Rear end drive device for a robot, control system, method and robot

Abstract

A kind of rear-end driving device, control system and method for driving front-end continuum robot.The continuum robot includes catheter and probe in catheter, rear-end driving device includes movable platform and catheter propulsion motor.At least three tendons are arranged on movable platform, for connecting catheter and at least three force sensors;At least three force sensors are used to perceive the external force suffered by at least three tendons and generate feedback signal;At least three tendon tensioning screw rod motor groups are used to control the tensioning and relaxation of at least three tendons to adjust the pose of catheter;Probe knob motor is used to control the rotary motion of probe;Probe propulsion screw rod motor group is used to control the forward or backward motion of probe.Catheter propulsion motor is used to control the forward or backward motion of catheter.By using the scheme of the application, the pose of front-end continuum robot and forward, backward or rotary motion can be further controlled by controlling rear-end driving device.

Description

TECHNICAL FIELD

[0001] The present application relates to an interventional medical robot, and more particularly to a backend driving device, a control system and a control method for driving a continuum robot, and a corresponding continuum robot system. BACKGROUND

[0002] Pulmonary diseases are one of the world's largest health problems and one of the eight leading causes of death worldwide, including pulmonary embolism, acute respiratory failure and pneumonia. Coronavirus disease (COVID-19) is a new type of pneumonia that has emerged in recent years. Timely diagnosis and treatment can reduce the symptoms of various pulmonary diseases, reduce the severity of various pulmonary diseases, improve the health of patients, improve the post-treatment life quality of patients and prolong the survival period of patients.

[0003] Early diagnosis and accurate diagnosis are of great significance for good recovery of pulmonary diseases and improvement of post-treatment life quality of patients with pulmonary diseases. However, due to the physiological structure and function of the lungs and the limitations of existing medical technology and equipment, early diagnosis or accurate diagnosis of some pulmonary diseases (originating from the bronchiole and bronchiole) is difficult. Especially for the diseases in the bronchiole area, since the inner diameter range is about 0.5-1 mm, there is no commercial or reported medical equipment that can reach this area to carry out subsequent detection and diagnosis. The existing medical imaging technology for the lungs, such as X-ray (represented by CT), ultrasonic imaging, nuclear magnetic resonance imaging and bronchoscopy, cannot well diagnose diseases in this area. However, for diseases that are difficult to diagnose, percutaneous biopsy or biopsy under bronchoscopy is still the gold standard for diagnosing diseases in the medical field.

[0004] Although the minimum diameter of the bronchoscope can reach 1.8 mm, it needs manual intervention of medical staff, which will increase the risk of infection. In addition, the accuracy and safety of manual operation are relatively low.

[0005] Therefore, the bronchiole advancement probe needs to achieve a sub-millimeter level of outer diameter size and exhibit good biopsy tissue sampling capability. In addition, obtaining the apparent image of the pathological tissue at the front end of the probe and sensing the mechanical information of the pathological tissue in this area will better assist in achieving disease diagnosis. On this basis, better and safer controllable advancement requires the design of a corresponding backend electromechanical system and the selection of a suitable driving mechanism to achieve the intended goal.

[0006] Therefore, a corresponding backend driving device for an interventional medical robot, a corresponding control system and a control method are needed. SUMMARY

[0007] The purpose of the present application is to propose a scheme for realizing precise and safe control of a continuum robot comprising a probe and a catheter.

[0008] According to a first aspect of the present application, a rear-end driving device is provided for driving a front-end continuum robot, characterized in that the continuum robot comprises a catheter and a probe located in the catheter, the rear-end driving device comprises a movable platform and a catheter propulsion motor, the movable platform is provided with at least three tendons, at least three force sensors, at least three tendon tensioning lead screw motor sets, a probe knob motor and a probe propulsion lead screw motor set, wherein:

[0009] The distal ends of the at least three tendons are connected to the catheter, and the proximal ends of the at least three tendons are fixed to the at least three force sensors respectively,

[0010] The at least three force sensors are respectively arranged on the at least three tendon tensioning lead screw motor sets and are configured to sense external forces acting on the at least three tendons and generate feedback signals,

[0011] The at least three tendon tensioning lead screw motor sets are respectively connected to the corresponding force sensors through the lead screw slides thereon, for respectively controlling the tensioning and loosening of the at least three tendons by moving the force sensors on the lead screw slides to adjust the pose of the catheter,

[0012] The probe knob motor is connected to the probe and arranged on the lead screw slide of the probe propulsion lead screw motor set for controlling the rotational movement of the probe,

[0013] The probe propulsion lead screw motor set is connected to the probe knob motor through the lead screw slide thereon for controlling the forward or backward movement of the probe, and

[0014] The catheter propulsion motor is used to control the corresponding forward or backward movement of the movable platform through the bottom lead screw located below the movable platform to further control the forward or backward movement of the catheter.

[0015] In one embodiment, the probe propulsion lead screw motor set is arranged at the center of the movable platform, and the at least three tendon tensioning lead screw motor sets are arranged distributed on both sides of the probe propulsion lead screw motor set.

