrument 1400 from the manipulator unit 1200 and replaces it with another instrument 1400, for example, from a tablet 1020 in the operating room. Although the use of instruments 1400 is shown herein, any of the instruments described herein may be used with MIRS 1000.FIG. 2 is a perspective view of the control unit 1100. The user control unit 1100 includes a left eye display 1112 and a right eye display 1114 to present a coordinated stereoscopic view of the surgical area to the surgeon S that enables depth perception. The information presented to surgeon S may be presented in the form of a graphical user interface through which input may be provided to a controller 1820 (FIG. 40 ). The user control unit 1100 also includes one or more input devices 1116 that, in turn, cause the manipulator unit 1200 (shown in FIG. 1) to manipulate one or more tools. The input devices 1116 provide at least the same degrees of freedom as the instruments 1400 to which they are connected to enable the surgeon S to telepresence or to give the impression that the input devices 1116 are integrated with (or directly connected to) the instruments 1400. In this manner, the user control unit 1100 provides the surgeon S with the feel of directly controlling the instruments 1400. To this end, position, force, stress, or tactile feedback sensors (not shown), or any combination of such feedback, may be returned from the instruments 1400 to the surgeon's hand or hands via the one or more input devices 1116.The user control unit 1100 is shown in Figure 1 to be in the same room as the patient so that the surgeon S can monitor the procedure directly, be physically present if desired, and talk directly to an assistant, rather than via the telephone or other communication means. However, in other embodiments, the user control unit 1100 and surgeon S may be located in a different room than the patient, in a completely different building than the patient, or in a different location remote from the patient, which allows remote surgical procedures.FIG. 3 is a perspective view of the auxiliary device unit 1150. The accessory device unit 1150 may be coupled to the endoscope (not shown) and may include one or more processors to process the captured images for subsequent display, e.g., via the user control unit 1100 or on another suitable display located locally (e.g., on the device 1150 itself, as shown, on a wall-mounted display) and / or remotely. For example, when a stereoscopic endoscope is used, the accessory unit 1150 may process the captured images to present coordinated stereo images of the surgical site to the surgeon S via the left eye display 1112 and the right eye display 1114. Such coordination may include alignment between the opposing images and adjustment of the stereo working distance of the stereoscopic endoscope. As another example, image processing may include using previously determined camera calibration parameters to compensate for imaging errors of the imaging device, such as optical aberrations.FIG. 4 shows a perspective view of the manipulator unit 1200. The manipulator unit 1200 includes the components (e.g., arms, docking points, motors, sensors, and the like) that provide for manipulation of the instruments 1400 and an imaging device (not shown), such as a stereoscopic endoscope used to capture images of the surgical site. In particular, instruments 1400 and imaging device may be manipulated by teleoperated mechanisms with one or more mechanical wrists. Moreover, instruments 1400 and imaging device are positioned and manipulated through incisions or natural apertures in patient P such that a center of movement that is remote from the manipulator and typically is at a point along the instrument shaft is held at the incision or natural aperture, either by kinematic-mechanical and / or software constraints. In this way, the size of the incision can be minimized. In various embodiments, the manipulator unit 1200 may be configured as a patient-side cart with one or more arm assemblies 1300 that are supported and driven by a single cart and / or individual manipulators and / or that are supported and driven by separate carriages. In other embodiments, the manipulator unit 1200 may be configured as a table-mounted manipulator system in which one or more arm assemblies 1300 are attached to the operating table 1010 on which the patient P is lying. In other embodiments, one or more arm assemblies 1300 may be secured to the ceiling or other objects in the environment. Note that any of the mounting configurations of the arm assemblies may be used in combination with each other.FIG. 5 is a schematic illustration of a portion of a medical device 2400, according to an embodiment. In some embodiments, the medical device 2400 or any of the components included therein is optionally part of an instrument of a surgical system performing surgical procedures, and this surgical system may comprise a manipulator unit, a series of kinematic connections, a series of cannulas, or the like. The medical device 2400 (and any of the instruments described herein) may be used in any suitable surgical system, such as the MIRS system 1000 shown and described above. Medical device 2400 comprises a shaft (not shown), a proximal joint member (not shown) connected to the shaft, a distal joint member 2610 connected to the proximal joint member, a first tool member 2462, a second tool member 2482, a molded fiber carrier 2466 defining an inner lumen 2468, and a molded fiber 2588 extending distally within molded fiber lumen 2468. The form fiber 2588 may be a single optical fiber or a bundle of multiple optical fibers, collectively referred to as a "form fiber.". The molded fiber 2588 (and any of the molded fibers described herein) may be any of the types shown and described in U.S. Pat. No. 8,358,883 B2 (filed Feb. 6, 2012), entitled "Fiber Optic Shape Sensor," which is incorporated herein by reference in its entirety.Although not shown in FIG. 5, the medical device 2400 may also include one or more tension members (not shown) (e.g., a cable, a strap, or the like) connected to the tool members 2462, 2482. The medical device 2400 is configured such that movement of the tension members causes movement of the distal joint member 2610, movement of the tool members 2462 and / or 2482, or both movement of the distal joint member 2610 and movement of the tool members 2462 and / or 2482.The tool members 2462, 2482 may rotate about a tool member rotation axis (not shown in FIG. 5 ). The tool elements 2462, 2482 may be, for example, a pair of jaws, a cautery device, a cutter, or other medical tool. The tension member(s) is(are) coupled to the tool members 2462, 2482, extend (extend) from the tool members 2462, 2482, and is / are guided by the shaft and extend / extend proximally to a power transmission mechanism (not shown in FIG. 5 ) of the medical device where they are coupled to drive components (not shown in FIG. 5 ) within the mechanical structure. The tension members may be actuated by the drive components (not shown) such that tension on the tension members of one or both of the tool members 2462, 2482 moves to rotate about the axis of rotation of the tool members as described in U.S. Provisional Patent Application Serial No. 63 / 233,904, entitled "Surgical Instrument Cable Control and Routing Structures," which is incorporated herein by reference in its entirety.In some embodiments, for example, the pitch angle of the tool members 2462, 2482 of the medical device 2400 may be varied by moving the proximal ends of the tension members to effect rotation of the distal joint member 2610. In particular, a power transfer mechanism (not shown, but may be similar to power transfer mechanism 4700 described below) may retract the proximal end of one of the tension members while releasing the same length of the proximal end of another of the tension members to effect rotation of distal link 2610. In other embodiments, the medical device 2400 may include additional tension members to alter the yaw angle and / or grip of the tool members 2462, 2482 relative to the distal joint member 2610. For example, the yaw angle, grip, or both the yaw angle and grip can be varied by moving the proximal ends of the various tension members. Thus, the medical device 2400 may include any number of tension members to produce the desired movement of the joint member 2610 and the tool members 2462, 2482. In some embodiments, the medical device 2400 may include, for example, two tension members to effect the desired pitch. In other embodiments, the medical device 2400 may include four tension members and function in a similar manner as described in U.S. Patent Publication No. 2020 / 0390430 (filed Aug. 21, 2020), entitled "Low-Friction, Small Profile Medical Tools Having Easy-to-Assembly Components," which is incorporated herein by reference in its entirety. In other embodiments, the medical device 2400 may include six tension members and function in a similar manner as shown and described in U.S. Patent Publication No. 2020 / 0390430, incorporated herein by reference.The tool elements 2462, 2482 may together perform gripping, shearing or cutting functions. Thus, the axis of rotation of the tool elements can also function as a cutting axis if the tool elements rotate in opposite directions. Thus, in some embodiments, the medical device 2400 may provide at least three degrees of freedom (i.e., yaw about the axis of rotation of the tool elements, pitch about the axis of rotation of the distal member or about the axis of rotation of the proximal member, and a cutting or gripping motion about the axis of rotation of the tool elements).The molded fiber carrier 2466 is coupled to the tool members 2462 and 2482 via an intermediate coupling mechanism, such as a differential, cam mechanism, torsion spring mechanism, or other suitable intermediate structure (not shown). A distal end of the forming fiber 2588 is fixedly connected to the forming fiber carrier 2466 within the forming fiber lumen 2468 at a distal end of the forming fiber lumen 2468. Thus, the molded fiber carrier 2466 and the molded fiber 2588 are indirectly connected to the first and second tool members 2462, 2482. In other words, the molded fiber carrier 2466 and the molded fiber 2588 are spaced apart from the first tool member 2462 and the second tool member 2482, respectively. In operation, the intermediate coupling mechanism is coupled to the tool members 2462, 2482, and the intermediate coupling mechanism rotates as a result of rotation of one or both tool members 2462, 2482. The molded fiber carrier 2466 is coupled to the intermediate coupling mechanism. Rotation of the intermediate coupling mechanism causes the forming fiber carrier 2466 and the forming fiber 2588 connected thereto to also flex proportionally. The bending of the forming fiber 2588 generates a sensor signal indicative of the degree of bending.In some embodiments, the forming fiber 2588 has a straight portion at the distal end of the forming fiber 2588 that can facilitate accurate measurement of bends in the other parts of the forming fiber and also minimize reflection of light (e.g., laser light). The straight portion may have a predetermined length (e.g., at least 3 mm, between 3 mm and 6 mm), and the lumen 2468 of the forming fiber is sized to receive the straight portion. In some embodiments, the forming fiber 2588 may have a minimum bending radius of, for example, 5 mm to 6 mm. The forming fiber 2588 is coupled to the forming fiber carrier 2466 such that movement of the forming fiber carrier 2466 causes the forming fiber 2588 to flex and generate a signal related to movement of the first tool member 2462, the second tool member 2482, or both. More specifically, as the position and / or orientation of one or both of the tool members 2462, 2482 changes, the molded fiber carrier 2466 is moved because the molded fiber carrier 2466 is coupled to the tool members 2462, 2482. This results in the forming fiber 2588 being fixedly connected to the forming fiber carrier 2466 moving and generating a signal related to the movement of the first tool member 2462 and / or the second tool member 2482.In some embodiments, the signal generated by the molded fiber 2588 includes a signal associated with an average of a first yaw angle θ 1 of the first tool element 2462 and a second yaw angle θ 2 of the second tool element 2482. As shown in FIG. 5, the yaw angle is a measure of the tool elements with respect to a centerline CL of the distal joint member 2610. In some embodiments, the molded fiber carrier 2466 is pivotally connected to the distal joint member 2610 about a first axis (see, e.g., carrier axis C 1 in FIG. 12 discussed below), and the first tool member 2462 and the second tool member 2482 are each pivotally connected to the distal joint member 2610 about a second axis (see, e.g., axis A 1 in FIGS. 8 and 9 discussed below), with the second axis offset from the first axis. In this manner, the molded