Method for controlling a slave device controlled by a master device in a robotic system for medical or surgical teleoperation with reduced transmitted speed or power, and related robotic system

Abstract

A method for controlling a slave device during teleoperation performed by a robotic system for medical or surgical teleoperation is disclosed. The method comprises: defining a nominal target pose of the slave device corresponding to a pose of a master device; modifying the nominal target pose to obtain a modified target pose of the slave device; and controlling a movement of the slave device during teleoperation such that the slave device follows the modified target pose. Obtaining the modified target pose comprises reducing a translational velocity module of the modified target pose relative to the velocity of the nominal target pose according to a transfer function and / or reducing an instantaneous power or energy transferred from the master device to the slave device according to a transfer function. A robotic system to which the aforementioned method is applied is also disclosed.

Description

[Technical field]

[0001] The present invention relates to a method and system for controlling teleoperations performed by a robotic system for medical or surgical teleoperation.

[0002] In particular, the present invention relates to a method for controlling, by passivation techniques (i.e., controlled reduction of transmitted speed or power), slave devices controlled by a master device movable by an operator in a robotic system for medical or surgical teleoperation. [Background technology]

[0003] In master-slave robotic systems for medical or surgical teleoperation, systems are known which have a master device that is not mechanically constrained to a "master controller" station of the robotic system, i.e. "wheel" masters (or "mechanically ungrounded", "mechanically unconstrained") or of the type shown, for example, in patent documents WO / 2019 / 020407, WO / 2019 / 020408 and WO / 2019 / 020409 in the name of the same applicant. Summary of the Invention [Problem to be solved by the invention]

[0004] In all master-slave robotic systems for medical or surgical teleoperation, especially those with an unconstrained master device as described above, during teleoperation the operator moves the master device and the control system enables the slave devices to move in a manner that follows / tracks the position and orientation of the master device.

[0005] In fact, during the aforementioned following / tracking, a drawback may occur that the position and instantaneous orientation of the master device do not match the position and instantaneous orientation of the slave device. This problem can be attributed to several causes, namely: 1. The presence of delays in the system, i.e., the time required for the operator's signal to travel from the tracking device to the control system and then to the motors that actuate the movement of the slave device; 2. Inherent limitations of the actuation system, i.e., the fact that the motors that actuate the movement of the slave device have maximum operating speeds and accelerations; 3. Mechanical resonance of the robot's mechanical parts, in this case by "intentionally" slowing down the dynamics to avoid inducing undesirable vibrations by colliding with the robot; This can result from causes including:

[0006] If the momentary error (distance) between the actual pose of the slave device and the correct pose commanded by the master device (i.e. the pose that would be obtained in the absence of the aforementioned phenomena / defects) becomes too large, several problems will occur, including:

[0007] Problem 1. The operator stops the robot, but it is still moving. In this case, The operator perceives a delay between the action he performs and the action performed by the robot. Also, the operator tends to close the control cycle with his vision and perception, subject to the aforementioned delays. In other words, the presence of delays prevents the operator from finely and accurately positioning the slave device after a fast movement.

[0008] Problem 2. When the operator changes direction rapidly (for example, in a spatially circular motion with the master device), the following further drawback becomes apparent: When turning, the accumulated "motion delay" makes the operator feel that the slave device is still "forward" when the master device is already "backward". In case of high instantaneous velocities (close to or higher than the velocity of the actuation system) and curved trajectories, the slave device tends to converge to the master device along the shortest possible (instantaneous) trajectory, ignoring the instantaneous trajectory created by the operator, resulting in distortion of the slave device's movement. In extreme situations, a circular trajectory of the master device is transformed into a rectangular trajectory of the slave device.

[0009] Known solutions in the art have failed to satisfactorily address the problems and shortcomings discussed above.

