Calibration device interface

Abstract

A method of calibrating an instrument interface of an instrument in a surgical robotic system, the surgical robotic system including a robot having a base and an arm extending from the base to a drive assembly for engaging with the instrument interface to transmit drive forces to the instrument, the instrument interface being configured to drive a joint of the instrument via a drive element, the method comprising: obtaining usage data indicative of usage of a joint of the instrument; comparing the usage data to one or both of a joint movement maximum range of the joint and an expected joint movement model of the joint; determining a calibration offset from the comparison to adjust a control relationship of a drive element arranged to drive the joint; and adjusting the control relationship of the drive element using the calibration offset so as to calibrate the instrument interface.

Description

Technical Field

[0001] This invention relates to instrument interfaces for calibrating instruments in a surgical robot system. The calibration uses usage data indicating the use of the instrument's joints. Background Technology

[0002] The use of robots to assist and perform surgery is known. Figure 1 A typical surgical robot 100 is shown, comprising a base 108, an arm 102, and instruments 105. The base supports the robot and is rigidly attached to, for example, the operating room floor, operating room ceiling, or trolley. The arm extends between the base and the instruments. The arm is hinged by means of a plurality of flexible joints 103 along its length, which are used to position the surgical instruments relative to the patient in a desired location. The surgical instruments are attached to the distal end 104 of the robotic arm. The surgical instruments pass through the body of the patient 101 at a port 107 to access the surgical site. The instrument includes an end effector 106 at its distal end for performing medical procedures.

[0003] Figure 2 A typical surgical instrument 200 for performing robotic laparoscopic surgery is shown. The surgical instrument includes an instrument interface 201 through which it is connected to a robotic arm. A shaft 202 extends between the interface 201 and a hinge 203. The hinge 203 terminates in an end effector 204. Figure 2 In the diagram, a pair of serrated clamps are shown as end effectors 204. A hinge 203 allows the end effector 204 to move relative to axis 202. It is desirable to provide at least two degrees of freedom for the movement of the end effector 204 via the hinge. A device interface is configured to engage with an arm drive assembly of a device-engageable robotic arm. When the device engages with the arm, the device interface engages with the drive assembly, thereby transmitting driving force to the device.

[0004] Figure 3A surgical robot with an arm 300 extending from a base 301 is shown. The arm includes multiple rigid limbs 302. The limbs are coupled via rotary joints 303. The proximal limb 302a is coupled to the base via a proximal joint 303a. It is coupled in series with the other limbs via additional joints 303. Suitably, a wrist 304 consists of four separate rotary joints. The wrist 304 couples one limb (302b) of the arm to the distal limb (302c). The distal limb 302c carries an attachment 305 for a surgical instrument 306. Each joint 303 of the arm has one or more motors 307 that can be operated to induce rotational movement at the corresponding joint, and one or more orientation and / or torque sensors 308 that provide information about the current configuration and / or load at that joint. Suitably, the motors are arranged proximal to the joints that drive their movement to improve weight distribution. For clarity, in Figure 3 Only some motors and sensors are shown in the diagram. The arm can typically be as described in patent application PCT / GB2014 / 053523 (WO 2015 / 132549).

[0005] The arm end is attached to attachment 305 for engagement with device 306. Suitablely, device 306 adopts a configuration regarding... Figure 2 The instrument has a diameter less than 8 mm. Suitablely, the instrument has a diameter of 5 mm. The instrument can have a diameter less than 5 mm. The instrument diameter can be the diameter of the shaft. The instrument diameter can be the diameter of the hinge profile. Suitablely, the diameter of the hinge profile matches or is narrower than the shaft diameter. Attachment 305 includes a drive assembly for driving the hinge of the instrument. The movable interface element of the drive assembly mechanically engages a corresponding movable interface element of the instrument interface to transmit driving force from the robotic arm to the instrument. During a typical surgery, one instrument is replaced with another several times. Therefore, during surgery, the instrument can be attached to and detached from the robotic arm. The characteristics of the drive assembly interface and the instrument interface facilitate their alignment when engaged with each other, thereby reducing the accuracy required for user alignment.

[0006] Instrument 306 includes an end effector for performing the surgery. The end effector can take any suitable form. For example, the end effector can be a smooth clamp, a serrated clamp, a gripper, a pair of cutting forceps, a needle for suturing, a camera, a laser, a scalpel, a stapler, a cauterizer, or a suction device. (See also: Regarding...) Figure 2The device includes a hinge between a device axis and an end effector. The hinge includes several joints that allow the end effector to move relative to the device axis. The joints in the hinge are actuated by drive elements, such as cables. These drive elements are fixed at the other end of the device axis to an interface element of the device interface. Therefore, the robotic arm transmits driving force to the end effector in such a way that movement of the drive component interface element causes movement of the device interface element, which in turn causes movement of the drive elements, which in turn causes movement of the joints in the hinge, and the movement of the joints causes movement of the end effector.

[0007] Controllers for the motors, torque sensors, and encoders are distributed within the robot arm. These controllers are connected to a control unit 309 via a communication bus. The control unit 309 includes a processor 310 and a memory 311. The memory 311 stores software in a non-transitory manner, which can be executed by the processor to control the operation of the motors 307 to cause the arm 300 to operate in the manner described herein. Specifically, the software can control the processor 310 to drive the motors (e.g., via a distributed controller) based on inputs from sensors 308 and from a surgeon command interface 312. The control unit 309 is coupled to the motors 307 to drive them based on the outputs produced by the execution of the software. The control unit 309 is coupled to the sensors 308 to receive sensed inputs from the sensors and to the command interface 312 to receive inputs from them. For example, the respective connections can be cables or fiber optic cables, and / or can be provided wirelessly. The command interface 312 includes one or more input devices, whereby the user can request movement of the end effector in a desired manner. Input devices may be, for example, manually operable mechanical input devices, such as control handles or joysticks, or non-contact input devices, such as optical gesture sensors. Software stored in memory 311 is configured to respond to these inputs according to a predetermined control strategy, and to move the joints of the arm and the instruments accordingly. The control strategy may include safety features that regulate the movement of the arm and instruments in response to command inputs. Thus, in general, the surgeon at command interface 312 can control the movement of instrument 306 to perform a desired surgical procedure. Control unit 309 and / or command interface 312 may be located remotely from arm 300.

[0008] The illustrated surgical robot includes a single robotic arm. Other surgical robot systems may include multiple surgical robots and / or multiple robotic arms. For example, other example surgical robot systems may include a surgical robot with multiple robotic arms, each capable of receiving and manipulating surgical instruments, or they may include multiple surgical robots, each having a robotic arm capable of receiving and manipulating surgical instruments.

[0009] Arm 102 is attached to an attachment for connection with a device, an example of which may be... Figure 4 As seen in [the image], the attachment includes a drive assembly for driving the hinge portion of the instrument 105. The drive assembly interface 400 is connected to the instrument interface, an example of which is [described in the image]. Figure 5 Shown at position 500. Movable interface elements 401, 402, and 403 of the drive assembly engage with corresponding movable interface element 502 of the instrument interface to transmit driving force from the robot arm 102 to the instrument 105. Figure 4 and Figure 5 In the illustrated example, the drive assembly interface element includes protruding fins 401, 402, 403, and the instrument interface element includes a cup 502 for receiving the fins. Both the fins and the cup can be provided in a circular manner, regardless of the embodiment. In some embodiments, the drive assembly interface element includes a cup, and the instrument interface element includes fins retractable into the cup. Other arrangements are possible for the respective drive assembly interface elements and the respective instrument interface elements to engage with each other. Linear movement of the drive assembly interface element causes a corresponding linear movement of the instrument interface element.

[0010] Figure 6 This is a schematic diagram of the drive mechanism for the instrument interface of a typical medical device. Figure 6 In the illustrated drive mechanism, the drive assembly interface element 602 includes a cup portion, and the instrument interface element 604 includes fins retractable into the cup portion 602. The drive assembly interface element 602 (of the robot arm) engages with the instrument interface element 604 of the instrument. Figure 6In this design, a drive element 606 is fixed at one end to a device interface element 604 and at the other end to an end effector 608 via a joint 610. The joint forms part of a hinge portion 203. The drive component interface element 602 engages with the device interface element 604, such that the motion of the drive component interface element is transmitted to the device interface element, thereby generating a corresponding motion of the device interface element. The device interface element is fixed to the drive element, such that the motion of the device interface element 604 is converted into the motion of the drive element 606. Since the drive element is also fixed to the end effector 608, the motion of the device interface element is directly converted into the motion of the end effector. Therefore, the motion of the drive component interface element generates the motion of the end effector. The robot arm 102 transmits driving force to the end effector 608 of the device 105 in the following manner: the movement of the drive component interface element 602 causes the device interface element 604 to move, the movement of the device interface element causes the drive element 606 to move, the movement of the drive element causes the joint 610 of the hinge portion 203 to move, and the movement of the joint causes the end effector 608 to move. In this example, the movement of the drive component interface element is converted into the movement of the end effector based on a set of fixed parameters (length of the drive element, friction of the joint, etc.). In this way, the relationship between the position of the drive component interface element and the end effector is fixed. Summary of the Invention

[0011] This summary is provided to introduce the choice of concepts further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0012] According to one aspect of the invention, a method is provided for calibrating an instrument interface of an instrument in a surgical robot system, the surgical robot system including a robot having a base and an arm extending from the base to a drive assembly for engaging the instrument interface to transmit driving forces to the instrument, the instrument interface being configured to drive joints of the instrument via drive elements, the method comprising: obtaining usage data indicating the use of joints of the instrument; comparing the usage data with one or both of a maximum range of joint movement of the joint and a anticipated model of joint movement of the joint; determining a calibration offset by the comparison to adjust control relationships of drive elements arranged to drive the joint; and using the calibration offset to adjust the control relationships of the drive elements to calibrate the instrument interface.