[0016] In one embodiment, the rear-end driving device further comprises a plurality of encoders respectively arranged on the tendon tensioning screw motor set, the probe advancing screw motor set, the catheter advancing motor and the probe knob motor for recording actual displacement of the tendon tensioning screw motor set, the probe advancing screw motor set and the catheter advancing motor and actual rotation angle of the probe knob motor and generating feedback signals.

[0017] In one embodiment, the force sensor comprises an upper end through hole for connecting proximal ends of the at least three tendons, a lower end through hole for connecting the tendon tensioning screw motor set through a screw block of the tendon tensioning screw motor set, and a strain gauge arranged around a middle groove for sensing deformation of the middle groove to calculate tension force received by the connected tendons.

[0018] In one embodiment, the rear-end driving device further comprises an external magnetic control platform, the external magnetic control platform comprising at least three pairs of electromagnetic coils, each pair of electromagnetic coils being oppositely arranged in any dimension in a three-dimensional space for applying an electromagnetic field to a probe tip of the probe coated with a magnetic skin to control and adjust the pose of the probe tip.

[0019] According to a second aspect of the present application, a control system for a continuum robot is provided, the continuum robot comprising a catheter and a probe located in the catheter, the control system comprising:

[0020] an input module for receiving input information, the input information comprising at least quantities representing initial displacement of the catheter, quantities representing tendon extension and contraction in the catheter, and quantities representing initial displacement of the probe,

[0021] a feedback module for receiving feedback signals returned from the catheter and the probe respectively, the feedback signals comprising at least tendon end tension force signals, probe front end image signals and probe front end optical signals,

[0022] a control module for determining displacement control quantities of the catheter and the probe respectively based on at least the input information, the feedback signals and target positions of the catheter and the probe, to control advancing or retreating movement of the catheter, advancing, retreating or rotating movement of the probe, and pose of the catheter and the probe.

[0023] In one embodiment, the control system further comprises an environmental disturbance collection module for collecting environmental disturbance information and providing it to the control module, wherein the environmental disturbance information comprises self-vibration of the continuum robot, spatial displacement caused by vibration around biological tissue and friction force received by the continuum robot.

[0024] In one embodiment, the quantity characterizing the initial displacement of the catheter comprises a displacement quantity of a movable platform for controlling the movement of the catheter, and the quantity characterizing the initial displacement of the probe comprises a displacement quantity of a probe advancing screw motor group for controlling the movement of the probe.

[0025] According to a third aspect of the present application, there is provided a continuum robot system, characterized in that the continuum robot system comprises a continuum robot and a backend driving device according to the first aspect of the present application, the continuum robot comprising a catheter and a probe located in the catheter, and the backend driving device being used to drive the continuum robot at the front end.

[0026] In one embodiment, the continuum robot system according to the third aspect of the present application further comprises a control system for the continuum robot according to the second aspect of the present application, and the control system is used to control the movement and pose of the continuum robot.

[0027] According to a fourth aspect of the present application, there is provided a control method for a continuum robot, characterized in that the continuum robot comprises a catheter and a probe located in the catheter, and the control method comprises:

[0028] receiving input information, the input information at least comprising a quantity characterizing the initial displacement of the catheter, a quantity characterizing the tendon stretching and contraction in the catheter, and a quantity characterizing the initial displacement of the probe,

[0029] receiving feedback signals returned from the catheter and the probe respectively, the feedback signals at least comprising a tendon end tension signal, a probe front end image signal and a probe front end optical signal,

[0030] determining a displacement control quantity of each of the catheter and the probe according to at least the input information, the feedback signals and target positions of the catheter and the probe, so as to control the advancing or retreating movement of the catheter, the advancing, retreating or rotating movement of the probe, and the pose of the catheter and the probe.

[0031] In one embodiment, the control method further comprises collecting environmental interference information and providing it to the control module, wherein the environmental interference information comprises self-vibration of the continuum robot, spatial displacement caused by vibration around the biological tissue, and friction force received by the continuum robot.

[0032] In one embodiment, controlling the pose of the catheter comprises controlling the stretching and contraction of the tendons of the catheter to control the pose of the catheter by using an antagonistic tendon driving strategy, and when one side of the tendon is tightened and the opposite side of the tendon is relaxed, the catheter will bend to the side where the tendon is tightened.

[0033] In one embodiment, controlling the pose of the probe includes driving the probe tip coated with a magnetic skin of the probe by an external magnetic control platform using a magnetic drive bending strategy to achieve contactless pose control of the probe.

