Method and system for engaging a surgical tool with an actuator of a tool driver in a surgical robotic system

Abstract

The present invention is entitled "Method and system for engaging a surgical tool with an actuator of a tool driver in a surgical robotic system". The present invention discloses a system and a computerized method for detecting the engagement of a surgical tool with a tool driver of a robotic arm in a surgical robotic system. The method may include activating the actuator of the tool driver to rotate a drive disk to mechanically engage with a tool disk in the surgical tool. While activating the actuator, one or more motor operating parameters of the actuator that cause the rotation of the drive disk are monitored. The method detects when the drive disk is mechanically engaged with the tool disk based on the monitored one or more motor operating parameters. Other embodiments are also described and claimed herein.

Description

Technical Field

[0001] One embodiment of the present invention is directed to a control unit for detecting successful engagement of a surgical robotic tool with one or more actuators in a surgical robotic arm in a surgical robotic system.Other embodiments are also described herein. Background Art

[0002] A surgical robotic system gives an operator or user (such as a surgical surgeon) the ability to perform one or more actions of a surgical procedure using the surgical robotic system. In a surgical robotic system, surgical tools or instruments such as endoscopes, clamps, cutting tools, dilators, needles, energy transmitters, etc. are mechanically coupled to a robotic joint of a surgical robotic arm so that movement or actuation of the robotic joint directly causes rotation, pivoting, or linear movement of a portion of the tool (e.g., rotation of an endoscopic camera, pivoting of a grasping forceps jaw, or translation of a needle). Once the tool is attached to (e.g., contacts) a tool driver in the arm, operator commands can cause movement of the attached tool and activate its function, such as closing the clamp, adjusting the curvature of the endoscope, extending the instrument beyond the cannula wall, applying pressure using a clamping tool, and other movements and actions.

[0003] Due to the different nature of surgical procedures, different surgical tools or instruments may be selectively attached to the same arm of a surgical robotic system before and during a surgical procedure. To avoid equipment failure during a surgical procedure, it is important that the surgical tool or instrument is not only attached to the robotic joint of the surgical robotic arm, but also mechanically engaged to the robotic joint of the surgical robotic arm. That is, the mechanism in the surgical tool that imparts motion to or causes the instrument feature to activate (e.g., open, close, cut, apply pressure, etc.) should be mechanically engaged to an actuator in the tool drive of the robotic arm of the surgical robotic system before the surgical tool is used during a surgical procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Embodiments of the present invention are shown by way of example and not by way of limitation in the accompanying drawings, in which like reference numerals indicate similar elements. It should be noted that references to "one" embodiment of the present invention in this disclosure do not necessarily refer to the same embodiment, and that they represent at least one embodiment. In addition, for the purposes of simplicity and reducing the total number of drawings, a given drawing may be used to illustrate features of more than one embodiment of the present invention, and all elements in the drawings may not be required for a given embodiment.

[0005] Figure 1 is a pictorial view of an example surgical robotic system in a surgical setting;

[0006] Figure 2is an illustration of a system for detecting engagement of a surgical tool with a tool driver of a surgical robotic arm;

[0007] Figure 3 is a block diagram showing a surgical tool, a tool driver, and a control unit;

[0008] FIG. 4A to FIG. 4C shows different states of the tool disc and the drive disc during the engagement process;

[0009] Figure 5A is a flow chart illustrating a process performed by a control unit for engaging a surgical tool with a tool driver;

[0010] Figure 5B is a flow chart illustrating another process for a control unit to detect engagement of a tool disk with a drive disk based on one or more operating parameters of an actuator driving the drive disk;

[0011] Figure 5C is a flow chart illustrating another process for a control unit to detect engagement of a surgical tool of a surgical robotic system with a tool driver;

[0012] Figure 6 A block diagram of a feedback loop is shown; and

[0013] Figure 7 A block diagram of a controller used in a feedback loop is shown. DETAILED DESCRIPTION

[0014] Embodiments of devices, systems, and methods for detecting engagement of a detachable surgical robotic tool with a tool drive of a surgical robotic arm in a surgical robotic system are described herein. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the techniques described herein may be implemented without one or more of the specific details or with other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.

[0015] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. Thus, the phrases "one embodiment" or "an embodiment" appearing in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics (such as those shown in different figures) may be combined in any suitable manner in one or more embodiments.

[0016] See also Figure 1, which is a pictorial view of an example surgical robotic system 100 in a surgical setting. The surgical robotic system 100 includes a user console 102, a control tower 103, and one or more surgical robotic arms 104 at a surgical platform 105 (e.g., a table, a bed, etc.). The surgical robotic system 100 may incorporate any number of devices, tools, or accessories for performing surgical procedures on a patient 106. For example, the surgical robotic system 100 may include one or more surgical tools 107 for performing surgical procedures. The surgical tool 107 may have an end effector at its distal end (which is also the distal end of the surgical robotic arm 4 to which the surgical tool 107 is attached) for performing surgical procedures, such as cutting, grasping, stabbing, or energy emission.

[0017] Each surgical tool 107 may be manipulated manually, robotically, or both during a surgical procedure. For example, the surgical tool 107 may be a tool used to access, view, or manipulate the internal anatomy of the patient 106. In one embodiment, the surgical tool 106 is a grasping forceps that can grasp the patient's tissue. The surgical tool 106 may be manually controlled directly by the hand of the bedside operator 108; or it may be robotically controlled by sending electronic commands to actuate 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, in a ceiling or side wall, or in another suitable structural support.

[0018] Generally, a remote operator 109 (such as a surgeon) may use the user console 102 to remotely manipulate the surgical robotic arm 104 and / or attached surgical tools 107 (e.g., teleoperation). The user console 102 may be located in the same operating room as the rest of the surgical robotic system 100, such as in FIG. Figure 1 As shown. However, in other environments, the user console 102 may be located in an adjacent or nearby room, or the user console may be in a remote location, such as in a different building, city, or country. The user console 102 may include a chair 110, foot-operated controls 113, one or more handheld user interface devices UID 114, and at least one user display 115, the at least one user display being configured to display, for example, a view of a surgical site within a patient 106. In the example user console 102, a remote operator 109 sits in the chair 110 and views the user display 115 while manipulating the foot-operated controls 113 and the handheld UID 114 to remotely control the surgical robotic arm 104 and the surgical tool 107 (which is mounted on the distal end of the surgical arm).

[0019] In some variations, the bedside operator 108 may also operate the surgical robotic system 100 in an “above bed” mode, wherein the bedside operator 108 (user) is now on one side of the patient 106 and simultaneously manipulates i) a robotically driven tool (with an end effector) attached to the surgical robotic arm 104 (e.g., using a handheld UID 114 held in one hand) and ii) a manual laparoscopic tool. For example, the bedside operator's left hand may manipulate the handheld UID to control the surgical robotic components, while the bedside operator's right hand may manipulate the manual laparoscopic tool. Thus, in these variations, the bedside operator 108 may perform both robotic-assisted minimally invasive surgery and manual laparoscopic surgery on the patient 106 simultaneously.

[0020] During the example procedure (surgical operation), the patient 106 is prepared and covered with a drape in a sterile manner to achieve anesthesia. The initial entry to the surgical site (to facilitate access to the surgical site) can be performed manually when the arm of the surgical robot system 100 is in a stowed configuration or a retracted configuration. Once the entry is completed, the initial positioning or preparation of the surgical robot system 100 (including its surgical robot arm 104) can be performed. Next, the surgical operation continues, and the remote operator 109 at the user console 102 uses the controls 113 and UID 114 operated by the foot to manipulate various end effectors and possible imaging systems to perform the surgical operation. Manual assistance can also be provided by a bedside person (e.g., a bedside operator 108) wearing a sterile work suit at the operating bed or operating table, and the bedside person can perform tasks such as retracting tissue, performing manual repositioning, and tool replacement on one or more surgical robot arms 104. Non-sterile personnel can also be present to assist the remote operator 109 at the user console 102. When a procedure or surgical intervention is complete, the surgical robotic system 100 and the user console 102 may be configured or set to a state that facilitates post-operative procedures, such as cleaning or sterilization and medical record entry or printout via the user console 102 .