[0010] Therefore, there is a strong need in the art of master-slave teleoperated robotic systems (with or without a tethered master) and related control methods to control the slave operation of a slave device relative to a master device based on a control algorithm in a manner that overcomes or at least mitigates the problems and shortcomings discussed above. [Means for solving the problem]

[0011] The object of the present invention is to provide a method for controlling a slave device, controlled by a master device and movable by an operator, by means of passivation techniques, which makes it possible to at least partially overcome the above-mentioned drawbacks of the prior art and in particular to meet the above-mentioned needs felt in the art.

[0012] This object is achieved by the method according to claim 1.

[0013] Further embodiments of such a method are defined by claims 2 to 17.

[0014] It is also an object of the present invention to provide a robotic system for medical or surgical teleoperation arranged to be controlled by the above-mentioned method, and such object is achieved by a system as claimed in claim 18.

[0015] A further embodiment of such a system is defined by claim 19.

[0016] Further characteristics and advantages of the method according to the invention will become apparent from the following description of preferred embodiments given by way of non-limiting indication, with reference to the attached drawings, in which: [Brief description of the drawings]

[0017] [Figure 1A] FIG. 1 illustrates a master-slave robotic system for medical or surgical teleoperation according to an embodiment of the present invention. [Figure 1B] FIG. 2 illustrates in more detail the master and slave devices included in the robotic system of FIG. 1, in accordance with one embodiment of the present invention. [Diagram 2] FIG. 1 shows a schematic diagram of an embodiment of a control method included in the present invention. [Diagram 3] FIG. 1 illustrates a transfer function between a nominal slave device speed module (or input speed / speed Vin) and a modified device speed module (or output speed / speed Vout) according to an embodiment of the control method of the present invention. [Figure 4] FIG. 1 illustrates the relationship between nominal slave device speed module (or input speed / speed Vin) and scale multiplication factor according to one embodiment of the control method of the present invention. [Diagram 5] FIG. 1 shows the modified target pose trajectory of the slave device for each nominal trajectory (or "virtual target") determined by control that does not include the passivation action provided by the method. [Figure 6]FIG. 1 shows the modified target pose trajectory of the slave device for each nominal trajectory (or "virtual target") determined by the control including the passivation action provided by the method. [Figure 7] FIG. 6 is a diagram showing an example of the change over time in the control speed module of a slave device relative to the nominal speed module in a situation corresponding to FIG. 5. [Figure 8] FIG. 7 is a diagram showing an example of the change over time in the control speed module of a slave device relative to the nominal speed module in a situation corresponding to FIG. 6; [Figure 9A] FIG. 1 shows the actions performed by the "passivator" block according to an implementation option of the method of the present invention. [Figure 9B] Control flow diagram for implementation options of the method of the present invention [Figure 10A] FIG. 1 illustrates the actions performed by the "passivator" block according to another implementation option of the method of the present invention. [Figure 10B] Control flow for another implementation option of the method of the present invention DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] With reference to FIGS. 1 to 10, a method for controlling a slave device during teleoperation performed by a robotic system 100 for medical or surgical teleoperation will be described.

[0019] The aforementioned robotic system comprises at least one master device 110 adapted to be operated by an operator 150 and at least one slave device including a surgical instrument 170 adapted to be controlled by the master device.

[0020] The master device 110 is preferably a "wheel" type master device without force feedback for mono-lateral teleoperation. Thus, for example, the master device may be a "wheel" type without force feedback for mono-lateral teleoperation, as well as a master mechanically constrained to an operating console.

[0021] The master device 110 is preferably a type of master device that is not mechanically constrained to an operating console.

[0022] The method comprises the steps of defining a nominal target pose in a workspace of the slave device (corresponding to a respective pose of the master device in the workspace of the master device), modifying the nominal target pose to obtain a modified target pose of the slave device, and configuring the slave device to follow said modified target pose during teleoperation by controlling a movement of the slave device within the workspace of the slave device.

[0023] The step of modifying the above-mentioned nominal target pose to obtain a modified target pose includes reducing the translational velocity module of the modified target pose relative to the velocity of the nominal target pose and / or reducing the instantaneous power or energy transferred from the master device to the slave device according to a respective transfer function.