fiber carrier 2466 can move relative to the distal joint member 2610 and relative to the first tool member 2462 and the second tool member 2482 during use. In some embodiments, the distal end of the forming fiber 2588 is located between the first axis and the second axis. In some embodiments, the molded fiber carrier 2466 is indirectly coupled to the first tool member 2462 and the second tool member 2482 such that an angular position of the molded fiber carrier 2466 relative to the second axis is associated with an average yaw angle of the first tool member 2462 and the second tool member 2482.In some embodiments, an intermediate coupling mechanism, such as a differential mechanism (not shown in FIG. 5 ), is coupled to the first tool member 2462 and the second tool member 2482, and the molded fiber carrier 2466 is pivotally connected to the differential mechanism via a transmission (or other mechanical coupling). The differential mechanism may be coupled between the first tool member 2462 and the second tool member 2482, for example. Such a differential embodiment is described herein with reference to the medical device 4400. The measurement of the position of the tool members 2462, 2482 (e.g., an angular position of the tool members 2462, 2482 relative to the shaft of the medical device 2400) is determined as the forming fiber 2588 bends relative to the mean / differential between the two tool members 2462, 2482. In some embodiments, the motion of the forming fiber 2588 is limited by the use of a differential to account for the limits of the bending radius of the forming fiber 2588 and the straight portion at the distal tip of the forming fiber 2588. In some embodiments, the rotational movement of the form fiber carrier 2466 is limited by the differential. In some embodiments, the rotational movement of the forming fiber carrier 2466 is limited to + / - 45 degrees relative to a centerline (not shown in FIG. 5 ) of the forming fiber carrier 2466. In some embodiments, the molded fiber carrier 2466 includes a transmission (not shown) coupled to the differential. In some embodiments, the movement of the forming fiber carrier causes the forming fiber to generate a signal related to the movement of the distal joint member. In some embodiments, movement of the forming fiber carrier causes the forming fiber to generate a signal related to movement of a proximal joint.The differential mechanism may also allow the use of a single forming fiber 2588 to determine the position of the two tool members 2462 and 2482. Thus, as described herein, a single molded fiber 2588 may be used to determine the position and orientation of the tool members 2462, 2482 (e.g., relative to the shaft of the medical device 2400), where the molded fiber 2588 is not directly connected to the tool members 2462, 2482.In alternative embodiments, other intermediate coupling mechanisms may be utilized between the tool members 2462 and 2482 and the molded fiber carrier 2466, rather than a differential. For example, a cam mechanism may be coupled to the tool elements to average the positions of the tool elements. Such an embodiment is illustrated in Figs. 23-29E and will be described below. In another example, a torsion spring mechanism may be coupled to the tool members and used to average the positions of the tool members as shown and described in FIGS. 30-38. In some alternative embodiments, the transmission connecting the differential to the distal form fiber carrier may be replaced with cables. In some alternative embodiments, the differential may be used with other types of position sensors, such as a Hall effect sensor.In some embodiments, medical device 2400 may also include a connector (not shown in FIG. 5 ) coupled between distal joint member 2610 and proximal joint member (not shown in FIG. 5 ). More specifically, the link includes a proximal end portion connected to the proximal link at the rotation axis of the proximal link and a distal end portion connected to the distal link 2610 at the rotation axis of the distal link. Thus, the distal joint member 2610 is rotatable with respect to the link about the axis of rotation of the distal joint member and the link is rotatable with respect to the proximal joint member about the axis of rotation of the proximal joint member. By coupling it to the link, the distal joint member 2610 is also rotatable about the axis of rotation of the proximal joint member. An embodiment with a connector is described in more detail below with respect to the medical device 4400.In some embodiments, the connector defines an internal channel through which the forming fiber 2588 may extend. In some embodiments, other elongate members may also extend through the internal channel of the connector, such as an electrical wire, cable, tension member, or the like. In some embodiments, the internal channel includes a tapered entrance at a proximal end of the internal channel. In some embodiments, a distal end of the link is disposed distally from the distal axis of rotation of the link.FIG. 6 is a schematic illustration of a portion of a medical device 3400 according to another embodiment. In some embodiments, the medical device 3400, or any of the components included therein, is optionally part of an instrument of a surgical system performing surgical procedures, and this surgical system may include a manipulator unit, a series of kinematic links, a series of cannulas, or the like. The medical device 3400 (and any of the instruments described herein) may be used in any suitable surgical system, such as the MIRS system 1000 shown and described above. The medical device 3400 may include a shaft (not shown in FIG. 6 ), a proximal joint member (not shown) coupled to the shaft, a distal joint member 3610 coupled to the proximal joint member, a first tool member 3462, a second tool member 3482, a position sensor 3588, and a differential mechanism 3800 (also referred to herein as a "differential") coupled between the tool members 3462 and 3482 and the position sensor 3588. The position sensor 3588 is connected to or at least partially located within the distal joint member 3610. The position sensor 3588 may be, for example, a molded fiber (such as the molded fiber 2488) described above or a Hall effect sensor.Although not shown in FIG. 6, the medical device 3400 may also include one or more tension members (e.g., a cable, a strap, or the like) (not shown in FIG. 6 ) connected to the tool members 3462, 3482. The medical device 3400 is configured such that movement of the tension members causes movement of the distal joint member 3610, movement of the tool members 3462 or 3482, or both movement of the distal joint member 3610 and movement of the tool members 3462 or 3482.The tool elements 3462, 3482may rotate about an axis of rotation of the tool elements (not shown in FIG. 6 ). The tool elements 3462, 3482 may be, for example, a pair of jaws, a cautery device, a cutter, or another medical tool. The tension member(s) is(are) coupled to the members 3462, 3482, extend from the tool members 3462, 3482, and are guided through the shaft and extend proximally to a mechanical structure (not shown in FIG. 6 ) of the medical device where they are coupled to drive components (not shown in FIG. 6 ) within the mechanical structure. The tension members may be actuated by the drive component (not shown) such that the tension on the tension members rotates one or both of the tool members 3462, 3482 about the axis of rotation of the tool members.The tool members 3462, 3482 may collectively perform gripping, shearing, or cutting functions. Thus, the axis of rotation of the tool elements can also function as a cutting axis if the tool elements rotate in opposite directions. Thus, in some embodiments, the medical device 3400 may provide at least three degrees of freedom (i.e., yaw about the axis of rotation of the tool elements, pitch about the axis of rotation of the distal or proximal members, and a cutting or gripping motion about the axis of rotation of the tool elements).The differential 3800 is coupled to the first tool element 3462 and the second tool element 3482, and the position sensor 3588 is coupled to the differential 3800. The differential 3800 rotates in response to rotation of the first tool member 3462 and / or the second tool member 3482. The position sensor 3588 deflects depending on the rotation of the differential 3800. As described herein, the differential 3800 allows the first tool element 3462 and the second tool element 3482 to rotate independently of each other while the differential 3800 is coupled to (and generates motion in) the position sensor 3588. In some embodiments, the differential 3800, may be coupled to the position sensor 3588 via an optional pinion gear (not shown in FIG. 6 ) disposed in series between the tool elements 3462, 3482 and the position sensor 3588. The position sensor 3588 is thus indirectly coupled to the tool elements 3462 and 3482 via the differential 3800 and the optional transmission. In other words, the position sensor 3588 is spaced apart from the first tool member 3462 and the second tool member 3482, but may be used to determine the orientation and position of the tool members 3462, 3482.During use of the medical device 3400, movement of the first tool member 3462 or the second tool member 3482 relative to the other tool member results in movement of the position sensor 3588 via the differential 3800, and the position sensor 3588 generates a signal related to movement of the position sensor 3588. In some embodiments, the signal generated by the position sensor 3588 is associated with an average of a first yaw angle θ 1 of the first tool element 3462 and a second yaw angle θ 2 of the second tool element 3482, as shown in FIG. 6. As described herein, yaw angle is a measure of the tool elements relative to a centerline CL of the distal joint member 3610.In some embodiments, the differential 3800 is configured such that the ratio of the movement of the first tool element 3462 and the second tool element 3482 to the movement of the position sensor 3588 is greater than 1:1. In this manner, the differential 3800 may reduce the amount of motion transmitted to the position sensor 3588, thus accounting for space constraints within the medical device 3400. In some embodiments, the ratio of the movement of the tool elements 3462, 3482 to the position sensor 3588 is about 2:1. in other embodiments, the ratio of the movement of the tool elements 3462, 3482 to the position sensor 3588 is about 3:1. In some embodiments, the rotational motion of the tool members 3462, 3482 may each be + / -110 degrees, while the rotational motion of the position sensor 3588 may be limited to + / -45 degrees relative to a centerline of the position sensor 3588 (or the centerline CL of the distal link 3610).In some embodiments, the position sensor 3588 is a molded fiber, and the medical device includes a molded fiber carrier (not shown in FIG. 6 ) connected to the differential 3800. The forming fiber may be a single forming fiber or a bundle of multiple forming fibers. The position sensor 3588 may be at least partially disposed in a lumen of the molded fiber carrier.In some embodiments, the differential 3800 includes a housing, a first planetary gear, a second planetary gear, and a ring gear (not shown in FIG. 6, respectively). The medical device also includes a transmission, a first sun gear, and a second sun gear (not shown in FIG. 6, respectively). The first sun gear is fixedly connected to the first tool member 3462 and coupled to the first planet gear in the differential housing, and the second sun gear is fixedly connected to the second tool member 3482 and coupled to the second planet gear in the differential housing. The first and second planet gears are also splined within the housing. The ring gear is integrated into an outer portion of the housing and coupled to the transmission that is indirectly connected to the position sensor 3588. The housing is configured to rotate as one of the first tool members 3462 or the second tool member 3482 rotates relative to the other tool member, respectively, such that a direction of the average of the positions of the tool members 3462, 3482 changes (e.g., relative to the distal joint member) and rotation of the housing causes rotation of the position sensor 3588. An orientation of the housing is associated with an average of a first yaw angle of the first tool element 3462 and a second yaw angle of the second tool element 3482.As the direction of the average of the positions of the tool members 3462, 3482 changes, the differential housing is rotated accordingly, which in turn moves the position sensor 3588, which is operatively connected thereto. The position sensor 3588 may also provide the orientation of the distal joint member 3610 (e.g., relative to the proximal joint member) and position and velocity data associated with the proximal joint member, the elbow, or other joints, and