[0021] In one embodiment, the teleoperator 109 holds and moves the UID 114 to provide input commands to move the robotic arm actuator 117 in the surgical robotic system 100. The UID 114 may be communicatively coupled to the rest of the surgical robotic system 100, for example, via the console computer system 116. The UID 114 may generate spatial state signals corresponding to the movement of the UID 114, such as the position and orientation of the handheld housing of the UID, and the spatial state signals may be input signals for controlling the movement of the robotic arm actuator 117. The surgical robotic system 100 may use control signals derived from the spatial state signals to control the proportional movement of the actuator 117. In one embodiment, the console processor of the console computer system 116 receives the spatial state signals and generates corresponding control signals. Based on these control signals (which control how the actuator 117 is energized to move the segments of the surgical robotic arm 104), the movement of the corresponding surgical tool attached to the arm may simulate the movement of the UID 114. Similarly, interaction between the teleoperator 109 and the UID 114 may generate, for example, a grasp control signal that causes the jaws of the grasper of the surgical tool 107 to close and grasp tissue of the patient 106 .

[0022] The surgical robotic system 100 may include several UIDs 114, wherein respective control signals are generated for each UID controlling an actuator and a surgical tool (end effector) of a respective surgical robotic arm 104. For example, the teleoperator 109 may move a first UID 114 to control the movement of an actuator 117 in a left robotic arm, wherein the actuator responds by moving a link, gear, etc. in the surgical robotic arm 104. Similarly, movement of a second UID 114 by the teleoperator 109 controls the movement of another actuator 117, which in turn moves other links, gears, etc. of the surgical robotic system 100. The surgical robotic system 100 may include a right surgical robotic arm 104 fixed to a bed or table on the right side of a patient, and a left surgical robotic arm 104 on the left side of the patient. The actuators 117 may include one or more motors controlled so that they drive the rotation of the joints of the surgical robotic arm 104, so as to, for example, change the orientation of an endoscope or grasper of a surgical tool 107 attached to the arm relative to the patient. The motion of several actuators 117 in the same surgical robot arm 104 may be controlled by a spatial state signal generated from a particular UID 114. The UID 114 may also control the motion of a corresponding surgical tool grasper. For example, each UID 114 may generate a corresponding grasping signal to control the motion of an actuator (e.g., a linear actuator) that opens or closes the jaws of the grasper at the distal end of the surgical tool 107 to grasp tissue within the patient 106.

[0023] In some aspects, the communication between the surgical platform 105 and the user console 102 can be through the control tower 103, which can convert user commands received from the user console 102 (and more specifically from the console computer system 116) into robotic control commands transmitted to the surgical robot arm 104 on the surgical platform 105. The control tower 103 can also transmit the status and feedback from the surgical platform 105 back to the user console 102. The communication connection between the surgical platform 105, the user console 102 and the control tower 103 can be carried out via wired and / or wireless links using any suitable data communication protocol in a variety of data communication protocols. Any wired connection can be optionally built into the floor and / or wall or ceiling of the operating room. The surgical robotic system 100 can provide video output to one or more displays, including displays in the operating room and remote displays that can be accessed via the Internet or other networks. The video output or feed can also be encrypted to ensure privacy, and all or part of the video output can be saved to a server or electronic health record system.

[0024] Figure 2 2 is an illustration of a subsystem or portion of a surgical robotic system 100 for detecting engagement of a surgical tool 240 with a tool driver 230 of a surgical robotic arm 220. The surgical robotic arm 220 may be relative to Figure 1 The control unit 201 may be one of the surgical robot arms 104 of the surgical robot system 100 shown and discussed. Figure 1 As discussed in greater detail herein, the control unit 210 may detect engagement based on one or more motor operating parameters of one or more actuators (eg, actuator 238 - j) in the tool driver 230 .

[0025] There is a tool driver 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 accomplished by, for example, a human user holding the housing of the surgical tool 240 in their hand and moving the surgical tool in the direction of the arrow 280 shown until the outer surface of the surgical tool 240, in which one or more tool disks (e.g., tool disk 244-i) are present, contacts the outer surface of the tool driver 230, in which one or more drive disks (e.g., drive disk 234-j) are present. In the example shown, the tool driver 230 is a segment of a surgical robotic arm 220 located at a distal end portion of the surgical robotic arm 220. The proximal end portion of the arm 220 is secured to a surgical robotic platform, such as Figure 2 Not shown but examples thereof can be found in the above Figure 1 The operating table.

[0026] The control unit 210 is responsible for controlling the movement of the various motorized joints in the surgical robot arm 220 (including the drive disk 234), which enables the operation of the end effector 246 (its position and orientation and its surgical function) that simulates the operation of the user input device. When the surgical tool 240 is engaged to transmit force or torque from the tool driver 230, this is achieved via a mechanical transmission in the surgical tool 240. The control unit 210 can be implemented as a programmed processor, for example, as Figure 1 The control unit 210 is part of the control tower 103 of the surgical operation center. It can respond to one or more user commands received via local or remote user input (e.g., a joystick, touch controller, wearable device, or other user input device communicated via the console computer system 116). Alternatively, the control unit 210 can respond to one or more autonomous commands or controls (e.g., received from a trained surgical machine learning model executed by the control unit 210 or by the console computer system 116), or a combination thereof. These commands instruct the movement of the robotic arm 220 and the operation of its attached end effector 246.

[0027] The end effector 246 may be any surgical instrument, such as jaws, a cutting tool, an endoscope, a dilator, an implantation tool, etc. Different surgical tools, each having a different end effector, may be selectively attached (one at a time) to the robotic arm 220 for use during surgery or other medical procedures. Figure 2 The end effector 246 shown in the example of FIG. 2 is a jaw located at the distal end of the surgical tool 240 and can be retracted into or extended out of a cannula (e.g., a thin tube that can be inserted into a patient undergoing surgery) as shown.

[0028] The robot arm 220 includes a tool driver 230 in which there are one or more actuators, such as actuator 238-j. Each actuator can be a linear or rotary actuator having one or more corresponding electric motors (e.g., brushless permanent magnet DC motors), whose drive shafts can be coupled to corresponding drive discs 234-j through a transmission device (e.g., a gear train that achieves a given gear reduction ratio, not shown). The tool driver 230 includes one or more drive discs 234 that can be arranged on a plane or flat surface of the tool driver 230, wherein the figure shows several such drive discs 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 driver 230 and is designed to mechanically engage (e.g., securely fasten via snaps, friction or other mating features) a mating tool disc 244-j of a surgical tool 240 to achieve direct torque transfer between the two. This can occur once, for example, the plane or flat surface of the surgical tool 240 and the corresponding or mating plane or flat surface of the tool driver 230 contact each other.

[0029] In addition, a motor drive circuit (not shown, but which may be mounted, for example, in the tool driver 230 or elsewhere in the surgical robot arm 220) is electrically coupled to the input drive terminals of the constituent motors of the one or more actuators 238. The motor drive circuit manipulates the power consumed by the motor to adjust, for example, the speed of the motor or its torque according to the motor drive circuit input, which may be set or controlled by the control unit 210, which results in energized rotation of the associated drive disk (e.g., drive disk 234-j).

[0030] When the paired drive disk 234-j is mechanically engaged to the corresponding tool disk 244-j, the energized rotation of the drive disk 234-j causes the tool disk 244-j to rotate, for example, the two disks can rotate as one disk, thereby imparting motion to, for example, a linkage, gears, cable, chain or other transmission device within the surgical tool 240 for controlling the movement and operation of an end actuator 246 that can be mechanically connected to the transmission device.

[0031] Different surgical tools may have different numbers of tool trays based on the type of motion and number of degrees of freedom that their end effectors perform, such as rotation, articulation, opening, closing, extension, retraction, application of pressure, etc.

[0032] Furthermore, within the surgical tool 240 , more than one tool disk 244 may contribute to a single movement of the end effector 246 to achieve goals such as sharing the load between two or more motors that each drive a mating drive disk 234 .