[0034] With the scheme of the present application, antagonistic tendon-driven strategy can be used to achieve precise and safe closed-loop control of the pose and advancing, retreating or rotating motion of the catheter and probe in the continuum robot at the distal end through the backend driving device and / or closed-loop control system according to input information, feedback information and environmental disturbance information. In addition, antagonistic tendon-driven strategy and magnetic drive method can be combined as a composite driving strategy to achieve more precise movement control of the catheter and probe. Through the scheme of the present application, functions such as bronchial navigation, tissue appearance imaging, in-situ force detection and biopsy sampling of the continuum robot in the pathological region can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0035] Non-limiting and non-exhaustive embodiments of the present application are described with reference to the following drawings, by way of example only, in which:

[0036] Figure 1 A schematic diagram of a backend driving device according to an embodiment of the present application is shown;

[0037] Figure 2 A conceptual schematic diagram of a robotic system according to an embodiment of the present application is shown;

[0038] Figure 3 A catheter structure schematic diagram according to an embodiment of the present application is shown;

[0039] Figure 4 An application schematic diagram of antagonistic tendon-driven strategy according to an embodiment of the present application is shown;

[0040] Figure 5A A schematic diagram of tendon tension signal change of a force sensor is shown;

[0041] Figure 5B A catheter state schematic diagram corresponding to the tendon tension signal change is shown;

[0042] Figure 6 A schematic diagram of a control system for a continuum robot according to the present application is shown;

[0043] Figure 7A A flowchart schematic diagram of a control method for a continuum robot according to the present application is shown;

[0044] Figure 7B A conceptual diagram of a control method for a continuum robot according to the present application is shown;

[0045] Figure 8 FIG. 1 shows a schematic diagram of a probe tip structure according to an embodiment of the present application;

[0046] Figure 9A FIG. 4 shows a schematic diagram of an application of a magnetic-driven bending strategy according to an embodiment of the present application; and

[0047] Figure 9B FIG. 5 shows a schematic diagram of a three-dimensional electromagnetic coil in an exogenous magnetic control platform according to the present application. DETAILED DESCRIPTION

[0048] In order to make the above and other features and advantages of the present application more comprehensible, the present application will be further described below with reference to the drawings. It is to be understood that the specific embodiments presented herein are by way of example and not by way of limitation.

[0049] Spatially relative terms such as "upper", "lower", "middle", "end", and "side" can be used herein for ease of description to describe one element's or portion's relationship to another element, portion, or portion, as illustrated in the figures. Such spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0050] The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting. Unless specifically set forth herein, "a", "an" and "the" are not limited to one but can include a plurality. The terms "including", "comprising", and "having" specify the presence of stated features, operations, members, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, operations, members, elements, and / or combinations thereof.

[0051] The present application is hereinafter described in conjunction with the accompanying drawings only by way of example.

[0052] For ease of understanding and description, the term "distal end" used herein refers to an end that is further away from a rear-end driving device, and the term "proximal end" refers to an end that is closer to the rear-end driving device. The term "rear end" refers to an end that is away from a human body with respect to a continuum robot, and the term "front end" refers to an end that is into a human body with respect to a continuum robot.

[0053] According to one aspect of the present invention, a rear-end drive device is provided for driving a front-end continuous robot, the continuous robot including a guide tube and a probe located in the guide tube, the rear-end drive device including a movable platform and a guide tube propulsion motor, the movable platform being provided with at least three tendineae (e.g., three, four, five or more tendineae), at least three force sensors (e.g., corresponding three, four, five or more force sensors), at least three tendineae tensioning screw motor assemblies (e.g., corresponding three, four, five or more tendineae tensioning screw motor assemblies), a probe knob motor and a probe propulsion screw motor assembly.

[0054] Figure 1 A schematic diagram of a rear-end drive device 100 according to an embodiment of the present invention is shown. In this embodiment, the rear-end drive device 100 is used to drive a front-end continuous robot, the continuous robot including a conduit (also referred to as a conduit robot) 102 and a probe (also referred to as a probe robot) 104 located in the conduit 102. Specifically, the rear-end drive device 100 includes a movable platform 106 and a conduit propulsion motor 108. The movable platform 106 is provided with four tendons 110, four force sensors 112, four tendon tensioning screw motor assemblies 114, a probe knob motor 116, and a probe propulsion screw motor assembly 118.

[0055] like Figure 1 As shown, the distal ends of the four tendineae 110 are connected to the conduit 102 through tendineae holes 130 on the conduit 102, and the proximal ends of the four tendineae 110 are respectively fixed to four force sensors 112.

[0056] Four force sensors 112 are respectively installed on four tendon tensioning screw motor assemblies 114 and are configured to sense the external force on the four tendons 110 and generate corresponding feedback signals.

[0057] Specifically, each chord tensioning screw motor assembly 114 also includes a screw slider 120A, on which a bracket is provided for fixing a force sensor 112A. The four chord tensioning screw motor assemblies 114 are respectively connected to the corresponding force sensor 112 through their screw sliders 120A, and are used to control the tensioning and relaxation of the four chordaes 110 by moving the force sensor 112 on it, so as to adjust the position of the conduit 102.

[0058] The probe knob motor 116 is connected to the probe 104 and is mounted on the lead screw slider 120B of the probe push lead screw motor assembly 118, and is used to control the rotational movement of the probe 104.

[0059] The probe advancing lead screw motor set 118 is connected with the probe knob motor 116 through the lead screw slider 120B thereon, for controlling the advancing or retreating movement of the probe 104 by moving the probe knob motor 116 on the lead screw slider 120B. Specifically, the probe advancing lead screw motor set 118 further comprises the lead screw slider 120B, and a bracket is arranged on the lead screw slider 120B for fixing the force sensor 112B thereon. The catheter advancing motor 108 is located at the rear end of the movable platform 106, for controlling the corresponding advancing or retreating of the movable platform 106 through the bottom lead screw 124 located below the movable platform 106, so as to further control the advancing or retreating movement of the catheter 102.