[0013] Determining the calibration offset may include determining a deviation value based on the comparison, the deviation value indicating a deviation of joint usage from the expected joint usage; and determining the calibration offset based on the deviation value. The control relationship of the drive element may include the positioning of the drive element, and adjusting the control relationship may include adjusting the positioning of the drive element using the calibration offset.

[0014] The control relationship of the drive element may include a configuration of a gear assembly arranged to drive the drive element, and adjusting the control relationship may include adjusting the configuration of the gear assembly using the calibration offset. Adjusting the control relationship may include changing from a first gear ratio to a second gear ratio, moving the drive element, and changing from the second gear ratio back to the first gear ratio.

[0015] The control relationship of the drive element may include the tension of the drive element, and adjusting the control relationship may include adjusting the tension of the drive element using the calibration offset.

[0016] The method may include obtaining the usage data from memory and / or from the instrument. The usage data may include joint angle data of the joints of the instrument. The usage data may include instrument driver position data of instrument drivers configured to drive the joints of the instrument. The usage data may be obtained based on one or more of the following: instrument type, program to be performed using the instrument, stage in the program to be performed using the instrument, action within the program to be performed using the instrument, ID of the surgical robot system to which the instrument is attached, and surgeon ID.

[0017] Comparing the usage data with the maximum range of joint movement of the joint may include at least one of the following: probability density of instrument actuator position and / or joint angle position, machine learning algorithm, statistical analysis technique, and goodness-of-fit technique.

[0018] Determining the calibration offset may include identifying a characteristic instrument actuator position and / or joint angle by comparing the usage data with a corresponding maximum range of joint movement of the instrument actuator position and / or the joint, and the method may include determining the calibration offset based on the characteristic instrument actuator position and / or joint angle. Determining the calibration offset may include calculating the difference between the characteristic instrument actuator position and / or joint angle and the midpoint of the maximum range of joint movement of the instrument actuator position and / or the joint.

[0019] Adjusting the positioning of the drive element may include: separating the instrument interface element from the drive element, modifying the position of the drive element relative to the instrument interface element, and reconnecting the interface element to the drive element.

[0020] The method may include driving the joint using a calibrated instrument interface.

[0021] According to another aspect of the invention, an instrument interface calibrator is provided for calibrating an instrument interface of an instrument in a surgical robot system, the surgical robot system including a robot having a base and an arm extending from the base to a drive assembly for engaging the instrument interface to transmit driving force to the instrument, the instrument interface being configured to drive joints of the instrument via drive elements, the calibrator being configured to: obtain usage data indicating the use of the joints of the instrument; compare the usage data with one or more of a maximum range of joint movement of the joint and a expected joint movement model of the joint; determine a calibration offset based on the comparison to adjust the control relationship of the drive elements arranged to drive the joint; and output the calibration offset by adjusting the control relationship of the drive elements of the joint for calibrating the instrument interface.

[0022] The calibrator may be configured to: determine the calibration offset by determining a deviation value based on the comparison, the deviation value indicating a deviation of joint usage from the expected joint usage; and determine the calibration offset based on the deviation value. The control relationship of the drive element may include the positioning of the drive element, and adjusting the control relationship may include adjusting the positioning of the drive element using the calibration offset. The control relationship of the drive element may include one or more of the following: a configuration of a gear mechanism arranged to drive the drive element, and adjusting the control relationship includes adjusting the configuration of the gear mechanism using the calibration offset; the tension of the drive element, and adjusting the control relationship includes adjusting the tension of the drive element using the calibration offset.

[0023] The calibrator may be configured to obtain the usage data from memory and / or from the instrument. The usage data may include instrument driver position data and / or joint angle data of the instrument's joints. The calibrator may be configured to obtain the usage data based on one or more of the following: instrument type, the procedure to be performed using the instrument, a stage in the procedure to be performed using the instrument, actions within the procedure to be performed using the instrument, the ID of the surgical robot system to which the instrument is attached, and the surgeon's ID.

[0024] The calibrator may be configured to compare the usage data with the maximum range of joint movement of the joint by using at least one of the following: probability density of instrument actuator position and / or joint angle position, machine learning algorithm, statistical analysis technique, and goodness-of-fit technique.

[0025] The calibrator may be configured to determine the calibration offset by identifying a characteristic instrument actuator position and / or joint angle based on a comparison of the usage data with the instrument actuator position and / or the maximum range of joint movement of the joint, and the calibrator may be configured to determine the calibration offset based on the characteristic instrument actuator position and / or joint angle. The calibrator may also be configured to determine the calibration offset by calculating the difference between the characteristic instrument actuator position and / or joint angle and the midpoint of the maximum range of joint movement of the instrument actuator position and / or the joint.

[0026] Any feature of any aspect described herein may be combined with any other feature of any aspect described herein. Any apparatus feature may be rewritten as a method feature, and vice versa. For the sake of brevity only, these are not fully stated. Attached Figure Description

[0027] The invention will now be described by way of example with reference to the accompanying drawings.

[0028] In the attached diagram:

[0029] Figure 1 A surgical robot performing a surgical procedure is shown;

[0030] Figure 2 Surgical instruments are shown;

[0031] Figure 3 The surgical robot was shown;

[0032] Figure 4 The interface of the drive components for the surgical robot arm is shown;

[0033] Figure 5 The instrument interface of the surgical instrument is shown;

[0034] Figure 6 The drive mechanism of the device is shown;

[0035] Figure 7a The diagram shows the position data of the drive component interface element for the instrument driver.

[0036] Figure 7b This shows the result after resetting to zero. Figure 7a The location data of the driver component interface element;

[0037] Figure 8 Another example of a device interface is shown;

[0038] Figure 9 An example of a drive assembly interface element interlocked with a device interface element is shown;

[0039] Figure 10An example of the connection between the drive element and the instrument interface element is shown;

[0040] Figure 11 This illustrates another example of the connection between a drive element and a device interface element;

[0041] Figure 12 This illustrates another example of the connection between a drive element and a device interface element;

[0042] Figure 13 This illustrates another example of the connection between a drive element and a device interface element;

[0043] Figure 14 A method for calibrating the instrument interface is shown; and

[0044] Figure 15 Components of an exemplary computation-based device are shown. Detailed Implementation

[0045] The following description is presented by way of example to enable those skilled in the art to make and use the invention. The invention is not limited to the embodiments described herein, and various modifications to the disclosed embodiments will be apparent to those skilled in the art. The embodiments are described by way of example only.

[0046] The following description describes the techniques of the invention in the context of surgical robotic systems, although the features described below are not limited to such systems but can be applied more generally to robotic systems. In some instances, the techniques of the invention can be applied to remotely operated robotic systems. Robotic systems may include manufacturing systems, such as vehicle manufacturing systems, parts handling systems, laboratory systems, and manipulators, such as manipulators for hazardous materials or surgical manipulators.

[0047] When using linear actuators to control the driving force of joints (e.g., rotary joints), the range of motion of the joints can be greater than the range of motion of the actuators. A device with an end effector can be mounted to a robotic arm. The end effector drives multiple joints of the device. The robotic arm can generate driving forces that are transmitted to the device. Suitably, the robotic arm includes a drive assembly having drive assembly interface elements that engage with a device interface having device interface elements, thereby transmitting driving forces from the robotic arm to the device. The drive assembly interface elements are linearly movable. The device interface elements are correspondingly linearly movable. The movement of the device interface elements is arranged to cause movement of portions of the end effector about one or more joints of the end effector.

[0048] Therefore, the linearly actuated drive component interface element drives the linearly movable instrument interface element to drive the rotational movement of the end effector joint. The joint can have a range of motion (e.g., angular movement) greater than the range of motion of the linearly movable instrument interface element. This means that the movement of the instrument interface element across its entire range of motion may be insufficient to control the movement of the joint within a portion of its (relatively large) range of motion.