[0024] Such a conversion function depends on the instantaneous velocity of the master device, and / or the instantaneous power or energy of the master device, and / or the distance between the current position of the slave device and the nominal target pose of the slave device.

[0025] According to one embodiment of the method, the step of modifying the nominal target pose to obtain a modified target pose causes a control loss of position consistency between the master device and the slave device, reducing the delay of the slave device's movement relative to the master device's movement as perceived by an operator during teleoperation.

[0026] It should be noted that while this loss of consistency may at first glance seem disadvantageous, it can have surprisingly useful technical effects, particularly in reducing the delay perceived by an operator during remote operation of a slave device's movements relative to those communicated to the master device (e.g., when such movements change direction).

[0027] According to one embodiment of the method, the aforementioned step of modifying the nominal target pose comprises decreasing a translational velocity module of the modified target pose.

[0028] According to an implementation option, the translational velocity of the modified target pose is expressed with reference to a Cartesian coordinate system in the workspace of the slave device.

[0029] According to another implementation option, the translational velocities of the modified target pose are expressed with reference to the spatial coordinates of the slave device's joints.

[0030] Thus, depending on the implementation options discussed above, the method provides velocity related effects for control points or velocity related effects for joints.

[0031] In the second case, the joints referred to are those that allow to control the degrees of freedom of the slave surgical instrument 170, e.g. a slave joint of the surgical instrument, each of which controls a yaw rotational and a pitch rotational degree of freedom; a slave joint surgical instrument joint that controls the roll rotation degree of freedom about the shaft of the surgical instrument; a joint for controlling three translational degrees of freedom X, Y, Z, typically located on a robotic manipulator 160 upstream of the slave surgical instruments 170 (the master device controls the robotic manipulator 160 associated with each slave surgical instrument 170); Includes.

[0032] According to an implementation option, the transfer function that modifies the translational velocity of the modified target pose decomposes the velocities and processes each velocity component (e.g., the components associated with the decomposition according to the coordinates of the selected reference coordinate system) in a mutually independent manner.

[0033] According to a possible embodiment, the method applies to unidirectional or bidirectional teleoperation from a master device to a slave surgical instrument.

[0034] Embodiments applicable to unidirectional teleoperation include applying the method to situations where the master device has no feedback (as opposed to bidirectional teleoperation where feedback is included in the master device).

[0035] According to one embodiment of the method, the transfer function that modifies the translational velocity of the modified target pose depends only on the velocity of the master device.

[0036] In this case, a continuous, monotonically non-decreasing function, defined as a linear function, is applied to velocity values ​​below a predefined threshold velocity value, and a non-linear function is applied to velocity values ​​above said threshold velocity value.

[0037] In the linear section of the function, the velocity module of the modified target pose of the slave device remains unchanged relative to the velocity module of the nominal target pose.

[0038] In the non-linear section of the function, the velocity module of the modified target pose of the slave device is reduced relative to the velocity module of the nominal target pose.

[0039] According to a specific implementation option, the value of said threshold velocity is between 0.015 m / s and 0.025 m / s.

[0040] According to an implementation option, the non-linear section of the speed transition function described above tends towards a horizontal asymptote that defines the maximum speed of the slave device target.

[0041] According to implementation options, the above mentioned slave device target maximum speed value corresponds to the maximum speed module that the slave device itself can reach.

[0042] Depending on the implementation options, the maximum speed of the slave device target is adjustable.

[0043] According to one embodiment of the method, a transfer function that modifies the translational velocity of the modified target pose depends on the nominal target pose velocity and the virtual distance between the position of the nominal target pose and the current position of the slave device.

[0044] According to an implementation option, said transfer function is a virtual distance transfer function, which is a continuous, monotonically non-decreasing function, such function being defined as a linear function for virtual distance values ​​below a given threshold distance value and as a non-linear function for virtual distance values ​​above said threshold distance value.