[0033] In another aspect, within the tool driver 230, there may be two or more motors with their drive shafts coupled (via a transmission) to rotate the same output shaft (or drive disk 234) to share the load.

[0034] In another aspect, within the surgical tool 240, there may be a transmission that transfers torque from two drive disks 234 (via respective tool disks 244) for performing complementary actions in the same degree of freedom, e.g., a first drive disk 234-i rotates a drum within the housing of the surgical tool 230 to receive one end of a cable, and a second drive disk 234-j rotates another drum within the housing of the surgical tool 230 to receive the other end of the cable. As another example, two tool disks 234-i, 234-j may be used to achieve extension and shortening of the end effector along a single axis, one for extension and the other for retraction, e.g., via different cables. This is in contrast to an actuator that also moves in one degree of freedom (e.g., longitudinally extending and shortening along a single axis of motion) but only requires a single tool disk to control its entire range of motion. As another example, an actuator that moves with multiple degrees of freedom (e.g., such as wrist-like motion, motion along multiple axes, activation of an energy transmitter in addition to end effector motion, etc.) may require the use of several tool discs (each tool disc is coupled to a corresponding drive disc). In another type of surgical tool 240, a single tool disc 244 is sufficient to perform both extension and retraction motions via direct input (e.g., gears). As another example, where the end effector 246 is a jaw, two or more tool discs 244 can cooperatively control the motion of the jaw to achieve load sharing, as discussed in more detail herein.

[0035] In some embodiments, the control unit 210 initially detects the type of surgical tool 240 when the surgical tool 240 is first attached or mounted on the tool driver 230 such that the tool disc is substantially coplanar and coaxially aligned with the corresponding drive disc (although the tool disc and drive disc may not yet be successfully engaged). 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), etc. that identifies its tool or end effector information, such as one or more of the following: identification of the tool or end effector type, a unique tool or end effector ID, the number of tool trays used, the positions of those tool trays used (e.g., from a total of six possible tool trays 244-e, 244-f, 244-g, 244-h, 244-i, 244-j), the transmission type of the tool tray (e.g., direct drive, cable drive, etc.), the movement or actuation applied by the tool tray to the end effector, one or more tool calibration values ​​(e.g., the rotational position of the tool tray determined during factor testing / assembly of the tool), whether the movement of the end effector is constrained by maximum or minimum movement, and other tool attributes. In one embodiment, the information storage unit 242 identifies the minimum information that the control unit 210 can use to perform a lookup of various tool attributes, such as a tool ID.

[0036] The tool driver 230 may include a communication interface 232 (e.g., a memory writer, near field communication NFC, transceiver, RFID scanner, barcode reader, etc.) to read information from the information storage unit 242 and transfer the information to the control unit 210. In addition, in some embodiments, there may be more than one information storage unit in the surgical tool 240, such as one information storage unit associated with each tool tray 244. In this embodiment, the tool driver 230 may also include a corresponding sensor for each possible information storage unit that will be present in a given tool.

[0037] join

[0038] After the surgical tool 240 is attached to the tool driver 230 so that the tool disc is aligned with and superimposed on the corresponding drive disc (although not necessarily mechanically engaged), and after obtaining the tool disc information (e.g., read by the control unit 210), the control unit 210 performs an engagement process to detect when all tool discs expected to be attached to the corresponding drive discs are mechanically engaged with their corresponding drive discs (e.g., their mechanical engagement has been achieved, or the tool driver is now considered to be engaged with the tool). That is, attaching the surgical tool 240 to the tool driver 230 does not necessarily ensure the proper pairing required for the mechanical engagement of the tool disc with the corresponding drive disc (e.g., due to misalignment of the mating features). The engagement process may include activating one or more motors of the actuator (e.g., actuator 238-j) that drives the corresponding drive disc 234-j. Then, based on one or more monitored motor operating parameters of the actuator 238-j, the mechanical engagement of the tool disc 244-i with the drive disc 234-j can be detected when the actuator drives the drive disc 234-j, as discussed in more detail below. This process may be repeated for each drive tray 234 (of a tool driver 230 ) that is expected to be currently attached to a corresponding tool tray 244 (eg, as determined based on tool tray information obtained for the particular surgical tool 240 currently attached).

[0039] Upon detecting that a particular type of surgical tool 240 has been attached to the tool driver 230, the control unit 210 activates one or more actuators (e.g., motors) of the tool driver 230 that have been previously associated with that type of surgical tool 240. In some embodiments, each actuator associated with a corresponding drive disk 234 of a surgical tool 240 may be activated simultaneously, sequentially, or a combination of both. Figure 3An example of a surgical tool 240 utilizing four tool disks (such as tool disk 244-i) is shown, which are arranged in a coplanar manner on mating surfaces of their housings. Each tool disk contributes to at least a portion of the movement and / or activation of the end effector 246. Upon detecting the attachment of the surgical tool 240 to the tool driver 230 (e.g., engagement of the mating surfaces of the corresponding housings), the control unit 210 (or its processor 312 when executing instructions stored in the memory 314 as an engagement control 316) performs a determination that only the corresponding four drive disks (such as drive disk 234-j) need to be rotated (needed to activate the corresponding actuator 238-j, see Figure 2 ) to perform the joining process.

[0040] return Figure 2 During operation of the actuator 238-j, after detecting attachment of the surgical tool 240 to the tool driver 230, when the motor of the actuator 238-j is signaled to begin moving, the one or more sensors 236-j measure one or more motor operating parameters of the actuator. In one embodiment, for a cable-driven surgical tool, the actuator 238-j will rotate in a direction that causes its attached (but not yet engaged) tool tray 244-i to wind the cable into the drive housing of the tool 240. For example, see Figure 4A , wherein the movement 445 of the tool tray 244 prevents the unwinding of the cable 446, thereby holding the tool tray 244 in place or starting to rotate the tool tray 244 in the direction of the movement 445 (of the winding cable 446). This rotation of the tool tray 244 continues until engagement is achieved, as shown below in conjunction with Figure 4B and Figure 4C Further explanation.

[0041] In another embodiment, the selected actuator is signaled to rotate so as to cause the tool tray 244 to which it is attached to rotate, thereby causing the end effector 246 connected to the tool tray 244 to move toward a physical constraint (e.g., the jaws open until they stop against the cannula wall, a maximum value in the range of motion is achieved when hitting a hard stop in the fully open position, etc.). In another embodiment, such as an endoscopic embodiment in which two actuators share the load of rotation as an endoscopic camera, where there may not be a hard stop to prevent the camera from rotating, the selected actuator causes the tool tray 244-i to which it is attached to rotate in a direction opposite to the movement of the other tool tray 244-j, which may also be rotatably coupled to the same output shaft in the transmission housing of the tool 240. In this case, once one of the tool trays 244-i, 244-j is engaged, it will act as a physical constraint for the other tool tray. Other predetermined directions of motion consistent with the discussion herein may also be used.

[0042] Additionally, in some embodiments, the control unit 210 gradually ramps or increases the movement of the actuator (e.g., the control unit 210 signals or commands the actuator to begin rotating at a slow speed at the beginning of the movement, then gradually increases the speed, and then gradually decreases the speed when engagement is detected).

[0043] In one embodiment, calibration values ​​stored in the information storage unit 242 of the surgical tool 246 can be used to accelerate tool engagement. For example, the calibration value may include the factory-determined position (angle) of a particular tool disk 244-j recorded during product assembly or testing. The engagement process may require knowledge of the original position of the corresponding drive disk 234-j. This knowledge can be obtained by the control unit 210 executing a tool driver calibration routine in which it determines when a particular drive disk 234-j reaches the original position (when the control unit actuates the drive disk 234-j) so that the control unit 210 now knows the position of the drive disk 234-j. It should be noted that the control unit 210 can do this while relying solely on the output from the position sensor in the tool driver 230, and the tool 240 itself can be passive because there are no electronic sensors therein.

