Combination and / or homing of surgical tools in surgical robotic systems

Abstract

In a surgical robot system, coupling and / or homing are provided for the motor control unit of a surgical instrument. When two or more motors control the same motion, the motors can be used to detect coupling even when no physical stop is provided. The motors operate in a manner that does not attempt opposite or identical motions to each other, so that upon coupling, one of the motors acts as a stop for the other motor. Then, a change in motor operation indicates coupling. A known angle of transmission linking the coupled motor and motor drive to the surgical instrument indicates the groove or current position of the surgical instrument.

Description

Technology Field

[0001] The embodiment relates to a control unit for detecting the successful engagement and / or homing of a surgical robotic tool by means of one or more actuators within a surgical robotic arm of a surgical robotic system. Other embodiments are also described. Background Technology

[0002] A surgical robot system provides an operator or user, such as a surgeon, with the ability to perform one or more actions of a surgical procedure using the surgical robot system. In a surgical robot system, surgical tools or instruments, such as endoscopes, clamps, cutting tools, spreaders, needles, energy emitters, etc., are mechanically coupled to the robot joints of the surgical robot arms, so that the movement or operation of the robot joints directly causes rotation, pivoting, or linear movement of parts of the tools (e.g., rotation of the endoscope camera, pivoting of the grabber jaw, or translation of the needle). Once the tool is attached to (e.g., contacted) the tool drive within the arm, operator commands can cause movement of the attached tool and activate its functions, such as closing the clamp, adjusting the bend of the endoscope, extending the instrument outward from the cannula wall, applying pressure using the clamping tool, as well as other movements and actions.

[0003] Due to the diverse characteristics of surgical procedures, different surgical tools or instruments may be selectively attached to the same arm of the surgical robot system before and during the surgical procedure. To prevent equipment malfunction during the surgical procedure, it is important that the surgical tools or instruments are not only mechanically attached to the robotic joint of the surgical robot arm but also coupled. That is, before the surgical tool is used during the surgical procedure, a mechanism within the surgical tool that imparts movement to the instrument's features or enables its activation (e.g., opening, closing, cutting, applying pressure, etc.) must be mechanically coupled to an actuator located within the tool drive unit of the surgical robot system's arm.

[0004] As an introduction, the preferred embodiments described below include a method, system, instructions, and a computer-readable medium for coupling and / or homing the motor control unit of a surgical tool in a surgical robot system. When two or more motors control the same motion, the motors may be used to detect coupling even when no physical stop is provided. The motors operate in a manner that does not attempt opposite or identical motions to each other, so that when coupled, one of the motors acts as a stop for the other motor. Then, a change in motor operation indicates coupling. Known angles of transmission linking the coupled motors and motor drives to the surgical tool indicate the home or current position of the surgical tool.

[0005] In a first embodiment, a method for coupling a motor control unit of a surgical tool in a surgical robot system is provided. First and second motors connected to first and second drive discs, respectively, are rotated. The first and second drive discs come into contact with first and second tool discs. Both the first and second tool discs are linked to the surgical tool. The first and second motors rotate such that the first and second drive discs rotate in opposite directions to each other for the movement of the surgical tool. The coupling of the first and second motors with each of the first and second discs is detected from a change in the performance of the first and second motors.

[0006] In a second aspect, a surgical robot system for coupling a motor control unit in a robotic surgical system is provided. A surgical tool is connected by transmission to first and second rotary tool pads. The surgical tool is connected such that the rotation of the first and second rotary tool pads rotates the surgical tool. The tool drive unit has first and second rotary drive units that are alignable with the first and second rotary tool pads. A processor is configured to detect the alignment of the first and second rotary tool pads with the first and second rotary drive units by a change in a signal.

[0007] In a third aspect, a method for homing the rotational position of a surgical tool in a surgical robot system is provided. The coupling of first and second rotational tool pads with first and second rotational drive units is detected. Once the coupling is detected, the rotational angle of the surgical tool linked to the first and second rotational tool pads is determined from the first and second rotational angles of the first and second rotational drive units.

[0008] The present invention is limited by the following claims, and nothing in this section shall be construed as a limitation to such claims. Further aspects and advantages of the present invention are discussed below with reference to preferred embodiments and may subsequently be claimed independently or in combination. Brief explanation of the drawing

[0009] Embodiments of the present invention are illustrated as examples, not limitations, in the accompanying drawings where similar reference numerals denote similar elements. It should be noted that references to "one" or "one" embodiment of the invention disclosed herein do not necessarily refer to the same embodiment, but mean at least one. Furthermore, for the sake of brevity and to reduce the total number of drawings, the given drawings may be used to illustrate features of more than one embodiment of the invention, and not all elements of the drawings may be required for a given embodiment. FIG. 1 is a drawing using an illustration of an exemplary surgical robot system in an operating arena. FIG. 2 is an example of a system for detecting the coupling of a surgical tool to a tool drive unit of a surgical robot arm. FIG. 3 is a block diagram illustrating a surgical tool, a tool drive unit, and a control unit. FIGS. 4a to 4c are drawings illustrating different states of the tool disk and the drive disk during the joining process. FIG. 5a is a flowchart illustrating a process performed by a control unit to combine a surgical tool with a tool drive unit. FIG. 5b is a flowchart illustrating another process for a control unit to detect the coupling of a tool disk to a drive disk based on one or more operating parameters of an actuator that drives a drive disk. FIG. 5c is a flowchart illustrating another process for a control unit to detect the coupling of a surgical tool with a tool drive unit of a surgical robot system. Figure 6 is a block diagram of a feedback loop. FIG. 7 is a block diagram of a controller for use in a feedback loop. FIG. 8 is a diagram illustrating an example of the relationship between the rotation angles between the motor and the corresponding drive unit disk, tool disk, and surgical tool. FIG. 9 is a drawing illustrating one embodiment of a driving current used in coupling. FIG. 10 is a flowchart illustrating another process for a control unit to detect coupling and / or homing. Specific details for implementing the invention

[0010] Embodiments of an apparatus, system, and method for detecting the coupling of a detachable surgical robot tool to a tool drive unit of a surgical robot arm of a surgical robot system are described herein. In the following description, a number of specific details are provided to provide a complete understanding of the embodiments. However, those skilled in the art will recognize that the techniques described herein may be implemented without one or more of the specific details, or by other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not illustrated or described in detail to avoid obscuring certain aspects.

[0011] Throughout this specification, references to "one embodiment" or "one embodiment" mean that a specific feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment of the present invention. Accordingly, the appearance of the phrases "in one embodiment" or "in one embodiment" in various places throughout this specification does not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics such as those illustrated in different drawings may be combined in any suitable manner in one or more embodiments.

[0012] Referring to FIG. 1, this is a drawing using an illustration of an exemplary surgical robot system (100) in a surgical arena. The surgical robot system (100) includes a user console (102), a control tower (103), and one or more surgical robot arms (104) on a surgical platform (105), such as a table, bed, etc. The surgical robot system (100) may incorporate any number of devices, tools, or accessories used to perform surgery on a patient (106). For example, the surgical robot system (100) may include one or more surgical tools (107) used to perform surgery. The surgical tool (107) may have an end effector at its distal end (also the distal end of the robotic surgical arm (4) to which the surgical tool (107) is attached) for performing surgical operations such as cutting, grasping, poking, or energy release.

[0013] Each surgical tool (107) may be operated manually, robotically, or both during surgery. For example, the surgical tool (107) may be a tool used to enter, observe, or manipulate the internal anatomical structure of the patient (106). In one embodiment, the surgical tool (106) is a gripper capable of grasping the patient's tissue. The surgical tool (106) may be controlled manually and directly by the hand of a bedside operator (108); or it may be controlled robotically through the transmission of electronic commands to operate the movement of the surgical robot arm (104) to which the surgical tool (106) is attached. The surgical robot arm (104) is shown as a table-mounted system, but in other configurations, the surgical robot arm (104) may be mounted on a cart, ceiling or side wall, or other suitable structural support.

[0014] Generally, a remote operator (109), such as a doctor, may use a user console (102) for teleoperation, for example, to remotely operate the surgical robot arm (104) and the attached surgical tool (107). The user console (102) may be located within the same operating room as the rest of the surgical robot system (100), as illustrated in FIG. 1. However, in other environments, the user console (102) may be located within an adjacent or nearby room, or it may be in a remote location, for example, in a different building, city, or region. The user console (102) may include a seat (110), a foot-operated control (113), one or more handheld user interface devices (UIDs) (114), and at least one user display (115) configured to display a view of the surgical site, for example, inside the patient (106). In an exemplary user console (102), a remote operator (109) sits in a seat (110) and observes a user display (115) while operating a foot-operated controller (113) and a handheld UID (114) to remotely control a surgical robot arm (104) and a surgical tool (107) (mounted on the distal end of the surgical arm).

[0015] In some variations, the bedside operator (108) may also operate the surgical robot system (100) in "over the bed" mode, where the bedside operator (108) (user) is now at the side of the patient (106) and simultaneously operates i) a robot-driven tool (having an end effector) attached to the surgical robot arm (104) with, for example, a handheld UID (114) held in one hand, and ii) a manual laparoscopic tool. For example, the bedside operator's left hand may operate the handheld UID to control the surgical robot components, while the bedside operator's right hand may operate the manual laparoscopic tool. Thus, in these variations, the bedside operator (108) may perform both robot-assisted minimally invasive surgery and manual laparoscopic surgery on the patient (106).

[0016] During an exemplary procedure (surgery), the patient (106) is prepared for surgery and draped in a sterile manner to achieve anesthesia. Initial access to the surgical site may be performed manually while the arm of the surgical robot system (100) is in a stowed configuration or withdrawn configuration (to facilitate access to the surgical site). Once access is complete, initial positioning or preparation of the surgical robot system (100), including its surgical robot arm (104), may be performed. Next, the surgery proceeds with a remote operator (109) on a user console (102) using a foot-operated controller (113) and UID (114) to operate various end effectors and possibly imaging systems to perform the surgery. Manual assistance may also be provided on the operating bed or table by a sterile-gowned bedside operator (108) capable of performing tasks such as tissue retraction, performing manual repositioning, and exchanging tools on one or more of the surgical robot arms (104). There may also be a non-sterile operator to assist the remote operator (109) at the user console (102). When the procedure or surgery is completed, the surgical robot system (100) and the user console (102) may be configured or set to a state to facilitate postoperative procedures, such as cleaning or sterilization and inputting or outputting healthcare records through the user console (102).

[0017] In one embodiment, a remote operator (109) holds and moves a UID (114) to provide an input command to move a robot arm actuator (117) in a surgical robot system (100). The UID (114) may be coupled to the rest of the surgical robot system (100) communically, for example, through a console computer system (116). The UID (114) may generate a spatial state signal corresponding to the movement of the UID (114), for example, the position and orientation of the handheld housing of the UID, and the spatial state signal may be an input signal for controlling the movement of the robot arm actuator (117). The surgical robot system (100) may use a control signal derived from the spatial state signal to control the proportional movement of the actuator (117). In one embodiment, a console processor of the console computer system (116) receives the spatial state signal and generates a corresponding control signal. Based on these control signals that control how the actuator (117) is powered to move a segment of the surgical robot arm (104), the movement of the corresponding surgical tool attached to the arm can mimic the movement of the UID (114). Similarly, the interaction between the remote operator (109) and the UID (114) can generate a gripping control signal that causes, for example, the jaws of the gripper of the surgical tool (107) to close and grip the tissue of the patient (106).