[0045] In the linear section of the function, the velocity module of the modified target pose of the slave device remains unchanged relative to the velocity module of the nominal target pose.

[0046] In the non-linear section of the function, the velocity module of the modified target pose of the slave device is reduced relative to the velocity module of the nominal target pose by an amount given by the transfer function of the virtual distance.

[0047] According to a specific implementation option, the value of said threshold distance is between 0.5 mm and 5 mm.

[0048] According to an implementation option, the virtual distance transfer function (non-passivated virtual distance) is a continuous, monotonically non-decreasing function having the value of "virtual distance + max distance" as an asymptote, where the parameter "max distance" is an adjustable parameter that specifies the maximum allowed virtual distance between the position of the modified target pose and the position of the slave device.

[0049] According to a specific implementation option, the value of said maximum virtual distance is between 0.5 mm and 5 mm.

[0050] With respect to the aforementioned "poses" of the master and slave devices, it should be noted that for the purposes of this description, each "pose" should be understood as being characterized by the respective values ​​of the degrees of freedom of the slave device.

[0051] Typically, these degrees of freedom consist of seven, including three translational degrees of freedom (X,Y,Z), three rotational degrees of freedom (e.g., the aforementioned "roll", "pitch", and "yaw"), and one open / close degree of freedom ("grasp").

[0052] Thus, a "pose" is defined by the values ​​of each of the aforementioned degrees of freedom, and the velocity (i.e., speed) associated with the pose refers to the velocity (i.e., speed) of the temporal evolution of each degree of freedom. Translational velocity refers to the translational velocity in the coordinate system of the translational degrees of freedom X, Y, Z.

[0053] Furthermore, with regard to poses, in this specification, the following definitions are used for "master pose", "slave pose", "nominal target pose", and "modified target pose".

[0054] "Master pose" is the current pose of the master device in the reference coordinate system of the master device's workspace (also referred to as "master space" in this specification and drawings, including, for example, the space defined by a tracking mechanism included in the robotic system).

[0055] "Slave pose" is the current pose of the slave device in the reference coordinate system of the slave device's workspace (also referred to in this specification and drawings as "slave space").

[0056] The "nominal target pose" (hereinafter sometimes referred to as the "proxy pose") is the pose of the master device mapped into the workspace of the slave device. The "nominal target pose" is defined as such because it is the pose that the slave device should follow under "nominal" conditions, i.e. in the absence of any further control mechanisms or processing.

[0057] It should be noted that the determination of the "nominal target pose" depends solely on the translation offset between the centers of the Master and Slave reference coordinate systems and the application of a scale factor to the translation. The translation offset may, for example, be specified in the alignment step, directly by an operator, or derived by operation of an available algorithm.

[0058] The "modified target pose" (hereinafter sometimes called "target pose") is the reference pose of the slave device, i.e. the pose to which the slave device must converge following the movements controlled by the control system. This pose in principle coincides with the nominal target pose, but may differ from it if there are reasons to change it due to further predefined control actions and associated algorithms.

[0059] In this specification, the modification of the nominal target pose (proxy pose) to obtain a modified target pose (target pose) can be performed, for example, based on information about the current position of the slave device, thereby reducing the delay between the movement of the slave device as perceived by the operator and the movement communicated to the master device.

[0060] Such a correction can be achieved, for example (as described further below), by inserting an additional translation offset between the proxy pose and the target pose.

[0061] A robotic system 100 for medical or surgical teleoperation in accordance with the present invention is described below.

[0062] The robotic system comprises at least one master device 110 adapted to be operated by an operator 150 and at least one slave device including a surgical instrument 170 adapted to be controlled by the master device.

[0063] The robotic system further comprises a control unit configured to control the slave device based on the movement of the master device during teleoperation.

[0064] The control unit is further configured to perform the steps of defining a nominal target pose in the workspace of the slave device corresponding to a respective pose of the master device in the workspace of the master device, modifying said nominal target pose to obtain a modified target pose of the slave device, and controlling a movement of the slave device within the workspace of the slave device such that the slave device follows said modified target pose during teleoperation.