[0044] Next, the control unit 210 may activate the corresponding actuator of the drive disk 234-j, causing the drive disk 234-j to rotate at a high speed until the position variable of the drive disk 234-j approaches the factory-determined position. When the drive disk meets the threshold distance relative to the factory-determined position (e.g., the original position of the tool disk), which means that the mating features of the tool disk and the drive disk are close to alignment, the speed may be reduced to increase the probability that the mating features will engage each other when they initially meet. This process can be applied to direct transmission devices as well as tool disks that utilize cable-driven actuators (such as Figure 4A For the latter, the calibration value may include a rotation count (e.g., the number of complete rotations of the motor drive shaft) that may be used to limit continued rotation of the drive disc 234-j once the engagement is detected, so as to ensure that the maximum spool length of the cable is not exceeded, or the rotational angle of the engaged tool disc 244-j and drive disc 234-j is not exceeded.

[0045] In some embodiments, the motor operating parameters monitored by the control unit 210 (via the sensor 236) are interpreted as meaning successful mechanical engagement of the tool disk with the drive disk. These operating parameters may include a measurement of the torque applied by the actuator 238-j 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 238-j at a particular speed (e.g., where the sensor 236-j may include a current sensing resistor in series with the motor input drive terminals), a measurement of the electrical impedance seen at the input drive terminals of the motor when attempting to drive the actuator 238-j at a particular speed (e.g., where the sensor 236-j may also include a voltage sensing circuit for measuring the voltage at the motor input drive terminals), the speed of the actuator 238-j (e.g., where the sensor 236-j may include a position encoder on the output shaft of the actuator 238-j or on the drive shaft of the motor), and other parameters referred to herein as motor operating parameters. When monitoring one or more motor operating parameters of a particular actuator, when one or more of these parameters transmits to satisfy (e.g., meets or reaches) a predetermined condition or threshold, the detection of such a condition may be interpreted as a mechanical engagement event by the control unit 210. It is noted that satisfying the predetermined condition may, for example, mean that the monitored operating parameter exhibits some change according to the threshold relative to 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 engagement detection process.

[0046] In some embodiments, the control unit 210 determines that mechanical engagement of the tool disk 244-j with the drive disk 234-j has occurred using certain motor operating parameters detected during operation of the actuator 238-j, such as one or more of the following: i) torque that satisfies (e.g., rises and reaches) a torque threshold, ii) motor current that satisfies (e.g., rises and reaches) a current threshold, iii) impedance that drops below an impedance threshold, iv) motor speed that drops below a motor speed threshold, or a combination thereof. The following are some examples of such processes.

[0047] In one embodiment, where a tool disk 244-j uses a cable 446 to control the movement of its end actuator 246, the actuator 238-j (which is driving the corresponding drive disk 234-j) will move in the direction of the wound cable (here, the control unit 210 can understand the movement direction 445 based on the type of tool 240 previously identified). Figure 4ASuch a tool disk 244 is shown having a pair of coupling features 447a, 447b on its disk surface, which coupling features are shown as hollow circles. Each coupling feature 447a, 447b can be a separate cylindrical cavity formed in the disk surface. The direction of motion 445 will cause the cable 446 to be wound around it, wherein in this initial state, the cable 446 has some slack, which will disappear as the cable 446 is wound along the direction of motion 445 as shown.

[0048] The drive disk 234 is concentrically aligned with the tool disk 244, as shown in FIG. Figure 4B That is, Figure 4B The drive disk 234 is shown aligned and superimposed on the tool disk 244 so that their respective disk surfaces are in contact with each other. The drive disk 234 has a pair of coupling features 448a, 448b shown as solid circles on its disk surface. Each coupling feature 448a, 448b can be a separate cylindrical pin formed on the disk surface. In this particular example, the size of each coupling feature 448 is designed to easily fit into any of the features 447 (once the two complementary features are aligned). Figure 4B In FIG. 4 , even if the tool disk and the drive disk surfaces of the features 447 a, 447 b and the features 448 a, 448 b are in contact with each other, they are not aligned. Figure 4B In the embodiment of the present invention, one or more paired or complementary feature pairs such as feature structures 447a-448a or feature structures 447a-448b have not yet mechanically engaged with each other. In such a case, the drive disk 234 continues to be driven by its actuator 238 to move (rotate) along the movement direction 445 until Figure 4C In the case shown, mechanical engagement is achieved.

[0049] like Figure 4C As shown, the drive disk 234 has reached a point in its rotation where both the coupling features 447a-448a and the coupling features 447b-448b as shown are mechanically engaged with each other so that they now move as a unit (if the drive disk 234 continues to rotate). In the example here, each pin-cavity pair is now interlocked, as shown in this figure. In addition, at this point, the cable 446 is now wound and taught, and can therefore be used to help hold the tool disk 244 in place (prevent it from rotating) as the drive disk 234 continues to rotate in the direction of motion 445. Figure 4C Further rotation of the drive disk 234 in this case may increase the tension in the cable 446 as the cable 446 pulls on its end effector 246 until a hard stop is reached, which creates a physical constraint preventing further movement in the direction of motion 445 of the now engaged drive disk 234.

[0050] The physical constraint of further rotating the drive disk 234 enables the control unit 210 to detect a mechanical engagement event, thereby measuring the motor operating parameters and comparing them with one or more thresholds that may have been predetermined to indicate engagement. For example, the speed / rate of the motor drops below one or more thresholds to indicate engagement because the motor is restricted from further movement in the winding direction. For another example, engagement occurs when the torque applied by the motor increases to a value greater than the value of the freely moving motor and / or greater than the value of the friction force caused by the tool disk and the drive disk and / or the attachment feature portion rubbing or sliding against each other before engagement. Similarly, in other embodiments, when engagement occurs and while continuing to power the motor in an attempt to continue to move the drive disk in a predetermined direction, the measured current and / or impedance approaches and may reach a maximum predetermined value. When one or more of these thresholds are met, the control unit 210 can conclude that engagement has occurred between the tool disk and the drive disk.

[0051] Other forms of physical constraints may be used by the control unit 210 to detect successful engagement of the drive disc and the tool disc. For example, motion constraints, such as mechanical limits to the range of motion imposed by the joints of the end effector (e.g., a joint that can only rotate from -45 degrees to 45 degrees about an axis), or physical barriers to motion (e.g., a cannula wall that blocks end effector motion) may also be used as the physical constraints / hard stops described above for cable-driven or non-cable-driven tools.

[0052] In some embodiments, the surgical tool 240 may not have a physical constraint / hard stop on at least one degree of freedom of motion from which the motor operating parameters may be measured. For example, the tool disc 244-j may be responsible for applying unconstrained rotation of the end effector 246 element about an axis. However, even in the case of such unconstrained motion, the control unit 210 can still detect the engagement of the drive disc 234-j with the tool disc 244-j by detecting changes in one or more motor operating parameters during the engagement detection process. For example, a motor operating parameter pattern, such as a repetitive torque peak caused by the feature 447 rotating through the feature 488 (and therefore not engaging each other), indicates that there is no engagement. Therefore, the cessation or absence of this torque peak pattern (when the drive disc 234-j continues to rotate) means that the control unit 210 has detected that the tool disc is engaged with the drive disc.

[0053] In some embodiments, a physical constraint may be created by using coordinated movement of multiple drive disks, and / or by engaging a single drive disk before engaging a second drive disk. For example, consider a situation where two or more tool disks (in the same housing of a surgical tool 240) are connected by a transmission in the housing of the tool 240 to share the load (end effector 246) when rotating in the same direction, such as when a cutting or clamping tool may need to apply a force that exceeds the force that a single actuator 238-j can provide. In such an embodiment, two or more actuators rotating in the same direction (their corresponding drive disks rotating in the same direction) drive the same output shaft inside the surgical tool 240 (due to the transmission in the surgical tool 240 connected to the corresponding tool disk). Now, if the two actuators are signaled to move in opposite directions, once one of the drive disks engages its corresponding tool disk, this becomes a physical constraint for the other drive disk (when the other drive disk has engaged its corresponding tool disk). When one of the two or more actuators is engaged (its drive disk engages its corresponding tool disk), the control unit 210 creates a constraint for the other actuator by signaling the engaged actuator, for example, to enter a position holding state. That is, the control unit 210 will command the first actuator 238-j to maintain its position, while the other unengaged actuator 238-i continues to be signaled to drive and thus rotate or move (toward the engagement between its drive disk 234-i and the tool disk 244-i). In this embodiment, one or both of the motor operating parameters of the actuator can be monitored to detect the engagement between the tool disk and the drive disk pair. In addition, if a hard stop does exist (the control unit 210 expects or knows that the particular tool 240 has a hard stop), the actuator of the engaged drive disk can be signaled to continue to drive or rotate in the same direction until the hard stop is detected. The other actuator can continue to rotate in the opposite direction and try to engage, while the engaged actuator keeps its position at the hard stop.