any flexible device portions through which the position sensor may traverse (e.g., a flexible device shaft). In some embodiments, the tension members that actuate the jaws extend along an outer portion of the jaws and the differential is housed within the tool members 3462, 3482. In alternative embodiments, the transmission connecting differential 3800, to distal position sensor 3588, could be replaced with cables.As described above, the differential 3800 may allow the use of a single position sensor 3588 to determine the position of the two tool elements 3462 and 3482. As described herein, a single position sensor 3588 may be used to determine the position and orientation of the tool members 3462, 3482, where the position sensor 3588 is indirectly connected to the tool members 3462, 3482.In some embodiments, the medical device 3400 may also include a connector (not shown in FIG. 6 ) coupled between the distal joint member 3610 and the proximal joint member (not shown in FIG. 6 ). More specifically, the link includes a proximal end portion connected to the proximal link at the rotation axis of the proximal link and a distal end portion connected to the distal link 3610 at the rotation axis of the distal link. Thus, the distal joint member 3610 is rotatable with respect to the link about the axis of rotation of the distal joint member and the link is rotatable with respect to the proximal joint member about the axis of rotation of the proximal joint member. By coupling it to the link, the distal joint member 3610 is also rotatable about the axis of rotation of the proximal joint member. An embodiment with a connector is described in more detail below with respect to the medical device 4400.In some embodiments, the connector defines an internal channel through which the position sensor 3588 may extend. In some embodiments, other elongate elements may also extend through the inner channel of the connector, such as an electrical wire, cable, tension member, or the like. In some embodiments, the internal channel includes a tapered entrance at a proximal end and a distal end of the internal channel. In some embodiments, a distal end of the link is disposed distally from the axis of rotation of the distal link.FIGS. 7-22C are various views of a medical device 4400 (and portions thereof), according to an embodiment. In some embodiments, the medical device 4400 or any of the components included therein are optionally portions of a surgical system instrument that performs surgical procedures, and the surgical system may include a manipulator unit, a series of kinematic links, a series of cannulas, or the like. The medical device 4400 (and any of the instruments described herein) may be used in any suitable surgical system, such as the MIRS system 1000 shown and described above. As shown in FIG. 7, the medical device 4400 includes a power transmission mechanism 4700, a shaft 4410, a wrist assembly 4500, and an end effector 4460. The medical device 4400 may also include one or more tension members (not shown in FIGS. 7-22C ). The tension members may be, for example, cables, straps, or the like that connect the force transfer mechanism 4700 to the wrist assembly 4500 and the end effector 4460.Referring to FIGS. 8 and 9, the medical device 4400 is configured such that movement of one or more of the tension members causes rotation of the end effector 4460 about a first rotational axis A 1 (also referred to herein as the "axis of the tool members") that functions as a yaw axis (the term yaw is arbitrary), rotation of the wrist assembly 4500 about a second rotational axis A 2 (also referred to herein as the "distal rotational axis of the wrist mechanism"), or a third rotational axis A 3 (also referred to herein as the "proximal rotational axis of the wrist mechanism"), intersecting (or gripping) rotation of the tool members of the end effector 4460 about the first rotational axis A 1, or a combination of these movements. FIG. 8 shows distal joint member 4610 and proximal joint member 4510 in a straight configuration. FIG. 9 shows distal joint member 4610 rotated relative to proximal joint member 3510 (i.e., in an "angled" configuration) with tool members 4462, 4482 in a closed configuration. The change in pitch and / or yaw of the medical device 4400 may be accomplished by manipulation of the tension members in a manner similar to the device 2400 described above, and is described in U.S. Provisional Patent Application No. 63 / 233,904, entitled "Surgical Instrument Cable Control and Routing Structures," and U.S. Patent Publication No. 2020 / 0390430 (filed Aug. 21, 2020), entitled "Low-Friction, Small Profile Medical Tools Having Easy-to-Assembly Components," the disclosure of which is incorporated herein by reference above.The force transfer mechanism 4700 provides for the movement of the individual tension members to produce the desired movement (pitch, yaw, and / or grip) on the wrist assembly 4500 and end effector 4460. In particular, the force transfer mechanism 4700 includes components that can be controlled to move some of the tension members in a proximal direction (i.e., retract certain tension members), while at the same time allowing other tension members to move in a distal direction (i.e., to loosen or "pay out rope"). In this manner, the power transfer mechanism 4700 may effect the desired movement while maintaining the desired tension within the tension members. As shown in FIG. 7, the power transmission mechanism 4700 includes a series of drive components, such as caps 4710 and 4720, which rotate or "wind" a proximal portion of one of the tension members to produce the desired movement of the tension member. In some embodiments, two proximal ends of a tension member connected to opposite directions of a single degree of freedom are connected to two independent capstans 4710 and 4720. This arrangement, commonly referred to as an antagonistic drive system, allows independent control of the movement (e.g., retraction or deployment) of each of the ends of the tension members. The force transfer mechanism 4700 generates movement of the tension members that causes the desired articulation movements (pitch, yaw, and / or grip) on the wrist assembly 4500 and the end effector 4460. Accordingly, the force transfer mechanism 4700 includes components and control elements to move a first proximal end portion of the tension member across the first capstan 4710 in a first direction (e.g., a proximal direction) and a second proximal end portion of the tension member across the second capstan 4720 in a second opposite direction (e.g., a distal direction). The power transmission mechanism 4700 may also move both proximal end portions of the tension member in the same direction. In this way, the power transmission mechanism 4700 may maintain the desired tension within the tension members.In some embodiments, the power transfer mechanism 4700 may include any of the assemblies or components described in U.S. Provisional Patent Application Serial No. 63 / 233,904, entitled "Surgical Instrument Cable Control and Routing Structures," the disclosure of which is incorporated herein by reference in its entirety. However, in other embodiments, in all medical devices described herein, the two ends of a tension member may be wound around a single drive roller. In this alternative arrangement, commonly referred to as a self-antagonistic drive system, the two ends of the traction element are operated with a single drive motor.Moreover, although shown as implemented with capstans in the figure, in other embodiments, the power transfer mechanism 4300 may include one or more linear actuators that generate translation (movement along a straight line) of a portion of the cables. Such proximal force transmitting mechanisms may include, for example, a universal joint, a lever, or any other suitable mechanism for directly pulling (or releasing) an end portion of one of the cables. In some embodiments, the proximal power transfer mechanism 4700 may include, for example, one of the proximal mechanical structures or components described in U.S. Patent Application Pub. No. US 2015 / 0047454 A1 (filed on Aug. 15, 2014), entitled "Lever Actuated Gimbal Plate" or U.S. Pat. No. U.S. Pat. No. 6,817,974 B2 (filed Jun. 28, 2001), entitled "Surgical Tool Having Positively Positionable Tendon-Actuated Multi-Disk Wrist Joint", each of which is incorporated herein by reference in its entirety.The shaft 4410 may be any elongated shaft connected to the wrist assembly 4500 and the power transmission mechanism 4700. In particular, the shaft 4410 includes a proximal end portion 4411 connected to the force transfer mechanism 4700 and a distal end portion 4412 connected to the wrist assembly 4500 (e.g., to a proximal joint member of the wrist assembly 4500). The shaft 4410 defines a passage or series of passages through which the tension members and other components (e.g., (e.g., electrical wires, ground wires, or the like) may be routed from the power transmission mechanism 4700 to the wrist assembly 4500. In some embodiments, the shaft 4410 may be at least partially made of an electrically conductive material such as stainless steel. In such embodiments, the shaft 4410 may include an inner insulative cover and / or an outer insulative cover. Thus, the shaft 4410 may be a shaft construction that is comprised of a plurality of different components. For example, the shaft 4410 may include (or be coupled to) a spacer (not shown) that provides the desired fluid seals, electrical isolation properties, and other desired components for coupling the wrist 4500 to the shaft 4410. Although wrist assembly 4500 (and other joint assemblies or joint members described herein) is described as being coupled to shaft 4410, any of the joint assemblies and joint members described herein may be coupled to the shaft via any suitable intermediate structure, such as a spacer, a cable guide, additional joints and / or members, or the like. In some embodiments, the shaft 4410 may be a substantially rigid member, while in other embodiments, the shaft 4410 may be a flexible member. In some embodiments, each of the medical devices described herein may include spacers, gaskets, cable guides, or other structures as described in U.S. Provisional Patent Application Serial No. 63 / 319,926, filed February 15, 2022, entitled "Surgical Instrument Including Electrical and Fluid Isolation Features," the disclosure of which is incorporated herein by reference in its entiretyEnd effector 4460 includes a first tool member 4462 and a second tool member 4482, which in this embodiment are a pair of jaws as shown in FIGS. 7-21. In alternative embodiments, end effector 4460 may also include other types of tools, such as a cautery, a cutter, or other medical tool. The first tool element 4462 (also referred to herein as a "first jaw") and the second tool element 4482 (also referred to herein as a "second jaw") may each rotate about the axis of rotation A 1 of the tool elements.As shown in FIGS. 8-10, wrist mechanism 4500 includes proximal joint member 4510, distal joint member 4610, and link 4580 (see, e.g., FIGS. 9 and 10 ). Proximal link 4510 has a proximal end 4511 and a distal end 4512. The distal joint member 4610 has a proximal end portion 4611 and a distal end portion 4612. As described in detail herein, the link 4580 is coupled between the proximal joint member 4510 and the distal joint member 4610 to form the wrist unit 4500. The proximal link 4510 is connected to the link 4580 via a pivot joint so that the link 4580 is rotatable about the third rotational axis A 3 with respect to the proximal link 4510. The distal joint member 4610 is also pin-jointed to the link member 4580 such that the distal joint member 4610 is rotatable about the second rotational axis A 2 with respect to the link member 4580 and about the third rotational axis A 3 with respect to the proximal joint member 4510. In this manner, the link 4580 maintains the coupling between the proximal joint member 4510 and the distal joint member 4610 during rotation of the distal joint member 4610 relative to the proximal joint member 4510. For example, as shown in FIGS. 9 and 10, the distal joint member 4610 and the proximal joint member 4510 may be connected in rolling contact with a spline. Thus, the angle between the centerline of link 4580 and the centerline of distal joint member 4610 must be the same or substantially the same at all times as the angle between the centerline of link 4580 and the centerline of proximal joint member 4510. In some embodiments, proximal link 4510 is fixedly connected to shaft 4410 such that proximal link 4510 is non-rotatable relative to the shaft. However, in other embodiments, proximal link 4510 may be rotatably connected to shaft 4410.For example, as shown in FIG. 11, the link 4580 includes a proximal end 4581 and a distal end 4582 and defines an internal path 4583 through which one or more elongate members may extend. The