[0065] In said step of modifying the nominal target pose to obtain a modified target pose for the slave device, the control unit is configured to reduce the translational velocity module of the modified target pose (relative to the velocity of the nominal target pose) or to reduce the instantaneous power or energy transferred from the master device to the slave device according to a respective transfer function that depends on the instantaneous velocity of the master device, and / or the instantaneous power or energy of the master device, and / or the distance between the current position of the slave device and the nominal target pose of the slave device.

[0066] According to some possible embodiments of the robotic system, the control unit is configured to execute a method for controlling the slave devices according to any one of the previously claimed embodiments.

[0067] Further details are provided below, by way of non-limiting example, with reference to some specific embodiments of the method and robotic system according to the invention, with reference to FIGS.

[0068] As mentioned above, the "master pose" of the master device, mapped into the slave device space and appropriately scaled by a possible scale factor, uniquely defines the "nominal target pose" of the slave device ("proxy pose") used as a reference by the control unit to control the slave device.

[0069] As already explained, the method includes modifying the aforementioned nominal target pose of the slave device so as to reduce the delay experienced by the operator in executing his commands during teleoperation, at the expense of losing positional consistency between the master and slave devices. Such reduction is achieved by reducing the energy introduced by the operator into the slave system, a technique defined herein as "passivation".

[0070] This is accomplished, for example, as shown in FIG. 2, by a block shown as a "passivator" which modifies the nominal target pose (shown in FIG. 2 as "target slave-pre-passiv") to obtain a modified target pose (shown in FIG. 2 as "target slave-post-passiv").

[0071] An implementation option involves modifying the target pose to reduce the power (or equivalently, energy) introduced into the system by the master device.

[0072] In an implementation option, the modification of the target pose of the slave device is performed by decreasing the velocity module of that target pose of the slave device.

[0073] The velocity of the target pose of the slave device can be expressed by a system of cartesian axes or in the space of the joints of the robot system.

[0074] In an implementation option, the passivation process is performed independently for each velocity component into which the slave device's target pause velocity vector is decomposed.

[0075] According to an implementation option (shown as "Option A" in Figures 9A and 9B), the velocity module after passivation depends on the velocity module of its target pose before passivation through a velocity transfer function.

[0076] According to another implementation option (shown as "Option B" in Figures 10A and 10B), the velocity module after passivation depends on the velocity module of its target pose before passivation and further on the position of the slave device.

[0077] In Figures 9 and 10, the nominal target pause speed (before passivation) is referred to as the "non-passivated slave target speed" and the corrected target pause speed (after passivation) is referred to as the "passivated slave target speed."

[0078] In Option A, the aforementioned speed conversion function is a linear function for speed values ​​below a predetermined threshold speed value, and during the linear section of the conversion function, the target speed module of the slave device is not altered.

[0079] On the other hand, the aforementioned speed transfer function is a non-linear function for speed values ​​above the threshold speed value, and in the non-linear section of the transfer function, the speed module of the target of the slave device is reduced based on the speed of the target of the non-passivated slave device.

[0080] According to one embodiment of this method (eg, as shown in FIG. 3), the aforementioned speed transfer function is a continuous, monotonically non-decreasing function.

[0081] According to one embodiment, the aforementioned non-linear section of the speed transfer function has a tendency towards an asymptote that depends on the value of the target maximum speed of the slave device.

[0082] According to an implementation option of the method, said maximum speed value of a slave device corresponds to the maximum speed module value achievable by said slave device.

[0083] According to some possible implementation options, said asymptote can be a horizontal asymptote or a diagonal asymptote.

[0084] Specifically, according to an implementation option, said asymptote is a horizontal asymptote, said horizontal asymptote being located at a velocity value equal to the sum of said maximum velocity value of the slave device and an offset value (DELTA).

[0085] As an implementation option, the offset value (DELTA) above may be null.