[0054] return Figure 2, and as described above, the tool identification performed by the control unit 210 enables the control unit to understand the characteristics of the end effector 246 of the surgical tool 240. For example, the control unit 210 can use the identification process to determine whether two (or more) tool trays in the tool 240 work together to apply end effector motion, whether one or more motions of the end effector are subject to hard stops or physical constraints, the range of motion of the end effector, which actuators will be used by the tool 240, and factory-defined calibration values ​​such as the home position of the tool tray. It is noted that the calibration value can cover a range, such as 290 degrees + / - 4 degrees. Based on such calibration values, such as the home position of the tool tray 244-i, and based on the current position of the corresponding drive disk 234-i (determined using the position encoder in the tool driver 230), the control unit 210 can track the difference during the engagement process (when the actuator is signaled to rotate). As long as the difference is greater than a predetermined threshold, the actuator is signaled to turn quickly (fast rotation), and then in response to the difference becoming less than the threshold (meaning the drive plate is close to the calibration value home position), the actuator is signaled to turn slowly (slow rotation). It is expected that this will increase the chances of detecting reliable engagement.

[0055] In some embodiments, after the control unit 210 detects engagement, the control unit 210 may take one or more additional actions relative to the end effector 246 to confirm the engagement. For example, the control unit 210 may subject the end effector to a predetermined set of one or more movements to test engagement, such as signaling the drive disc to reverse direction to move the end effector in a direction opposite to the operation it performed during the engagement process, moving the end effector to achieve an expected maximum degree of movement, etc. Such movement enables the control unit 210 to, for example, again reach a hard stop or reach a physical constraint, as detected as discussed herein based on one or more motor operating parameters, to confirm mechanical engagement between the tool disc and the drive disc.

[0056] Additionally, in some embodiments, the control unit 210 may utilize a hard stop or physical constraint to set a reference position of the end effector. For example, knowing that a hard stop will occur when the end effector reaches 270° of rotation in a certain direction, the control unit 210 may set a calibration value for the position of the corresponding actuator or drive disk. The motion of the actuator or drive disk may then be tracked based on the number of rotations of the drive disk, the motor shaft, the gear ratio, the drive disk / motor indexing, etc.

[0057] Additionally, in some embodiments, when attempting to achieve engagement of the tool disk with the drive disk, the control unit 210 may signal actuation of one or more motors within a specified amount of time, within a specified number of rotations, or a combination thereof. When engagement is not achieved within a threshold amount of time, number of rotations, etc., the control unit 210 may provide a notification to an operator of the surgical robotic system (e.g., Figure 1 ) to detach and then reattach the surgical tool 240 in order to restart the engagement process.

[0058] After the control unit 210 detects the mechanical engagement of the drive disk with the tool disk, the operator may command movement of one or more joints of the surgical robot arm 220. As described above, the commands are received from or originate from one or more UIDs (e.g., UID 114) as spatial state signals from the UIDs, which are converted into corresponding control signals (e.g., desired motor speed or current and rotational direction) provided by the control unit 210 to energize one or more actuators of the tool driver 230, thereby changing the attitude, position, or other state of the end effector. In one embodiment, in the case where two or more actuators cooperatively control the movement of the end effector, such as when two or more tool disks are used to apply movement of the end effector with the same degrees of freedom, the control unit 210 also implements cooperative control techniques to ensure that the actuators operate in a complementary manner when moving the end effector, share loads associated with the movement of the end effector, do not oppose each other when applying such movement, maintain balance between the actuators so that one actuator does not continuously perform more or less work than the other actuators, etc. For example, when two or more actuators are used to control the opening, closing, and clamping force application of the jaws of the end effector 246, the control unit utilizes a multi-actuator operation control technique that identifies the first actuator of the two or more actuators as a master actuator and identifies the remaining one or more actuators as slave actuators. Then, the position command that has been provided to signal the master actuator to move the end effector 246 to the command position is also provided to signal the slave actuator to move the end effector 246 to the same command position. For example, if the master and slave actuators are duplicated, 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 provided to each slave actuator. However, in some embodiments, some compensation may be made to how the motion of the actuators complement each other, such as reversing the polarity of the slave actuator when the directions of rotation of the master and slave actuators are different, adjusting the gain (e.g., the gain of the commanded motor current) when the properties of the motors are different, etc., as discussed in more detail herein.

[0059] Figure 3 240, tool driver 230, and control unit 210. The surgical tool 240 can be attached to the tool driver 230 by bringing the complementary or mating surfaces of their respective housings into contact with each other. Attachment can also include fastening the housings to each other. In addition, the control unit 210 can use one or more sensors (not shown) of the tool driver 230 to detect attachment, including reading data identifying the surgical tool 240 from the surgical tool 240, which indicates which tool trays (e.g., tool trays 244-j) are used to control the movement of the end effector 246, including calibration values, which indicate whether the tool has a hard stop or indicate which tool trays contribute to the movement of other tool trays in the surgical tool 240 or are connected to other tool trays in the surgical tool through a transmission. The data can be transmitted to the control unit 210 via a communication link (e.g., a wired or wireless link) established between the communication interface 318 of the control unit 210 and the sensor readout circuit (not shown) in the tool driver 230. The data may then be stored in the memory 314 as part of an engagement control program (engagement control 316 ) and may be associated with that particular surgical tool 240 as long as that particular surgical tool remains attached to the tool driver 230 .

[0060] The control unit 210 including its programmed processor 312 may be integrated into the surgical robotic system 100 ( Figure 1 ), for example as a shared microprocessor and program memory within control tower 103. Alternatively, control unit 210 may be implemented in a remote computer, such as in a room different from the operating room, or in a room with a remote computer. Figure 1 In addition, although not shown, the control unit 210 may also include user interface hardware (e.g., keyboard, touch screen, microphone, speaker) that enables manual control of the robotic arm and its attached tool 240, power devices (e.g., battery), and other components typically associated with electronic devices for controlling surgical robotic systems.

[0061] The memory 314 is coupled to one or more processors 312 (collectively referred to herein as "processors" for simplicity) to store instructions for execution by the processors 312. In some embodiments, the memory is non-transitory and may store one or more program modules including the tool controls 320 and the engagement controls 316, the instructions of which configure the processors 312 to perform the engagement processes described herein. In other words, the processors 312 may operate under the control of the execution of programs, routines, or instructions stored in the memory 314 as part of the tool controls 320 and the engagement controls 316 to perform methods or processes in accordance with the aspects and features described herein.

[0062] In response to detecting the attachment of the surgical tool 240 to the tool driver 230, the engagement control 316 executes (or more specifically, configures the processor 312 to execute) a process for detecting mechanical engagement of a tool disk with a corresponding drive disk (which is driven by an actuator), such as engagement of the tool disk 344-i with the corresponding drive disk 334-i. The engagement control 316 can signal (via the tool control 320) one or more actuators of the tool driver 230 to apply motion of their respective drive disks. In some embodiments, these instructions or signals include instructions to energize, start, or otherwise provide power to a motor so that the motor can generate or apply a specific amount of torque, causing the drive disk to rotate at a specific speed and direction by applying a certain voltage command, current command, etc. In addition, the movement of each drive disk during the engagement detection process can be controlled to start quickly initially, and then slowly decrease once close engagement or close alignment of mating features is detected or a predetermined time limit is reached without detecting engagement. For example, based on the relative position of the drive disc and the tool disc (which may be based on known calibration values), the actuator speed is ramped down to a predetermined speed (eg, until the drive disc is within a threshold distance where the mating features become aligned).