[0049] In such systems, it is useful to identify usage deviations of the joint, for example, when the use of the joint differs from its intended use. This intended use of the joint can typically lie in the middle of its range of motion. Appropriately determining a calibration offset allows for adjustment of the joint control by the instrument interface. This adjustment enables the instrument interface to more easily control the joint throughout its desired range of motion. Therefore, usage deviations can be identified and the instrument interface calibrated to compensate for such deviations. This improves the joint control achieved through the instrument interface.

[0050] In the following description, the technology will be referred to as a single instrument interface element coupled to a single drive element for driving a single joint. More generally, the technology described herein is applicable to multiple instrument interface elements, each coupled to a corresponding drive element for driving a corresponding joint.

[0051] Robotic surgical systems enable the collection of telemetry data from surgical procedures. This telemetry data can be analyzed, for example, in real time during the surgical procedure, or non-real-time, for example, after a surgical procedure (or more than one) has been performed. The telemetry data captured by the surgical robotic system appropriately includes data relating to the angular positions of one or more joints. This telemetry data allows for the analysis of system performance and provides evidence to help design future modifications to the system. This technique aims to optimize the range of instrument degrees of freedom by analyzing collected data relating to the use of joints driving the instrument's end effector and, based on this, recalibrating the instrument. In one example of a surgical robotic system, the joints of the robotic arm can be progressively numbered from J1 (which connects the first rigid length of the robotic arm to the base on which the arm is mounted, i.e., the proximal end of the arm) toward the distal end of the arm. In one embodiment, the joints that enable movement of the instrument's end effector are labeled J9, J10, and J11.

[0052] refer to Figure 4 The actuators for joints J9-J11 can form part of the robot arm drive assembly. The J9-J11 actuators can be appropriately operated to control the movement of the drive assembly interface elements 401, 402, and 403. Figure 4In the example shown, there are three drive component interface elements. Each drive component interface element is driven by a corresponding driver among the J9-J11 drivers. Each drive component interface element is arranged to engage with a corresponding instrument interface element. In other examples, there may be fewer or more drive component interface elements, which may be driven by a corresponding number of drivers and may engage with a corresponding number of instrument interface elements.

[0053] Drive component interface elements 401, 402, and 403 can be driven along corresponding linear paths 409, 410, and 411 in the drive component interface. Each instrument actuator (for joints J9-J11) has a total stroke length of 12 mm. That is, each instrument actuator is operable to drive its corresponding drive component interface element along a linear path of 12 mm in total length. Other total stroke lengths of the actuators are also possible. The total stroke length of each instrument actuator does not need to be the same. The total stroke length of the instrument actuator does not need to be the same as the length of the linear path along which the interface element driven by that instrument actuator travels in the drive component interface. Reference Figure 4 As can be seen, the central linear path 410 is shorter than the two outer paths 409 and 411. The instrument driver configured to drive the central interface element 402 can be the same as the instrument driver configured to drive the two outer interface elements 401 and 403. Suitablely, the total stroke length of the instrument driver is the same as or greater than the length of the linear path along which the interface element driven by the driver moves. In one example, the central drive assembly interface element is arranged such that the length of its linear path is ±2.8 mm from the center zero position. The two outer drive assembly interface elements are each arranged such that the length of their linear paths is ±6.6 mm from the center zero position.

[0054] The (initial) zero position of each actuator is located at the midpoint of its stroke. For optimal actuator use, the distribution should resemble a distribution about the midpoint, such as a symmetrical distribution or a Gaussian distribution. This means the actuator will primarily operate in the middle region of its stroke and will not frequently need to operate in the outermost region of its stroke. By analyzing the position data of the actuators driving instrument joints J9-J11, deviations when using at least one actuator can be identified.

[0055] Once a deviation has been identified regarding a joint, a calibration offset can be determined to adjust the control of that joint by the relevant instrument actuator. This method can be used for instrument joints with a greater range of motion than the actuators driving those joints. The ability to identify and compensate for usage deviations is very useful for increasing the range of motion of the joint by the amount determined by the deviation (β). The steps to be followed for recalibrating or “re-zeroing” an instrument may include:

[0056] Obtain usage data for a given device.

[0057] Usage data can be captured during the program. Usage data from earlier stages of the program can be obtained. Data captured during the program can be combined with data obtained about previous programs.

[0058] Instrument use can be any one or more of the following: use of a specific type of instrument, use of an instrument in a specific procedure or part of a procedure, use of an instrument by a specific surgeon (e.g., a surgeon associated with a specific surgeon ID in a robotic system).

[0059] Determine the usage bias (β). The analysis of the acquired usage data and the determination of the usage bias can be performed in various ways, ranging from simple analysis of probability densities (e.g., patterns, medians) to machine learning algorithms. This analysis can include various techniques within statistical analysis to measure, for example, the goodness of fit between the calculated probability density and the measured probability density.

[0060] Adjust the control relationship of the drive element, which connects the movable portion of an end effector that can rotate around the joint (e.g., the clamp of the instrument) to the instrument interface element.

[0061] For example, when the instrument is configured for alignment (for a gripper tool, this could be a case where the instrument's clamps are straight and closed), the position of the instrument interface element relative to the drive element (e.g., the drive cable) can be adjusted. This adjustment can be mechanical. The effective drive cable length between the end effector joint and the instrument interface element can be adjusted. The control relationship is appropriately adjusted such that the position adopted by the instrument interface element is equal to the initial zero position of the drive assembly interface element connected to the instrument driver plus the usage deviation (β) of that particular joint (associated with the drive assembly interface element). This method allows the drive assembly interface element and the instrument interface element to engage with each other when the instrument is attached to the arm in a manner that allows the control relationship to be zeroed again.

[0062] Update the software parameters related to instrument calibration to account for usage bias (β) and ensure the instrument's kinematics are accurate.

[0063] The techniques described herein are particularly applicable to robotic systems that use linear actuators to actuate rotary joints because linear actuators have a more limited and defined range of motion. Increasing the range of motion of such linear actuators typically compromises the compactness of the drive mechanism. In contrast, rotary actuators tend to have a greater range of motion because they can rotate indefinitely (or at least practically so).

[0064] Appropriately, the control relationships can also be adjusted, at least partially, within the software. The software allows modification of parameters related to the kinematics of the machine. This modification of parameters enables adjustment of the control relationships.

[0065] Considering the various aspects of the usage data mentioned in this paper, such as for each procedure (or a specific part of a procedure) or instrument type, the analysis of the usage data can show evidence of different biases from surgeon to surgeon. It may be necessary to tailor calibration biases to the specific needs of each individual case. In some arrangements, this can be achieved by combining multiple biases. Bias can be weighted according to importance and / or user preference. For example, in the case where a first bias β1 is determined regarding surgeon ID and a second bias β2 is determined regarding a specific procedure, the overall bias β can be determined based on a weighted combination of β1 and β2. In one instance, β = aβ1 + bβ2. In another instance, β = aβ1 + (1-a)β2 (where a ≤ 1). The weighting coefficients a and b can be determined empirically or chosen according to user preference.

[0066] Usage deviations can be calculated or updated during instrument operation. In such cases, weighting factors can vary with one or more of the instrument's movement, the attitude of the instrument's end effector, and previous movements of that end effector and / or the instrument. Conveniently, analysis of usage data for all instrument joints (three in the example discussed herein) allows for an assessment of how much the user enjoys using the system.

[0067] Weights can be calculated based on the accuracy of the data mapping onto a specific model used to characterize the movement of one or more joints (e.g., using R² values) and / or based on the data used to derive a given offset (e.g., the amount of data), and / or based on the number of programs that derive the data, and / or based on the number of different robotic arms that derive the data.

[0068] In some cases, reducing the sacrificial range of motion through gears to obtain more torque can be useful. In these cases, the instrument can be calibrated based on the range of motion where more torque is expected to be required (e.g., a program or part of a program).

[0069] A method for calibrating a device interface includes obtaining usage data indicating the use of a joint of the device. The usage data is compared to the maximum range of motion of the joint. Alternatively or additionally, the usage data may be compared to, for example, a model of expected joint motion in a specific scenario. The model may be a given probability density function. A calibration offset is determined based on the comparison to adjust the control relationships of drive elements arranged to drive the joint. The control relationships are adjusted using the calibration offset, thereby calibrating the device interface.

[0070] Appropriately, the method can be performed using an instrument interface calibrator. The instrument interface calibrator can be used to calibrate the instrument interface of an instrument in a surgical robotic system, the surgical robotic system including a robot having a base and an arm extending from the base to a drive assembly for engaging with the instrument interface to transmit driving forces to the instrument. The instrument interface is configured to drive joints of the instrument via drive elements. The calibrator is configured to: obtain usage data indicating the use of joints of the instrument; compare the usage data with the maximum range of joint movement, and / or compare the usage data with a expected joint movement model; determine a calibration offset based on the comparison to adjust the control relationship of the drive elements arranged to drive the joints; and

[0071] The calibration offset is output by adjusting the control relationship of the joint's drive elements to calibrate the instrument interface. The expected joint movement is, for example, the expected joint movement in a specific scenario. The model can be a given probability density function.