[0060] The front end of the movable platform 106 further comprises a catheter holder 126 for connecting and clamping the catheter 102 with the movable platform 106.

[0061] In addition, it should be noted that, according to the dashed box of the probe advancing lead screw motor set 118 in Figure 1 , the probe advancing lead screw motor set 118 comprises the advancing motor at the rear end, the long strip-shaped lead screw base at the front end, and the lead screw slider 120B. As can be understood by those skilled in the art, the structure of the tendon tensioning lead screw motor set 114 is generally similar to that of the probe advancing lead screw motor set 118.

[0062] In one embodiment, the probe advancing lead screw motor set is arranged at the center of the movable platform, and the at least three tendon tensioning lead screw motor sets (for example, the four tendon tensioning lead screw motor sets in Figure 1 ) are arranged to be distributed on both sides of the probe advancing lead screw motor set.

[0063] In one embodiment, the number of tendons 110 in the rear-end driving device 100 can be at least three, the number of force sensors 112 can be at least three, and the number of tendon tensioning lead screw motor sets 114 can be at least three. As can be understood by those skilled in the art, the specific number of each can be determined according to the preference or demand of the operator (for example, a doctor), or can be determined according to market factors such as cost, price, etc., and the present application does not make additional limitations thereon.

[0064] In one embodiment, the rear-end driving device 100 comprises a plurality of encoders 122 arranged on the tendon tensioning lead screw motor set, the probe advancing lead screw motor set, the catheter advancing motor, and the probe knob motor, respectively, for recording the actual displacement of the tendon tensioning lead screw motor set, the probe advancing lead screw motor set, and the catheter advancing motor, and the actual rotation angle of the probe knob motor, and generating a feedback signal. For example, in the case of Figure 1In the illustrated embodiment, multiple encoders 122 are disposed at the front end of four chord tensioning screw motor assemblies 114 and probe advance screw motor assembly 118, while encoders 122 are integrated into the probe knob motor 116 and the catheter advance motor 108. Specifically, the encoder 122 on the chord tensioning screw motor assembly 114 records the actual displacement of the screw slider 120A on the screw to provide feedback and further control the tension and relaxation of the chord 110. The encoder 122 on the probe advance screw motor assembly 118 records the actual displacement of the screw slider 120B on the screw to provide feedback and further control the forward or backward movement of the probe 104. The encoder 122 in the probe knob motor 116 records the actual rotation angle of the probe knob motor 116 to provide feedback and further control the rotational movement of the probe 104. The encoder 122 in the catheter advance motor 108 records the actual displacement of the movable platform 106 on the bottom screw 124 to provide feedback and further control the forward or backward movement of the catheter 102. Furthermore, as those skilled in the art will understand, the encoder 122 can be located inside or outside each motor / motor group, depending on the actual application, and the present invention does not limit this.

[0065] In one embodiment, such as Figure 1 As shown, the force sensor 112 includes an upper through hole, a lower through hole, a central groove, and strain gauges 128 disposed around the central groove. The upper through hole is used to connect to the proximal end of the tendon chord 110, and the lower through hole is used to connect to the tendon tensioning screw motor assembly 114 via the screw slider 120A—for example, via a bracket on the screw slider 120A. The force sensor 112 as a whole serves as the force-bearing carrier for the strain gauges 128, thereby enabling the strain gauges 128 to sense the deformation of the groove to calculate the tensile force on the connected tendon chord 110. As those skilled in the art will understand, the present invention does not limit the specific type or structure of the force sensor 112; any force sensor 112 capable of connecting the tendon chord 110 and the tendon tensioning screw motor assembly 114 and capable of calculating the tensile force on the tendon chord 110 can be used in the present invention.

[0066] In one embodiment, the back-end drive unit 100 further includes an external magnetic control platform, which includes at least three pairs of electromagnetic coils (such as...). Figure 9B As shown), each of at least three pairs of electromagnetic coils is arranged relative to each other in any dimension of three-dimensional space to apply an electromagnetic field to the magnetically coated probe tip to control and adjust the pose of the probe tip. As will be further described below, an exogenous magnetic control platform is used to implement a magnetically driven bending strategy to control the pose of the magnetically coated portion of the distal end of the probe without contact.

[0067] In one embodiment, the catheter 102 and the probe 104 move synchronously when the movable platform 106 is advanced or retracted by the catheter propulsion motor 108. During the movement of the continuum robot, the steering of the catheter 102 is controlled by the tendon tensioning screw motor set 114. Upon reaching the target region, the catheter motor and the tendons remain stationary, and the probe propulsion screw motor set 118 and / or the probe rotation motor 116 are driven to achieve independent advancement, retraction or rotation of the probe.

[0068] Figure 2 A conceptual schematic of a robotic system according to an embodiment of the present application is shown. In this embodiment, the robotic system is used for pulmonary bronchial inspection. Specifically, the robot mainly consists of two parts, a catheter and a fiber-optic based probe located in the catheter. The robot is driven by the backend driving device as described above and the closed-loop control system with multi-information feedback as described below to intervene into the patient's pulmonary bronchus, thus achieving multiple functions such as intrabronchial navigation, tissue appearance imaging, in-situ force detection, and biopsy sampling, etc.