[0018] The surgical robot system (100) may include several UIDs (114), each of which generates a control signal for each UID that controls the surgical tool (end effector) and actuator of each surgical robot arm (104). For example, a remote operator (109) may move a first UID (114) to control the movement of an actuator (117) within the left robot arm, wherein the actuator responds by moving a linkage, gear, etc., within such surgical robot arm (104). Similarly, the movement of a second UID (114) by the remote operator (109) controls the movement of another actuator (117), which subsequently moves another linkage, gear, etc., of the surgical robot system (100). A surgical robot system (100) may include a right surgical robot arm (104) fixed to a bed or table to the right of the patient, and a left surgical robot arm (104) to the left of the patient. An actuator (117) may include one or more motors, and the motors are controlled to drive the rotation of the joints of the surgical robot arms (104) to change the orientation of, for example, a grasper of a surgical tool (107) or an endoscope attached to such arms relative to the patient. The movement of several actuators (117) within the same surgical robot arm (104) may be controlled by a spatial state signal generated from a specific UID (114). The UID (114) may also control the movement of each surgical tool grasper. For example, each UID (114) can generate a respective gripping signal to control the movement of an actuator, such as a linear actuator, that opens or closes the jaws of a gripper at the distal end of a surgical tool (107) to grip tissue within a patient (106).

[0019] In some cases, communication between the surgical platform (105) and the user console (102) may be made through a control tower (103), which can convert user commands received from the user console (102) (and more specifically from the console computer system (116)) into robot control commands transmitted to the surgical robot arm (104) on the surgical platform (105). The control tower (103) may also transmit status and feedback from the surgical platform (105) back to the user console (102). Communication connections between the surgical platform (105), the user console (102), and the control tower (103) may be made via wired and / or wireless links using any suitable protocol among various data communication protocols. Any wired connection may optionally be embedded in the floor and / or walls or ceiling of the operating room. The surgical robot system (100) may provide video output to one or more displays, including a display within the operating room as well as a remote display accessible via the Internet or another network. Video output or feeds may also be encrypted to ensure privacy, and all or part of the video output may be stored on a server or electronic healthcare record system.

[0020] FIG. 2 is an example of a subsystem or part of a surgical robot system (100) for detecting the coupling of a surgical tool (240) to a tool drive unit (230) of a surgical robot arm (220). The surgical robot arm (220) may be one of the surgical robot arms (104) of the surgical robot system (100) exemplified and discussed in relation to FIG. 1. The control unit (201) may be, for example, part of the control tower of FIG. 1. As discussed in more detail herein, coupling may be detected by the control unit (210) based on one or more motor operating parameters of one or more actuators (e.g., actuator (238-j)) within the tool drive unit (230).

[0021] There is a tool drive unit (230) to which different surgical tools (e.g., surgical tool (240), as well as other detachable surgical tools—not shown) can be selectively attached (one at a time). This can be done, for example, by a human user holding the housing of the surgical tool (240) in their hand and moving the surgical tool in the direction of the illustrated arrow (280) until the outer surface of the surgical tool (240) having one or more tool discs (e.g., tool disc (244-i)) comes into contact with the outer surface of the tool drive unit (230) having one or more drive unit discs (e.g., drive unit disc (234-j)). In the illustrated example, the tool drive unit (230) is a segment of the surgical robot arm (220) at the distal end portion of the surgical robot arm (220). The proximal end portion of the arm (220) is fixed to a surgical robot platform, such as a surgical table, which is not shown in FIG. 2 but whose example can be seen in FIG. 1.

[0022] The control unit (210) is responsible for controlling the movement of various motorized joints within the surgical robot arm (220) (including the drive unit disk (234)), thereby enabling the operation of the end effector (246) (its position and orientation as well as its surgical function) which mimics the operation of a user input device. This is achieved through mechanical transmission within the surgical tool (240) when the surgical tool (240) is coupled to transmit force or torque from the tool drive unit (230). The control unit (210) is a programmed processor and may be implemented, for example, as part of the control tower (103) of FIG. 1. It may respond to one or more user commands received through a local or remote user input unit (e.g., a joystick, a touch controller, a wearable device, or another user input device communicating via the console computer system (116). Alternatively, the control unit (210) may respond to one or more autonomous commands or controls, or a combination thereof (e.g., received from a trained surgical machine learning model being executed by the control unit (210) or the console computer system (116). The commands direct the movement of the robot arm (220) and the operation of its attached end effector (246).

[0023] The end effector (246) may be any surgical instrument such as a jaw, cutting tool, endoscope, spreader, implant tool, etc. Different surgical instruments having different end effectors may be selectively attached to the robotic arm (220) (one at a time) for use during surgery or other medical procedures. The end effector (246) illustrated in the example of FIG. 2 is a jaw located at the distal end of the surgical instrument (240) and may retract into or extend outside the cannula (e.g., a thin tube that can be inserted into a patient undergoing a surgical procedure) as illustrated.

[0024] The robot arm (220) includes a tool drive unit (230), and within the tool drive unit there is one or more actuators such as actuators (238-j). Each actuator may be a linear or rotary actuator having one or more electric motors (e.g., brushless permanent magnet DC motors) whose drive shafts can be coupled to each drive unit disk (234-j) through a transmission (e.g., a gear train achieving a given gear reduction ratio - not shown). The tool drive unit (230) includes one or more drive unit disks (234) that can be arranged on a planar or flat surface of the tool drive unit (230), wherein the drawing shows several such drive unit disks arranged on the same plane of the flat surface. Each drive disc (e.g., drive disc (234-j)) is exposed on the outer surface of the tool drive unit (230) and is designed to be mechanically coupled (e.g., firmly connected via snap, friction, or other matching features) to the matching tool disc (244-j) of the surgical tool (240) to enable direct torque transmission between the two. This can occur once, for example, the flat or flat surface of the surgical tool (240) and the corresponding or matching flat or flat surface of the tool drive unit (230) come into contact with each other.

[0025] Additionally, a motor driver circuit (not shown, but may be installed, for example, within the tool drive unit (230) or elsewhere within the surgical robot arm (220)) is electrically coupled to the input drive terminal of one or more of the actuators (238) constituent motors. The motor driver circuit manipulates the power drawn by the motor to regulate the speed or torque of the motor, which may be set or controlled by the control unit (210), for example, according to the motor driver circuit input, and this causes the kinetic rotation of the associated drive unit disk (e.g., drive unit disk (234-j)).

[0026] When the matching drive unit disk (234-j) is mechanically coupled to each tool disk (244-j), the power rotation of the drive unit disk (234-j) causes the tool disk (244-j) to rotate, for example, these two disks rotate as a single unit to impart motion to a linkage device, gear, cable, chain, or other transmission means within the surgical tool (240) to control the movement and operation of an end effector (246) that can be mechanically coupled to a transmission means.

[0027] Different surgical tools may have different numbers of tool discs based on the type of movement, such as rotation, articular movement, opening, closing, extension, retraction, and pressure application, and the number of degrees of freedom in which movement is performed by their end effectors.

[0028] Additionally, within the surgical tool (240), more than one tool disk (244) can contribute to a single movement of the end effector (246) to achieve a goal such as load sharing by two or more motors driving the drive disk (234) that each matches.

[0029] In another sun, within the tool drive unit (230), there may be two or more motors that share a load and are coupled (via transmission) so that their drive shafts rotate the same output shaft (or drive unit disk (234)).

[0030] In another embodiment, within the surgical tool (240), there may be a transmission that converts torque from two drive discs (234) (via each tool disc (244)) to perform complementary movements with the same degree of freedom, for example, the first drive disc (234-i) rotates a drum within the housing of the surgical tool (230) to receive one end of a cable, and the second drive disc (234-j) rotates another drum within the housing of the surgical tool (230) to receive the other end of a cable. As another example, the extension and shortening of an end effector along a single axis can be achieved using two tool discs (234-i, 234-j), for example, via different cables, one performing extension and the other performing retraction. This contrasts with an effector that also moves with one degree of freedom (e.g., lengthwise extension and shortening along a single axis of movement) but requires only a single tool disc to control its entire range of movement. As another example, an effector moving with multiple degrees of freedom (e.g., wristed movement, movement along multiple axes, activation of an energy emitter in addition to end effector movement) may require the use of several tool discs (each coupled to a drive disc). In other types of surgical tools (240), a single tool disc (244) is sufficient to perform both extension and retraction movements through a direct input (e.g., a gear). As another example, where the end effector (246) is a jaw, two or more tool discs (244) may cooperatively control the movement of the jaw for load sharing, as discussed in more detail herein.

[0031] In some embodiments, when a surgical tool (240) is first attached to or installed on a tool drive unit (230) (although the tool disk and the drive unit disk are probably not yet successfully coupled) and the tool disk is aligned substantially in the same plane and coaxially with the corresponding drive unit disk, the control unit (210) initially detects the type of the surgical tool (240). In one embodiment, the surgical tool (240) has an information storage unit (242), such as a solid-state memory, an RFID tag, a barcode (including a two-dimensional or matrix barcode), which identifies its tool or end-effector information, such as identification of the tool or end-effector type, a unique tool or end-effector ID, the number of tool disks used, the position of such tool disks used (e.g., from a total of 6 possible tool disks (244-e, f, g, h, i, j)), the type of transmission for the tool disks (e.g., direct drive, cable drive, etc.), what movement or operation the tool disk imparts to the end-effector, one or more tool calibration values ​​(e.g., rotational position of the tool disk as determined during factory testing / assembly of the tool), whether the movement of the end-effector is constrained by a maximum or minimum movement, and one or more of other tool attributes. In one embodiment, the information storage unit (242) identifies minimal information, such as a tool ID, which the control unit (210) can use to search for various tool attributes.

[0032] The tool drive unit (230) may include a communication interface (232) (e.g., a memory writer, near field communication (NFC), a transceiver, an RFID scanner, a barcode reader, etc.) for reading information from an information storage unit (242) and transmitting the information to a control unit (210). Additionally, in some embodiments, there may be more than one information storage unit within the surgical tool (240), such as one information storage unit associated with each tool disk (244). In such embodiments, the tool drive unit (230) may also include a corresponding sensor for each possible information storage unit present within the given tool.