[0072] Now for reference Figure 7a And 7b, which shows the use of a needle retainer tool in surgery ( Figure 7a ) and the needle holder tool for resetting to zero ( Figure 7b The location data of the driver component interface elements 25 hours later. Figure 7a In the diagram, the probability density data for the J9 actuator is shown at position 702. Fitting a Gaussian distribution to this data results in a peak being identified at approximately -1 mm (shown by dashed line 704) on the x-axis. Therefore, a 1 mm offset can be identified. Applying a 1 mm offset to the J9 actuator causes this probability density data to shift, centering the distribution around the zero point of the actuator (see [reference]). Figure 7b ).

[0073] Determining the calibration offset may include: determining a deviation value based on a comparison, which indicates the deviation of joint use from expected joint use; and determining the calibration offset based on the deviation value. In the example above, the deviation value is determined as the difference between the peak of the distribution fitted to the usage data and the zero position, where usage can be expected to be centered. The calibration offset in this example is the opposite of the deviation value, so as to move the distribution toward the zero position. In other examples, the deviation value may be scaled to obtain the calibration offset. The calibration offset may be some other function of the deviation value. The calibration offset may be calculated based on usage data of one or more instrument joints and / or the current position of the end effector.

[0074] Other representative parameters, such as the mean, mode, or median of joint values, can be used alternatively or separately to calculate the deviation. The calibration offset can be calculated using one or a combination of these means, modes, and medians. The calibration offset can be calculated using difference values ​​and / or deviation values ​​that respectively indicate how much difference or deviation exists in the data. Such values ​​can include, for example, R² or σ values.

[0075] The zero position within the motion range of the instrument actuator can be obtained by driving the corresponding drive component interface element to one end of the stroke range. The entire stroke range is known. This allows the zero position to be set at the position of the drive component interface element at the end of the stroke plus half the stroke length. Alternatively, the drive component interface element can be driven to both ends of the stroke range and a zero position can be set at the midpoint. The zero position can be set by positioning one or more sensors at the midpoint, such that the drive component interface element is sensed whenever it is driven beyond the midpoint. The zero position can also be joint-based, set by positioning one or more sensors at the midpoint of joint rotation, such that the joint is sensed whenever it is driven beyond its midpoint.

[0076] The control relationships of a drive element arranged to drive a joint may include control relationships implemented using the drive element. The control relationships of a drive element arranged to drive a joint may include control relationships associated with driving the joint using the drive element. Control relationships may include the relationship between a device interface and a joint, for example, the relationship between a device interface element of a device interface and a joint. Control relationships may include the relationship between a device interface element and a portion of a drive element and / or a portion of a drive element and a joint.

[0077] Adjusting the control relationship may include physically modifying the length of a portion of the drive element that connects the instrument interface element to the joint. For example, the physical relationship between the joint and the instrument interface element can be modeled by a linear function, where f(x) = p + qx. In this example, q can remain constant while p can change. p can represent the offset in the control relationship. q can represent the gain in the control relationship. Preferably, in such a control relationship, p and q can be adjusted independently of each other.

[0078] The control relationship of the drive element appropriately includes the positioning of the drive element. Adjusting the control relationship includes adjusting the positioning of the drive element to calibrate the offset. The positioning of the drive element is appropriately relative to the instrument interface, such as the position relative to the instrument interface element.

[0079] Adjusting the positioning of the drive element appropriately includes separating the instrument interface element from the drive element, modifying the position of the drive element relative to the instrument interface element, and reconnecting the interface element to the drive element.

[0080] When an instrument interface element is connected to a drive element, movement of the instrument interface element causes movement of the drive element. The movement distance of the drive element can be the same as the movement distance of the instrument interface element. For example, when the instrument interface element clamps onto a drive cable that acts as the drive element, a 2 mm movement of the instrument interface element will directly cause a 2 mm movement of the drive cable. Alternatively, when the instrument interface element is separated from the drive element, the movement of the instrument interface element is independent of the movement of the drive element. That is, the movement of the instrument interface element does not cause movement of the drive element. There may be another state where the movement of the instrument interface element causes a larger or smaller movement of the drive element. For example, in this other state, a 2 mm movement of the instrument interface element may cause a movement of more than 2 mm or less than 2 mm of the drive element.

[0081] The positioning of the drive element can be adjusted in various ways. Adjusting the positioning of the drive element can include mechanically adjusting its position. For example, when an interface element is coupled to the drive element via a clamping mechanism such as a screw-fastening clamp, the instrument interface element can be separated from the drive element by loosening the screw of the screw-fastening clamp, thus releasing the clamp. When released, the clamp can move relative to the drive element. After repositioning the clamp as needed, the screw can be tightened to securely connect the instrument interface element to the drive element.

[0082] Now for reference Figure 8 The illustration shows an example of an instrument interface 800. The instrument interface includes three instrument interface elements 802, 804, and 806, each connected to a corresponding drive element 808, 810, and 812 by a corresponding coupling mechanism. In the illustrated example, the coupling mechanism includes screws configured to releasably secure the drive element to the instrument interface element. As shown, the drive element includes a drive cable. The positioning of the drive element can be adjusted by loosening the screws securing the drive cable to the instrument interface element to allow movement of the instrument interface element without causing a corresponding movement of the drive cable, by moving the instrument interface element relative to the drive cable to calibrate the offset, and by tightening the screws so that subsequent movement of the instrument interface element will cause a corresponding movement of the drive cable.

[0083] The screw of the coupling mechanism can engage with a lug attached to the drive cable. Tightening the screw can fix the position of the lug (and drive cable) relative to the instrument interface element. Loosening the screw can allow relative movement between the lug (and drive cable) and the instrument interface element. The screw 814 for the central instrument interface element 804 can move within the channel 816 of the instrument interface element. The length of the channel determines the amount of adjustment that can be made in the positioning of the drive cable. The screw can be tightened at any desired position along the channel. This method allows the calibration offset to vary smoothly. In an alternative, the channel may include multiple recesses in discrete positions. The screw can be received in any of these recesses. In this alternative, the position of the screw is discrete rather than continuously variable, and therefore the calibration offset can take one of a set of discrete values. In this arrangement, the discrete value selected as the calibration offset is appropriately the discrete value closest to the calculated calibration offset value. In embodiments where the drive element is in the form of a cable with a continuous loop, the cable can be secured relative to the instrument interface elements (802, 804, 806) by means of a releasable coupling (e.g., a tightening screw). The releasable coupling is suitably configured to act on the drive element, for example, by pressing the drive element. In this arrangement, the drive cable can be positioned relative to the instrument interface element at any desired location.

[0084] The connection between the drive component interface element and the instrument interface element can be different from that used in other applications. Figure 4 and Figure 5 The form shown is illustrated. For example, the interface elements can be aligned along the longitudinal axis of one or both of the distal portions of the arm and the instrument. In this configuration, driving force can be transmitted via a push-pull arrangement, such as a longitudinally movable rod. The drive assembly interface elements and the instrument interface elements can have any desired interlocking form, examples of which are shown in... Figure 9 As shown in the image. Figure 9 A longitudinally extending drive assembly interface element 902 is shown, interlocking with a corresponding longitudinally extending instrument interface element 904 by protruding a lug 906 in a recess on a receivable element. In this arrangement, the connection between the drive element (e.g., a drive cable) and the instrument interface element is also suitably achieved via a lug in a recess on the receivable element. Figure 10This arrangement is illustrated. The instrument interface element is shown at 1002. The drive element includes a drive cable 1004 and a lug 1006. The lug is received in a recess 1008 of the instrument interface element to connect the drive cable to the instrument interface element. The instrument interface element includes additional recesses, two of which, 1010 and 1012, are illustrated by way of example. The control relationship can be adjusted by changing the recess where the lug 1006 is located. That is, calibration can be performed by moving the lug from one recess to another. The recesses provide a discrete set of locations where the lug can be located. The recess closest to the desired lug location is appropriately selected. The lug spacing can be selected to provide the required calibration accuracy. Therefore, in Figure 10 In the example shown, the control relationship involves the connection between the lug and the recess. Adjusting the control relationship appropriately includes using a calibration offset to change the recess where the lug is located.