elongated elements may be, for example, an electrical wire, cable, or position sensor such as a molded fiber described herein. In some embodiments, as shown in FIGS. 12-16, internal channel 4583 includes a tapered entrance on both a proximal end of internal channel 4583 and a distal end of internal channel 4583. The tapered entrances may prevent sharp bending of the forming fiber 4588, thereby maintaining a desired minimum bending radius of the forming fiber 4588. In some embodiments, a distal end 4582 of the link 4580 is disposed distal from the distal link rotational axis A2. Link 4580 also includes protrusions 4587 and 4586 that serve to rotatably connect link 4580 to proximal link 4510 and distal link 4610, respectively. For example, the protrusions 4587 and 4586 may be received in the corresponding openings (not shown) in the links 4510 and 4610. In other embodiments, the link 4580 may have openings and the links 4510, 4610 may have corresponding protrusions that may be received in the openings of the link 4580.As shown in FIGS. 12-20, the wrist 4500 also includes a differential 4800, a pinion gear 4830, a molded fiber carrier 4466, and a molded fiber 4588. The forming fiber 4588 may be a single optical fiber or a bundle of multiple optical fibers. The molded fiber carrier 4466 includes a molded fiber lumen 4468, and the molded fiber 4588 extends distally within the molded fiber lumen 4468 (see FIG. 15 ). More specifically, the forming fiber 4588 has a straight distal end portion 4589 (see FIG. 15 ) that is fixedly connected to the forming fiber carrier 4466 within the forming fiber lumen 4468. The distal end portion 4589 has a desired length and facilitates accurate measurement of bends in the other portions of the forming fiber 4588. For example, the straight distal end portion 4589 enables accurate transmission and reflection of optical signals for position and orientation determination. The straight distal end portion 4589 may have a predetermined length (e.g., at least 3 mm, between 3 mm and 6 mm), and the molded fiber lumen 4468 includes a distal portion shaped to receive the straight distal end portion 4589. In some embodiments, the forming fiber 4588 may have a minimum bend radius of, for example, between 5 mm and 6 mm. The molded fiber 4588 extends through the proximal joint member 4510, through the internal channel 4583 of the connector member 4580 and distally within the molded fiber lumen 4468.The forming fiber support 4466 is pivotally connected to the distal link 4610 about a support axis C1 shown in FIG. 12 that is offset or spaced from the axis of the tool A1. Thus, the distal end portion 4589 of the forming fiber 4588 is located between the carrier axis C1 and the axis of the tool A1. The molded fiber carrier 4466 is connected to the tool elements 4462 and 4482 via the differential 4800 and the transmission 4830. In this manner, the molded fiber carrier 4466 and the molded fiber 4588 are indirectly coupled to the first and second tool members 4462, 4482. In other words, the molded fiber carrier 4466 and the molded fiber 4588 are respectively spaced from the first tool member 4462 and the second tool member 4482. The differential 4800 allows the first tool member 4462 and the second tool member 4482 to rotate independently of each other while simultaneously coupled to (and producing movement within) the molded fiber carrier 4466. As described above for previous embodiments, the forming fiber 4588 is coupled to the forming fiber carrier 4466, such that movement of the forming fiber carrier 4466 causes bending and / or movement of the forming fiber 4588. Because the molded fiber carrier 4466 is coupled to the first tool member 4462 and the second tool member 4482 via the differential 4800 and the transmission 4830, when the first tool member 4462 or the second tool member 4482 rotates relative to the other tool member, the movement causes the molded fiber carrier 4466 to move and the molded fiber 4588 coupled thereto also moves, thereby generating a signal related to the movement of the first tool member 4462, the second tool member 4482, or both. In some embodiments, the signal generated by the molded fiber 4588 includes a signal associated with an average of a first yaw angle of the first tool element 4462 and a second yaw angle of the second tool element 4482.The gear 4830 includes a proximal gear 4831, a distal gear 4832, and two middle gears 4833 and 4834. The molded fiber carrier 4466 includes a spur gear 4828 coupled to and engaging the proximal gear 4831. The distal gear 4832 is coupled to and engages an integral ring gear 4822 of the differential 4800 to transfer motion from the differential 4800 to the molded fiber carrier 4466, as described in more detail below. The intermediate gear 4833 couples the distal gear 4832 to the intermediate gear 4834 and the intermediate gear 4834 in turn couples to the proximal gear 4831. The gears of the transmission 4830 are shown by way of example. In alternative embodiments, there may be a different number of gears or gear configuration, for example with a greater or lesser number of gears.The differential 4800 is connected to the first tool element 4462 and the second tool element 4482 and to the molded fiber carrier 4466 (via the transmission 4830). More specifically, differential 4800 includes a housing 4820 with integral ring gear 4822 on an outer portion of housing 4820, such as shown in FIGS. 13, 15, 17, and 19-22C. As described above, ring gear 4822 meshes with distal gear 4832 of transmission 4830. The differential 4800 includes a first planetary gear 4824 and a second planetary gear 4825 disposed within the housing 4820 (see FIGS. 19-22C ). The planet gears 4824, 4825 are each rotatably coupled to the housing 4820 and are rotatable relative to the housing 4820 about their respective axes. The first planet gear 4824 is coupled to and engages a first sun gear 4826 connected to the first tool member 4462, and the second planet gear 4825 is coupled to and engages a second sun gear 4827 connected to the second tool member 4482 (see FIGS. 19-21 ). The first planetary gear 4824 and the second planetary gear 4825 also mesh within the housing 4820 (see FIGS. 22A-22C ).As one of the first tool members 4462 and / or the second tool member 4482 rotates relative to the other tool member, such that a direction of the average of the positions of the tool members 4462, 4482 changes (e.g., relative to the distal joint member 4610), the associated sun gear 4826 or 4827 of the respective tool member 4462 or 4482 meshes with the corresponding planet gear 4824 or 4825 of the differential 4800, which in turn causes the housing 4820 to rotate about the axis A1. Rotation of the housing 4820 causes rotation of the transmission 4830 through the engagement of the ring gear 4822 with the distal gear 4832 of the transmission 4830. The gear 4830 then causes movement of the molded fiber carrier 4466 via the engagement between the proximal gear 4831 of the gear 4830 and the spur gear 4828 of the molded fiber carrier 4466. Specifically, the molded fiber carrier 4466 rotates relative to the distal joint member 4610 about the rotational axis C 1. This, in turn, causes the forming fiber 4588 to move.To further illustrate the rotation of the housing 4820, an example will be described in which the first tool member 4462 rotates relative to the second tool member 4482. For example, consider the case that the first tool element 4462 rotates about the axis A1via first tension members relative to the second tool element 4482, the second tool element 4482 being fixed about the axis A1by second tension members. In such an example, rotation of the first tool member 4462 about the axis A 1 causes the first sun gear 4826 (which is fixedly connected to the first tool member 4462) to rotate about the axis A 1, which in turn causes the first planetary gear 4824 (which is rotatably connected to the first sun gear 4826) to rotate about the axis of the first planetary gear 4824. At this time, the second sun gear 4827 (which is connected to the second tool member 4482) is held stationary because the second tool member 4482 is fixed. The second planetary gear 4825 (rotatably connected to the second sun gear 4827) wraps around the second sun gear 4827 that is fixed. Thus, the second planet gear 4827 rotates about its own axis while orbiting about the second sun gear 4827 of the second tool member 4482. The orbital motion of the second planet gear 4825 (which is located in the housing 4820) in turn causes rotation of the housing 4820 of the differential 4800, and thus movement of the molded fiber carrier 4466 and the molded fiber 4588. In other examples, the housing 4820 rotates as the second tool member 4482 rotates relative to the first tool member 4462, and also as both tool members 4462 and 4482 rotate together in the yaw direction relative to the wrist 4500.As the direction of the average of the positions of the tool members 4462, 4482 changes, the differential housing 4820 is rotated accordingly, which in turn moves the forming fiber 4588, operatively connected thereto. The rotation or orientation of the housing 4820 is associated with an average of a first yaw angle of the first tool element 4462 and a second yaw angle of the second tool element 4482. More specifically, the measurement of the position of the tool elements 4462, 4482 is determined by bending the forming fiber 4588 in proportion to the average / differential between the two tool elements 4462, 4482. The use of the differential 4800, limits the movement of the forming fiber 4588 to accommodate the limits of the bending radius of the forming fiber 4588, and to accommodate the straight portion at the distal tip of the forming fiber 4588. In some embodiments, the differential 4800 and / or the transmission 4830 are configured such that the ratio of the angle of rotation of the first tool member 4462 and the second tool member 4482 to the angle of rotation of the molded fiber carrier 4466 is greater than 1:1. In this manner, the differential 4800 and / or the transmission 4830 may reduce the motion transferred to the molded fiber carrier 4466, thereby accounting for space conditions within the medical device 4400. In some embodiments, the ratio of movement of the tool members 4462, 4482 to the forming fiber carrier 4466 is about 2:1. in other embodiments, the ratio of movement of the tool members 4462, 4482 to the forming fiber carrier 4466 is about 3:1. As the forming fiber 4588 moves and / or bends, the forming fiber 4588 generates a signal related to the movement of the forming fiber 4588. In some embodiments, the signal generated by the form fiber 4588 is associated with an average of a first yaw angle of the first tool element 4462 and a second yaw angle of the second tool element 4482.As described herein, the differential 4800 may allow for the use of a single molded fiber sensor to determine the position of the two tool elements 4462 and 4482. The single molded fiber sensor (e.g., molded fiber 4588) may be used to determine the position and orientation of the tool members 4462, 4482, where the molded fiber 4588 is not directly connected to the tool members 4462, 4482. In addition to the position and orientation information of the tool members 4462, 4482, in some embodiments, movement of the molded fiber carrier 4466 also causes the molded fiber 4588 to generate a signal associated with movement of the distal joint member 4610. In some embodiments, the movement of the molded fiber carrier 4466 additionally causes the molded fiber 4588 to generate a signal related to the movement of a proximal joint and / or joint member such as the proximal joint member 4510 and other flexible instrument parts (e.g., a flexible instrument shaft). Accordingly, the molded fiber 4588 can be used to determine the position and orientation of the tool members 4462, 4482, as well as other parts of the medical device.FIGS. 23-29E show a portion of a medical device 5400, according to an embodiment. In some embodiments, the medical device 5400 or any of the components included therein are optionally portions of a surgical system instrument that performs surgical procedures, and the surgical system may include a manipulator unit, a series of kinematic connections, a series of cannulas, or the like. The medical device 5400 (and any of the instruments described herein) may be used in any suitable surgical system, such as the MIRS system 1000 shown and described above. The medical device 5400 includes a wrist 5500 and an end effector 5460 having a first tool element 5462 and a second tool element 5482. The medical device 5400 may also include a shaft (not shown) and a power transmission mechanism (not shown), which may be the same or similar to the shaft 4410 and the power transmission mechanism 4700 described above, and may function the same or similar. The medical device 5400 also includes one or more tension members 5420 (see FIGS. 23 and 24 ). The tension