[0086] Therefore, in this case, the speed conversion function works in this way: when the speed of the master device increases beyond the threshold speed value, the speed module of the slave device increases continuously, but less than proportionally, gradually reaching but not exceeding the maximum speed value of the slave device.

[0087] Depending on the implementation options, the offset value (DELTA) mentioned above can be adjusted.

[0088] Option A can be interpreted geometrically as follows: a scale factor N is given that determines the ratio of the magnitude of the movements of the master device and the slave device. The target pose velocity of the slave device is then obtained by multiplying the instantaneous velocity of the master device by the scale factor N. Thus, the passivation process according to the implementation option of option A is equivalent to instantaneously multiplying by a scale factor N, which is a variable control multiplication parameter and depends on the velocity of the master device itself. Such a control multiplication parameter (or "multiplication scale factor" as illustrated in FIG. 4) has a value of 1 when the velocity module of the master device is less than the aforementioned threshold velocity value, and increases substantially linearly and monotonically non-decreasingly when the velocity module of the slave device changes.

[0089] According to one embodiment of the method, the value of said threshold velocity is between 0.015 m / s and 0.025 m / s as a function of the velocity limits of the slave system joints.

[0090] Specifically, according to an implementation option, the aforementioned threshold velocity value is 0.02 m / s.

[0091] According to an embodiment of the method based on Option B above (FIG. 10), the speed of the target of the slave device is a function of both the target speed of the slave device before passivation and the virtual distance between the target of the passivated slave device and the slave device itself.

[0092] According to such an embodiment, the target velocity of the passivated slave device (i.e., the modified target pose velocity) is equal to the nominal target pose velocity (i.e., the velocity of the unpassivated slave target) reduced by a transfer function that depends on the virtual distance between the slave device and the predicted slave target position without passivation (i.e., associated with the nominal target pose).

[0093] According to such an embodiment, the virtual distance transformation function has the following characteristics: If the virtual distance is less than the limit virtual distance, the virtual distance conversion function is equal to zero. In an implementation option, the limit virtual distance is 2.5 mm. For error values ​​larger than such limit virtual distance, the virtual distance transfer function behaves as a continuous function with an asymptote equal to y=din-dmax, where din is the predicted virtual distance and dmax is a configurable parameter. In an implementation option, dmax is equal to 5 mm.

[0094] According to one embodiment, the method provides for the slave device to stop with a delay following cessation of motion communicated by the surgeon to the master device, with control determined by the speed transfer function described above, and the delay is reduced.

[0095] According to one embodiment, this method reduces the delay experienced by the user when the slave device changes direction relative to the movements the surgeon communicates to the master device, with control determined by the speed transfer function described above.

[0096] This is obtained by modifying the target pose relative to the nominal target pose, as illustrated in FIGS.

[0097] It should be noted that in FIG. 5, the modified target pose trajectories for the slave device (shown in solid lines as "by control") are shown relative to their respective nominal trajectories determined by control that does not include the passivation action of the method (shown in dashed lines as "virtual target").

[0098] FIG. 6 shows the modified target pose trajectories (shown as solid lines as "by control") of the slave device relative to their respective nominal trajectories (shown as dashed lines as "virtual targets") determined by the control according to one embodiment of the method of the present invention including a passivation action.

[0099] It should be noted that the examples of Figures 5 and 6 show, by way of example, two-dimensional trajectories in the plane of two coordinates X, Y, but the described concept can be easily and obviously extended to the case of three-dimensional trajectories in space of three coordinates X, Y, Z.

[0100] FIG. 7 corresponds to the situation of FIG. 5 and shows an example of the change in time of the module of the nominal speed (shown in dashed lines as “virtual target”) without the passivation action, and the change in time of the module of the controlled speed of the slave device (shown in solid lines as “controlled”).

[0101] FIG. 8 corresponds to the situation of FIG. 6 where a passivation action has been performed according to an embodiment of the method of the invention, and shows an example of the variation over time of the module of the nominal speed (shown in dashed lines as "virtual target") and of the module of the controlled speed of the slave device (shown in solid lines as "controlled").