[0085] like Figure 11 As shown, the connection between the instrument interface element and the drive element can be achieved via a rack and pinion. The instrument interface element is schematically shown at 1102. The drive cable 1104 is formed by a single loop and passes around two pulleys. One pulley is connected to a joint 1106 around which the clamp 1108 of the gripper tool can rotate. The other pulley 1110 is connected to a pinion 1112. The pinion can engage with a rack 1114 fixed to the instrument interface element 1102. Movement of the instrument interface element 1102 causes a corresponding movement of the rack driving the pinion. Rotation of the pinion causes rotation of the pulley 1110, thereby driving the drive cable to cause rotation of the joint 1106. The instrument interface element can be separated by the relative movement of the rack and pinion (i.e., Figure 11 The relative movement between the instrument interface element 1102 and the drive cable 1104 (in the vertical direction) separates them from the drive cable. The relative movement between the instrument interface element 1102 and the drive cable 1104 can occur in this disengagement configuration. The rack and pinion can be separated by the relative movement between them (again in the vertical direction). Figure 11 (In the vertical direction) and re-engage to reconnect the instrument interface element and drive cable. Alternatively, the rack can be on the joint side, and the pinion on the instrument interface element side. For example, the instrument interface element can be coupled to a ring-shaped drive element extending over two pulleys, one of which is attached to the pinion. Rotation of the pinion drives the rack, which can be directly coupled to the end effector joint or via another drive element. Therefore, in this arrangement, the control relationship involves the rack and pinion engagement. Adjusting the control relationship appropriately includes adjusting the configuration of the rack and pinion engagement using a calibration offset. This arrangement allows for easy modification of the calibration offset when the rack and pinion are disengaged by actuating the rack.

[0086] The control relationship of the drive element may additionally or alternatively involve the configuration of the gear mechanism arranged to drive the drive element. Adjusting the control relationship appropriately includes using calibration offsets to adjust the configuration of the gear mechanism.

[0087] The movement of the drive element can be proportional to the movement of the instrument interface element. For example, in the case where the instrument interface element is coupled to the drive element via a gear mechanism, a 2 mm movement of the interface element may cause the drive element to move more than 2 mm or less than 2 mm, depending on the gear mechanism. In such instances, adjusting the positioning of the drive element may include, but is not necessary, disengaging the instrument interface element from the drive element, modifying the position of the drive element relative to the instrument interface element, and reconnecting the instrument interface element to the drive element. In some arrangements, a gear mechanism is one example, and the position of the drive element relative to the instrument interface element can be modified by altering the configuration of the gear mechanism. For example, adjusting the control relationship may include changing from a first gear ratio to a second gear ratio, moving the drive element, and changing back from the second gear ratio to the first gear ratio.

[0088] like Figure 12 As shown, the gear mechanism may include pulleys of different diameters. The drive element includes two cable loops, forming a proximal drive element 1202 and a distal drive element 1204. The drive element includes four pulleys arranged around an axle 1206. The proximal drive element 1202 is constrained to move around a first pulley 1208, and the distal drive element 1204 is constrained to move around a second pulley 1210. The second pulley 1210 is rotatably fixed relative to the first pulley 1208 such that when the first pulley rotates, the second pulley also rotates. A third pulley 1212 and a fourth pulley 1214 are also positioned on the axle 1206 and configured to rotate about the axis of the first pulley 1208. The third and fourth pulleys are also rotatably fixed relative to the first pulley such that when the first pulley 1208 rotates, the third pulley 1212 and the fourth pulley 1214 also rotate. Each of the first to fourth pulleys has a diameter. The diameter of each pulley is different from the diameter of each of the other pulleys. In this example, the fourth pulley 1214 has a smaller diameter than the first pulley 1208, but the diameters of the second pulley 1210 and the third pulley 1212 are both larger than the diameter of the first pulley 1208.

[0089] The robot arm drive assembly transmits driving force to the end effector 1216 of the instrument via the instrument interface element 1218. The distal drive element 1204 can be moved such that it can be constrained to move around one of the second, third, or fourth pulleys. Since each of these pulleys has a different diameter, changing the pulley around which the distal drive element is constrained to move will change the ratio of the diameter of the driving pulley (first pulley) to the diameter of the driven pulley (one of the second to fourth pulleys).

[0090] The ratio by which the displacement of the end of the proximal drive element 1202 is converted into the displacement of the end of the distal drive element 1204 can be changed by altering the ratio of the diameter of the drive pulley to the diameter of the driven pulley. Therefore, changing the pulley around which the distal drive element is constrained changes the proportion of motion transmitted from the instrument interface element 1218 to the end effector. The drive element shown includes a drive mechanism (not shown) that includes a mechanism configured to allow the operator to change the pulley around which the distal drive element is constrained. For example, the drive mechanism may include a gearbox, a switch, or a lever.

[0091] One or more pulleys can move relative to another pulley to change the tension in the drive element. The axle 1206 around which the first pulley rotates can move toward or away from the axis of rotation of the pulley 1220 connected to the end effector 1216. This will correspondingly decrease or increase the tension in the distal drive element 1204, respectively. Decreasing the tension in the drive element allows the drive element to move more easily between the second pulley 1210, the third pulley 1212, and the fourth pulley 1214. Increasing the tension in the drive element increases the friction between the drive element and the pulleys. Increasing the tension in the drive element allows the drive element to more easily transmit the rotation of a corresponding pulley of the second, third, or fourth pulley to the pulley 1220 connected to the end effector, thereby causing movement of the end effector.

[0092] Using this arrangement, the control relationship can be adjusted by modifying the displacement of the distal drive element 1204 caused by the displacement of the proximal drive element 1202. The displacement of the distal drive element caused by the displacement of the proximal drive element can be selected based on the calibration offset.

[0093] Gear assemblies may include two truncated cones, such as Figure 13As shown. Instrument interface element 1302 is fixed to proximal drive element 1304. Proximal drive element 1304 engages a first truncated cone 1306. The first truncated cone has two parallel planar circular surfaces 1306a and 1306b and a curved surface 1306c. The diameter of circular surface 1306a is larger than the diameter of circular surface 1306b. Proximal drive element 1304 is constrained to move around the first truncated cone 1306. At least one point on proximal drive element 1304 is fixed to the curved surface 1306c of the first truncated cone 1306 at or toward the end of the first truncated cone closest to surface 1306b. Engaging element 1308 is positioned between the first truncated cone 1306 and a second truncated cone 1310. The second truncated cone 1310 has two parallel planar circular surfaces 1310a and 1310b and a curved surface 1310c. The diameter of circular face 1310a is smaller than the diameter of circular face 1310b. The second truncated cone 1310 is oriented 180 degrees to the first truncated cone 1306, so that it is in an inverted position relative to the first truncated cone. In other instances, the planes of the cones may not be circular; for example, they may be approximately elliptical. The cones may also be truncated at an angle such that the planes of the truncated cones are not parallel. A coupling element 1308 movably engages face 1306c of the first truncated cone 1306 and face 1310c of the second truncated cone 1310. Faces 1306c and 1310c are parallel to each other at the point where the coupling element engages them. The coupling element 1308 rotates about axis 1312. Axis 1312 is parallel to a pen line that intersects the faces completely at the point where the coupling element engages faces 1306c and 1310c. The width of the coupling element is equal to the distance between the first and second truncated cones. The distal actuation element 1314 engages the second truncated cone 1310. The distal actuation element 1314 is constrained to move about the second truncated cone 1310. At least one point on the distal actuation element 1314 is fixed to the curved surface 1310c of the second truncated cone 1310. The proximal actuation element 1304 and the distal actuation element 1314 may be fixed to the first truncated cone 1306 and the second truncated cone 1310, respectively, using beads, pins, clips, or other adhesives. Alternatively, the curved surfaces 1306c and 1310c of the first and second truncated cones may include one or more grooves. The proximal actuation element 1304 may be located in the groove of the curved surface 1306c of the first truncated cone 1306. The distal actuation element 1314 may be located in the groove of the curved surface 1310c of the second truncated cone 1310.

[0094] In this example, the robotic arm (not shown) transmits driving force to the end effector of the instrument in the following manner: movement of the drive assembly interface element (not shown) causes movement of the instrument interface element 1302, which in turn causes movement of the proximal drive element 1304. The movement of the proximal drive element causes rotation of the first truncated cone 1306. The rotation of the first truncated cone causes rotation of the engagement element 1308, which in turn causes rotation of the second truncated cone 1310. The rotation of the second truncated cone 1310 causes movement of the drive element 1314, which in turn causes joint movement, thereby causing movement of the end effector.

[0095] The ratio of the displacement l1 of the proximal drive element 1304 to the displacement l2 of the distal drive element 1314 depends on the relative rotation of the two truncated cones. Therefore, the ratio of the displacement of the proximal drive element to the displacement of the distal drive element varies with the following: a) the diameter d1a of the first truncated cone 1306 at the point where the proximal drive element engages the first truncated cone; b) the diameter d2a of the second truncated cone 1310 at the point where the distal drive element engages the second truncated cone; c) the diameter d1b of the first truncated cone 1306 at the point where the engaging element 1308 engages the first truncated cone; and d) the diameter d2b of the second truncated cone 1310 at the point where the engaging element 1308 engages the second truncated cone.