[0069] Figure 3 A schematic of a catheter structure according to an embodiment of the present application is shown. In this embodiment, the catheter adopts a hollow tubular structure, which has two bending degrees of freedom, and four through-holes are arranged around the catheter for placing tendons, for example.

[0070] In one embodiment, a 3D printing technology is used to achieve a catheter thickness of 300 μιη, which is conducive to promoting the diagnosis of pathological areas such as fine bronchial areas.

[0071] Figure 4 A schematic of the application of an antagonistic tendon driving strategy according to an embodiment of the present application is shown. Controlling the pose of the catheter includes controlling the pose of the catheter by controlling the extension and retraction of the tendons of the catheter using the antagonistic tendon driving strategy, as described below with respect to Figure 5A and Figure 5B When one side of the tendon is tensioned and the opposite side of the tendon is relaxed, the catheter will bend to the side of the tensioned tendon.

[0072] Specifically, in order to obtain a stable bending pose, the antagonistic tendon driving strategy is adopted for the catheter. The catheter is jointly driven by at least three (for example, four) tendons passing through the tendon holes, and when one side of the tendon is tensioned and the opposite side of the tendon is relaxed, the catheter will bend to the side of the tensioned tendon. The bending angle and radius of the catheter can be estimated by the relative tensioning amount of the at least three (for example, four) tendons.

[0073] In order to determine the relationship between the pose of the front end of the catheter and the extension and retraction amount of the tendon, a piecewise constant curvature approximation (PCCA) model is used to divide the steerable front end of the catheter into m actuation segments with the same curvature, and a corresponding geometric model is established for one of the segments.

[0074] First, the base coordinate system of the catheter is set as {X o -Y o -Z o}, and coordinate systems {O i} and {O i+1} are constructed at the center of the upper surface of the i-th segment and the i+1-th segment, respectively. The Z axis is perpendicular to the upper surface of each segment, the X axis points to the installation hole of the first driving tendon from the center, and the Y axis in each coordinate system is determined by the right-hand rule. It is assumed that the X i axis has a rotation angle a with the X o axis around the Z i axis, and the direction of the Z i axis remains the same as the Z o axis. On this basis, the transformation matrix T between the coordinate systems O i and O i+1 can be expressed as:

[0075]

[0076] In the above formula, β represents the bending angle, l represents the arc length of the virtual central axis (the thicker curve in the center in FIG. 5), s represents the sin function, c represents the cos function, Rot(y, β) means that the coordinate system is rotated counterclockwise by β degrees around the y axis, and Rot(z, a) means that the coordinate system is rotated counterclockwise by a degrees around the z axis.

[0077] The matrix expression can be further simplified as:

[0078]

[0079] In the above formula, n i , o i , and a i represent the unit vectors of the i-th coordinate system, and p represents the position vector of the coordinate origin.

[0080] Combining formula (1) and formula (2), the expressions of the rotation angle a and the bending angle β can be obtained:

[0081]

[0082] Further, the tendon extension amount of the catheter can be expressed as:

[0083]

[0084] In the above formula, r1 represents the distance between the tendon hole where the first tendon is located and the center of the plane, Vl i represents the elongation / shortening distance of the i-th tendon in the analyzed segment. After accumulating the bending deformation of all segments of the catheter, the corresponding tendon extension amount expression can be obtained:

[0085]

[0086] Based on the above expressions, the pose of the catheter tip can be precisely controlled by controlling the extension and contraction of the tendons.

[0087] For a further understanding of the application, Figure 5A a schematic diagram of the tendon tension signal change of the force sensor is shown, Figure 5B a schematic diagram of the catheter state corresponding to Figure 5A the tendon tension signal change of the force sensor. In conjunction with Figure 5A and Figure 5B shown, for ease of understanding, the first tendon tension here can correspond to the tension on the tendon "1" in Figure 5B , while the third tendon tension can correspond to the tension on the tendon "3" located on the opposite side of the tendon "1" in Figure 5B . Specifically, when the first tendon tension is static and does not reach the tension limit, the catheter is not in contact with the outside; when the first tendon tension increases and the third tendon tension on the opposite side decreases, the catheter bends towards the first tendon side; when the first tendon tension increases to the tension limit, the catheter is in contact with the outside; at this time, the first tendon tension is reduced from the tension limit and the third tendon tension is optionally increased, the catheter ends the contact with the outside. In other words, when the tension of a certain tendon reaches the set tension limit during the intervention, the controller issues an instruction to the lead screw motor below the corresponding tendon to advance slightly so that the tendon is properly relaxed; at the same time, an instruction is issued to the opposite side lead screw motor of the corresponding tendon to retreat slightly so that the opposite side tendon is properly tightened, under such cooperative control, the collision force of the catheter tip will be reduced accordingly.