[0033] combination

[0034] After the surgical tool (240) is attached to the tool drive unit (230) (although not necessarily mechanically coupled) and the tool disk is aligned and superimposed on the corresponding drive unit disk, and after the tool disk information is acquired, for example, read by the control unit (210), the control unit (210) performs a coupling process to detect when all the tool disks expected to be attached to each drive unit disk are mechanically coupled to their respective drive unit disks (e.g., when their mechanical coupling is achieved, or when the tool drive unit is now considered coupled to the tool). That is, attaching the surgical tool (240) to the tool drive unit (230) does not necessarily guarantee the proper alignment required for the mechanical coupling of the tool disk with the corresponding drive unit disk (e.g., due to misalignment of the alignment features). The coupling process may include activating one or more motors of an actuator (e.g., actuator (238-j)) driving the corresponding drive unit disk (234-j). Subsequently, based on one or more monitored motor operation parameters of the actuator (238-j), while the actuator drives the drive disk (234-j), the mechanical coupling of the tool disk (244-i) with the drive disk (234-j) can be detected, as will be discussed in more detail below. This process can be repeated for all drive disks (234) (of the tool drive (230)) that are expected to be attached to each tool disk (244) at present (e.g., as determined based on tool disk information obtained for a specific surgical tool (240) currently attached).

[0035] When a specific type of surgical tool (240) is detected to be attached to a tool drive unit (230), the control unit (210) activates one or more actuators (e.g., motors) of the tool drive unit (230) that were previously associated with such a type of surgical tool (240). In some embodiments, each actuator associated with a corresponding drive unit disk (234) of the surgical tool (240) may be activated simultaneously, sequentially, or in a combination of simultaneous and sequential activation. FIG. 3 illustrates an example of a surgical tool (240) using four tool disks, such as tool disks (244-i), arranged in a coplanar manner on the matching surface of its housing. Each tool disk contributes to at least a portion of the movement and / or activation of the end effector (246). When detecting the attachment of the surgical tool (240) to the tool drive unit (230) (e.g., the joining of the matching surfaces of each housing), the control unit (210) (or its processor (312) which is executing instructions stored in memory (314) as a joining control (316)) performs a process of determining that only four corresponding drive disks, such as drive disks (234-j), need to be rotated to perform the joining process (corresponding actuators (238-j) need to be activated - see FIG. 2).

[0036] Returning to FIG. 2. During the operation of the actuator (238-j), after the detected attachment of the surgical tool (240) to the tool drive unit (230), one or more sensors (236-j) measure one or more motor operation parameters of the actuator (238-j) as signaled for its motor to start moving. In one embodiment, the actuator (238-j) will rotate in a direction that causes its attached tool disk (244-i) (although not yet coupled) to wind the cable within the transmission housing of the tool (240) for a cable-driven surgical tool. For example, refer to FIG. 4a, where the movement (445) of the tool disk (244) prevents the unwinding of the cable (446), thereby keeping the tool disk (244) in place or causing the tool disk (244) to start rotating in the direction of the movement (445) (winding the cable (446)). This rotation of the tool disk (244) continues until the coupling is achieved as further described later in relation to FIG. 4b and FIG. 4c.

[0037] In another embodiment, the selected actuator is signaled to rotate its attached tool disk (244) so ​​that the end effector (246) connected to the tool disk (244) moves toward a physical constraint (e.g., the jaws are open until they stop against the cannula wall, and the maximum range of motion is achieved when it strikes against a hard stop in a fully open position). In another embodiment, such as an endoscope embodiment where two actuators share the load of rotating the endoscope camera, where there may be no hard stop against the rotation of the camera, the selected actuator rotates its attached tool disk (244-i) in a direction opposite to the movement of another tool disk (244-j) which is also rotatably coupled to the same output shaft within the transmission housing of the tool (240). In such a case, as soon as one of the tool disks (244-i, 244-j) is coupled, it will act as a physical constraint for the other tool disk. Other predetermined directions of movement may also be used in consistency with the discussion in this specification.

[0038] Additionally, in some embodiments, the movement of the actuator is gradually ramped or increased by the control unit (210) (e.g., the control unit (210) signals or commands the actuator to start rotating at a slow speed at the start of the movement, then gradually increase the speed, and then gradually decrease the speed upon detection of coupling).

[0039] In one embodiment, a calibration value stored in the information storage unit (242) of the surgical tool (246) may be used to facilitate tool assembly. For example, the calibration value may include a factory-determined position (angle) of a specific tool disk (244-j) recorded during product assembly or testing. The assembly process may require knowledge of the home position of the corresponding drive disk (234-j). This knowledge may be obtained by the control unit (210) performing a tool drive calibration routine that determines when the specific drive disk (234-j) has reached the home position (as the control unit operates the drive disk (234-j), so that the position of such drive disk (234-j) is now known by the control unit (210). Note that the control unit (210) may do so relying only on the output from the position sensor within the tool drive (230), and that the tool (240) itself may be passive in that it does not have an electronic sensor inside.

[0040] Next, the control unit (210) can activate the corresponding actuator of the drive disk (234-j) to rotate the drive disk (234-j) at high speed until the position variable of the drive disk (234-j) approaches the factory-determined position. When the drive disk meets a critical distance to the factory-determined position (e.g., the groove position of the tool disk), which means that the matching features of the tool disk and the drive disk are nearly aligned, the speed can be reduced to increase the likelihood that the matching features will engage with each other at their initial contact. This process can be operated for both the direct transmission and the tool disk using a cable to drive the effector (as in FIG. 4a). In the latter case, the correction value may include a rotation count (e.g., a number of complete rotations of the motor drive shaft) that can be used to limit the continued rotation of the drive disk (234-j) once the coupling is detected, in order to ensure that the maximum length of the cable winding is not exceeded or that the rotation angle of the combined tool disk (244-j) and the drive disk (234-j) is not exceeded.

[0041] In some embodiments, motor operating parameters monitored by the control unit (210) (via the sensor (236)) are interpreted as signifying a successful mechanical coupling of the tool disk with the drive disk. These include a measurement of torque applied by the actuator (238-j), such as measured by a torque or force sensor; a measurement of the current supplied to the motor of the actuator (238-j) when attempting to drive the actuator to move it to a predetermined speed (e.g., where the sensor (236-j) may include a current sensing resistor in series with the motor input drive terminal); a measurement of the electrical impedance shown at the input drive terminal of the actuator's motor when attempting to drive the motor to move it to a predetermined speed (e.g., where the sensor (236-j) may also include a voltage sensing circuit for measuring the voltage at the motor input drive terminal); the speed of the actuator (238-j) (e.g., where the sensor (236-j) may include a position encoder (sensor) on the output shaft of the actuator (238-j) or on the drive shaft of the motor); and motor operating parameters referred to herein. Other parameters may be included. While monitoring one or more motor operating parameters of a specific actuator, when one or more of these parameters satisfy a predetermined condition or threshold (e.g., satisfy or reach), the detection of such a situation may be interpreted by the control unit (210) as a mechanical coupling event. It should be noted that satisfying a predetermined condition may mean, for example, that the monitored operating parameter indicates a certain change in the operating parameter of another motor that is part of the same actuator (238-j) or part of another actuator (238-i) that is simultaneously controlled by the control unit (210) during the coupling detection process, depending on the threshold.

[0042] In some embodiments, detection of certain motor operating parameters during the operation of the actuator (238-j), such as i) torque that meets a torque threshold (e.g., rises and reaches), ii) motor current that meets a current threshold (e.g., rises and reaches), iii) impedance that falls below an impedance threshold, iv) motor speed that falls below a motor speed threshold, or one or more combinations thereof, is used by the control unit (210) to determine that mechanical engagement of the tool disk (244-j) with the drive disk (234-j) has occurred. The following are some examples of such a process.

[0043] In one embodiment, when a tool disk (244-j) uses a cable (446) to control the movement of its end effector (246), an actuator (238-j) (driving the corresponding drive disk (234-j)) will move in a direction of winding the cable (wherein, the direction of movement (445) which the control unit (210) may have knowledge of, based on having a previously identified type of tool (240)). FIG. 4a illustrates such a tool disk (244) having a pair of coupling features (447a, 447b) on its disk surface, illustrated as a hollow circle. Each coupling feature (447a, 447b) may be a separate cylindrical cavity formed within the disk surface. The direction of motion (445) will wind the cable (446) around it, and here, under these initial conditions, the cable (446) has some slack as illustrated, which disappears as the cable (446) is wound in the direction of motion (445).

[0044] As shown in FIG. 4b, the driving disk (234) is aligned concentrically with the tool disk (244). That is, FIG. 4b illustrates the driving disk (234) aligned and superimposed on the tool disk (244) such that their respective disk surfaces are in contact with each other. The driving disk (234) has a pair of coupling features (448a, 448b) on its disk surface, which is illustrated as a solid circle. Each coupling feature (448a, 448b) may be a separate cylindrical pin formed on the disk surface. In this particular example, each of the coupling features (448) is sized so that it can be easily fitted into either of the features (447) once the two complementary features are aligned. In FIG. 4b, the feature parts (447a, 447b) and feature parts (448a, 448b) are misaligned even though the surfaces of their respective tool and drive disks are in contact with each other. In other words, in FIG. 4b, one or more matching or complementary pairs of feature parts, such as feature parts (447a-448a) or feature parts (447a-448b), are not yet mechanically coupled to each other. During such conditions, the drive disk (234) is continuously driven by its actuator (238) and moves (rotates) in the direction of movement (445) until mechanical coupling is reached under the conditions shown in FIG. 4c.

[0045] As illustrated in FIG. 4c, while rotating, the drive disk (234) reaches a point where both the coupling features (447a-448a) and the coupling features (447b-448b) are mechanically coupled to each other as illustrated, and they now move as a single unit (as the drive disk (234) continues to rotate). In the example of this specification, each pin-joint pair is now interlocked as illustrated in this figure. Additionally, at this point, the cable (446) is taught to be wound up and thus can serve to help keep the tool disk (244) in place (preventing its rotation) as the drive disk (234) continues to rotate in the direction of motion (445). Additional rotation of the drive disk (234) under the conditions of FIG. 4c can increase the tension within the cable (446) as the cable (446) pulls its end effector (246) until it reaches a hard stop that creates a physical constraint against additional movement in the direction of movement (445) of the combined drive disk (234).

[0046] The physical constraint on further rotation of the drive disk (234) enables the detection of a mechanical coupling event by having the control unit (210) perform a comparison against one or more thresholds that may be predetermined to indicate its measurement and coupling of motor operating parameters. For example, a motor speed / velocity falling below one or more thresholds indicates coupling because the motor is constrained from further movement in the winding direction. As another example, coupling occurs when the torque applied by the motor increases to a value greater than that of the freely moving motor and / or greater than the friction caused by the tool disk and the drive disk and / or attachment features rubbing or sliding against each other before coupling. Similarly, in another embodiment, the measured current and / or impedance may approach and reach a maximum predetermined value as coupling occurs and power continues to be supplied to the motor in an attempt to continue the movement of the drive disk in a predetermined direction. When one or more of these thresholds are satisfied, the control unit (210) may conclude that coupling has occurred between the tool disk and the drive disk.

[0047] Other forms of physical constraints may be used by the control unit (210) to detect successful coupling of the drive unit disk and the tool disk. For example, a mechanical limiting of the range of motion imparted by the joint of the end effector (e.g., a joint that can only rotate around an axis from -45 degrees to 45 degrees) or a motion constraint such as a physical barrier to movement (e.g., a cannula wall that prevents the movement of the end effector) may also be used as the physical constraint / hard stop discussed above for cable-driven or non-cable-driven tools.