[0063] The engagement control 316 monitors one or more motor operating parameters of the motor of the actuator of the tool driver 230. As described herein, the motor operating parameters may include the torque applied by the motor, the voltage provided to the motor, the impedance presented at the input drive terminal of the motor when attempting to drive the motor to move at a certain speed, the motor speed, and other motor operating parameters. One or more of these parameters can be monitored by comparing them to a threshold value, so that when the threshold value is reached, it is considered that a mechanical engagement event has occurred (e.g., between the tool disk 344-i and the drive disk 334-i). As described herein, when the corresponding mating features of the tool disk and the drive disk are aligned with each other and fastened to the drive disk, the rotation will result in, for example, immediate rotation and proportional rotation of the mechanically engaged tool disk (such as with the drive disk), and mechanical engagement is expected to be detected. When one or more motor operating parameters meet a threshold value (e.g., reaching or exceeding a threshold indicating that a hard stop has been reached, a maximum torque, voltage or impedance value, a torque, voltage or impedance value greater than the friction force initially present when the tool 240 is first attached to the tool driver 230), such engagement is expected to be detected. Thus, the engagement control 316 infers or deduces that the tool disk 344 - i and the drive disk 334 - j are engaged with each other (eg, the corresponding disk mating features are secured to each other).

[0064] Note that the engagement control 316 need not monitor sensor readings of all motor parameters available from the tool driver 230. Rather, the engagement control 316 may monitor only one or more characteristics of interest to determine when a threshold associated with engagement is met based on, for example, whether the surgical tool 240 is subject to any hard stops or physical motion constraints, whether one or more tool trays operate in concert (cooperate with each other) to impart motion on the surgical tool 240, whether the tool trays impart motion on the surgical tool 240 via a cable or directly (e.g., through a gearbox), or a combination thereof.

[0065] In some embodiments, the engagement control 316 monitors patterns of motor operating parameters, such as patterns of torque, voltage, motor speed, impedance, etc., that are the result of the drive disk 234-j rotating over the tool disk 244-j but without mechanical engagement. That is, an amount of torque, force, voltage, etc., can be measured that is greater than the amount exhibited by a freely moving drive disk (where the surgical tool 240 is not attached to the tool driver 230) and less than a mechanically engaged drive disk (when, for example, the mating features of the tool disk and the drive disk pass each other, the tool housing and the tool driver housing are in contact but not engaged). When this motor parameter pattern change is detected, such as due to encountering a hard stop or physical motion constraint, the engagement control 316 is considered to have detected mechanical engagement. Even when there are no hard stops or motion constraints available, or without having to drive the drive disk to a hard stop or other motion constraint of the tool, the motor operating pattern based on the monitoring and interpretation pattern enables the engagement control 316 to detect engagement (between the tool disk 344-j and the drive disk 334-j).

[0066] In some embodiments, when the engagement control 316 detects mechanical engagement of the tool disc with the drive disc, it can also initiate a verification process or engagement check, in which the actuator of the tool driver 230 is signaled to undergo a predetermined set of one or more movements to verify the detected engagement. For example, the actuator can be instructed to rotate its corresponding drive disc in a direction opposite to the engagement direction (the direction in which the drive disc rotated when the engagement was initially detected, for example, in the direction of rotation). Figure 4A The drive disc may then be rotated back in the engagement direction until a second engagement is detected (e.g., when a particular motor parameter reaches a threshold consistent with the tool disc reaching a hard stop or motion constraint, when a particular motor parameter reaches a threshold consistent with a resistance to rotating the tool disc that is not caused solely by friction (friction between the tool disc and the corresponding drive disc), or a combination thereof).

[0067] The engagement control 316 generates a notification for the operator of the surgical robotic system based on the detection of engagement of the tool disc with the drive disc, or based on the countdown timer having expired without the engagement being detected. The notification may indicate that engagement has occurred so that the surgical tool 240 is ready for use, or that engagement has not occurred and therefore the surgical tool 240 should be reattached.

[0068] Figure 5A is a flow chart illustrating a process 500 of engaging a surgical tool of a surgical robotic system with a tool driver according to an 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 a memory (e.g., Figure 3 A processor 312 and a memory 314, wherein the processor 312 is configured according to instructions of the tool control 320 and the engagement control 316).

[0069] See also Figure 5A , processing logic begins by activating an actuator of a tool driver to rotate a drive disk of the tool driver (processing block 502). For example, processing logic may activate a linear or rotary actuator of a tool driver (e.g., tool driver 230) to turn or rotate a drive disk (e.g., drive disk 234-j). Further, as discussed herein, when mechanically engaged, rotation of a drive disk (e.g., disk 234-j) will cause immediate or direct rotation of a corresponding tool disk (e.g., disk 244-j) of a surgical tool (e.g., surgical tool 240).

[0070] Processing logic monitors one or more motor operating parameters of the actuator that cause the drive disk to rotate while activating the motor (processing block 504). In some embodiments, the monitored motor operating parameters may include torque, motor current, motor speed, or a combination thereof.

[0071] Based on one or more monitored motor operating parameters, processing logic detects when the drive disc is mechanically engaged with the tool disc (processing block 506). In one embodiment, detection occurs when or in response to at least one of the one or more monitored motor operating parameters satisfying a corresponding condition or threshold. For example, the condition may be associated with a value of the motor operating parameter that occurs in response to the motor reaching a physical constraint that prevents further rotation of the tool disc (e.g., when a physical obstacle to movement is encountered, a mechanical limit of the range of motion is reached; when opposition with another activated motor actuator occurs, a maximum degree of movement of the end effector of the tool is reached, etc.). As another example, the condition may represent a motor operating parameter exhibited when there is friction caused by the drive disc contacting and sliding against the tool disc during rotation, but the drive disc is not mechanically latched or fastened to the tool disc. In the embodiments discussed herein, when mechanical engagement of the drive disc with the tool disc is detected, the processing logic may perform one or more additional actions, such as generating a system or operator notification, initiating one or more engagement verification operations, storing a reference value, etc.

[0072] Figure 5B is a flow chart showing a process 550 for detecting engagement of a tool tray with a drive tray based on one or more motor operating parameters of an actuator driving the drive tray. The process 550 is performed by processing logic, which may include any combination of hardwired circuits and programmed processors, where, for example, the process 550 may be performed by a processor 312 programmed according to the tool control 320 and engagement control 316 described above. The process may begin by detecting that a detachable surgical tool has been attached to a tool driver of a robotic arm of a surgical robotic system (processing block 552). The attachment may be detected based on a sensor of the tool driver entering a wireless detection range or conductively connecting with an information storage unit in the detachable surgical tool. As described herein, the information storage unit may include a tool identifier and may also include additional tool attributes, such as which of several available tool trays in the tool housing are actually connected to the end effector in the detachable surgical tool via a transmission device in the housing, what type of transmission device in the tool controls the movement of the end effector (e.g., cable drive, direct drive, etc.), the direction of allowed movement or rotation, whether there is any range of such movement or rotation, calibration values ​​(e.g., cable length, current cable length, maximum winding, rotational position of the tool tray or original position of the tool tray, etc.), and other tool attributes discussed herein.

[0073] At least one motor of the tool driver is then started so that at least one motor rotates an associated drive disk corresponding to a tool disk (the tool disk is connected to control the movement of the end effector through a transmission in the surgical tool) (processing box 554). In one embodiment, a signal is sent to the tool control 320 to notify the current to be provided to the motor, the torque to be achieved by the motor, or the direction of motion so that the motor will cause the drive disk to rotate at a predetermined speed in a predetermined direction. In other words, the processing logic causes a signal to be sent to the motor drive circuit, thereby commanding the motor drive circuit to apply power to the motor or energize the motor. In some embodiments, the predetermined speed is set based on determining, 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 encountered (e.g., hard stop, physical constraint, reverse motion constraint) or a combination of such factors when the attachment of the tool driver to the detachable surgical tool is detected. Then one or more motor operating parameters of at least one motor of the tool driver are monitored (processing box 556). The monitored motor operating parameters may correspond to those parameters (e.g., torque, speed) controlled by the processing logic to cause the motor to move.