[0088] According to another aspect of the application, a control system for a continuum robot is provided. Figure 6A schematic diagram of a control system for a continuum robot according to an embodiment of the present application is shown. The control system 300 comprises an input module 302, a feedback module 306 and a control module 304. The input module 302 is configured to receive input information, which includes at least a quantity indicative of an initial displacement of the catheter, a quantity indicative of a tendon stretch in the catheter and a quantity indicative of an initial displacement of the probe. It is appreciated that the input information can also include feedback information received from the feedback module 306 described below. The feedback module 306 is configured to receive feedback signals returned from the catheter and the probe, which include at least a tendon tip tension signal, a probe tip image signal and a probe tip optical signal. The control module 304 is configured to determine displacement control quantities for the catheter and the probe respectively based on at least the input information, the feedback signals and target positions of the catheter and the probe, so as to control the advancing or retreating motion of the catheter, the advancing, retreating or rotating motion of the probe and the pose of the catheter and the probe by, for example, the backend drive arrangement. In one embodiment, the quantity indicative of the initial displacement of the catheter includes a displacement quantity of a movable platform for controlling the movement of the catheter, and the quantity indicative of the initial displacement of the probe includes a displacement quantity of a probe advancing lead screw motor set for controlling the movement of the probe.

[0089] In one embodiment, as shown in Figure 6 the control system 300 further comprises an environmental disturbance acquisition module 308 configured to collect environmental disturbance information and provide the environmental disturbance information to the control module 304, wherein the environmental disturbance information includes self-vibration of the continuum robot, spatial displacement caused by vibration around the biological tissue and friction force received by the continuum robot, etc. It is appreciated that the environmental disturbance information refers to information collected from any external factor that can affect the continuum robot, which is not limited by the present application. In addition, the quantity indicative of the initial displacement of the catheter can include a displacement quantity of a movable platform for controlling the movement of the catheter, and the quantity indicative of the initial displacement of the probe can include a displacement quantity of a probe advancing lead screw motor set for controlling the movement of the probe.

[0090] According to still another aspect of the present application, there is provided a continuum robot system, which comprises a continuum robot and a backend drive arrangement as described above, wherein the continuum robot comprises a catheter and a probe located in the catheter, and the backend drive arrangement is configured to drive the continuum robot at the front end. Preferably, the continuum robot system can further comprise a control system for the continuum robot as described above, and the control system is configured to control the motion and pose of the continuum robot.

[0091] According to still another aspect of the present application, there is provided a control method for a continuum robot. Figure 7A A flowchart of a control method 400 for a continuum robot according to an embodiment of the present application is shown.

[0092] As Figure 7A shown, the control method 400 includes:

[0093] receiving input information S402, the input information including at least a quantity representing an initial displacement of the catheter, a quantity representing a tendon stretch in the catheter, and a quantity representing an initial displacement of the probe;

[0094] receiving feedback signals returned from the catheter and the probe respectively S404, the feedback signals including at least a tendon tip tension signal, a probe tip image signal, and a probe tip optical signal;

[0095] controlling the catheter and the probe according to at least the input information and the feedback signals S408, specifically, determining a displacement control quantity for each of the catheter and the probe according to at least the input information, the feedback signals, and a target position of the catheter and the probe, to control the advancing or retreating movement of the catheter, the advancing, retreating, or rotating movement of the probe, and the pose of the catheter and the probe through, for example, a back-end driving device.

[0096] In one embodiment, as Figure 7A shown, the control method 400 further includes collecting environmental interference information and providing it as a feedback signal S406 to the control module. As described above, the environmental interference information includes information collected from any external factor affecting the continuum robot, such as the self-vibration of the continuum robot, the spatial displacement caused by the vibration around the biological tissue, and the friction force received by the continuum robot.

[0097] Figure 7B A conceptual diagram of a control method for a continuum robot according to the present application is shown. By inputting the catheter initial displacement quantity, the catheter tendon stretch quantity, and the probe initial displacement quantity, while considering the tendon tip tension signal, the probe tip image signal, the probe tip optical signal, and the environmental interference factors, the control system itself or an operator can accurately and safely control the advancing, retreating, or rotating movement of the catheter and the optical fiber probe and their poses through the control system, thereby realizing functions such as endobronchial navigation, tissue appearance imaging, in-situ force detection, and biopsy sampling.

[0098] Figure 8A schematic diagram of a probe tip structure according to an embodiment of the present application is shown. Specifically, in this embodiment, the probe adopts a multi-fiber array design, with the periphery, for example, four single-mode optical fibers, configured as input-output shared optical fibers, which can introduce external light sources into the probe front end, while also outputting reflected light signals to the photoelectric signal processing end for calculating the force size and bending direction of the probe front end, thereby achieving mechanical information sensing of pathological regions and pathological tissues and minimally invasive operation of the intervention process; the central optical fiber acts as a receiving end, outputting the light signals reflected by the pathological tissues to the visual signal processing end for navigation within the pathological region and imaging of the appearance of the pathological tissues. In addition, the probe tip also includes: a sampling tip, which can be used to realize the biopsy sampling function; a ring-shaped hollow reflector, designed as a circular ring-shaped half-reflective half-transmissive lens, which can be used for light signal reflection of the optical fiber and can transmit the input light source of the optical fiber to the probe front end as a visual light source; a bendable main body, designed in a spring shape, which can be used to simultaneously support the axial force compression and lateral force bending of the probe. It should be noted that after coating the surface of the probe tip with a magnetic skin, non-contact pose control of the probe tip can be achieved through the magnetic drive bending strategy described below.