[0048] In some embodiments, the surgical tool (240) may not have physical constraints / hard stops in at least one degree of freedom of movement from which motor operating parameters can be measured. For example, the tool disk (244-j) may be responsible for imparting unconstrained rotation of the end effector (246) element around an axis. However, even with such unconstrained movement, the control unit (210) can still detect the coupling of the drive disk (234-j) to the tool disk (244-j) by detecting a change in one or more motor operating parameters during the coupling detection process. For example, a motor operating parameter pattern such as a repetitive torque spike caused by a feature (447) rotating past (and consequently not coupled to each other) feature (488) indicates a lack of coupling. Therefore, the cessation or non-presence of such a torque spike pattern (while the drive unit disk (234-j) continues to rotate) means that the control unit (210) has detected the tool disk to drive the disk coupling.

[0049] In some embodiments, physical constraints may be created by the use of coordination of movement of multiple drive discs and / or by causing a single drive disc to be coupled before a second drive disc is coupled. For example, consider a case where two or more tool discs (within the same housing of the surgical tool (240)) are connected by a transmission within the housing of the tool (240) to share a load (end effector (246)) when two or more tool discs are rotating in the same direction, such as when a cutting or clamping tool needs to apply more force than can be supplied by a single actuator (238-j). In such an embodiment, two or more actuators rotating in the same direction (each of which a drive disc is rotating in the same direction) are driving the same output shaft inside the surgical tool (240) (due to a transmission within the surgical tool (240) connected to a corresponding tool disc). Now, when two actuators are signaled to move in opposite directions, as soon as one of the drive discs engages with its corresponding tool disc, this becomes a physical constraint on the other drive disc (when the other drive disc engages with its corresponding tool disc). When one of two or more actuators engages (when its drive disc engages with its corresponding tool disc), the control unit (210) creates a constraint on the other actuator by signaling the engaged actuator to enter, for example, a position-holding state. That is, while the first actuator (238-j) is commanded by the control unit (210) to hold its position, the other unengaged actuator (238-i) continues to be signaled to drive and thus rotate or move (toward the engagement between its drive disc (234-i) and the tool disc (244-i). In this embodiment, one or both of the motor operating parameters of the actuator can be monitored to detect coupling between the tool disk and the drive disk pair.Additionally, if a hard stop exists (the control unit (210) anticipates or knows that this particular tool (240) has a hard stop), the actuator of the coupled drive disk may be signaled to continue driving or rotating in the same direction until the hard stop is detected. While the already coupled actuator maintains its position at the hard stop, the other actuator may attempt to continue rotating in the opposite direction and coupling.

[0050] Returning to FIG. 2. And as discussed above, the tool identification performed by the control unit (210) enables the control unit to obtain knowledge of the characteristics of the end effector (246) of the surgical tool (240). For example, the control unit (210) can use such identification process to determine whether two (or more) tool discs within the tool (240) work in cooperation to impart end effector movement, whether a hard stop or physical constraint is applied to one or more movements of the end effector, what the range of movement of the end effector is, which actuator will be used by the tool (240), and factory-specific calibration values ​​such as the groove position of the tool disc. Note that the calibration values ​​may include a certain range, e.g., 290 degrees + / - 4 degrees. Based on such a correction value, for example, the home position of the tool disk (244-i), and based on the current position of the corresponding drive disk (234-i) (determined using the position encoder of the tool drive (230)), the control unit (210) can track the difference during the coupling process (as the actuator is signaled to rotate). If the difference is greater than a predetermined threshold, the actuator is signaled to rotate quickly (fast rotation), and in response to the difference becoming smaller than the threshold (meaning the drive disk is approaching the correction value home position), the actuator is signaled to rotate slowly (slow rotation). This is expected to increase the likelihood of detecting a reliable coupling.

[0051] In some embodiments, after the coupling is detected by the control unit (210), the control unit (210) may take one or more additional actions on the end effector (246) to confirm the coupling. For example, the control unit (210) may apply a predetermined set of one or more movements to the end effector to test the coupling, such as signaling the drive disk to reverse the direction to move the end effector in the opposite direction to what it did during the coupling process, or moving the end effector to achieve an expected maximum degree of movement. Such movement enables the control unit (210) to reach a hard stop or a physical constraint, which is detected as discussed herein based on one or more motor operating parameters, for example, to confirm the mechanical coupling between the tool disk and the drive disk.

[0052] Additionally, in some embodiments, the control unit (210) may use a hard stop or physical constraint to set a reference position of the end effector. For example, if it is known that a hard stop exists when the end effector reaches a rotation of 270° in a predetermined direction, the control unit (210) may set a correction value for the position of the corresponding actuator or drive disk. Subsequently, the movement of the actuator or drive disk may be tracked based on the number of rotations of the drive disk, the motor shaft, the gear ratio, the drive disk / motor indexing, etc.

[0053] Additionally, in some embodiments, the control unit (210) may signal one or more motors to operate for a specified number of times, a specified number of rotations, or a combination thereof when attempting to achieve coupling of the tool disk with the drive disk. When coupling is not achieved within a threshold amount of time, number of rotations, etc., the control unit (210) may issue a warning to the operator of the surgical robot system (e.g., the operator of the system (100) of FIG. 1) to detach the surgical tool (240) and then reattach it to restart the coupling process.

[0054] After the mechanical coupling of the drive unit disk with the tool disk is detected by the control unit (210), the operator may command the movement of one or more joints of the surgical robot arm (220). As discussed above, the command is received from or derived from one or more UIDs (e.g., UID (114)), as a spatial state signal from a UID that is converted into a corresponding control signal (e.g., desired motor speed or current and rotation direction) provided by the control unit (210) to power one or more actuators of the tool drive unit (230) to change the pose, position or other state of the end effector. In one embodiment, when two or more actuators cooperatively control the movement of an end effector, for example, when two or more tool discs impart movement of the end effector with the same degree of freedom, the control unit (210) further performs cooperative control techniques to ensure that the actuators operate in a complementary manner when moving the end effector, share the load associated with the movement of the end effector, do not compete with each other in imparting such movement, and maintain a balance between the actuators so that one actuator does not continuously perform more or less work than another actuator. For example, when two or more actuators are used to control the opening, closing, and application of gripping force of the jaws of the end effector (246), the control unit uses a multi-actuator operation control technique in which the first actuator among the two or more actuators is identified as the master actuator and the remaining one or more actuators are identified as slave actuators. Subsequently, a position command provided to signal the master actuator to move the end effector (246) to a commanded position is also provided to signal the slave actuator to move the end effector (246) to the same commanded position.For example, when a master actuator and a slave actuator are simulated, if the master actuator receives a specific polarity (the direction of rotation of its motor) and a specific motor current value to satisfy a given end effector position command, the same polarity and current value may also be supplied to each of the slave actuators. However, in some embodiments, some compensation for the way the actuator movements complement each other may be provided, for example, as discussed in more detail herein, such as reversing the polarity of the slave when the directions of rotation of the master and slave actuators are different, or adjusting the gain (e.g., of the commanded motor current) when the properties of the motors are different.

[0055] FIG. 3 is a block diagram illustrating an example of a surgical tool (240), a tool drive unit (230), and a control unit (210). The surgical tool (240) may be attached to the tool drive unit (230) by bringing the complementary or matching surfaces of their respective housings into contact with each other. Attachment may also include fastening the housings together. Additionally, one or more sensors (not shown) of the tool drive unit (230) may be used by the control unit (210) to detect attachment, including reading data from the surgical tool (240) that identifies the surgical tool (240), indicates which tool disk (e.g., tool disk (244-j)) is used to control the movement of the end effector (246), includes a calibration value, indicates whether the tool has a hard stop, or indicates which tool disk contributes to the movement of another tool disk within the surgical tool (240) or is connected to another tool disk by transmission. Data may be transmitted to the control unit (210) via a communication link (e.g., wired or wireless link) established between the communication interface (318) of the control unit (210) and a sensor reading circuit (not shown) within the tool drive unit (230). Data may then be stored in memory (314) as part of a combined control program (combined control (316)) and may be associated with such specific surgical tool (240) as long as such specific surgical tool is attached to and maintained in the tool drive unit (230).

[0056] The control unit (210), including its programmed processor (312), may be integrated into the surgical robot system (100) (Fig. 1) as a shared microprocessor and program memory, for example, within the control tower (103). Alternatively, the control unit (210) may be implemented on a remote computer, for example, in a room other than the operating room, or in a building other than the surgical arena shown in Fig. 1. Additionally, the control unit (210) may also include user interface hardware (e.g., keyboard, touchscreen, microphone, speaker) that can enable manual control of the robot arm and its attached tool (240), power device (e.g., battery), and other components associated with electronic devices for controlling the surgical robot system, although not illustrated.

[0057] A memory (314) for storing instructions for execution by a processor (312) is coupled to one or more processors (312) (generally referred to as "processors" for brevity in this specification). In some embodiments, the memory is non-transient and may store one or more program modules including tool control (320) and coupling control (316), and its instructions configure the processor (312) to perform the coupling process described herein. In other words, the processor (312) may operate under the control of the execution of a program, routine, or instruction stored in the memory (314) as part of the tool control (320) and coupling control (316) to execute a method or process according to the manner and features described herein.

[0058] In response to detecting attachment of the surgical tool (240) to the tool drive unit (230), the coupling control (316) performs a process to detect mechanical coupling of the tool disk with the corresponding drive unit disk (driven actuator), such as coupling of the tool disk (344-i) with the corresponding drive unit disk (334-i) (or more precisely, configures the processor (312) to perform such process). The coupling control (316) may signal (via the tool control (320)) that one or more of the actuators of the tool drive unit (230) impart motion to their respective drive unit disks. In some embodiments, these commands or signals include commands to power, activate, or otherwise provide power to the motor so that the motor can generate or apply a specific amount of torque by applying a specific voltage command, current command, etc., thereby causing the drive unit disk to rotate at a specific speed and direction. Additionally, the movement of each drive disk can be controlled to start rapidly initially during the coupling detection process, and then ramp down slowly when a predetermined time limit is reached—either when a coupling is close, when alignment of the matching features is detected, or when a coupling is not detected. For example, based on the relative position of the drive disk to the tool disk (which may be based on known calibration values), the actuator speed ramps down to a predetermined speed (e.g., until the drive disk is within a critical distance where the matching features are aligned).