members 5420 may be, for example, cables, straps, or the like that connect the power transmission mechanism to the wrist 5500 and the end effector 5460.As described above for previous embodiments, the medical device 5400 is configured such that movement of one or more of the tension members 5420 causes rotation of the end effector 5460 about a first rotational axis A 1 (also referred to herein as the "tool element axis") that acts as a yaw axis (the term yaw is arbitrary), rotation of the wrist assembly 5500 about a second rotational axis A 2 (also referred to herein as the "wrist distal rotational axis"), or a third rotational axis (not shown) (also referred to herein as the "wrist proximal rotational axis"), intersecting (or gripping) rotation of the tool elements of the end effector 5460 about the first rotational axis A 1, or a combination of these movements. FIG. 23 shows distal joint member 5610 in a straight configuration and tool members 5462 and 5482 in an open configuration (rotated away from each other). The change in pitch angle and / or yaw angle of the medical device 5400 may be accomplished by manipulating the tension members 5420 in a manner similar to the devices 2400 and 4400 described above and as described in provisional patent application U.S. Ser. No. 63 / 233,904, entitled "Surgical Instrument Cable Control and Routing Structures" and U.S. Pat. Publication No. 2020 / 0390430 (filed Aug. 21, 2020), entitled "Low-Friction, Small Profile Medical Tools Having Easy-to-Assembly Components," the disclosure of which is hereby incorporated by reference herein.In this embodiment, the first tool member 5462 and the second tool member 5482 are a pair of jaws as shown in FIGS. 23-29E. In alternative embodiments, end effector 5460 may also include other types of tools, such as a cautery, a cutter, or other medical tool. The first tool member 5462 (also referred to herein as a "first jaw") and the second tool member 5482 (also referred to herein as a "second jaw") may each rotate about the axis of rotation A 1 of the tool members. More specifically, the first tool member 5462 and the second tool member 5482 are rotatably connected to the distal joint member 5610 by a pin 5615.Wrist assembly 5500 includes a proximal joint member (not shown) that may be the same or similar to proximal joint member 4510, a distal joint member 5610, and optionally a link member (not shown) that may be the same or similar to link 4580. Distal joint member 5610 has a proximal end 5611 and a distal end 5612. The optional link may be coupled between the proximal joint member and the distal joint member 5610 to form the wrist mechanism 5500 in the same manner as described for the wrist mechanism 4500. In some embodiments, the proximal joint member is fixedly connected to the shaft such that the proximal joint member is not rotatable relative to the shaft. However, in other embodiments, the proximal link may be rotatably connected to the shaft.For example, as shown in Figs. 24-25, wrist 5500 also includes an intermediate coupling mechanism 5840, a molded fiber carrier 5466 and a molded fiber 5588. In this embodiment, the intermediate coupling mechanism functions as a cam mechanism 5840 which will be described in detail below. The molded fiber carrier 5466 is rotatably connected to the first tool member 5462 and the second tool member 5482 via the pin 5615 such that the molded fiber carrier 5466 can rotate about the tool axis A1 with the first jaw 5462 and / or the second jaw 5482. The molded fiber carrier 5466 defines a molded fiber lumen 5468 in which a distal end of the molded fiber 5588 extends. In this manner, the forming fiber 5588 is connected to the forming fiber carrier 5466 such that movement of the forming fiber carrier 5466 causes bending and / or movement of the forming fiber 5588. For example, as shown in Figs. 24-27, the forming fiber lumen 5468 has a closed distal end. In alternative embodiments, the molded fiber lumen 5468 may extend through the molded fiber carrier 5466 to an open end, through an opening through the pin 5615, and out the distal end of the molded fiber carrier 5466. In some alternative embodiments, the molded fiber carrier 5466 and the pin 5615 may be integrally formed as a single component. In another alternative embodiment, the molded fiber carrier 5466 forms a single component together with the pin 5615, and the molded fiber lumen 5468 extends through the molded fiber carrier 5466 to an open end, through an opening in the pin 5615, and extends outside and distal of the molded fiber carrier 5466 and the molded fiber carrier 5466 forms a single component together with the pin 5615.Because the molded fiber carrier 5466 is rotatably coupled to the first tool member 5462 and the second tool member 5482, when the first tool member 5462 and / or the second tool member 5482 rotate relative to each other and / or are moved relative to the distal joint member 5610, the movement causes the molded fiber carrier 5466 to move and in turn the molded fiber 5588 coupled thereto to move. The forming fiber 5588 thereby generates a signal related to the movement of the first tool member 5462, the second tool member 5482, or both tool members 5462 and 5482, as described in more detail below. In some embodiments, the signal generated by the molded fiber 5588 includes a signal associated with an average of a first yaw angle of the first tool element 5462 and a second yaw angle of the second tool element 5482.The forming fiber 5588 may be a single optical fiber or a bundle of multiple optical fibers. The forming fiber 5588 has a straight distal end portion 5589 (see FIG. 25 ) that is fixedly connected to the forming fiber carrier 5466 within the forming fiber lumen 5468 such that the distal end portion 5589 of the forming fiber 5588 is spaced apart (e.g., remotely positioned) from the first tool member 5462 and the second tool member 5482. In other words, the forming fiber 5588 is indirectly connected to the first die member 5462 and the second die member 5482. The distal end portion 5589 has a desired length and facilitates accurate measurement of bends in the other portions of the forming fiber 5588. For example, the straight distal end portion 5589 enables accurate transmission and reflection of optical signals for position and orientation determination. The straight distal end portion 5589 may have a predetermined length (e.g., at least 3 mm, between 3 mm and 6 mm), and the lumen of the forming fiber 5468 includes a distal portion shaped to receive the straight distal end portion 5589. In some embodiments, the forming fiber 5588 may have a minimum bending radius of, for example, 4 mm to 5 mm. The forming fiber 5588 extends through the proximal joint member (not shown), through the internal channel of the connector member (not shown), and distally within the forming fiber lumen 5468.The cam mechanism 5840 includes a cam plate 5842 that forms cam slots 5844 and 5845 and a notch 5846. The molded fiber carrier 5466 is received in the notch 5846 of the cam plate 5842, so that upon rotation of the cam plate 5842, the molded fiber carrier 5466 coupled in the notch 5846 also rotates about the tool axis A 1. Moreover, cam plate 5842 rotates relative to each other and / or relative to distal member 5610 in response to rotation of first tool member 5462 and / or second tool member 5482. Accordingly, the cam plate 5842 functions as an intermediate coupling mechanism to connect the molded fiber carrier 5466 to the first and second tool members 5462, 5482. The cam plate 5842 may also slide or translate relative to the molded fiber carrier 5466 in the directions of arrows T1 and T2 parallel to a centerline CLsfc of the molded fiber carrier 5466 as shown in FIG. 25 and described in more detail below. Thus, as described below, the cam mechanism can produce eccentric movement of the cam 5842.For example, as shown in FIGS. 25-27, the cam plate 5842 is disposed between the first tool member 5462 and the second tool member 5482. The first tool member 5462 has a cam pin 5448 received in the cam slot 5844 of the cam plate 5842, and the second tool member 5482 has a cam pin 5449 received in the cam slot 5845 of the cam plate 5842. As the first tool member 5462 rotates about the tool axis A1, the cam pin 5448 moves within the cam slot 5844, and as the second tool member 5482 rotates about the tool axis A1, the cam pin 5449 moves within the slot 5845. Thus, the rotational movement of the first tool member 5462 and the second tool member 5482 causes the pins to move in the cam slots 5844 and 5845 of the cam plate 5842. This movement, in turn, causes the cam 5842 to rotate. The cam slots 5844 and 5855 are rectilinear and slightly angled with respect to a centerline CLsfc of the forming fiber carrier 5466. They are sized and positioned on the cam 5842 to provide minimal coupling between the cam 5842 and the tool members 5462 and 5482, but not so strong as to interfere with the movement of the tool members 5462 and 5482. If the cam slots 5844 and 5845 were positioned to extend orthogonally to the centerline CLsfc of the molded fiber carrier 5466, the range of motion of the tool members 5462 and 5482 would be too limited (e.g., to less than the desired available range of motion of the tool members 5462, 5482) and adverse coupling would result between the cam pins 5448 and 5489 and the cam plate 5842. Instead, it is desirable that the cam slots 5844 and 5845 be orthogonal or as close as possible orthogonal to the travel path of the cam pins 5448 and 5449 as the tool members 5462, 5482 move between fully open and closed configurations. Therefore, the location of the cam slots 5844 and 5845 relative to the location and movement of the cam pins 5448, 5489 is important to the proper functioning of the cam mechanism 5840,Although cam slots 5844 and 5845 are shown on cam plate 5842 in the same plane as molded fiber carrier 5466, in alternative embodiments, the cam slots may be offset from molded fiber carrier 5466. In some alternative embodiments, the molded fiber carrier 5466 may be positioned distal from the cam slots 5844 and 5845 and not proximal as with the medical device 5400.As described above, the length and position of the cam slots 5844, 5845 and the movement of the cam plate 5842 relative to the molded fiber carrier 5466 ensure that the molded fiber carrier 5466 and the molded fiber 5588 connected thereto are held in a central position between the first tool element 5462 and the second tool element 5482 throughout the rotational movement of the first tool element 5462 and the second tool element 5482. Similarly, the rotational position of the cam 5842 is associated with the average of the first yaw angle of the first tool member 5462 and the second yaw angle of the second tool member 5482. As shown in Figs. 28A-29A, a molded fiber vector V is defined at the center line CLsfc of the molded fiber carrier 5466. As the first tool member 5462 and the second tool member 5482 are rotated relative to the distal joint member 5610 (FIG. 28A ) and / or to each other (FIGS. 28B and 28C ), the centerline CLsfc of the molded fiber carrier 5466 is maintained centered between the first tool member 5462 and the second tool member 5482. Thus, the distal end 5589 of the molded fiber 5588 (coupled to the molded fiber carrier 5466) is aligned along the vector V associated with the average of the first yaw angle of the first tool element 5462 and the second yaw angle of the second tool element 5482, and outputs a signal associated with the vector V.FIGS. 29A-29E show example positions of the first tool member 5462 and the second tool member 5482 as well as the position and orientation of the cam plate 5842 relative to the molded fiber carrier 5466 during rotational movement of the first tool member 5462 and the second tool member 5482 relative to each other and / or rotated relative to the distal joint member 5610. A portion of the second tool member 5482 is not shown for illustration. FIG. 29A shows the first tool member 5462 and the second tool member 5482 rotated away from each other in a first orientation. In this orientation, a gap G1 is formed between the cam plate 5842 and the molded fiber carrier 5466. FIG. 29B shows the first tool member 5462 and the second tool member 5482 rotated away from each other in a second orientation in which the jaws are spaced slightly further apart than in the first orientation and also rotated downwardly about axis A1 relative to the distal member 5610. In this orientation, a gap G2 substantially equal to the gap G1 is formed between the cam plate 5842 and the molded fiber carrier 5466 and the cam pins 5448 and 5449 are positioned approximately at the center of the corresponding cam slots 5844 and 5845. FIG. 29C shows the first tool member 5462 and the second tool member 5482 rotated at maximum distances from each other (note that the pins 5448 and 5449 are at maximum moving distances within the cam slots 5844 and 5845). In this