[0099] Figure 9A A schematic diagram of the application of a magnetic drive bending strategy according to an embodiment of the present application is shown, Figure 9B A schematic diagram of a three-dimensional electromagnetic coil in an external source magnetic control platform according to the present application is shown. Controlling the pose of the probe includes driving the magnetic skin of the distal end of the probe through the external source magnetic control platform using the magnetic drive bending strategy to achieve non-contact pose control of the probe.

[0100] In combination Figure 9A and Figure 9B As shown, specifically, in one embodiment, the probe tip is coated with a magnetic skin, and to achieve high-precision control of the probe, an external source magnetic control platform is used, using the electromagnetic field generated by the electromagnetic coil group of the platform as a driving source, and the driving principle is as shown in Figure 9A .

[0101] wherein the magnetic field strength B generated by the electromagnetic coil at a distance r0 from the axis can be calculated by formula (6). coil

[0102]

[0103] The magnetic field strength B generated by the coil group under the same direction and size of energization environment can be calculated by formula (7).

[0104] B = 2B coil (7)

[0105] In the above formula, μ0=4π×10 -7 ​Tm / A represents the magnetic permeability in vacuum, R represents the radius of the electromagnetic coil, N represents the number of turns of the coil, and I represents the current applied to the coil. In this magnetic field environment, the probe tip will be subjected to both magnetic force and magnetic torque to produce bending. The expressions of the corresponding magnetic force F and magnetic torque T can be represented by equations (8) and (9):

[0106]

[0107] T = M x B (9)

[0108] wherein represents the gradient of the magnetic field, and M represents the self-magnetization intensity vector of the probe tip. By adjusting the magnetic field strength or the angle θ between the magnetic field direction and the magnetization direction, the deflection direction of the probe tip can be precisely controlled. Specifically, after the probe tip is placed in a magnetic field with sufficient strength, when the self-magnetization direction of the probe tip and the magnetic field direction form an angle θ, the probe tip will deflect by an angle θ so that the self-magnetization direction is coaxial with the external magnetic field direction. The magnetic field strength can be calculated according to the size of the input current, and accordingly, the magnetic field strength can be adjusted by adjusting the size of the input current, so as to force the probe tip to offset the self-structure strength and obtain the corresponding target deflection angle.

[0109] In addition, as shown in Figure 9B , in one embodiment, the magnetic drive bending strategy according to the present application adopts three pairs of electromagnetic coils of an external magnetic control platform to realize high-precision control of the probe tip coated with a magnetic skin in three-dimensional space.

[0110] Specifically, three groups of coils along the X, Y, and Z directions are used to generate electromagnetic fields. Due to the vector superposition between the electromagnetic fields generated by each group of coils, an electromagnetic field with any direction and any strength in three-dimensional space can be obtained, so that the probe tip coated with a magnetic skin can be controlled to deflect in any direction or angle in three-dimensional space.

[0111] In one embodiment, the above antagonistic chordae tendinae driving strategy is combined to simultaneously control the forward movement, backward movement, or rotation of the catheter and the probe therein, and after the probe enters the target position, the pose of the probe tip is more accurately controlled by means of the magnetic drive bending strategy.

[0112] The technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by the present specification, as long as there is no contradiction in such a combination.

[0113] Although the application has been described in connection with the embodiments thereof, it will be understood that the description and drawings are illustrative only and are not limiting on the application. Numerous modifications and variations are possible in light of the above teachings without departing from the spirit of the application.

Claims

1. A back end drive device for driving a continuum robot of a front end, characterized by, The continuum robot comprises a catheter and a probe located in the catheter, the backend driving device comprises a movable platform and a catheter propulsion motor, at least three tendons, at least three force sensors, at least three tendon tension lead screw motor groups, a probe knob motor and a probe propulsion lead screw motor group are arranged on the movable platform, wherein: The distal end of the at least three tendons is connected to the catheter, and the proximal end of the at least three tendons is fixed to the at least three force sensors respectively, The at least three force sensors are respectively arranged on the at least three tendon tension lead screw motor groups and are configured to sense the external force acting on the at least three tendons and generate feedback signals, The at least three tendon tension lead screw motor groups are connected to the corresponding force sensors through the lead screw slides thereon, respectively, for controlling the tension and relaxation of the at least three tendons by moving the force sensors on the lead screw slides, to adjust the pose of the catheter, The probe knob motor is connected to the probe and arranged on the lead screw slide of the probe propulsion lead screw motor group, for controlling the rotational movement of the probe, The probe propulsion lead screw motor group is connected to the probe knob motor through the lead screw slide thereon, for controlling the forward or backward movement of the probe, and The catheter propulsion motor is used to control the corresponding forward or backward movement of the movable platform by the bottom lead screw located below the movable platform, to further control the forward or backward movement of the catheter.

2. The backend driving device according to claim 1, wherein: The probe propulsion lead screw motor group is arranged at the center of the movable platform, and the at least three tendon tension lead screw motor groups are arranged distributed on both sides of the probe propulsion lead screw motor group.