[0074] return Figure 5B , the processing logic repeatedly checks to see if the engagement condition has been met, for example, the monitored motor operating parameter has reached a threshold value (processing box 558). If so, a mechanical engagement event is marked, which indicates that the drive disc has mechanically engaged with its corresponding tool disc (processing box 564). As discussed herein, the threshold indicates a condition associated with the mechanical engagement of the drive disc. For example, when the torque, current, or impedance associated with the motor at a predetermined speed or rate exceeds the value associated with the motor that only encounters the friction force between the tool driver and the tool disc, mechanical engagement is expected. The threshold can be a value greater than the torque, voltage, impedance, etc. required to overcome such friction. For another example, the movement of the end effector may be subject to physical constraints, such as the maximum range of motion of the joint, hard stops (e.g., imposed by the cannula wall), the reverse movement of another drive disc, and other physical constraints. In this case, the speed and direction of the motor's movement are selected to advance the end effector or tool disc toward the physical constraint. Then, when the physical constraint is reached, the monitored torque, current, impedance will reach a maximum peak, and the speed will drop to zero. In this example, one threshold may refer to the torque or motor current set close to its maximum value, and the other threshold may refer to the speed set below the nominal speed of the motor during drive disk rotation (e.g., substantially zero). Thus, the two thresholds act as a check on each other to make the detection of engagement more robust.

[0075] In response to the detected engagement of the drive disk with the corresponding tool disk, the movement of the drive disk is stopped (processing box 566). In one embodiment, when the movement is stopped, one or more reference values ​​associated with the position or state of the end effector can be stored for later reference and use. For example, in the case where a physical constraint is used to detect engagement, the division value, rotation count, etc. of the motor at that moment can be stored and later used to reposition the end effector at or near the physical constraint. The physical constraint can be, for example, a maximum cable length, a cannula wall, a maximum value of the range of motion, etc. In addition, in the case of a cable-driven tool, in order to prevent excessive tensioning of the cable, the movement of the drive disk can be stopped or the motor can be disabled simultaneously or nearly simultaneously in response to the detection performed at box 558.

[0076] Once engagement of all relevant drive disks (those corresponding to the tool disk in use for a particular surgical tool) is detected in processing block 567 (where the processes described above in blocks 554-556-558-564-566 may have been performed for each respective drive disk), a notification of tool engagement is generated (processing block 568). The notification may be a visual notification (e.g., a graphical user interface notification), an auditory notification (e.g., a tone, sound, etc.), a sensory notification (e.g., a tactile notification), or a combination of such notifications generated by the user interface hardware of the surgical robotic system.

[0077] Returning briefly to processing block 558, when an engagement condition is not met (e.g., a monitored motor operating parameter does not meet a threshold value such that mechanical engagement of the tool disc and the corresponding drive disc does not occur), a determination is made as to whether a time or rotation limit has been reached (processing block 560). Failure to engage may be due to a broken cable, the tool disc and the drive disc are not close enough to each other to engage, etc.). The time limit may be a predetermined maximum time interval (a countdown timer value) that the drive disc is allowed to rotate without detecting mechanical engagement with the tool disc. Similarly, the rotation limit may be the number of motor rotations required to apply one or more complete rotations of its corresponding drive disc. For example, if the rotation limit is associated with one complete rotation of the drive disc, it is assumed that engagement should occur within a single rotation of the drive disc. If a time limit, rotation limit, or some combination of limits is not met (processing block 560), one or more motor operating parameter values ​​continue to be monitored (returning to processing block 556). However, if one or more limits are met (processing block 560), a notification similar to the notification of processing block 568 is generated that an error has occurred and tool engagement 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 driver and then reattach them to restart the system. Figure 5B The joining process.

[0078] Now go to Figure 5C, which is a schematic diagram of a process performed by a control unit for engaging a surgical robotic tool with a tool driver as part of a surgical robotic system. The system includes Figure 2 The surgical robotic tool 240 shown has one or more tool trays at its proximal end and an end effector at its distal end, as shown. As shown, a tool driver (e.g., tool driver 230) is mounted at the distal end of the surgical robotic arm 220, wherein the tool driver 230 has one or more drive trays 234, each driven by a rotary motor within the housing of the tool driver. Each drive tray 234 will be attached to a tool tray 244 of the surgical tool 240 to apply motion to the end effector 246.

[0079] Continue to see Figure 5C , the process for engaging the tool disc with the drive disc is performed by the control unit, and specifically by one or more processors of the control unit that are configured (or programmed) to perform this operation. The operation may begin by detecting that a surgical tool is attached to the tool driver (box 582); this may be accomplished by the processor wirelessly or via a wired connection that reads an identification or other attribute of the tool that has come into contact with the tool driver, so that the tool disc comes into contact with the corresponding or corresponding drive disc. The control unit may then actuate each drive disc by rotating the motor (box 584), and during actuation detect whether the drive disc is engaged to the corresponding tool disc (box 586); when a pair of coupling features (there may be more than one pair, for example, such as FIG. 4A to FIG. 4C When two pairs (shown, or more) of the drive disc and the tool disc become interlocked, the drive disc is considered to be engaged to the tool disc. To detect engagement, the control unit identifies a change in the sensed motor state (the state of the actuator or its motor operating parameter), including a drop in the speed of the rotating motor below a predetermined speed threshold and an increase in the torque of the rotating motor above a predetermined torque threshold. The speed threshold may correspond to a speed at which the motor substantially stops, wherein the torque threshold is a value between: i) a minimum torque at which the motor overcomes the friction between the drive disc and the tool disc before engagement; and ii) a maximum torque produced by the motor. The change in motor state may be caused by at least one of the following: the end effector reaching a joint limit, an external force on the end effector, a motion constraint caused by another motor of the tool driver being activated, and a combination thereof. Depending on the specific surgical tool, there may be more than one tool disc for operating the end effector. In this case, the above-described engagement process is also performed for each additional tool disc (which has a corresponding drive disc in the tool driver). The process then continues to box 588, where the control unit signals, for example, a user interface subsystem of the surgical robotic system to report engagement of the surgical tool, but only if all tool discs for a particular tool have been detected as engaged with their corresponding drive discs.

[0080] In one embodiment, a feedback loop may be used to monitor one or more motor operating parameters and detect when a threshold is reached. Figure 6 A block diagram of a feedback loop for controlling the speed of a motor of a tool drive using speed feedback is shown. The feedback loop can be implemented in hardware, firmware, software, or a combination thereof. Controller 602 receives a speed command. Controller 602 can be, for example, a proportional-integral-derivative controller (e.g., Figure 7 PID controller 702) that provides a loop / feedback mechanism to provide 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 known as the speed setpoint). For example, the direction can be the winding direction of the cable-driven tool tray 244-j. As another example, the direction can be the direction that will be opposite to the movement of another motor whose attached tool tray 244-i should cooperate with the tool tray 244-j. As another example, the direction can be the direction that causes the motor to advance the end actuator toward a hard stop (such as a physical barrier or a mechanical limit of the range of motion). In one embodiment, the controller 602 can use various values, such as the torque required to achieve the speed, the current required to achieve the speed, the impedance indicating the speed, etc., as a measure for generating the controller current output to the motor / actuator 604.

[0081] A sensor such as a torque sensor, a speed sensor, or a combination of these sensors measures the actual speed of the motor / actuator. The actual speed is then provided as feedback back to the controller 602, which can calculate an error based on the difference between the actual speed of the motor and the command speed. The controller 602 responds to the difference by adjusting its controller output, such as a motor current command to the motor / actuator 604, a torque to be achieved by the motor / actuator 604, an impedance value, etc., which will cause the motor / actuator 604 to move toward the speed command or set point. In some embodiments, the controller 602 may output motor operating parameters such as torque, current, impedance, speed, etc. calculated as a result of executing a feedback loop.

[0082] In another embodiment, the controller 602 may include a saturation block (not shown) to ensure that the controller output (e.g., the value of the motor current) does not exceed a threshold, such as a current threshold, a torque threshold, an impedance threshold. The value used by or input to the saturation block can be dual-purpose, i.e., also used as a motor operating parameter value provided to the processor (for the purpose of being monitored during the engagement process).