orientation, a gap G 3 is formed between the cam plate 5842 and the molded fiber carrier 5466 that is larger than the gap G 1 and the gap G 2. More specifically, as the first tool member 5462 and the second tool member 5482 are moved further away from each other, the cam pin 5448 moves to a position at the top of the cam slot 5844, the cam pin 5449 moves to a position at the bottom of the cam slot 5845, and the cam plate 5842 slides in the direction T2 relative to the molded fiber carrier 5466. The cam plate 5842 thus rotates and simultaneously moves.FIG. 29D shows the first tool member 5462 and the second tool member 5482 in a partially closed orientation relative to each other (i.e., rotated relative to each other) and slightly rotated relative to the distal member 5610. As the first tool member 5462 and the second tool member 5482 are moved closer to each other, the cam pin 5448 moves to a position near the bottom of the cam slot 5844, the cam pin 5449 moves to a position near the top of the cam slot 5845, and the cam plate 5842 slides in the direction T1 relative to the molded fiber carrier 5466 to define a gap G4 between the molded fiber carrier 5466 and the cam plate 5842 that is smaller than the gaps G1, G2, and G3. FIG. 29E shows the first tool member 5462 and the second tool member 5482 in a fully closed orientation with respect to each other. In this position, the cam pin 5448 moves to a position at the lower end of the cam slot 5844, the cam pin 5449 moves to a position at the upper end of the cam slot 5845, and the cam plate 5842 slides in the direction T1 relative to the molded fiber carrier 5466 and closes the gap between the molded fiber carrier 5466 and the cam plate 5842.As one of the first tool members 5462 and / or the second tool member 5482 rotates relative to the other tool member such that a direction of the average of the positions of the tool members 5462, 5482 changes (e.g., relative to the distal joint member 5610), the molded fiber carrier 5466 moves as a result of the engagement between the cam mechanism 5840 and the first tool member 5462 and the second tool member 5482. For example, as shown in Figs. 29A-29E, the molded fiber carrier 5466 rotates about the tool axis A1 relative to the distal joint member 5610. This, in turn, causes the forming fiber 5588 to move. The rotation or orientation of the molded fiber carrier 5466 is associated with an average of a first yaw angle of the first tool element 5462 and a second yaw angle of the second tool element 5482 (shown as vector V in FIGS. 28A-29A). More specifically, the measurement of the position of the tool elements 5462, 5482 is determined as the forming fiber 5588 bends in proportion to the average between the two tool elements 5462, 5482. The use of the cam mechanism 5840 may limit the range of motion of the first tool member 5462 and the second tool member 5482 and / or the range of motion of the forming fiber 5588, to account for the limits of the bending radius of the forming fiber 5588, and to account for the straight portion at the distal tip portion 5589 of the forming fiber 5588. In some embodiments, the signal generated by the molded fiber 5588 is associated with an average of a first yaw angle of the first tool element 5462 and a second yaw angle of the second tool element 5482.As described herein, the cam mechanism 5840 may enable the use of a single molded fiber sensor (e.g., molded fiber 5588) to determine the position of the two tool members 5462 and 5482. The single molded fiber sensor can be used to determine the position and orientation of the tool members 5462, 5482, where the molded fiber 5588 is not directly connected to the tool members 5462, 5482. In addition to providing information about the position and orientation of the tool members 5462, 5482, in some embodiments, the movement of the molded fiber carrier 5466 also causes the molded fiber to generate a signal related to the movement of the distal joint member 5610. In some embodiments, the movement of the molded fiber carrier 5466 additionally causes the molded fiber 5588 to generate a signal related to the movement of a proximal joint and / or joint member such as the proximal joint member and other flexible instrument portions (e.g., a flexible instrument shaft). Accordingly, the molded fiber 5588 can be used to determine the position and orientation of the tool members 5462, 5482 as well as other parts of the medical device.FIGS. 30-38 show a portion of a medical device 6400 (and portions thereof), according to an embodiment. In some embodiments, the medical device 6400 or any of the components included therein are optionally portions of a surgical system instrument that performs surgical procedures, and the surgical system may include a manipulator unit, a series of kinematic connections, a series of cannulas, or the like. The medical device 6400 (and any of the instruments described herein) may be used in any suitable surgical system, such as the MIRS system 1000 shown and described above. The medical device 6400 includes a wrist 6500 and an end effector 6460 having a first tool element 6462 and a second tool element 6482. The medical device 6400 may also include a shaft (not shown) and a power transmission mechanism (not shown), which may be the same or similar to the shaft 4410 and the power transmission mechanism 4700 described above, and may function the same or similar. The medical device 6400 also includes one or more tension members (not shown) such as the tension members 5420 described above. The tension members may be, for example, cables, straps, or the like that connect the power transmission mechanism to the wrist 6500 and the end effector 6460.As discussed above for previous embodiments, the medical device 6400 is configured such that movement of one or more of the tension members causes rotation of the end effector 6460 about a first rotational axis A 1 (also referred to herein as the "tool element axis") that acts as a yaw axis (the term yaw is arbitrary), rotation of the wrist assembly 5500 about a second rotational axis A 2 (also referred to herein as the "distal wrist axis of rotation"), or a third rotational axis (not shown) (also referred to herein as the "proximal wrist axis of rotation"), intersecting (or gripping) rotation of the tool elements of the end effector 6460 about the first rotational axis A 1, or a combination of these movements. FIG. 30 shows distal joint member 6610 in a straight configuration and tool members 6462 and 6482 in a closed configuration relative to one another. The change in pitch angle and / or yaw angle of the medical device 6400 may be accomplished by manipulating the tension members in a manner similar to the devices 2400 and 4400 described above and as described in U.S. Provisional Patent Application Serial No. 63 / 233,904, entitled "Surgical Instrument Cable Control and Routing Structures" and U.S. Patent Publication No. 2020 / 0390430 (filed August 21, 2020), entitled "Low-Friction, Small Profile Medical Tools Having Easy-to-Assembly Components," the disclosure of which is hereby incorporated by reference herein.In this embodiment, the first tool member 6462 and the second tool member 6482 are a pair of jaws as shown in Figs. 30-35 and 37. In alternative embodiments, end effector 6460 may also include other types of tools, such as a cautery, a cutting tool, or other medical tool. The first tool member 6462 (also referred to herein as a "first jaw") and the second tool member 6482 (also referred to herein as a "second jaw") may each rotate about the rotational axis A 1 of the tool members (see FIG. 30 ). More specifically, the first tool member 6462 and the second tool member 6482 are rotatably connected to the distal joint member 6610 via a pin 6615.Wrist assembly 6500 includes a proximal joint member (not shown) that may be the same or similar to proximal joint member 4510, a proximal joint member 6610, and optionally a link member (not shown) that may be the same or similar to link member 4580. Distal joint member 6610 has a proximal end 6611 and a distal end 6612. The optional link is coupled between the proximal joint member and the distal joint member 6610 to form the wrist mechanism 6500 in the same manner as described for the wrist mechanism 4500. In some embodiments, the proximal joint member is fixedly connected to the shaft such that the proximal joint member is not rotatable relative to the shaft. However, in other embodiments, the proximal link may be rotatably connected to the shaft.For example, as shown in FIGS. 31-37, the wrist 6500 also includes an intermediate coupling mechanism 6860, a molded fiber carrier 6466 and a molded fiber 6588 (see FIG. 33). In this embodiment, the intermediate coupling mechanism 6860 is a torsion spring mechanism that includes a first spring 6864 and a second spring 6865 and will be described in more detail below. The molded fiber carrier 6466 is coupled to the first tool member 6462 and the second tool member 6482 via the pin 6615 such that the molded fiber carrier 6466 can rotate about the tool axis A 1 with the first jaw 6462 and / or the second jaw 6482. The molded fiber carrier 6466 defines a molded fiber lumen 6468 in which a distal end of the molded fiber 6588 extends (see FIG. 33). The forming fiber 6588 is thus coupled to the forming fiber carrier 6466 such that movement of the forming fiber carrier 6466 causes bending and / or movement of the forming fiber 6588. The molded fiber carrier 6466 also defines an opening 6467 to which the springs of the torsion spring mechanism 6860 are coupled as described below.Because the molded fiber carrier 6466 is rotatably coupled to the first tool member 6462 and the second tool member 6482, when the first tool member 6462 or the second tool member 6482 rotates relative to the other tool member or is moved relative to the distal joint member 6610, movement causes the molded fiber carrier 6466 to move and in turn the molded fiber 6588 coupled thereto to move. The forming fiber 6588 thereby generates a signal related to the movement of the first tool member 6462, the second tool member 6482, or the movement of both tool members 6462 and 6482, as described in more detail below. In some embodiments, the signal generated by the molded fiber 6588 includes a signal associated with an average of a first yaw angle of the first tool element 6462 and a second yaw angle of the second tool element 6482.The forming fiber 6588 may be a single optical fiber or a bundle of multiple optical fibers. The forming fiber 6588 has a straight distal end portion 6589 (see FIG. 33 ) fixedly connected to the forming fiber carrier 6466 within the forming fiber lumen 5468 such that the distal end portion 6589 of the forming fiber 6588 is spaced apart (e.g., remotely positioned) from each of the first tool member 6462 and the second tool member 6482. In other words, the forming fiber 5588 is indirectly connected to the first die member 6462 and the second die member 6482. The distal end portion 6589 has a desired length and facilitates accurate measurement of bends in the other portions of the forming fiber 6588. For example, the straight distal end portion 6589 enables accurate transmission and reflection of optical signals for position and orientation determination. The straight distal end portion 6589 may have a length of at least 3 mm, for example between 3 mm and 6 mm, and the lumen of the forming fiber 6468 includes a distal portion shaped to receive the straight distal end portion 5589. In some embodiments, the forming fiber 6588 may have a minimum bending radius of, for example, 4 mm to 5 mm. The forming fiber 6588 extends through the proximal joint member (not shown), through the internal channel of the connector member (not shown), and distally within the forming fiber lumen 6468.The intermediate coupling mechanism 6860 (also referred to as a "torsion spring mechanism") includes a first torsion spring 6864 and a second torsion spring 6865 mounted on opposite sides of the molded fiber carrier 6466. Torsion springs 6864, 6865 may be spiral torsion springs (also referred to as "clocksprings"), helical torsion springs, torsion bars or fibers, or any other suitable torsion spring construction. In this embodiment, the torsion spring mechanism comprises two clock springs. The first clock spring 6864 includes a loop end 6861 and a tab 6868 at an opposite end of the loop end 6861 (see FIGS. 34 and 36B ). Similarly, the second clock spring 6865 has a loop end 6863 and a tab 6869 at an opposite end of the loop end 6863 (see Figs. 34 and 36B). The loop end 6861 of the clock spring 6864 is connected to a pin 6448 (see FIGS. 31-35 ) of the first tool member 6462, and the tab 6868 is connected to the opening 6467 of the molded fiber carrier 6466. The loop end 6863 of the clock spring 6865 is connected to a pin 6449 (see FIG. 35 ) of the second tool member 6482, and the tab 6869 is connected to the opening 6467 of the molded fiber carrier 6466. The