[0096] Frustal cones 1306 and 1310 may include one or more recesses. A proximal drive element 1304 may be located in a recess of the first frustal cone 1306. A distal drive element 1314 may be located in a recess of the second frustal cone 1310. If each frustal cone includes multiple recesses, each drive element may be configured to move between the respective recesses. For example, the position of the frustal cones may be manually adjusted such that the relative position between each cone and a corresponding drive element constrained to move about the cone is changed. The manual mechanism may be a screw that can be tightened. Alternatively, a dedicated driver, such as a servo motor, may be used to change the position of the cones. Due to the change in the relative position between the drive element and the frustal cone, the drive element may slide onto the surface of the cone into different recesses. Therefore, there may be multiple points (values ​​of h) on the cone at which the drive element can engage the cone. Thus, there may be discrete numbers of possible values ​​d1a and d2a, and a discrete ratio between them.

[0097] The drive element can be secured to the truncated cone in another manner. For example, the drive element can be secured to the truncated cone using fastening elements such as beads, clips, pins, or adhesive. Alternatively, friction between the drive element and the truncated cone can allow the drive element to engage the respective truncated cone. The drive element can be configured to engage the truncated cone at any point on its curved surface. The drive element can be configured to engage the curved surface at any point along the longitudinal axis of the truncated cone (at any value of h). For example, the proximal drive element 1304 can be secured to the first truncated cone 1306 at any value of h. Therefore, a continuous range of possible values ​​d1a may exist. Similarly, a continuous range of possible values ​​d2a may exist.

[0098] The engaging element may include one or more protrusions that engage with one or more grooves or notches in a truncated cone. For example, a first truncated cone may include multiple grooves at different points (different values ​​of h) along its longitudinal axis. The engaging element can be moved from one groove to another. For example, the position of the engaging element can be manually adjusted such that the relative position between the engaging element and each truncated cone is changed. The manual mechanism may be a screw that can be tightened. Alternatively, a dedicated drive, such as a servo motor, can be used to change the position of the engaging element. In some instances, it may be necessary to move the truncated cone to allow engagement to switch from one groove to another. Therefore, there may be a discrete number of points where the engaging element can engage with the first truncated cone, and a possible value of the discrete number d1b. Similarly, there may be a discrete number of points where the engaging element can engage with the second truncated cone, and a possible value of the discrete number d2b. Therefore, there may be a possible ratio of the discrete numbers d1b / d2b.

[0099] Alternatively, the joining elements can be configured to engage with the truncated cones in another way, such that the joining elements can engage with both truncated cones at any point along their respective longitudinal axes. Therefore, there may be a continuous range of values ​​d1b and d2b, and a large continuous range of possible values ​​for the ratio between these two values.

[0100] The engaging element can be configured to move between any two points on the curved surface of each truncated cone. For example, the engaging element can be a sphere that can rotate to move along the axis of rotation of the cone. In instances where the truncated cone does not include grooves, the engaging element can engage with the truncated cone due to friction between the engaging element and the cone. The engaging element is capable of transmitting frictional driving force in a manner similar to a belt.

[0101] Using this arrangement, the control relationship can be adjusted by modifying one or more of the values ​​of d1a, d1b, d2a, and d2b. Different values ​​and their ratios are appropriately selected based on the calibration offset.

[0102] Instead of using coupling mechanisms (e.g., screw-clamp coupling mechanisms) for manual calibration, an automatic adjustment mechanism can be provided. In cases of manual calibration, the instrument is typically in an inactive state during the calibration period. For example, the instrument can be calibrated before the program begins or before it is mounted onto the robot arm during the program. Providing an automatic adjustment mechanism saves time and effort and improves the practicality of the technology. In some instances, the instrument can be adjusted by the automatic adjustment mechanism during the program. That is, the control of the instrument can be updated as the program is executed to optimize the use of the instrument during program execution. This approach can maximize the range of motion of the instrument joints while potentially reducing the shape factor of the instrument interface (and therefore the arm drive assembly interface and arm drive assembly).

[0103] The automatic adjustment mechanism may include additional instrument drivers to which the drivers for joints J9-J11 are mounted. Appropriately, each of the J9, J10, and J11 drivers is mounted to a corresponding additional driver. The additional drivers can be driven to move the position of the J9-J11 drivers, and thus move the position of the drive assembly interface elements driven by these drivers.

[0104] The automatic adjustment mechanism may include a disengagement mechanism for disengaging one or more instrument interface elements from their respective drive elements. An instrument actuator, used for recalibrating controlled joints, may be driven to adjust the relative positions of the instrument interface elements and drive elements. The disengagement mechanism then allows the instrument interface elements and their respective drive elements to re-engage each other. The disengagement mechanism may release the clamps of the coupling mechanism to disengage the instrument interface elements from the drive elements. The disengagement mechanism may also tighten the clamps of the coupling mechanism to re-engage the instrument interface elements and drive elements. The disengagement mechanism allows the instrument interface elements and drive elements to move between a disengagement configuration where the movement of one does not affect the movement of the other, and an engagement configuration where the movement of one follows the movement of the other.

[0105] When the drive component interface element is in its zero position, such as at the midpoint of its travel range, its position is known, and the instrument interface elements can be correspondingly positioned along their respective travel ranges to allow engagement between the drive component interface elements and the instrument interface elements when the instrument is mounted to the robotic arm. However, when the instrument has been recalibrated, the new “zero” position of at least one instrument interface element will not be in its original zero position. This means that when all instrument interface elements have moved back to their original zero positions, the end effector configuration will differ from that of the end effector of an uncalibrated instrument. For example, the clamp of a gripper tool may no longer extend straight but may be at an angle. For packaging and transportation, a known instrument configuration is convenient. This allows for more efficient packaging and / or reduces the likelihood of damage during transport. The instrument appropriately includes a memory for storing calibration information. This calibration information, stored locally on the instrument, identifies the recalibrated zero position of the instrument interface elements. The memory can be read by the surgical robot system before or during instrument attachment to the robotic arm. The memory can be read wirelessly via a wireless transceiver on the instrument. The memory can be read via a wireless connection established when the instrument is attached to the robotic arm. Alternatively, calibration information can be stored in the instrument's memory, which can be associated with the instrument's instrument ID. When the instrument is attached to the robot arm, the instrument ID can be queried, and the calibration information associated with that instrument ID can be retrieved from a memory location accessible to the robot system. This memory location can be local to the robot system or located remotely. For example, the memory location could be on a remote server. When reading calibration information, the system can control the end effector joint to be in a desired position, such as a zeroed-out position.

[0106] When the instrument interface element is in the re-zero position and the instrument is attached to the robot arm, the drive component interface element of the arm drive assembly can be configured to move along its respective path and attempt to find the position where each drive component interface element can engage with the corresponding instrument interface element.

[0107] Alternatively, the recalibrated instrument can be stored and / or transported together with the instrument interface element in its original zero position, allowing the end effector to be in a different configuration (e.g., not straight). This makes it easy to mount the instrument onto the robot arm, as the instrument interface element can thus easily engage with the drive assembly interface element. As before, calibration information can be obtained, allowing the system to drive the J9-J11 driver to the end effector's "re-zeroed" position. This enables convenient mounting of the instrument onto the robot arm while allowing the instrument's end effector to be inserted through the port, where the end effector is in the appropriate port insertion position (e.g., for a gripper tool, the clamp is closed and straight).

[0108] The control relationship of the drive element may additionally or alternatively include the tension of the drive element. Adjusting the control relationship may include adjusting the tension of the drive element using a calibration offset. The device may include an internal biasing mechanism. The internal biasing mechanism may be adjusted to modify the effective length of the drive element. For example, the drive cable may be divided into multiple sections. The cable loop may be closed using a coupling device such as a screw lock, which may be adjusted to modify the effective cable length.

[0109] As described herein, a calibration offset can be determined for a single joint, such as J9, J10, and J11 (i.e., the joint that controls the movement of the end effector). In some embodiments, the calibration offset of a joint may take into account the movement and / or calibration offsets of one or more other joints. For example, the calibration offset determined with respect to J9 may be determined based on the movement and / or calibration offsets with respect to one or both of J10 and J11. This approach allows for a larger range of motion for one joint (e.g., J9) by taking into account one or both of other joints (e.g., J10 and J11).

[0110] In one embodiment, the usage data used in the methods described herein can be obtained from memory. The usage data can be stored at the device or in memory associated with the device. The memory is suitably on-device memory. The usage data can be stored in the device's memory and transmitted to the system via an interface (e.g., along with other device data). This arrangement has the advantage that usage data for a specific device is available, regardless of the robotic system to which the device is attached.

[0111] The memory can be local to the surgical robot system. For example, the memory can be located at the console of the surgical robot system. Usage data can reside on a memory drive connected to the robot system (e.g., the console or arm). This method allows for the organization of usage data for multiple instruments of a single type at the surgical robot system, which are attached to the surgical robot system one or more times. Multiple instruments of a single type do not need to all be simultaneously attached to the surgical robot system. Therefore, usage data for a given instrument (e.g., a gripper tool) can be established within one or more programs using one or more gripper tools.