[0102] As already explained, according to one embodiment of the method, the operation of the speed transfer function corresponds to control with passivation, in which the control method limits the amount of power and / or energy transferred to the control system of the slave device if the power and / or energy introduced by the operator through the movement of the master device exceeds a predefined power and / or energy threshold level.

[0103] As already explained, by providing three orthogonal translational slave joints X, Y, Z (e.g. motorized slides), the modules of the slave velocities of said three orthogonal slave joints can be reduced, i.e. passivated, to slow down the movement of the control point of the slave surgical instrument, for example to avoid forcing the movement of the joint responsible for the stroke end movement (e.g. slide). It is therefore possible to intervene in the trajectory of the control point as the position of the pose of the control point changes over time. For example, if the system recognizes that the target pose will force the slave joint to reach the stroke end, it can decide to passivate the slave trajectory as described above.

[0104] As already explained, the control parameters intervene in order to influence the dynamics of the slave device, where "passivation" is understood as the reduction of virtual power.

[0105] Thus, the above-mentioned objects of the present invention can be fully achieved by the method disclosed above, with the features detailed above.

[0106] To meet foreseeable needs, those skilled in the art may make modifications and adaptations to the above method embodiments or substitute other functionally equivalent elements without departing from the scope of the following claims. Each feature described above as belonging to one possible embodiment may be implemented without regard to the other embodiments described. [Explanation of symbols]

[0107] 100 Robot System 110 Master Device 112 Master Device Orbit 120 Master Device Tracking Field Generator 150 Operator 160 Slave Robot Manipulator 170 Slave Surgical Instruments 172 Trajectory of Slave Surgical Instruments MFO "Master Frame Origin" or Master Reference System Origin MF "Master Frame" or Local Master Reference System SFO "Slave Frame Origin" or origin of the slave reference system SF "Slave Frame" or Local Slave Reference System

Claims

1. A method for controlling a slave device during remote operation performed by a robotic system (100) for remote operation of medical or surgical procedures, The robot system, At least one master device (110) adapted to be operated by an operator (150), A slave device comprising at least one surgical instrument (170) adapted to be controlled by the master device, Equipped with, The aforementioned method, A step of defining a nominal target pose in the workspace of the slave device that corresponds to an individual pose of the master device in the workspace of the master device, The steps include correcting the nominal target pose and obtaining the corrected target pose of the slave device, The steps include controlling the movement of the slave device in the slave device's workspace so that the slave device follows the modified target pose during remote operation, Includes, The step of correcting the nominal target pose and obtaining the corrected target pose of the slave device is: Decreasing the translational velocity module of the modified target pose with respect to the velocity of the nominal target pose, according to a conversion function that depends on the instantaneous velocity of the master device and / or the instantaneous power or energy of the master device and / or the distance between the current position of the slave device and the nominal target pose of the slave device. and / or, To reduce the instantaneous power or energy transmitted from the master device to the slave device according to a conversion function that depends on the instantaneous velocity of the master device and / or the instantaneous power or energy of the master device and / or the distance between the current position of the slave device and the nominal target pose of the slave device, including, method.

2. The step of correcting the nominal target pose and obtaining the corrected target pose of the slave device is: This reduces the control loss of positional consistency between the master device and the slave device, and reduces the delay in the movement of the slave device relative to the movement of the master device, which is perceived by the operator during remote operation. The method according to claim 1.

3. The step of modifying the nominal target pose is: This includes reducing the translational velocity module of the modified target pose, wherein the translational velocity of the modified target pose is expressed with reference to a Cartesian coordinate system in the workspace of the slave device. The method according to claim 1 or 2.

4. The step of modifying the nominal target pose is: This includes reducing the translational velocity module of the modified target pose, wherein the translational velocity of the modified target pose is expressed with reference to the spatial coordinate system of the slave device's joints. The method according to claim 1 or 2.