[0059] The coupling control (316) monitors one or more motor operating parameters of the motor of the actuator of the tool drive unit (230). As discussed above, the motor operating parameters may include the torque impeded by the motor, the voltage supplied to the motor, the impedance as seen at the input drive terminal of the motor when attempting to drive the motor to move it to a predetermined speed, the motor speed, and other motor operating parameters. One or more of these parameters may be monitored by comparing them to a threshold, so that when the threshold is reached, a mechanical coupling event is then considered to have occurred (e.g., between the tool disk (344-i) and the drive unit disk (334-i). As discussed above, the mechanical coupling is expected to be detected when the corresponding matching features of the tool disk and the drive unit disk are aligned and engaged with each other, and such rotation of the drive unit disk causes not only immediate but also proportional rotation of the tool disk that is mechanically coupled (integrally with the drive unit disk). Such coupling is expected to be detected when one or more of the motor operating parameters meet a threshold (e.g., a threshold indicating reaching a hard stop, maximum torque, voltage, or impedance value, reaching or exceeding a torque, voltage, or impedance value greater than is required to overcome the friction that initially appears when the tool (240) is first attached to the tool drive (230). Accordingly, the coupling control (316) infers or estimates that the tool disk (344-i) and the drive disk (334-j) are coupled to each other (e.g., engagement of their respective disk matching features).

[0060] Note that the coupling control (316) does not need to monitor sensor readings for all motor parameters available from the tool drive unit (230). Instead, the coupling control (316) may monitor only one or more characteristics of interest based, for example, whether any hard stop or physical movement constraint is applied to the surgical tool (240) to determine when a threshold associated with coupling is met, whether one or more tool discs operate simultaneously (cooperating with each other) to impart movement to the surgical tool (240), whether the tool discs impart movement to the surgical tool (240) via a cable or directly (e.g., via a gearbox), or a combination thereof.

[0061] In some embodiments, the coupling control (316) monitors a pattern of motor operating parameters, such as patterns of torque, voltage, motor speed, and impedance, resulting from the drive disk (234-j) rotating over the tool disk (244-j) without mechanical coupling. That is, a certain amount of torque, force, voltage, etc., may be measured that is greater than that which appears with a freely moving drive disk (when the surgical tool (240) is not attached to the tool drive (230)) and smaller than that which appears with a mechanically coupled drive disk (e.g., when the tool and the tool drive housing are in contact but not coupled, and the matching features of the tool and the drive disk pass each other). When such a motor parameter pattern as detected changes, for example, due to contact with a hard stop or a physical motion constraint, the coupling control (316) is referred to as having detected mechanical coupling. Monitoring and interpreting the pattern-based motor operation pattern also enables the coupling control (316) to detect coupling (between the tool disk (344-j) and the driving disk (334-j)) even when the hard stop or motion constraint is not available, or when there is no need to drive the driving disk to the tool's hard stop or other motion constraint.

[0062] In some embodiments, when the coupling control (316) detects a mechanical coupling of the tool disk with the drive disk, it may also initiate a verification process or coupling confirmation in which the actuator of the tool drive (230) is signaled to undergo a predetermined set of one or more movements to verify the detected coupling. For example, the actuator may be instructed to rotate each of their drive disks in a direction opposite to the coupling direction (the coupling direction is the direction in which the drive disk rotated when the coupling was initially detected, for example, in the movement direction (445) shown in FIG. 4a). Subsequently, the drive disk may be rotated back in the coupling direction until a second coupling is detected (e.g., when a specific motor parameter reaches a threshold consistent with the tool disk reaching a hard stop or movement constraint, when a specific motor parameter reaches a threshold consistent with the resistance against the rotating tool disk that is not caused solely by friction (friction between the tool disk and the corresponding drive disk), or a combination thereof).

[0063] The coupling control (316) generates a notification to the operator of the surgical robot system based on detecting the coupling of the tool disk to the drive disk, or based on a countdown timer that has expired without detecting coupling. The notification may indicate that coupling has occurred and the surgical tool (240) is ready for use, or that coupling has not occurred and the surgical tool (240) must be reattached.

[0064] FIG. 5a is a flowchart illustrating a process (500) for combining a surgical tool with a tool drive unit of a surgical robot system according to one embodiment of the present disclosure. The process (500) may be performed by a programmed processor (also referred to herein as processing logic) configured according to software stored in memory (e.g., the processor (312) and memory (314) of FIG. 3, wherein the processor (312) is configured according to instructions for tool control (320) and combination control (316).

[0065] Referring to FIG. 5a, the processing logic is initiated by activating the actuator of the tool drive unit to rotate the drive unit disk of the tool drive unit (processing block (502)). For example, the processing logic may activate the linear or rotary actuator of the tool drive unit (e.g., tool drive unit (230)) to rotate or turn the drive unit disk (e.g., drive unit disk (234-j)). Additionally, as discussed herein, when mechanically coupled, the rotation of the drive unit disk (e.g., disk (234-j)) will cause an immediate or direct rotation of the corresponding tool disk (e.g., disk (244-j)) of the surgical tool (e.g., surgical tool (240)).

[0066] The processing logic monitors one or more motor operating parameters of the actuator that cause rotation of the drive disk while activating the motor (processing block (504)). In some embodiments, the motor operating parameters monitored may include torque, motor current, motor speed, or a combination thereof.

[0067] Based on one or more monitored motor operating parameters, the processing logic detects when the drive disk is mechanically coupled with the tool disk (processing block (506)). In one embodiment, the detection occurs when at least one of the one or more monitored motor operating parameters satisfies a corresponding condition or threshold or in response thereto. For example, the condition may be associated with a value of a motor operating parameter that occurs in response to the motor reaching a physical constraint against further rotation of the tool disk (e.g., reaching a mechanical limit of the range of motion when contacting a physical barrier to movement, reaching the maximum range of motion of the tool's end effector, or resistance by another active motor actuator). As another example, the condition may represent a motor operating parameter that occurs when friction is present due to the drive disk contacting and sliding against the tool disk during rotation, but there is no mechanical latching or engagement of the drive disk with the tool disk. In the embodiments discussed herein, when a mechanical coupling of the drive unit disk with the tool disk is detected, one or more additional operations, such as generating a system or operator notification, initiating one or more coupling verification operations, and storing a reference value, may be performed by the processing logic.

[0068] FIG. 5b is a flowchart illustrating a process (550) for detecting the coupling of a tool disk with a drive disk based on one or more motor operating parameters of an actuator driving a drive disk. The process (550) is performed by processing logic that may include any combination of hardwired circuits and programmed processors, wherein, for example, the process (550) may be performed by a programmed processor (312) according to the aforementioned tool control (320) and coupling control (316). The process may begin by detecting that a detachable surgical tool is attached to a tool drive unit of a robotic arm of a surgical robot system (processing block (552)). Attachment may be detected based on the sensor of the tool drive unit entering a wireless detection range or being conductively connected to an information storage unit within the detachable surgical tool. As discussed herein, the information storage unit may include a tool identifier and additional tool attributes, such as which of several available tool discs within the tool housing is actually connected to an end effector within the surgical tool that is detachable by a transmission within the housing, what type of transmission within the tool controls the movement of the end effector (e.g., cable-driven, direct-driven, etc.), what direction of movement or rotation is permitted, whether any range of such movement or rotation exists, and calibration values ​​(e.g., cable length, current cable length, maximum winding rotation position of the tool disc or groove position of the tool disc, etc.), as well as other tool attributes discussed herein.

[0069] At least one motor of the tool drive unit is subsequently activated to cause at least one motor to rotate an associated drive unit disk corresponding to the tool disk (connected by a transmission within the surgical tool to control the movement of the end effector) (processing block (554)). In one embodiment, the current to be supplied to the motor, the torque to be achieved by the motor, or the direction of movement is signaled to the tool control (320) so that the motor will cause the drive unit disk to rotate in a predetermined direction at a predetermined speed. In other words, the processing logic causes the signal to be transmitted to the motor drive circuit to command the motor drive circuit to apply power to the motor or to power the motor. In some embodiments, the predetermined speed is set based on the determination of, for example, the type of tool, the type of tool drive transmission (e.g., cable drive, direct drive, etc.), the type of constraint to be contacted (e.g., hard stop, physical constraint, counter-motion constraint), or a combination of such factors upon the detected attachment of the tool drive unit to the detachable surgical tool. One or more motor operating parameters of at least one motor of the tool drive unit are subsequently monitored (processing block (556)). The monitored motor operating parameters may correspond to those controlled by processing logic to induce movement of the motor (e.g., torque, speed).

[0070] Returning to FIG. 5b, the processing logic repeatedly checks to determine whether the coupling condition is satisfied, for example, whether the monitored motor operating parameter has reached a threshold (processing block (558)). If so, a mechanical coupling event is flagged, indicating that the drive disk is mechanically coupled with its corresponding tool disk (processing block (564)). As discussed herein, the threshold indicates a condition associated with the mechanical coupling of the drive disk. For example, mechanical coupling is expected when the torque, current, or impedance associated with the motor at a predetermined speed or velocity exceeds their values ​​associated with the motor, causing the tool drive to contact the tool disk solely by friction. The threshold may be a value greater than the torque, voltage, impedance, etc. required to overcome such friction. As another example, physical constraints may be applied to the movement of the end effector, such as the maximum range of motion of the joint, a hard stop (e.g., implied by a cannula wall), the opposite movement of the other drive disk, and other physical constraints. In such cases, the movement speed and direction of the motor are selected to advance the end effector or tool disc toward the physical constraint. Subsequently, upon reaching the physical constraint, the monitored torque, current, and impedance will spike to their maximums, while the speed will drop to zero. In this example, one threshold may refer to a torque or motor current set near its maximum value, and the other threshold may refer to a speed set lower than the motor's nominal speed during the rotation of the drive disc, e.g., substantially zero. Thus, the two thresholds act as mutual checks to make the detection of the coupling more robust.

[0071] In response to the detected coupling of the drive disk with the corresponding tool disk, the movement of the drive disk is stopped (processing block (566)). In one embodiment, when the movement is stopped, one or more reference values ​​associated with such position or state of the end effector may be stored for subsequent reference and use. For example, if a physical constraint is used to detect the coupling, the motor index value, rotation count, etc. at such moment may be stored and subsequently used to reposition the end effector at or near the physical constraint. The physical constraint may be, for example, a maximum cable length, a cannula wall, a maximum range of motion, etc. Additionally, in the case of a cable-driven tool, to prevent excessive tension of the cable, the movement of the drive disk may be stopped or the motor may be deactivated simultaneously or nearly simultaneously in response to the detection performed in block (558).

[0072] Once the combination of all relevant drive unit disks (corresponding to the tool disk in use of a specific surgical tool) is detected in processing block (567) (where the process described in blocks (554-556-558-564-566) may have been performed for each individual drive unit disk), a notification of tool combination is subsequently generated (processing block (568)). The notification may be a visual notification (e.g., graphic user interface notification), an audible notification (e.g., tone, sound, etc.), a sensation (e.g., haptic notification), or a combination of such generated by the user interface hardware of the surgical robot system.

[0073] Returning briefly to the processing block (558), when the coupling condition is not met (e.g., because the monitored motor operating parameter does not meet the threshold, mechanical coupling between the tool disk and the corresponding drive disk does not occur), a determination is made as to whether a time or rotation limit has been reached (processing block (560)). The failure to couple may be due to a broken cable, the tool disk and drive disk not positioned close enough to allow coupling, etc. The time limit may be a predetermined maximum time interval (countdown timer value) during which the drive disk is allowed to rotate without detecting mechanical coupling with the tool disk. Similarly, the rotation limit may be multiple motor rotations required to provide one or more full rotations of each drive disk. For example, if the rotation limit is associated with one full rotation of the drive disk, it is assumed that coupling will occur within a single rotation of the drive disk. If a time limit, a rotation limit, or some combination of limits is not reached (processing block (560)), monitoring of one or more motor operation parameter values ​​continues (returns to processing block (556)). However, if one or more limits are reached (processing block (560)), a notification similar to the notification of processing block (568) is issued, indicating that an error has occurred and the tool coupling has failed (processing block (562)). In this case, the operator of the surgical system may be instructed to detach the surgical tool from the tool drive unit and then reattach them to restart the coupling process of FIG. 5b.