engagement of the two ends 6868 and 6869 of clock springs 6464 and 6465 respectively in the opening 6467 of the molded fiber carrier 6466 acts on the molded fiber carrier 6466 and causes it to rotate as the first tool member 6462 and / or the second tool member 6482 are rotated.As schematically shown in Figure 38, the opposing forces exerted by clocksprings 6864 and 6865 balance the position of the molded fiber carrier 6466 such that the molded fiber carrier 6466 (and the corresponding molded fiber 6588) is aligned with a centerline between the jaws. In particular, the opposing forces exerted by clock springs 6864 and 6865 balance forming fiber carrier 6466 such that a centerline CLsfof forming fiber carrier 6466 is held approximately midway between first tool member 6462 and second tool member 6482 as first tool member 6462 and second tool member 6482 move relative to each other and / or relative to distal joint member 6610. Similarly, the rotational position of the molded fiber carrier 6466 is associated with the average of the first yaw angle of the first tool element 6462 and the second yaw angle of the second tool element 6482. The orientation of the molded fiber carrier 6466 with respect to the average yaw angle is affected by the spring constant of the two clock springs 6864 and 6865. For example, if clock springs 6864 and 6865 have the same spring constant and friction and other losses are identical, then the counterforces applied to molded fiber carrier 6466 are identical and molded fiber carrier 6466 is held in the intermediate position between first tool member 6462 and second tool member 6482. However, small differences in spring constant between clocksprings (e.g., due to manufacturing tolerances, etc.) may result in the rotational position of the molded fiber carrier 6466 slightly deviating from the average of the first yaw angle of the first tool element 6462 and the second yaw angle of the second tool element 6482. Accordingly, in some embodiments, each of the instruments described herein (including instrument 6400) may include an electronic circuit system as described herein (see, e.g., electronic circuit board 1815 and methods described below) that may include a calibration module to ensure that an adjusted signal representative of the average yaw angle is generated. Thus, the forming fiber 6588 (coupled to the forming fiber carrier 6466) is aligned along the forming fiber vector V (shown in FIG. 37 ) associated with the average of the first yaw angle of the first tool element 6462 and the second yaw angle of the second tool element 6482, and outputs a signal associated with the vector V.When one of the first tool members 6462 and / or the second tool member 6482 rotates relative to the other tool member such that a direction of the average of the positions of the tool members 6462, 6482 changes (e.g., relative to the distal joint member 6610), the molded fiber carrier 6466 moves through the coupling between the torsion spring mechanism 6860 and the first tool member 6462 and the second tool member 6482. The molded fiber carrier 6466 rotates relative to the distal joint member 6610 about the tool axis A 1. This in turn causes the forming fiber 6588 to move. The rotation or orientation of the molded fiber carrier 6466 is associated with an average of a first yaw angle of the first tool element 6462 and a second yaw angle of the second tool element 6482. More specifically, the measurement of the position of the tool elements 6462, 6482 is determined as the forming fiber 6588 bends relative to the average between the two tool elements 6462, 6482. The use of the torsion spring mechanism 6860 is associated with the movement of the first tool member 6462 and the second tool member 6482 and the forming fiber 6588. In some embodiments, the design of the clockspring may also accommodate the limits of the bending radius of the molded fiber 6588 and the straight portion at the distal end portion 6589 of the molded fiber 6588. As the forming fiber 6588 moves or bends, the forming fiber 6588 generates a signal related to the movement of the forming fiber 6588. In some embodiments, the signal generated by the forming fiber 6588 is associated with an average of a first yaw angle of the first tool element 6462 and a second yaw angle of the second tool element 6482.As described herein, torsion spring mechanism 6860 may enable the use of a single molded fiber sensor (e.g., molded fiber 6588) to determine the position of the two tool members 6462 and 6482. The single molded fiber sensor can be used to determine the position and orientation of the tool members 6462, 6482, where the molded fiber 6588 is not directly connected to the tool members 6462, 6482. In addition to providing information about the position and orientation of the tool members 6462, 6482, in some embodiments, the movement of the molded fiber carrier 6466 also causes the molded fiber to generate a signal related to the movement of the distal joint member 6610. In some embodiments, the movement of the molded fiber carrier 6466 additionally causes the molded fiber 6588 to generate a signal related to the movement of a proximal joint and / or joint member such as the proximal joint member and other flexible instrument portions (e.g., a flexible instrument shaft). Accordingly, the molded fiber 6588 can be used to determine the position and orientation of the tool members 6462, 6482 as well as other parts of the medical device.FIG. 39 is a flow diagram illustrating a method of assembling a medical device described herein with a molded fiber sensor (e.g., 2588, 3588, 4588, 5588, 6588) to generate a signal related to motion of the molded fiber sensor associated with an average of a first yaw angle of a first tool element and a second yaw angle of a second tool element of the medical device. A method 90 includes providing, at 91, an instrument having a first tool member (e.g., a first jaw) and a second tool member (e.g., a second jaw) connected to a distal joint member. At 92, a forming fiber carrier is pivotally connected to the distal link, the forming fiber carrier defining a forming fiber lumen. At 93, a distal end of a forming fiber is coupled to the forming fiber carrier such that the forming fiber is indirectly coupled to the first tool member (e.g., a jaw) and the second tool member (e.g., a second jaw), and movement of the forming fiber carrier causes the forming fiber to generate a signal related to movement of the first and / or second jaws. For example, the distal end of the forming fiber may be fixedly connected to the forming fiber carrier within the forming fiber lumen. At 94, an intermediate coupling mechanism is optionally coupled to the forming fiber carrier such that the forming fiber is indirectly coupled to the first and second jaws via the forming fiber carrier and the intermediate coupling mechanism. The intermediate clutch mechanism may be, for example, a differential with transmission, a cam mechanism, a torsion spring mechanism, or any other suitable mechanism that functions as described herein.The medical devices described herein can be used to control the movement of the tool members (e.g., jaws) and process the signals generated by the molded fiber sensor (e.g., 2588, 3588, 4588, 5588, 6588). A medical device may include, for example, a first tool element and a second tool element, each connected to a distal joint member, a molded fiber carrier pivotably connected to the distal joint member, and a molded fiber fixedly connected in a molded fiber lumen of the molded fiber carrier, wherein the molded fiber is indirectly connected to the first tool element and the second tool element (e.g., the molded fiber is spaced apart from the tool elements). A method of using the medical device may include rotating the first or second tool member such that the molded fiber carrier is twisted and the molded fiber generates a signal proportional to the movement of the first or second tool member. For example, the signal generated by the forming fiber may include a signal associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.In some embodiments, each of the instruments or systems described herein may include an electronic circuit system (e.g., an instrument board or controller) to generate output from the molded fiber. The output may be used, for example, to provide haptic feedback to the user control unit 1100. In some embodiments, each of the instruments may include a printed circuit board including a memory and / or process that may be calibrated during manufacture such that the output of the molded fiber sensor is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw. For example, a schematic diagram of an embodiment of suitable components that may be included in an electronic circuit board 1815 is shown in FIG. 40. In some embodiments, the electronic circuit board 1815 is located within the instrument 1400 (e.g., within a proximal mechanical structure). In other embodiments, electronic circuit board 1815 is a component of other parts of surgical system 1000, such as user control unit 1100 and / or optional accessory unit 1150. However, the electronic circuit board 1815 may also include distributed computing systems in which at least a portion of the electronic circuit board 1815 is located at a location different from the remaining components of the surgical system 1000, e.g., at least a portion of the electronic circuit board 1815 may be an online controller.As shown, electronic board 1815 includes one or more processors 1802 and one or more associated memory devices 1804 configured to perform a plurality of computer-implemented functions (e.g., performing methods, steps, computations, and the like, and storing relevant data, as disclosed herein). In some embodiments, the electronic circuit board 1815 also includes a jaw sensor module 1806 to facilitate communication between the electronic circuit board 1815 and the various components of the surgical system 1000, such as the molded fiber sensors described herein.As used herein, the term "processor" refers not only to integrated circuits referred to in the art as being part of a computer, but also to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLD), an application specific integrated circuit, and other programmable circuits. Moreover, the storage device(s) 1804 may generally include one or more storage elements including, but not limited to, a computer readable medium (e.g., random access memory (RAM)), a computer readable non-transitory medium (e.g., flash memory), a floppy disk, a compact disc read-only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD), and / or other suitable storage elements. This memory device(s) 1804 may generally be configured to store suitable computer readable instructions, which, when implemented by the processor(s) 1802, configure the controller 1800 to perform various functions.In some embodiments, the electronic circuit board 1815 may be operatively coupled to (or include) a haptic feedback controller 1820. The haptic feedback controller 1820 may be configured to provide the operator with haptic feedback based on the inputs received from one of the fiber shape sensors described herein included in the device 1400.The jaw sensor module 1806 may include a sensor interface 1810 (e.g., one or more analog-to-digital converters) that enables signals transmitted from one or more sensors (e.g., molded fiber sensors 2588, 3588, 4588, 5588, 6588) to be converted to signals that may be understood and processed by the processors 1802. The sensors may be connected to the communication module 1806 in any suitable manner. The sensors may be connected to the communication module 1806, for example, via a cable connection and / or via a wireless connection, for example, via a suitable wireless communication protocol known in the art. The jaw sensor module 1806 may also include an output module 1812 configured to generate outputs in communication with the molded fiber sensors. The outputs generated may be, for example, one or more signals associated with an average yaw position of the jaws.Moreover, in some embodiments, communication module 1806 includes a calibration module 1814 configured to adjust the signals of the molded fiber sensors generated herein. In some embodiments, for example, the calibration module 1814 may include a calibration table or curve (e.g., an equation) that relates the output of a molded fiber (e.g., molded fiber sensors 2588, 3588, 4588, 5588, 6588) to the actual average of the first yaw angle of the first tool element and the second yaw angle of the second tool element as measured during assembly of the instrument. Similarly, the calibration table (or calibration curve) may describe a correlation between the orientation of the molded fiber sensor (e.g., the orientation of the housing 4280 or molded fiber carrier 6466) and the actual average of the first yaw angle of the first tool element and the second yaw angle of the second tool element. In