3. The rear end drive device according to claim 1, wherein Further comprising: A plurality of encoders are respectively arranged on the tendon tension lead screw motor groups, the probe propulsion lead screw motor group, the catheter propulsion motor and the probe knob motor, for recording the actual displacement of the tendon tension lead screw motor groups, the probe propulsion lead screw motor group and the catheter propulsion motor and the actual rotation angle of the probe knob motor and generating feedback signals.

4. The backend driving device according to claim 1, wherein: The force sensor comprises an upper end through hole, a lower end through hole, an intermediate groove and a strain gauge arranged around the intermediate groove, the upper end through hole is used to connect the proximal end of the at least three tendons, the lower end through hole is used to connect the tendon tension lead screw motor group through the lead screw slide of the tendon tension lead screw motor group, and the strain gauge is used to sense the deformation of the intermediate groove to calculate the tension of the connected tendon.

5. The backend driving device according to claim 1, wherein: The backend driving device further comprises an external magnetic control platform, the external magnetic control platform comprises at least three pairs of electromagnetic coils, each pair of electromagnetic coils in the at least three pairs of electromagnetic coils is oppositely arranged in any dimension in three-dimensional space, for applying an electromagnetic field to the probe tip coated with a magnetic skin of the probe to control and adjust the pose of the probe tip.

6. A control system for a continuum robot, characterized in that The continuum robot comprises a catheter and a probe located in the catheter, and the continuum robot is driven by a rear-end driving device, wherein the rear-end driving device comprises a movable platform and a catheter propulsion motor, the movable platform is provided with at least three tendons, at least three force sensors, at least three tendon tensioning screw motor groups, a probe knob motor and a probe propulsion screw motor group; and wherein the control system comprises: an input module for receiving input information, the input information at least comprising a quantity representing an initial displacement of the catheter, a quantity representing a tendon extension and contraction in the catheter, and a quantity representing an initial displacement of the probe, a feedback module for receiving feedback signals returned from the catheter and the probe respectively, the feedback signals at least comprising a tendon end tension signal, a probe front end image signal and a probe front end optical signal, a control module for determining a displacement control quantity of each of the catheter and the probe according to at least the input information, the feedback signals and target positions of the catheter and the probe, so as to control the forward or backward movement of the catheter, the forward, backward or rotating movement of the probe and the pose of the catheter and the probe through the rear-end driving device.

7. The control system according to claim 6, further comprising: an environmental disturbance collection module for collecting environmental disturbance information and providing it to the control module, wherein the environmental disturbance information comprises self-vibration of the continuum robot, spatial displacement caused by vibration around the biological tissue and friction force received by the continuum robot.

8. The control system of claim 6, wherein, The quantity representing the initial displacement of the catheter comprises a displacement quantity of the movable platform for controlling the movement of the catheter, and the quantity representing the initial displacement of the probe comprises a displacement quantity of the probe propulsion screw motor group for controlling the movement of the probe.

9. A continuum robotic system, comprising: The continuum robot system comprises a continuum robot and a rear-end driving device according to any one of claims 1-5, the continuum robot comprising a catheter and a probe located in the catheter, and the rear-end driving device is used to drive the front-end continuum robot.

10. The continuum robot system of claim 9, wherein, The continuum robot system further comprises a control system for the continuum robot according to any one of claims 6-8, and the movement and pose of the continuum robot are controlled by using the control system.

11. A control method for a continuum robot, characterized by, The continuum robot comprises a catheter and a probe located in the catheter, and the continuum robot is driven by a rear-end driving device, wherein the rear-end driving device comprises a movable platform and a catheter propulsion motor, the movable platform is provided with at least three tendons, at least three force sensors, at least three tendon tensioning screw motor groups, a probe knob motor and a probe propulsion screw motor group; and wherein the control method comprises: receiving input information, the input information at least comprising a quantity representing an initial displacement of the catheter, a quantity representing a tendon extension and contraction in the catheter, and a quantity representing an initial displacement of the probe, receiving feedback signals returned from the catheter and the probe respectively, the feedback signals at least comprising a tendon end tension signal, a probe front end image signal and a probe front end optical signal, At least according to the input information, the feedback signal and the target position of the catheter and the probe, the displacement control amount of each of the catheter and the probe is determined to control the advancing or retreating movement of the catheter, the advancing, retreating or rotating movement of the probe and the pose of the catheter and the probe by the rear-end driving device.

12. The control method of claim 11, further comprising: collecting and providing environmental interference information to the control module, wherein the environmental interference information includes self-vibration of the continuum robot, spatial displacement caused by vibration around biological tissue and friction force received by the continuum robot.

13. The control method of claim 11 or 12, wherein, controlling the pose of the catheter includes using an antagonistic tendon driving strategy to control the pose of the catheter by controlling the extension and contraction of the tendons of the catheter, when one side of the tendons is pulled tight and the opposite side of the tendons is relaxed, the catheter will bend to the side where the tendons are pulled tight.

14. The control method of claim 11 or 12, wherein, controlling the pose of the probe includes using a magnetic bending strategy to drive the probe tip coated with a magnetic skin of the probe by an external magnetic control platform to achieve non-contact pose control of the probe.

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