[0074] Now, referring to FIG. 5c, this is a diagram of a process performed by a control unit to combine a surgical robot tool with a tool drive unit as part of a surgical robot system. The system includes a surgical robot tool (240) illustrated in FIG. 2, having one or more tool discs at its proximal end and an end effector at its distal end as illustrated. A tool drive unit (e.g., tool drive unit (230)) is mounted at the distal end of a surgical robot arm (220) as illustrated, wherein the tool drive unit (230) has one or more drive unit discs (234), each driven by a rotary motor within the housing of the tool drive unit. Each drive unit disc (234) is attached to the tool disc (244) of the surgical tool (240) to impart motion to the end effector (246).

[0075] Referring again to FIG. 5c, the process for coupling the tool disk to the drive disk is performed by a control unit, specifically by one or more processors of the control unit configured (or programmed) to do so. Operation may begin by detecting that the surgical tool is attached to the tool drive (block (582)); this may be done wirelessly or via a wired connection by a processor reading the identification or other attributes of the tool that has come into contact with the tool drive so that the tool disk contacts the corresponding or each drive disk. The control unit then operates each drive disk via a rotary motor (block (584)), and during operation, may detect that the drive disk is coupled to each tool disk (block (586)); the drive disk is referred to as being coupled to the tool disk when a pair of coupling features of the drive disk and the tool disk (there may be more than one pair, e.g., two or more as shown in FIG. 4a through 4c) are mutually locked. To detect coupling, the control unit recognizes a detected change in the motor state (the state of the actuator, or its motor operating parameters), including when the speed of the rotary motor drops below a predetermined speed threshold and the torque of the rotary motor rises above a predetermined torque threshold. The speed threshold may correspond to the speed at which the motor substantially stops, where the torque threshold is a value between i) the minimum torque for the motor to overcome friction between the drive disc and the tool disc before coupling and ii) the maximum torque for the motor to be generated. The change in the motor state may be caused by at least one of the end effector reaching a joint limit, an external force on the end effector, a motion constraint caused by another motor of the tool drive to be activated, and a combination thereof. Depending on the specific surgical tool, there may be more than one tool disc used to actuate the end effector.In such cases, the aforementioned coupling process is also performed for each additional tool disk (having a corresponding drive disk within the tool drive unit). The process then continues to block (588), where the control unit signals the user interface subsystem of the surgical robot system to report, for example, the coupling of the surgical tool only when it is detected that all tool disks used for a specific tool have been coupled with their respective drive disks.

[0076] In one embodiment, a feedback loop may be used to monitor one or more motor operating parameters and to detect when a threshold is reached. FIG. 6 illustrates a block diagram of a feedback loop used to control the speed of a motor of a tool drive unit using speed feedback. The feedback loop may be implemented in hardware, firmware, software, or a combination thereof. A speed command is received by a controller (602). The controller (602) may be a proportional-integral-derivative controller (e.g., the PID controller (702) of FIG. 7) that provides a loop / feedback mechanism to provide an appropriate motor current (e.g., controller output (ctrlr out)) to drive the motor / actuator (604) at the speed and direction of the speed command (also referred to as a speed set value). For example, the direction may be the winding direction of the cable-driven tool disk (244-j). As another example, the direction may be opposite to the movement of the other motor to which its attached tool disc (244-i) must cooperate with the tool disc (244-j). As yet another example, the direction may be such that the motor advances toward a hard stop, such as a physical barrier or a mechanical limiting part of the range of motion. In one embodiment, the controller (602) may use various values, such as a desired torque to achieve speed, a current to achieve speed, an impedance indicating speed, etc., as a means for generating a current output of the controller to the motor / actuator (604).

[0077] A sensor, such as a torque sensor, a speed sensor, or a combination of sensors, measures the actual speed of the motor / actuator. The actual speed is then provided back to the controller (602) as feedback, which can calculate an error based on the difference between the actual speed of the motor and the commanded speed. The controller (602) responds to the difference by adjusting its controller output, such as a motor current command for the motor / actuator (604), the torque to be achieved by the motor / actuator (604), the impedance value, etc., to cause the motor / actuator (604) to move toward the speed command or set value. In some embodiments, the controller (602) may output motor operating parameters, such as calculated torque, current, impedance, speed, etc., as a result of running a feedback loop.

[0078] In another embodiment, the controller (602) may include a saturation block (not shown) to ensure that the controller output (e.g., a value controlling the motor current) does not exceed a threshold, such as a current threshold, a torque threshold, or an impedance threshold. The value used by or input to the saturation block may have a dual purpose, namely, it may also be used as a motor operating parameter value supplied to a processor (for the purpose of monitoring during the coupling process).

[0079] FIG. 7 illustrates a block diagram of a feedback loop including a controller (702) for controlling the speed of a motor of a tool drive unit. In one embodiment, the controller (702) is a proportional-integral (PI) controller and may be used within the controller (602) and may be partially implemented as hardware, firmware, software, or a combination thereof.

[0080] A speed command (e.g., a control variable setting value) is received by the controller (702). The controller (702) provides a loop / feedback mechanism to regulate and provide an appropriate current (e.g., controller output) to drive the motor / actuator (704) at the speed and direction of the speed command / setting value. For example, the direction may be the winding direction of the tool disc of a cable-driven surgical tool. As another example, the direction may be opposite to the movement of another motor of the tool drive unit. As yet another example, the direction may be a direction in which the motor advances the end effector toward a hard stop, such as a physical barrier or a mechanical limiting part of the range of motion. In one embodiment, the controller (702) may use various values, such as a desired torque to achieve the speed, a current to achieve the speed, an impedance indicating the speed, etc., as a means to generate the controller's current output to the motor / actuator (704).

[0081] Proportional control for adjusting speed in proportion to the error (e.g., as determined by feedback) (e.g., block ( k p )), and integral control for speed adjustment to account for past errors integrated over time (e.g., block ( k i Adjustment is performed on the original speed command, such as )). Integral adjustment is performed on a block in the feedback loop for anti-windup ( to further adjust the value of the integral adjustment. k b It can be further adjusted using the restoration term generated by ). The integrally adjusted value can be further adjusted by the block (1 / s) (e.g., before being added to the proportional set value adjusted value). In one embodiment, the saturation block may be used in the controller (702) as illustrated to ensure that the value controlling the current supplied to the motor does not exceed a threshold, e.g., a current threshold, a torque threshold, an impedance threshold, etc. After adjustment is performed by the block discussed above, and the generated current command value does not exceed the value set in the saturation block, the current command (e.g., an adjusted command corrected based on feedback and PI adjustment) is supplied to the current amplifier so that the commanded current to the motor actuator (704) can be amplified by a factor. The factor may be fixed based on the characteristics of the motor / actuator (704), based on feedback from the motor / actuator (704), etc. The motor / actuator (704) is activated according to the amplified current, and feedback on the speed response of the motor / actuator (704) (e.g., speed, torque, velocity, etc. as determined by a sensor coupled to the motor) is provided to a feedback loop implemented by the controller (702) as illustrated.

[0082] As discussed above, the value used by (or input to) the saturation block can be used as a motor operating parameter value supplied to the processor for monitoring purposes during the coupling process, such as representing the current motor current or current motor impedance.

[0083] In another embodiment, the feedback may be used as a motor operating parameter value supplied to the processor for monitoring purposes during the coupling process. Other variables (e.g., regulated and unregulated) calculated by the controller (702) may be used as the monitored motor operating parameters.

[0084] In one embodiment discussed above, two actuators share the load in moving a surgical instrument, such as sharing the load to rotate an endoscope. The surgical instrument (e.g., endoscope) may have a rotary joint without an encoder, and thus the position is determined from the angle of the motor or actuator. Without coupling, the rotation angle of the surgical instrument cannot be determined. There is no mechanical hard stop on the rotary joint, and thus the hard stop may not be used for homing. The rotary joint is coupled with two motors on the instrument drive. In normal operation, these two motors work cooperatively to drive the rotary joint. For example, in remote control after coupling and homing, one motor is the primary motor and is controlled in position mode, and the other motor is the secondary motor and is controlled in position or current (torque) mode. Both motors drive the movement of the surgical instrument in the same direction. Before the two motors drive the endoscope rotary joint, both motors must be coupled to the rotary joint, and the endoscope joint angle is calculated based on the motor joint position at the completion of coupling (i.e., homed).

[0085] FIG. 2 illustrates an exemplary surgical robot system for coupling and / or homing of motor control units in a robotic surgical system. Generally, two or more drive discs (234) are coupled with two or more tool pads or discs (244). The pads may have shapes other than discs, such as a plus ("+") shape. The examples in this specification use discs.

[0086] The surgical tool (240) is a surgical tool used in medicine or any of the surgical tools discussed herein. In one embodiment, the surgical tool (240) is an endoscope. Rather than having scissors, a clamp, or other tools, the surgical tool (240) has a camera at its distal end as an end effector (246). The endoscope shaft can rotate 360 ​​degrees without a hard stop. Since there is no hard stop or physical constraint on rotation, any number of rotations may be possible. Other tools for rotation or other movement may be used.

[0087] A robotic surgical tool (240) comprises a housing, a shaft, and an end effector (246) extending from a proximal end to a distal end. A tool disk (244) is positioned within the housing and linked to the end effector (246) (e.g., by a cable, a rod, and / or other transmission), and the end effector is driven by a drive disk (234) via the tool disk (244) and transmission after being properly coupled.

[0088] A rotary tool disc (244) is connected to the shaft of the surgical tool (240) to rotate the surgical tool (240). Two or more rotary tool discs (244) are connected via a transmission to link the tool discs (244) to the surgical tool (240). A gear mechanism, clutch, cable, belt, and / or other link mechanism receives a force, such as rotational force, from two or more tool discs (244) to rotate the surgical tool (240). The power to rotate the surgical tool is shared. In one embodiment, both tool discs (244) rotating in the same direction contribute to both rotating the surgical tool (240) in the same or opposite direction. In another embodiment, the transmission links two tool discs (244) rotating in opposite directions to rotate the surgical tool (240) in one of the directions.

[0089] The tool drive unit (230) includes an actuator (238) (e.g., a motor) connected directly or via transmission to a drive unit disk (234). The actuator (238) and the drive unit disk (234) form a rotary motor drive unit that is mating with the tool disk (244) (e.g., combining coupling features (447, 448)). The drive unit disk (234) is mated with the tool disk (244). The mating or coupling occurs once the surgical tool (240) is connected to the tool drive unit (230).