some embodiments, the calibration table (or calibration curve) may provide a gain factor to account for the reduced range of motion of the molded fiber sensor compared to the range of motion of the jaws. For example, in some embodiments where the molded fiber sensor moves at a ratio of less than 1:1 to jaw movement (e.g., in embodiments using a differential), the calibration table (or calibration curve) may include a multiplication factor. In use, the calibration module may facilitate methods for generating an adjusted output signal that is specific (or unique) to the instrument. In this way, the calibration module and methods may ensure that the molded fiber sensor output signal accounts for minor differences (e.g., due to part-to-part variations, minor differences in friction, manufacturing tolerances, etc.) in the components of the inter-coupling mechanisms described herein. The calibration module and methods may also account for differences in the range of rotation of the motion between the jaws and the molded fiber sensor (e.g., in embodiments where a differential is used).In some embodiments, each of the instruments described herein may include an electronic circuit system (e.g., system 1815) and perform methods for adjusting a signal output from a molded fiber. For example, FIG. 41 is a flow diagram of a method 190 for generating an adjusted output signal from a molded fiber sensor of a medical instrument, according to an embodiment. The medical instrument may be any of the medical instruments described herein and includes a proximal joint member, a first jaw coupled to the distal joint member, a second jaw coupled to the distal joint member, a molded fiber carrier rotatable relative to the distal joint member and defining a molded fiber lumen in which the molded fiber sensor is coupled, at least one memory device, and at least one processor operatively connected to the memory device. The method includes receiving a signal from the molded fiber sensor at the processor in response to movement of the first and / or second jaws, at 192. The method includes determining an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw based on the signal in a calibration module stored in the memory device at 193. The method includes providing the adjusted output signal associated with the average of the first yaw angle and the second yaw angle at 194.FIG. 42 is a flow diagram of a method 290 for calibrating a molded fiber sensor of a medical instrument, according to an embodiment. The medical instrument may be any of the medical instruments described herein and includes a proximal joint member, a first jaw coupled to the distal joint member, a second jaw coupled to the distal joint member, a molded fiber carrier rotatable relative to the distal joint member and defining a molded fiber lumen in which the molded fiber sensor is coupled, at least one memory device, and at least one processor operatively connected to the memory device. The method includes positioning the first jaw and the second jaw at a first average yaw angle ( 292). On condition that the first jaw and the second jaw are in the first average yaw angle, a first signal is received from the molded fiber sensor (293). The method includes assigning a value of the first signal to the first average yaw angle in a calibration module stored in the memory device ( 294). The first jaw and the second jaw are positioned at a second average yaw angle (295). The method includes receiving a second signal from the molded fiber sensor on condition that the first jaw and the second jaw are at the second average yaw angle (296). The method includes assigning a value of the second signal to the second average yaw angle in the calibration module (297) stored in the memory device.While various embodiments have been described above, it should be understood that the embodiments have been presented by way of example only and not limitation. In the methods and / or schemes described above, if certain events and / or flow patterns occur in a particular order, the order of certain events and / or operations may be changed. Although the embodiments have been particularly shown and described, various changes in form and details may be made.For example, all instruments described herein (and the components included therein) are optionally parts of a surgical assembly that performs minimally invasive surgical procedures and that may include a manipulator unit, a series of kinematic connections, a series of cannulas, or the like. Thus, any of the instruments described herein may be used in any suitable surgical system, such as the MIRS system 1000 shown and described above. Moreover, any of the instruments shown and described herein can be used to manipulate target tissue during surgery. This target tissue can be cancer cells, tumor cells, lesions, vascular occlusions, thromboses, concretions, uterine myomas, bone metastases, adenomamyosis, or any other body tissue. The presented examples of target tissues are not an exhaustive list. Moreover, a target structure may also be an artificial substance (or non-tissue) within or in connection with a body, such as a stent, a portion of an artificial tube, a fixation element within the body, or the like.For example, any of the components of a surgical instrument described herein may be made of any material, such as medical stainless steel, nickel alloys, titanium alloys, or the like. In addition, each of the members, tool elements, tension elements or components described herein may be comprised of multiple parts that are joined together later. In some embodiments, a member may be manufactured, for example, by assembling separately constructed components. In other embodiments, however, the members, tool elements, tension elements or components described here can also be constructed monolithically.Although the instruments are generally illustrated with the axis of rotation of the tool elements (e.g., axis A 1) perpendicular to an axis of rotation of the wrist links (e.g., axis A 2, axis A 3), each of the instruments described herein may also have an axis of rotation of the tool elements offset by any angle from the axis of rotation of the wrist.Although various embodiments have been described with specific features and / or combinations of components, other embodiments with a combination of arbitrary features and / or components from one of the above-described embodiments are also possible. The aspects have been described in the general context of medical devices and, in particular, surgical instruments, but the inventive aspects are not necessarily limited to use in medical devices.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 63 / 618,704

[0001] U.S. Pat. No. 5,792,135

[0003] U.S. Pat. No. 8,358,883 B2

[0042] US 63 / 233,904 [0044, 0069, 0071, 0086, 0101]US 2020 / 0390430

[0069] US 2015 / 0047454 A1

[0072] U.S. Pat. No. 6,817,974 B2

[0072] US 63 / 319,926

[0073] US 2020 / 0390430 [0086, 0101]

Claims

A medical device comprising: a distal joint member; a first jaw and a second jaw each connected to the distal joint member; a molded fiber carrier pivotably connected to the distal joint member and defining a molded fiber lumen; and a molded fiber having a distal end fixedly connected to the molded fiber lumen, wherein the molded fiber is indirectly connected to the first jaw and the second jaw, and wherein movement of the molded fiber carrier causes the molded fiber to generate a signal correlated with movement of the first and / or second jaws.The medical device of claim 1, further comprising: an intermediate coupling mechanism coupled to the molded fiber carrier; and the molded fiber indirectly connected to the first and second jaws through the molded fiber carrier and the intermediate coupling mechanism.The medical device of claim 2, wherein: the intermediate coupling mechanism is a differential coupled between the first jaw and / or the second jaw and also the molded fiber carrier; and the molded fiber is indirectly connected to the first jaw and the second jaw via the differential and the molded fiber carrier.The medical device of claim 2, wherein: the intermediate coupling mechanism comprises a cam mechanism that indirectly couples the molded fiber to the first and / or second jaws.The medical device of claim 2, wherein: the intermediate coupling mechanism therebetween comprises a torsion spring that indirectly connects the molded fiber to the first and / or second jaws.The medical device of claim 1, wherein: the signal generated by the molded fiber includes a signal associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.The medical device of claim 1, wherein: the molded fiber support is pivotally connected to the distal joint member about a first axis; and the first jaw and the second jaw are each pivotally connected to the distal joint member about a second axis, the second axis being offset from the first axis.The medical device of claim 3, wherein: the differential comprises a housing, a first planet gear, a second planet gear, and ring gear; the medical device further comprises a transmission, a first sun gear, and a second sun gear; the first sun gear is fixedly connected to the first jaw and coupled to the housing of the differential, the second sun gear is fixedly connected to the second jaw and coupled to the housing of the differential; the ring gear is integrated with the housing and coupled to the transmission, and the transmission is coupled to the molded fiber carrier; the housing of the differential is configured to rotate as one of the first jaw and the second jaw rotates relative to the other jaw, the rotation of the housing causing rotation of the molded fiber carrier and the molded fiber; and an orientation of the housing is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.The medical device of claim 8, wherein the molded fiber generates a signal correlated with an average of a yaw angle of the first jaw and a yaw angle of the second jaw based on the orientation of the housing.The medical device of claim 3, wherein: the motion of the form fiber carrier is limited by the differential.The medical device of claim 3, wherein: the molded fiber carrier comprises a gear coupled to the differential.The medical device of claim 1, wherein: the movement of the forming fiber carrier causes the forming fiber to generate a signal correlated with the movement of the distal joint member.The medical device of claim 1, wherein: the movement of the forming fiber carrier causes the forming fiber to generate a signal correlated with the movement of a proximal joint.A medical device, comprising: a distal joint member; a first jaw and a second jaw, each connected to the distal joint member; a position sensor coupled to the distal joint member; and a differential connected to the position sensor, the first jaw, and the second jaw, wherein movement of the first and / or the second jaw relative to the respective other jaw generates a sensor movement of the position sensor via the differential, and the position sensor generates a signal associated with the sensor movement.The medical device of claim 14, wherein: the signal generated by the position sensor is correlated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.The medical device of claim 14, wherein: the position sensor is a molded fiber, the medical device includes a molded fiber carrier coupled to the differential, and the molded fiber is at least partially placed in a lumen of the molded fiber carrier.The medical device of claim 16, wherein: the differential comprises a housing, a first planet gear, a second planet gear, and a ring gear; the medical device further comprises a transmission, a first sun gear, and a second sun gear; the first sun gear is fixedly connected to the first jaw and is coupled to the housing of the differential, the second sun gear is fixedly connected to the second jaw and is coupled to the housing of the differential; the ring gear is integrated with the housing and is coupled to the transmission and the transmission is coupled to the form fiber carrier; the housing of the differential is configured to rotate when one of the first jaw and the second jaw rotates relative to the other jaw, the rotation of the housing causes rotation of the position sensor; and an orientation of the housing is associated with an average of a first yaw angle of the first jaw and a second yaw angle of the second jaw.The medical device of claim 17, wherein the position sensor generates a signal associated with the average of the first yaw angle of the first jaw and the second yaw angle of the second jaw based on the orientation of the housing.The medical device of claim 16, wherein: the motion of the form fiber carrier is limited by the differential.The medical device of claim 19, wherein: the motion of the form fiber carrier is limited to + / - 45 degrees relative to a centerline of the form fiber carrier.

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