[0112] The storage device can be located remotely from the surgical robot system. For example, it can be situated on a remote server accessible to the surgical robot system. Usage data can be stored on a cloud server and downloaded at the start of the procedure. This approach enables the organization of usage data from multiple surgical robot systems and / or multiple users. Data from multiple users can be associated with individual usage data for each user. This usage data is then accessible to any of the surgical robot systems. Thus, a single system can benefit from usage data built up across numerous procedures.

[0113] You can also use any two or more of these methods in combination.

[0114] The method may include obtaining usage data from one or more joints of the instrument. For example, usage data may be received from the instrument. Usage data may be received from the instrument before operation (e.g., during a setup procedure). In this case, the usage data includes data relating to one or more previously executed procedures. Usage data may be received from the instrument during operation. The usage data may be or may include telemetry data from the instrument, such as telemetry data from one or more joints. The usage data thus obtained is appropriately stored in memory. For example, real-time usage data received from a joint during a procedure may be stored in instrument memory and / or surgical robot system memory (e.g., locally on the surgical robot system, such as memory at the console) and / or remote memory (e.g., memory on a server remote from the surgical robot system). The usage data appropriately describes the movement of one or more joints of the instrument.

[0115] Appropriately, the usage data may include joint angle data of the instrument's joints. For example, usage data may include joint angles and measurements of instrument use at each joint angle. This may include measurements of the time spent at each joint angle within the range of motion of each joint, such as at each division of 0.5 degrees, 1 degree, 2 degrees, 5 degrees, etc. Usage data may include instrument actuator position data related to the joints of the instrument. For example, usage data may include instrument actuator positions and measurements of instrument use at each position. This may include measurements of the time spent at each position within the range of instrument actuator positions, such as at each division of 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0116] Usage data can be obtained from the kinematic controller or other drive systems that control the movement of one or more joints of the device. Usage data can be obtained by measuring joint angles using sensors to sense joint angles. Alternatively or alternatively, usage data can be obtained by analyzing control signals sent to actuators used to drive the joints. Alternatively or alternatively, video processing techniques can be used to obtain usage data to analyze the attitude of the device's distal end, such as the attitude of the device's end effector. Based on this analyzed attitude, the joint angles associated with the attitude can be determined.

[0117] The sensor can sense joint angles in specific angular increments. The actuator can drive the joint in specific angular increments. The minimum angular increments that can sense and drive joint angles can be the same, but do not need to be. The data is appropriately included as a metric for each joint angle across the entire range of possible joint angles, with each joint angle separated by the minimum angular increment. This method can improve the accuracy of determining calibration offsets.

[0118] Another approach is to use data binning for joints within sub-ranges of angles. This creates a histogram that provides a metric for joint usage at each sub-range. The sub-ranges can have any desired size, such as 0.5-degree angular rotation, 1 degree, 2 degrees, 5 degrees, etc. Relatively smaller sub-range sizes will result in more accurate calibration offsets and / or calibration offsets with relatively high resolution, leading to higher accuracy. However, using smaller sub-ranges can be expected to generate relatively more computation. Relatively larger sub-range sizes can result in less accurate calibration offsets and / or calibration offsets with relatively low resolution. Using larger sub-ranges can be expected to generate relatively less computation, which can, for example, result in faster processing. The position of the instrument actuator can be determined using a corresponding binning method.

[0119] The size of the appropriately chosen subrange depends on the adjustment of the control relationship of the drive element. When the control relationship of the drive element is adjustable in discrete stages, a relatively low resolution calculation of the calibration offset may be sufficient. The greater the distance between the discrete stages, the lower the resolution required. Therefore, in these cases, it may be advantageous to utilize potentially faster and / or lower-cost processing by using a relatively large subrange. An example of a control relationship with discrete stages is providing multiple pulleys (as discussed in more detail elsewhere in this document), around which the drive cable can be wound, each pulley having a different diameter. The diameter of the pulley represents the discrete nature of the available adjustment. Preferably, the resolution of the calculated calibration offset is at least the same as the resolution of the available adjustment. This method maximizes the resolution available using the adjustment mechanism.

[0120] Conversely, when the control relationship of the drive element is smoothly adjustable, a relatively high resolution calculation of the calibration offset may be more appropriate. Therefore, in these cases, using a relatively small subrange to increase the resolution of the computable construction offset may be advantageous. An example of a smoothly adjustable control relationship is a screw-fastened connection between an instrument interface element and a drive element (discussed in more detail elsewhere in this document). When the screw is loosened, the position of the connection can be moved by a desired amount, not limited to a specific location.

[0121] The subranges used to form the histogram can all be the same size (width or angle width). This is not necessarily the case: the size (width or angle width) of one or more subranges can differ from the size (width or angle width) of one or more other subranges. When relatively high joint usage is known or expected to occur in a given portion of the possible movement range, the subrange spanning that given portion can be smaller than the subranges outside that given portion. This approach can help reduce processing (by using relatively large subranges outside the angle range of most interest, compared to cases where all subranges are small) while providing increased resolution for determining calibration offsets (compared to cases where all subranges are relatively large).

[0122] The data used is appropriately obtained based on one or more of the following: instrument type, the procedure to be performed using the instrument, the stage within the procedure to be performed using the instrument, the actions within the procedure to be performed using the instrument, the ID of the surgical robot system to which the instrument is attached, and the surgeon's ID. This allows for the use of deviation calculations, and therefore, calibrations that are more specific to certain use cases. This customization of calibration can improve its accuracy.

[0123] Comparing the data with the maximum range of joint movement appropriately includes at least one of the following: probability density of instrument actuator positions and / or joint angle positions, machine learning algorithms, statistical analysis techniques, and goodness-of-fit techniques. Appropriately, the bias value is determined using at least one of the following: probability density of instrument actuator positions and / or joint angle positions, machine learning algorithms, statistical analysis techniques, and goodness-of-fit techniques. The bias value can be identified based on the program to be executed, the program being executed, the program that has been executed, or some combination of more than one of these.

[0124] Probability density can include the mode, median, or some combination of the mode and median. Probability density can also include any other suitable measure of the probability of a specific instrument actuator position and / or joint angle within the maximum range of joint movement of the corresponding joint in the instrument actuator position and / or joint angle. Therefore, deviation values ​​can be identified based on the average of the instrument actuator position and / or the joint angle of that joint.

[0125] Machine learning algorithms can be used to monitor and / or predict instrument actuator positions and / or joint angles within the maximum range of joint movement that the joint may utilize. The machine learning algorithm can be trained on instrument joint data relating to one or more of the following: the type of instrument (e.g., the type of instrument whose interface forms part of it), the procedure performed using the instrument (e.g., the same procedure as the procedure to be performed using the instrument), a phase in the procedure performed using the instrument (e.g., a phase in the same procedure as the phase in the procedure to be performed using the instrument), an action within the procedure performed using the instrument (e.g., an action as the same as the action within the procedure to be performed using the instrument), and the surgeon ID (e.g., the same surgeon ID as the ID of the surgeon performing the procedure using the instrument). In this way, for example, the machine learning algorithm can be used to identify bias values ​​or potential bias values ​​for a given surgeon performing a particular procedure.

[0126] Similarly, statistical analysis techniques and / or goodness-of-fit techniques can be based on data relating to the planned procedure, the current procedure, previous procedures, or some combination thereof. Statistical techniques and / or goodness-of-fit techniques can model a set of predicted or known instrument actuator positions and / or joint angle positions. For example, a Gaussian model corresponding to a set of predicted or known instrument actuator positions and / or joint angle positions can be determined.

[0127] Determining the calibration offset appropriately includes identifying characteristic actuator positions and / or joint angles based on a comparison of usage data with the maximum range of joint movement of the instrument actuator position and / or joint, and the method includes determining the calibration offset based on the characteristic actuator positions and / or joint angles. The characteristic actuator positions and / or joint angles may include instrument actuator positions and / or joint angles determined based on at least one of probability density, machine learning algorithms, statistical analysis techniques, and goodness-of-fit techniques, and / or may be formed based on said instrument actuator positions and / or joint angles.

[0128] Characteristic actuator positions and / or joint angles may include, or may be formed, at the center of an extension of actuator positions and / or joint angles represented by usage data. The extension of positions and / or angles appropriately represents the range of positions and / or angles between the minimum actuator position and / or joint angle used by the joint and the maximum actuator position and / or joint angle used by the joint. The minimum actuator position and / or joint angle may be the lowest actuator position and / or joint angle represented by usage data, where joint usage exceeds a minimum usage threshold, e.g., the time spent at that actuator position and / or joint angle. The maximum actuator position and / or joint angle may be the highest actuator position and / or joint angle represented by usage data, where joint usage exceeds another minimum usage threshold, e.g., the time spent at that actuator position and / or joint angle. The minimum usage threshold and the other minimum usage threshold may be the same, but do not need to be the same. Featured actuator positions and / or joint angles may include, or be formed based on, intermediate actuator positions and / or joint angles between minimum and maximum actuator positions and / or joint angles. Featured actuator positions and / or joint angles may include, or be formed based on, actuator positions and / or joint angles where the probability density is at a peak. Featured actuator positions and / or joint angles may include, or be formed based on, actuator positions and / or joint angles where a turning point occurs in the probability density or in a smoothed probability density. Smoothing the probability density can, for example, help improve the accuracy of identifying featured actuator positions and / or joint angles by reducing the impact of noise on the identification of featured actuator positions and / or joint angles. Smoothing the probability density can help improve the accuracy of identifying featured actuator positions and / or joint angles where the actuator positions and / or joint angles are binned into histogram bins using data. The characteristic actuator positions and / or joint angles may include the peak of a function (e.g., a Gaussian function) fitted to a set of predicted or known actuator positions and / or joint angles, or may be formed based on the peak of the function.