[0090] The sensor (236) is one or more different sensors. For example, the sensor (236) is an encoder for detecting a position, such as the angular position of the motor shaft and / or the drive disk (234). The encoder may output position information so that the processor can determine the velocity from the time derivative of the position. As another example, the sensor (236) is a current sensor (e.g., a current sensing resistor in series with the motor input drive terminal) for detecting the amplitude of the current provided to and / or drawn by the actuator (238). Additional, different, or fewer sensors (236) may be provided for each actuator (238), such as providing both a current sensor and an encoder.

[0091] As illustrated in FIG. 9, a current source (901) may be provided. The current source (901) outputs current to the actuator (238). Based on a control signal, the current source (901) provides current to move the actuator (238) to a position, torque (e.g., current), or other control mode. Current is supplied to the actuator (238) to induce rotation to a given angular position (position mode) or to move at a given speed (e.g., current mode). Other control modes may be used.

[0092] In one embodiment illustrated in FIG. 9, a current source (901) adds a dithering current (902), such as a high-frequency (e.g., 60 Hz or higher (e.g., 100 Hz)) sinusoidal current. The dithering current (902) is of low amplitude, such as being 10% or less of the maximum current (908). The dithering current (902) is added to the ramp-up current (900) provided to the actuator (238). The dithering current (902) is added during the initial portion of the ramp-up current and removed upon completion of ramping. In another embodiment, the dithering current (902) is added over a different range, such as being added after the ramp-up current is initiated and / or removed after reaching the steady-state current (904). The dithering current (902) can help reduce static friction during contact between the tool disk (244) and the drive disk (234) for coupling.

[0093] The processor (312) of the control unit (210) is configured to detect the alignment of the rotary tool disk (244) with each rotary drive unit (e.g., rotary drive unit disk (234)) by a change in signal. The coupling of the drive unit disk (234) with the tool disk (244) is detected. The drive unit disk (234), under power from the motor or actuator (238), can slide against the tool disk (244) until coupled, at which point the tool and the drive unit disk (234, 244) rotate together.

[0094] The processor (312) is configured to detect coupling from a change in the performance or signal of the actuator (238). A signal from the sensor (236), such as current and / or speed, is used to detect coupling. Once coupled, the signal changes. For example, the speed drops to zero or below a threshold speed. As another example, the current spikes or exceeds a threshold current. In another example, both the low speed and the current spike are detected as indicating coupling or coupling.

[0095] Since two or more actuators (238) drive the surgical tool (240) in combination, a change in the signal to detect the combination can be performed for both motor drives. For example, the current and / or speed for each actuator (238) is monitored to detect the combination. The combination of the surgical tool (240) is detected for each actuator (238).

[0096] If a hard stop is not provided, the actuators (238) may be driven in opposite directions. The motor drive may attempt to rotate the surgical tool (240) in opposite directions and / or at different speeds, rather than attempting to rotate them together. Each actuator (238) drives the surgical tool (240). By operating in opposite directions, the actuators (238) may attempt to rotate the surgical tool (240) in opposite directions and / or at different speeds. The drive is in a position control mode, but current or other control modes may be used.

[0097] When the initial drive disc (234) is matched with the corresponding tool disc (244), the signal to such actuator or drive motor may not change much because this initial drive disc (234) is the only drive that rotates the tool. The current and / or speed may change due to resistance in rotating the surgical tool (240), but the speed may not change below a speed threshold and / or the current may not spike above a current threshold. Once the other or subsequent drive disc (235) is matched with the corresponding tool disc (244), the two motor drives are both coupled and attempt to rotate the surgical tool (240) in opposite directions and / or at different speeds. As a result, the speed for both motors drops below a threshold and / or the current for both motors spikes. The motor drives resist each other, acting as mutual hard or soft stops. If motors rotate in opposite directions at the same speed with the same strength or power, the speed drops to zero and the current spikes to a maximum. If the motors have different power and / or different speeds due to design or tolerances, a greater speed and / or a smaller current spike may be provided while still being below the speed threshold and / or above the current threshold, respectively.

[0098] The processor (312) is configured to verify the coupling. After alignment is detected, the coupling can be verified. Once coupled, the encoder indicates the rotational position of the tool disk (244). Since the tool disk (244) is linked to the same surgical tool (240), the tool disks have a known relative rotation with respect to each other. For example, the tool disk (244) is designed to have the same angle but opposite sign for any given rotational position of the surgical tool (240). In other examples, any relative combination of angles may be used. Due to the coupling, the position of the drive disk (234) corresponds to the position of the tool disk (244). If the angle at the time of coupling matches the designed angle, the coupling is verified.

[0099] The processor (312) is configured to hom the rotation angle of the surgical tool (240). Once coupled, the current rotation angle of the surgical tool (240) is determined. The surgical tool (240) is calibrated so that the angle of the rotational tool disk (244) for each rotation angle of the surgical tool (240) is known. At the time of coupling, the processor (312) determines the rotation angle of the surgical tool based on the rotation angle of the coupled rotational drive unit (e.g., actuator (238), drive unit disk (234), and / or tool disk (244)) as it is coupled. The calibration relates the angle of the coupled rotational drive unit to the angle of the surgical tool (240). Referring to FIG. 8, at the completion of coupling, the angles of the joint (e.g., tool disk) are α1 and α2, respectively, when the surgical tool (e.g., endoscope) is in the groove (0) position (θT). Both α1 and α2 are pre-calibrated and measured from the encoder based on the angles (θ1, θ2) of the two motors (M1, M2).

[0100] FIGS. 8 and 9 illustrate another embodiment of the detection of coupling for two motor drives operating to control the same movement of a surgical tool (240). A combination of position and current control modes is used to detect the coupling from a change in the signal.

[0101] The equation of motion after coupling can be expressed as follows:

[0102]

[0103] These equations of motion can be used for coupling detection and / or homing.

[0104] In the first step, the motor (M2) is set to operate in position control mode. The target position is set to the current position, and thus the motor (M2) is maintained in a normal state or at the current position.

[0105] In the second step, the motor (M1) is set to operate in current control mode. As shown in FIG. 9, the current (900) is ramped up until the speed reaches a threshold represented by the horizontal portion (904) of the current (900). The offset from the maximum current (908) for the horizontal portion (904) and the slope of the ramp-up can be determined experimentally.

[0106] A dithering current (902) is added to the current (900). For example, a high-frequency (e.g., 100 Hz) sinusoidal current provides low-amplitude dithering and is superimposed on the ramp-up current. This high-frequency current helps to overcome static friction between the disks (234, 244). The angular velocity (906) of the actuator (238) and the drive disk (234) is ramped up and then maintained in a steady state based on this current control. The direction of the current command (i.e., the direction of rotation) is arbitrary. A maximum current limit (908) is set between the maximum current for driving only the motor and the minimum current for driving the coupled motor and the endoscope. The limit can be determined experimentally.

[0107] During this second stage, a coupling to the motor (M1) is detected. A coupling is detected if the motor (M1) never moves—the current command ramps up to the maximum current. This may occur when the tool disk (244) is positioned to make contact or is aligned with the drive disk (234) when connected. A coupling is detected if the motor (M1) stops before or after reaching the desired speed. If the motor (M1) does not stop after a full rotation detected by the encoder, the speed limit may be reduced (e.g., by ½), and the second stage is repeated. If the second stage fails to detect a coupling again, an error is reported and the process is stopped.

[0108] In the third step, the motor (M1) is set to position mode, and the target position is set to the current position (θ1) to maintain the motor (M1) in its original position. In the fourth step, the motor (M2) is set to be in current control mode. The same current profile used in the second step (see FIG. 9) is used. The rotational direction for the current is set to be the shorter direction toward -(θ1 - α1) + α2. The same speed and / or motion conditions are used to determine whether coupling occurs for the motor (M2).

[0109] In steps 2 and 4, instead of checking for a stop, a change in speed can be used to detect the coupled state. Once coupled, the current command is immediately set to 0, and the process proceeds to the next step.

[0110] Speed ​​closed-loop control based on current saturation can be used to replace current ramp-up control in the second and fourth stages. In the second stage, the motor (M1) is set to speed control mode, and the target speed is set to a pre-limited value. The direction of the speed is selected arbitrarily. A coupled state is detected if the motor (M1) stops or if there is a sudden jump in the motor current measurement. In the fourth stage, the motor (M2) is set to speed control mode, and the target speed is set to a pre-limited value. The direction of the speed is at a shorter distance of -(θ1 - α1) + α2.

[0111] In the fifth step, the motor (M1) is maintained in position control mode, and the motor (M2) is maintained in current control mode. The joint angle of the motors (M1, M2) is checked to verify that the equation of motion is satisfied. If the angle matches the design angle, a complete coupling is verified. If the coupling fails twice in a row and / or verification fails, the coupling process is stopped and an error may be reported.

[0112] After successful coupling, homing can be established. The endoscope joint angle for the 0 position can be calculated from the motor (M1) joint angle using the equation of motion.

[0113] FIG. 10 illustrates an embodiment of a method for coupling a motor control unit of a surgical tool in a surgical robot system. The method also includes homing the rotational position of the surgical tool in the surgical robot system. For example, coupling and / or homing of the endoscope with tool actuator motors (M1, M2) is provided. The coupling drives the motors until the motor joint shafts of both are rigidly coupled to the endoscope shaft through a key and / or key hole or other coupling. Homing finds the joint angle between the zero position of the endoscope rotational joint and the primary joint encoder position.

[0114] The method is performed by the surgical robot system of FIG. 2 and FIG. 3 or by another surgical robot system. The method is performed when two motors drive the same movement of a surgical tool, such as rotation in the same direction by an endoscope. The method is performed when a processor of a control unit or other controller connects the surgical tool (240) to the tool drive unit (230). Once the identity of the surgical tool (240) is determined to be that it has two or more motors that combine power or movement to drive the same movement, the processor performs combination detection and / or homing.

[0115] The operations are performed in the illustrated order or in a different order. For example, operations (1002, 1004) are performed simultaneously. As another example, operations (1002, 1004) are repeated to detect the coupling of different motors. Additional, different, or fewer operations may be provided. For example, operations (1006 and / or 1008) are not provided for the detection of coupling. As another example, operations (1002, 1004) are not provided when other coupling detection is used. In yet another example, operation (1006) is not provided. In another example, operations are provided for remote control or surgical use of a coupled and homed endoscope or other surgical tool. In one embodiment, attachment of the surgical tool to the tool drive is detected (see operation (552) in FIG. 5b and operation (582) in FIG. 5c), which then triggers the detection of the coupling of the disk.

[0116] In operation (1000), a processor (e.g., a controller or control unit) detects the engagement of two or more rotary tool pads or disks (244) with each of two or more rotary drive parts (e.g., an actuator (238) and a drive pad or disk (234)). Using a releaseable (e.g., spring-loaded, physical barrier, or friction fit) fit, the drive disk (234) is engaged with the tool disk (244).