[0083] Figure 7A block diagram of a feedback loop is shown that includes a controller 702 for controlling the speed of a motor of a tool driver. In one embodiment, the controller 702 is a proportional integral (PI) controller and may be used within the controller 602 and may be implemented in part as hardware, firmware, software, or a combination thereof.

[0084] The controller 702 receives a speed command (e.g., a control variable setpoint). The controller 702 provides a loop / feedback mechanism to regulate and provide an appropriate current (e.g., a controller output) to drive the motor / actuator 704 at the speed and direction of the speed command / setpoint. For example, the direction may be the winding direction of a tool tray of a cable-driven surgical tool. As another example, the direction may be a direction that is opposite to the movement of another motor of the tool driver. As another example, the direction may be a direction that causes the motor to advance the end effector toward a hard stop (such as a physical barrier or a mechanical limit of the range of motion). In one embodiment, the controller 702 may use various values, such as the torque required to achieve the speed, the current required to achieve the speed, the impedance indicating the speed, etc., as a measure for generating the controller current output to the motor / actuator 704.

[0085] Adjustments are made to the raw speed command, such as scaling (e.g., block k p ) to adjust the speed proportional to the error (e.g., as determined by feedback), and integral adjustment (e.g., block k i ) to adjust the speed to account for past errors integrated over time. The integral adjustment can also be used by block k b The generated recovery term is adjusted in the feedback loop for anti-integral windup to further adjust the value of the integral adjustment. The integral-adjusted value can be further adjusted by block 1 / s (e.g., before being added to the value adjusted by the proportional setpoint). In one embodiment, a saturation block can be used in the controller 702 as shown in the figure to ensure that the value of the current provided to the motor does not exceed a threshold, such as a current threshold, a torque threshold, an impedance threshold, etc. After the adjustment is performed by the above block and the resulting current command value does not exceed the value set in the saturation block, the current command (e.g., an adjusted command that has been corrected based on feedback and PI adjustment) can be fed into the current amplifier so that the command current entering the motor actuator 704 can be amplified by a factor. The coefficient can 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 started according to the amplified current, and feedback on the speed response of the motor / actuator 704 (e.g., speed, torque, speed, etc. determined by a sensor coupled to the motor) is provided to the feedback loop implemented by the controller 702.

[0086] As described above, the values ​​used by (or input to) the saturation block may be used as motor operating parameter values ​​provided to the processor for monitoring during the engagement process, for example, representing current motor current or current motor impedance.

[0087] In another embodiment, feedback may be used as a motor operating parameter value provided to the processor for monitoring during the engagement process.Other variables (eg, regulated and unregulated) calculated in the controller 702 may be used as motor operating parameters that are monitored.

[0088] The above description of the illustrated embodiments of the present invention, including what is described below in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Although specific embodiments and examples of the present invention are described herein for illustrative purposes, those skilled in the art will recognize that various modifications are possible within the scope of the present invention. For example, although FIG. 4A to FIG. 4C A surgical tool 240 is shown having a cable-driven transmission connecting the tool tray 244 to an end effector (not shown), and the above-described engagement process is also applicable to other types of surgical tools having different transmissions (not necessarily cable-driven). These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Instead, the scope of the invention will be determined entirely by the following claims, which should be interpreted in accordance with established principles of claim interpretation.

Claims

1. A surgical robotic system for engaging a robotic surgical tool with a tool driver, the surgical robotic system comprising: a robotic surgical tool having one or more tool trays at a proximal end and an end effector at a distal end; a tool drive mounted at a distal end of the surgical robot arm, the tool drive having one or more drive disks each driven by a rotary motor, each drive disk configured for attachment to a tool disk of the surgical tool to impart motion to the end effector; A control unit, the control unit comprising one or more processors, the processors being configured to: detecting attachment of the surgical tool to the tool driver; actuating each drive disc by the rotary motor; During the actuation, detecting whether the drive disc is engaged to the corresponding tool disc based on a change in sensed motor state, the change in motor state comprising a speed of the rotary motor dropping below a predetermined speed threshold and a torque of the rotary motor rising above a predetermined torque threshold, wherein the speed threshold is lower than a nominal speed of the motor during actuation, and the torque threshold is a value between: i) a minimum torque of the rotary motor to overcome friction between the drive disc and the tool disc before engagement; and ii) a maximum torque generated by the rotary motor; and When engagement of each of the drive disks with a corresponding tool disk has been detected, engagement of the surgical tool is reported. 2 . The system of claim 1 , wherein the drive disc is engaged to the tool disc when a pair of coupling features of the drive disc and the tool disc interlock.

3. A system according to claim 1, wherein the change in the motor state is caused by at least one of the following: 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 being activated, and a combination thereof.

4. A method performed by a processor of a surgical robotic system for engaging a surgical tool of the surgical robotic system with a tool driver, the method comprising the following operations performed by the processor: activating an actuator of the tool driver to rotate a drive disk, wherein the drive disk will mechanically engage a tool disk in the surgical tool; When the actuator is activated to cause the drive plate to rotate, monitoring operating parameters of the actuator, the operating parameters including motor torque and motor speed; and Conditions are satisfied based on the operating parameters of monitored torque and speed to detect when the drive disk is mechanically engaged with the tool disk by determining that a measured torque of the actuator exceeds a threshold torque and a measured speed of the actuator is below a threshold speed, wherein the threshold torque is i) greater than the friction between the drive disk and the tool disk during rotation without mechanical engagement and ii) less than a maximum torque of the actuator, and the threshold speed is substantially zero.

5. The method of claim 4, wherein the condition indicates that the actuator has reached a physical constraint preventing further rotation of the drive plate.

6. The method of claim 5, wherein the physical constraint comprises a predefined motion constraint of the surgical tool, wherein the tool disc is winding a cable, and wherein the physical constraint comprises a motion constraint caused by a second drive disc that is also winding the cable or is holding the position of the cable. 7 . The method according to claim 4 , wherein the monitored one or more motor operating parameters are collected by one or more sensors.

8. The method of claim 4, wherein the drive disc and the tool disc include one or more pairs of coupling features, wherein when mechanical engagement is achieved, each pair of coupling features become interlocked with each other to rotate as one.

9. The method according to claim 4, further comprising: activating the actuator of the tool driver to rotate the drive disk at a first speed; as well as The actuator of the tool driver is activated to rotate the drive disk at a second speed that is lower than the first speed when the actuator arrives within a threshold angle from a reference position, wherein the reference position corresponds to a known calibrated engagement position.

10. The method according to claim 4, further comprising: detecting that at least one of the drive discs fails to mechanically engage with a corresponding tool disc; as well as A notification is generated to an operator of the surgical robotic system indicating the unsuccessful engagement.

11. A surgical robot system, comprising: a tool driver comprising one or more actuators configured to rotate one or more drive disks; a robotic surgical tool attached to the tool driver, the surgical tool comprising one or more tool discs configured to impart motion to an end effector of the surgical tool; A control unit comprising a memory and a processor communicatively coupled to the tool driver, the control unit being configured to: activating an actuator of the tool driver to rotate a drive disk into engagement with a tool disk in the surgical tool; When the actuator is activated to cause the drive plate to rotate, the operating parameters of the actuator are monitored, the operating parameters including motor torque and motor speed; detecting when the drive disc engages the tool disc based on the monitored operating parameters of the actuator satisfying an engagement condition by determining that a measured torque of the actuator exceeds a threshold torque and a measured speed of the actuator is below a threshold speed, wherein the threshold torque is i) greater than a friction force between the drive disc and the tool disc during rotation without mechanical engagement and ii) less than a maximum torque of the actuator, and the threshold speed is below a nominal speed of the motor during actuation; as well as Engagement of the surgical tool with the tool driver is reported when each of the one or more drive disks engages a corresponding tool disk.

12. The surgical robotic system of claim 11, wherein the engagement condition corresponds to a change in an operating parameter caused by the actuator reaching a physical constraint preventing further rotation of the drive disk.

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