5. The conversion function for modifying the translational velocity of the modified target pose processes each velocity component of the decomposed velocity in a mutually independent manner. The method according to claim 3.

6. The remote control is a one-sided or one-directional remote control from the master device to the slave surgical instrument. The method according to claim 1 or 2.

7. The conversion function for correcting the translational velocity of the modified target pose is a continuous, monotonic, non-decreasing function that depends only on the velocity of the master device. It is a linear function with respect to velocity values ​​below a predetermined threshold velocity value, and the velocity module of the modified target pose of the slave device remains unchanged with respect to the velocity module of the nominal target pose. The velocity function is nonlinear with respect to velocity values ​​exceeding the threshold velocity value, and the velocity module of the modified target pose of the slave device is reduced relative to the velocity module of the nominal target pose. It is stipulated that, The method according to claim 3.

8. The threshold velocity value is between 0.015 m / s and 0.025 m / s. The method according to claim 7.

9. The nonlinear section of the speed conversion function tends toward a horizontal asymptote that defines the maximum speed of the slave device target. The method according to claim 7.

10. The maximum speed value of the slave device target corresponds to the maximum speed module that the slave device can reach. The method according to claim 8.

11. The maximum speed of the slave device target is adjustable. The method according to claim 8.

12. The conversion function for correcting the translational velocity of the modified target pose depends on the velocity of the nominal target pose and the virtual distance between the position of the nominal target pose and the current position of the slave device. The method according to claim 3.

13. The aforementioned conversion function is a virtual distance conversion function, which is a continuous and monotonic non-decreasing function, The virtual distance value is a linear function with respect to a predetermined threshold distance value, and the velocity module of the modified target pose of the slave device remains unchanged with respect to the velocity module of the nominal target pose. The virtual distance value is a nonlinear function with respect to the value of the threshold distance, and the velocity module of the modified target pose of the slave device is reduced from the velocity module of the nominal target pose by an amount given by the virtual distance conversion function. It is stipulated that, The method according to claim 12.

14. The threshold distance value is between 0.5 mm and 5 mm. The method according to claim 13.

15. The virtual distance conversion function is a continuous and monotonic non-decreasing function with an asymptote of the value "virtual distance + maximum distance," where the parameter "maximum distance" is an adjustable parameter that defines the maximum allowable virtual distance between the position of the modified target pose and the position of the slave device. The method according to claim 13.

16. The maximum virtual distance value is between 0.5 mm and 5 mm. The method according to claim 15.

17. The master device is an ungrounded type master device, preferably without force feedback. and / or, The master device is a type of master device that is not mechanically constrained by the operating console. The method according to claim 1 or 2.

18. A robotic system (100) for remote control of medical or surgical procedures, At least one master device (110) adapted to be operated by an operator (150), A slave device comprising at least one surgical instrument (170) adapted to be controlled by the master device, A control unit configured to control the slave device based on the movement of the master device during remote operation, Equipped with, The control unit is To define nominal target poses in the workspace of the slave device that correspond to individual poses of the master device in the workspace of the master device, The nominal target pose is modified, and the modified target pose of the slave device is obtained. During remote control, the movement of the slave device in the slave device's workspace is controlled so that the slave device follows the modified target pose. It is configured to do the following: In the step of correcting the nominal target pose and obtaining the corrected target pose of the slave device, the control unit: Decreasing the translational velocity module of the modified target pose with respect to the velocity of the nominal target pose, according to a conversion function that depends on the instantaneous velocity of the master device and / or the instantaneous power or energy of the master device and / or the distance between the current position of the slave device and the nominal target pose of the slave device. and / or, To reduce the instantaneous power or energy transmitted from the master device to the slave device according to a conversion function that depends on the instantaneous velocity of the master device and / or the instantaneous power or energy of the master device and / or the distance between the current position of the slave device and the nominal target pose of the slave device, Configured to perform, Robot system.

19. The control unit is configured to perform the method for controlling the slave device described in claim 1 or 2. The robot system according to claim 18.

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