[0117] In operation (1002), a motor (e.g., actuator (238)) rotates. The rotation of the motor is performed under position control, but other control modes may be used. During remote control to rotate or translate a surgical tool in one direction, two motors rotate in a specific direction according to transmission from the tool disk (244) to the surgical tool (240) or other linkage device (e.g., both motors rotate in the same direction, or one motor rotates in one direction and the other motor rotates in a different direction). For coupling, the motors rotate in opposite directions. For example, by rotating one motor clockwise and the other motor counterclockwise, the endoscope is rotated clockwise. To rotate in opposite directions, the motors rotate in the same direction so that one motor attempts to rotate the endoscope clockwise and the other attempts to rotate the endoscope counterclockwise. Since there is no hard stop or physical limiter for rotation in the endoscope, the opposite rotations of the motors sharing the movement burden resist each other and act as a stop once coupled.

[0118] Due to the rotation of the motor, the drive disc (234), which is connected to the motor directly or through a gear mechanism, rotates. The drive disc (234) makes frictional contact with the tool disc (244). The rotation has sufficient force to overcome static friction, and thus the drive disc (234) rotates relative to the tool disc (244) linked to the surgical tool (e.g., surgical tool (240) or endoscope). The rotation will eventually create a physical coupling mechanism (e.g., protrusions and indentations, shaped extensions and slots, protrusions and stops, and / or snap-fit ​​holders and extensions) on the tool and the drive disc (234, 244).

[0119] Dithering in current, position, and / or other control modes may be used. By dithering the command signal, static friction can be more easily overcome, so that the drive disk (234) rotates at a greater speed than the tool disk (244) for coupling.

[0120] Once two or more pairs of tool and drive discs (234, 244) are aligned or combined, the opposite rotation acts as a stop. Once combined, the rotational force from each motor is transmitted through a linkage device or transmission linking the tool discs (234), thereby causing resistance to movement.

[0121] In an alternative embodiment, one of the motors is controlled in a position mode so that it does not rotate while the other motor is rotating to be coupled. Once one motor is coupled, the coupled motor drive does not rotate while the other motor is coupled. For example, the steps described above are performed with reference to FIG. 9.

[0122] In operation (1004), a processor (e.g., a control unit or controller) monitors and detects the coupling of a motor (e.g., an actuator (238)) with each tool disk (244). The detection is based on monitoring a change in the performance of the motor. The change may be expressed as a difference, for example, a difference in performance exceeding a threshold (e.g., the current doubles or increases by an amount exceeding X). The change may be expressed as an absolute value relative to the threshold, for example, a speed that transitions below the threshold speed (e.g., a speed that becomes zero) and / or a current that transitions above the threshold (e.g., a current spike).

[0123] Once a performance change occurs using one or more parameters (e.g., both current and speed) for each of the motors, coupling is detected. Coupling can be detected as coupling by all of the motors or by a subset of the motors. Once the performance characteristics of each of the motors or each of the subset of motors change, coupling of the surgical tool is detected. Alternatively, coupling is detected separately for each motor. Once all of the desired motors are coupled, the coupling process is terminated.

[0124] In operation (1006), a processor (e.g., a controller or control unit) confirms or verifies the coupling. Once the coupling is detected, verification is performed to verify the proper coupling. Verification relies on the transmission or linkage device between the tool disk (244) and the surgical tool (240). Since both tool disks (244) drive the same motion, the angles of the tool disks (244) relative to each other are fixed or within a tolerance range. The mechanism for coupling has a fixed orientation for the tool disk (244) and the drive disk (234), and thus the coupled tool disk (244) has such a fixed orientation when both are coupled. The angles of the drive disk (234) and the corresponding motor shaft are measured by a sensor (236) (e.g., an encoder). Due to the coupling, the angle corresponds to the angle of the tool disk (244).

[0125] The rotation angles are compared. If a rotation angle within the expected angle or threshold is detected, the coupling is verified. For example, the transmission or linkage device between the tool discs (244) is designed to have the same angle with opposite signs for any rotational position of the surgical tool (240) (e.g., endoscope). Once coupled, the rotational positions of the motor and the drive disc (234) have the same angle (e.g., the same absolute angle with different signs). Other angle combinations may be used.

[0126] In operation (1008), the processor (e.g., controller or control unit) determines the current rotation angle of the surgical tool once coupled. This homing determines the rotation angle of the medical instrument at the time of coupling.

[0127] The rotation angle is determined from the angles of the motor and each drive disk (234). Once combined, the angle of the drive disk (234) from the sensor (236) is the angle of the tool disk (244). A look-up table or other function from the calibration maps the angle of the tool disk (244) (and / or drive disk (234)) to the angle of the surgical tool. The transmission relates the angle of the tool disk (244) to the angle or position of the surgical tool, and the calibration measures the relationship. Once the angle for the disk (234, 244) is determined for each of the motor drives, the calibration is used to find the angle of the surgical tool (240).

[0128] The joining and / or homing process is subsequently terminated. If the joining is not detected in operation (1000), the joining is not verified in the confirmation of operation (1006), and / or the homing of operation (1008) fails, and the process for joining may be repeated or a different joining process may be performed. If multiple failures occur, an error message is sent. If the joining and / or homing is successfully performed, the surgical tool (240) and the motor drive are prepared for remote control during surgery.

[0129] The foregoing description of the exemplified embodiments of the invention, including those described below in the abstract, is not intended to be complete or to limit the invention to the exact form disclosed. While specific embodiments or examples of the invention are described herein for illustrative purposes, as will be recognized by those skilled in the art, various modifications are possible within the scope of the invention. For example, while FIGS. 4a through 4c illustrate a surgical instrument (240) having a cable-driven transmission connecting a tool disc (244) to an end effector (not shown), the aforementioned coupling process is also applicable to other types of surgical instruments having different transmissions (not necessarily cable-driven). These modifications may be made to the invention in consideration of the foregoing detailed description. The terms used in the following claims should not be interpreted as limiting the invention to the specific embodiments disclosed herein. Rather, the scope of the invention should be determined entirely by the following claims, which are to be interpreted in accordance with established principles of claim interpretation.

Claims

Claim 1 A method for tool coupling in a surgical robotic system, comprising: a step of detecting mechanical attachment of a surgical tool to a tool drive, wherein the surgical tool has a first tool disc and a second tool disc to be coupled to a first drive disc and a second drive disc, respectively, of the tool drive, and the first and second tool discs are linked to an end effector of the surgical tool; a step of operating the first and second motors in the same direction so that the first drive disc and the second drive disc are operated by the first motor of the tool drive and the second drive disc are operated by the second motor so that the first drive disc and the second drive disc are rotated in opposite directions to each other, wherein the transmission link of the surgical tool causes the first and second tool discs to rotate in opposite directions, thereby rotating the surgical tool in a predetermined direction; and a step of monitoring the performance of the first and second motors. A method comprising the step of detecting the coupling of the first and second tool disks with the first and second drive unit disks based on changes in the performance of the first and second motors. Claim 2 A method according to claim 1, wherein the operating step includes the step of operating the first and second motors in a position control mode. Claim 3 delete Claim 4 A method according to claim 1, wherein the movement of the surgical instrument comprises the rotation of an endoscope without a hard stop. Claim 5 A method according to claim 1, wherein the step of detecting coupling includes the step of detecting spikes of currents for the first and second motors. Claim 6 A method according to claim 1, wherein the detecting step comprises detecting first and second speeds below a speed threshold of the first and second motors, respectively. Claim 7 A method according to claim 1, further comprising the step of confirming that the first rotation angle of the first tool disk at the time of coupling is within a threshold amount having an opposite sign to the second rotation angle of the second tool disk at the time of coupling. Claim 8 A method according to claim 1, further comprising the step of determining the rotation angle of the surgical tool at the time of coupling from the first and second angles of the first and second motors while coupled with the first and second tool discs. Claim 9 A method according to claim 8, wherein the determining step includes the step of determining the rotation angle based on calibration. Claim 10 A surgical robot system for coupling, comprising: a surgical effector connected by transmission to first and second rotary tool pads, wherein the rotation of the first and second rotary tool pads is connected to rotate the surgical effector; and a tool drive unit having first and second rotary drive units each capable of aligning with the first and second rotary tool pads. A surgical robot system comprising a processor configured to detect alignment of the first and second rotary tool pads with the first and second rotary drive units, respectively, by a change in a signal while the first rotary drive unit is operated by the first motor of the tool drive unit and the second rotary drive unit is operated by the second motor of the tool drive unit, and while the first and second motors are operated in the same direction and the first and second rotary drive units are rotated in opposite directions, wherein the link of the surgical effector causes rotation in the opposite direction of the first and second rotary tool pads to rotate the surgical effector in a predetermined direction. Claim 11 In claim 10, the surgical effector comprises an endoscope rotatable about a longitudinal axis, in a surgical robot system. Claim 12 delete Claim 13 A surgical robot system according to claim 10, wherein the processor is configured to drive both the first and second rotary drive units in a position control mode. Claim 14 A surgical robot system according to claim 10, wherein the surgical robot system further comprises first and second encoders connected to the first and second rotary drive units, and the processor is configured to detect the change in the signal as the first and second speeds from the information from the first and second encoders are within a threshold amount of zero. Claim 15 A surgical robot system according to claim 10, wherein the surgical robot system further comprises current sensors connected to detect currents for the first and second rotary drive units, and the processor is configured to detect the change in the signal as the first and second currents for the first and second rotary drive units surge. Claim 16 A surgical robot system according to claim 10, wherein the processor is configured to verify the alignment by comparing the first rotation angle of the first rotation drive unit with the second rotation angle of the second rotation drive unit. Claim 17 A surgical robot system according to claim 10, wherein the processor is configured to determine the rotation angle of the surgical effector based on the rotation angles of the first and second rotary drive units when aligned with the first and second rotary tool pads. Claim 18 A surgical robot system according to claim 10, wherein the surgical robot system further comprises a current source configured to apply a dithering current to a current ramp in a current control mode for the first rotary drive unit, and the processor configured to detect the alignment from the change of the signal from the first rotary drive unit while in the current control mode. Claim 19 A method for homing the rotational position of a surgical tool in a surgical robot system, comprising the step of detecting the coupling of first and second rotational tool pads with first and second rotational drive units; and a step of determining a rotation angle of the surgical tool linked to the first and second rotation tool pads, wherein the rotation angle of the surgical tool is determined from the first and second rotation angles of the first and second rotation drive units once the coupling is detected, and the step of detecting the coupling comprises a step of rotating the first and second rotation drive units in contact with the first and second rotation tool pads, respectively, wherein both the first and second rotation tool pads are linked to the surgical tool, and when the link between the first and second rotation tool pads of the surgical tool uses rotation in the opposite direction of the first and second rotation tool pads to rotate the surgical tool in a predetermined direction, the first and second rotation drive units rotate such that the first and second rotation tool pads rotate in opposite directions to each other, and a step of rotating the first and second rotation drive units from a change in the performance of the first and second rotation drive units, respectively, the first and second rotation drive units with respect to the first and second rotation tool pads A method comprising the step of detecting a bond. Claim 20 In claim 19, the determining step comprises determining the rotation angle of the surgical tool based on the measured rotation angle from the calibration and motor encoder sensor. Claim 21 delete

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