[0129] Characteristic actuator positions and / or joint angles may be based on any one or more of the individual actuator positions and / or joint angles discussed herein. Characteristic actuator positions and / or joint angles are appropriately calculated as an average or weighted average of the individual actuator positions and / or joint angles described. The weighting among each of the individual actuator positions and / or joint angles is appropriately selected based on one or more of the instrument type, the procedure to be performed, the surgeon ID, etc. Therefore, in cases where a particular procedure is known to involve complex use of the instrument, it may be appropriate to give a heavier weight to the individual actuator positions and / or joint angles determined according to probability density, compared to individual actuator positions and / or joint angles determined to be intermediate between the minimum and maximum actuator positions and / or joint angles. This approach can help interpret different usage patterns.

[0130] Determining the calibration offset appropriately includes calculating the difference between the characteristic actuator position and / or joint angle and the midpoint of the maximum range of joint movement of the actuator position and / or joint. For example, determining the calibration offset includes calculating the difference between the characteristic actuator position and / or joint angle and the midpoint between the maximum actuator position and / or joint angle and the minimum actuator position and / or joint angle. This method allows determination of whether the extension of position and / or angle represented by the use of the device is offset within the range of possible positions and / or angles of use, or at the center of that range. Therefore, the determined calibration offset can be a measure of the degree to which the extension of joint movement is biased to one side of that range.

[0131] In some instances, the calibration offset determined for a single joint is based on at least one other joint in the instrument. The calibration offset determined for a single instrument joint can be based on all instrument joints. This method can be used to display usage data for multiple joints showing deviations from the expected joint usage posture. Therefore, the calibration of one joint can take into account the calibration and / or usage of another joint.

[0132] Now refer to Figure 14 A method for calibrating the instrument interface is described. Usage data is obtained (1402). The usage data indicates the use of the joints of the instrument. The usage data is compared with the maximum range of motion of the joints (1404). Alternatively or alternatively, the usage data may be compared with a model of expected joint motion. A calibration offset is determined (1406). The calibration offset is determined based on the comparison. The calibration offset is used to adjust the control relationship of the drive elements arranged to drive the joints. The control relationship of the drive elements is adjusted using the calibration offset (1408) to calibrate the instrument interface.

[0133] Now for reference Figure 15This document illustrates various components of an exemplary computing-based device 1500, which can be implemented as any form of computing and / or electronic device, and embodiments of the methods and enhanced systems described herein can be implemented within this computing-based device. The computing-based device 1500 includes one or more processors 1502, which may be a microprocessor, a controller, or any other suitable type of processor for processing computer-executable instructions. In some instances, such as when using a system-on-a-chip architecture, the processor 1502 may include one or more fixed-function blocks (also referred to as accelerators) that implement part of the methods in hardware (rather than software or firmware). Platform software, including an operating system 1504 or any other suitable platform software, can be provided on the computing-based device to enable, for example, the implementation of... Figure 14 The application software of the method 1505 can be executed on the device.

[0134] Computer-executable instructions may be provided using any computer-readable medium accessible by a computing-based device 1500. Computer-readable media may include, for example, computer storage media, such as memory 1506, and communication media. Computer storage media (i.e., non-transitory machine-readable media), such as memory 1506, include volatile and non-volatile, removable and non-removable media implemented in any method or technology to store information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other storage technologies, CD-ROM, digital versatile disk (DVD) or other optical storage devices, magnetic tape cassettes, magnetic tape, disk storage devices or other magnetic storage devices, or any other non-transfer medium that can be used to store information for access by a computing-based device. In contrast, communication media may contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms. As defined herein, computer storage media does not include communication media. Although the computer storage medium (i.e., a non-transitory machine-readable medium, such as memory 1506) is shown within the computing-based device 1500, it should be understood that the storage can be remotely distributed or located and accessed via a network or other communication link (e.g., using communication interface 1508).

[0135] The computing-based device 1500 also includes an input / output controller 1510 arranged to output display information to a display device 1512, which may be separate from or integrated with the computing-based device 1500. The display information can provide a graphical user interface. The input / output controller 1510 is also arranged to receive and process input from one or more devices, such as a user input device 1514 (e.g., a mouse or keyboard). This user input can be used to initiate authentication. In an embodiment, if the display device 1512 is a touch-sensitive display device, it can also be used as the user input device 1514. The input / output controller 1510 can also output data to devices other than the display device, such as a locally connected printing device (not shown). In the above description, for ease of explanation, the actions taken by the system are divided into functional blocks or modules. In practice, two or more of these blocks can be architecturally combined. Functions can also be divided into different functional blocks.

[0136] The techniques of the invention have been described in the context of surgical robotic systems, but at least some of the described features are not limited to such systems and can be applied more generally to robotic systems. In some instances, the techniques of the invention can be applied to remotely operated robotic systems. Some examples of situations in which the techniques of the invention may be useful include those involving exploration, investigation, or repair using a “snake-like” robot. In the case of a surgical robot, the end effector can be a surgical tool, such as a scalpel, surgical cutter, surgical forceps, or cauterizer. Robotic systems can include manufacturing systems, such as vehicle manufacturing systems, parts handling systems, laboratory systems, and manipulators, such as manipulators for hazardous materials or surgical manipulators.

[0137] The applicant hereby independently discloses each individual feature described herein, as well as any combination of two or more such features, provided that such features or combinations can be implemented based on this specification as a whole according to common general knowledge of those skilled in the art, regardless of whether such features or combinations of features solve any problem disclosed herein, and without limiting the scope of the claims. The applicant notes that aspects of the invention can consist of any such individual feature or combination of features. In view of the foregoing description, it will be apparent to those skilled in the art that various modifications can be made within the scope of the invention as defined by the claims.

Claims

1. An instrument interface calibrator for calibrating an instrument interface of an instrument in a surgical robotic system, the surgical robotic system including a robot having a base and an arm extending from the base to a drive assembly for engaging the instrument interface to transmit driving forces to the instrument, the instrument interface being configured to drive joints of the instrument via drive elements, the calibrator being configured to: Obtain usage data indicating the usage distribution of the joints of the device; The usage data is compared with one or more of the joint’s maximum range of motion and the joint’s expected range of motion model. The calibration offset is determined based on the comparison to adjust the control relationship of the drive elements arranged to drive the joint; as well as The calibration offset is output by adjusting the control relationship of the drive elements of the joint to calibrate the instrument interface.

2. The instrument interface calibrator of claim 1, wherein the calibrator is configured to: determine the calibration offset by determining a deviation value based on the comparison, the deviation value indicating a deviation of joint use from the expected joint use; and determine the calibration offset based on the deviation value.

3. The instrument interface calibrator according to claim 1 or claim 2, wherein the control relationship of the drive element includes the positioning of the drive element, and adjusting the control relationship includes adjusting the positioning of the drive element using the calibration offset.

4. The instrument interface calibrator according to claim 1 or claim 2, wherein the control relationship of the driving element includes one or more of the following: The configuration of the gear mechanism arranged to drive the drive element, and adjusting the control relationship includes adjusting the configuration of the gear mechanism using the calibration offset; The tension of the drive element, and adjusting the control relationship includes adjusting the tension of the drive element using the calibration offset.

5. The instrument interface calibrator according to claim 1 or claim 2, wherein the usage data includes instrument driver position data and / or joint angle data of the joints of the instrument.

6. The instrument interface calibrator according to claim 1 or claim 2, wherein the calibrator is configured to: The usage data is compared with the maximum range of joint movement by using at least one of the following: probability density of instrument actuator position and / or joint angle position, machine learning algorithm, statistical analysis technique, and goodness-of-fit technique; and The calibration offset is determined by identifying the characteristic instrument driver position and / or joint angle based on the usage data and a comparison with the instrument driver position and / or the maximum range of joint movement of the joint, and the calibrator is configured to determine the calibration offset based on the characteristic instrument driver position and / or joint angle.

7. The instrument interface calibrator of claim 6, wherein the calibrator is configured to determine the calibration offset by calculating the difference between the feature instrument driver position and / or joint angle and the midpoint of the maximum range of joint movement of the instrument driver position and / or the joint.

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