Operation force detection method of interventional robot

Abstract

The invention provides an operating force detection method of an interventional robot, and belongs to the technical field of interventional robots, the operating force detection method comprises the following steps: connecting a clamping mechanism for clamping a guide wire and a shell by using a plurality of elastic units, and arranging a sensor between the shell and the clamping mechanism. When the guide wire is subjected to external acting force, the external acting force is transmitted to the elastic units and the sensor through the clamping mechanism. The rigidity of the elastic element is lower than that of the sensor, so that the total attenuation value of the acting force can be reduced, and the detection error is obviously reduced. And calculating a first position offset of the elastic unit by using a first acting force detected by the sensor, and constructing a mechanical model for representing a relationship between the position offset of the elastic unit and the acting force. Calculating by utilizing the first position offset and a mechanical model to obtain a second acting force of the elastic unit on the clamping mechanism; finally, according to the number of the elastic units, the first acting force and the second acting force, initial acting force borne by the guide wire in the first direction is calculated.

Description

Technical Field

[0001] The present invention generally relates to the technical field of interventional robots, and in particular to an operation force detection method of an interventional robot. Background Art

[0002] The existing vascular intervention robot includes a master device and a slave device. The master device detects the doctor's hand grip, as well as the torque, rotation angle, thrust and pushing distance during the pushing and twisting movements, and converts them into electrical signals. The electrical signals are transmitted to the mechanical arm and manipulator of the slave device, and the mechanical arm and manipulator are controlled to simulate the doctor's operating movements, thereby replacing the doctor to perform actual surgical operations. This operation method can detect the doctor's pushing and twisting movements during the operation and transmit them to the slave control device of the intervention robot.

[0003] During the actual surgical process, it is necessary to detect the axial force of the guide wire at the master-end device and the slave-end device respectively to ensure that the master-end device detects the force provided by the doctor more accurately, so that the slave-end device can accurately control the strength of the guide wire; at the same time, when the slave-end device inserts the guide wire into the tissue, the resistance generated can be promptly fed back to the master-end device.

[0004] The existing master-end device and slave-end device detect the axial force of the guidewire by measuring the force only through the sensor. The force is transmitted from the guidewire to the clamping mechanism and finally to the sensor to complete the detection. Among them, the sensor is affected by its own large rigidity, which causes the force to be attenuated to a significant extent, which ultimately makes it difficult for the sensitivity and detection accuracy of the existing sensor to meet the requirements. Summary of the invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide an operation force detection method for an interventional robot.

[0006] The present invention provides an operation force detection method for an interventional robot, the interventional robot comprising: A master device and a slave device; the master device and / or the slave device comprises: A housing and a clamping mechanism for clamping a guide wire; the guide wire extends along a first direction; the clamping mechanism is arranged in the housing, and a plurality of elastic units with deformation capability are installed between the clamping mechanism and the housing; the extension direction of the elastic unit is perpendicular to the first direction; When the guide wire is subjected to an external force along the first direction, the clamping mechanism is driven to shift position along the first direction, so that both ends of the elastic unit are shifted position along the first direction, and the middle part of the elastic unit is deformed; A sensor is also installed in the housing; the sensor abuts against the clamping mechanism along the first direction, and is used to detect the force between the clamping mechanism and the housing along the first direction; Methods include: S1: constructing a force model of the guidewire along the first direction; the force model includes an initial force to be calculated on the guidewire along the first direction, the number of the elastic units, a first force generated by the abutment between the sensor and the clamping mechanism to be detected, and a second force generated by the deformation of one elastic unit on the clamping mechanism to be calculated; S2: using the sensor to detect the first force and obtain a specific value of the first force; S3: calculating a first position offset of the guide wire and the clamping mechanism along the first direction according to the first force; S4: constructing a mechanical model of the elastic unit; the mechanical model is used to represent the relationship between the force exerted by one of the elastic units on the clamping mechanism and the positional displacement when the two ends of one of the elastic units are displaced along the first direction; S5: Calculate, based on the first position offset and the mechanical model, the magnitude of the force exerted by one of the elastic units on the clamping mechanism when both ends of one of the elastic units generate the first position offset along the first direction, to obtain a specific value of the second force; S6: Substitute the second force and the first force into the force model to calculate and obtain the initial force.

[0007] According to the technical solution provided by the present invention, the force model is shown in Formula 1: Formula 1; in, F a represents the initial force, F 1 represents the first force, F 2 represents the second force, n Indicates the number of the elastic units.

[0008] According to the technical solution provided by the present invention, calculating the first position offset of the guide wire and the clamping mechanism along the first direction according to the first force includes: S3-1: Obtaining the axial stiffness of the sensor along the first direction; S3-2: Calculate the first position offset according to the axial stiffness and the first force.

[0009] According to the technical solution provided by the present invention, a mechanical model of the elastic unit is constructed, including: S4-1: Construct a deformation coordination equation group of the elastic unit; the deformation coordination equation group is used to represent the load when the elastic unit is deformed in various directions; the deformation coordination equation group contains unknown load displacement parameters and generalized displacement parameters; the load displacement parameters include the displacements generated by the elastic unit in various directions when it is subjected to various loads; the generalized displacement parameters include the generalized displacements corresponding to the loads in various directions; S4-2: Obtain specific values ​​of the load displacement parameter and the generalized displacement parameter; S4-3: Calculating the load parameters of the elastic unit according to the load displacement parameters, the generalized displacement parameters and the deformation coordination equations; the load parameters include the loads borne by the elastic unit in various directions; S4-4: Obtaining a force balance equation of the elastic unit; S4-5: Calculate the mechanical model according to the load parameters and the force balance equation.

[0010] According to the technical solution provided by the present invention, the deformation coordination equation group of the elastic unit is constructed, including: S4-1-1: define the deformation parameters of the elastic unit; the deformation parameters include: first position offset parameters of the two ends of the elastic unit along the first direction, second position offset parameters of the two ends of the elastic unit perpendicular to the first direction, and deflection angles of the ends connected to the shell and the ends connected to the clamping mechanism when the elastic unit is deformed; S4-1-2: Obtaining an initial deformation coordination equation group; the initial deformation coordination equation group includes the deformation parameters; S4-1-3: Set the second position offset parameter and the deflection angle in the initial deformation coordination equation group to zero respectively, to obtain the deformation coordination equation group.

[0011] According to the technical solution provided by the present invention, the deformation coordination equation group is shown in Formula 2: Formula 2: in, It represents the deflection angle caused by the deformation of the connection end between the elastic unit and the shell. It indicates the deflection angle caused by the deformation of the connection end between the elastic unit and the clamping mechanism. represents the second position offset parameter, to Both represent load displacement parameters, to All represent load parameters, to Both represent generalized displacement parameters.

[0012] According to the technical solution provided by the present invention, the force balance equation is shown in Formula 3: Formula 3; in, represents the resultant force on the elastic unit along its own extension direction, represents the resultant force on the elastic unit along the first direction, It represents the resultant force on the end where the elastic unit is connected to the shell; represents the force on the elastic unit along its own extension direction, represents the force of the elastic unit along the first direction, represents the second force, to All represent load parameters, l Represents the length of the elastic unit in its natural state.

[0013] According to the technical solution provided by the present invention, the mechanical model is shown in Formula 4: Formula 4; in, F 2 represents the second force, Indicates the first position offset; E represents the Young's modulus of the elastic element, I Represents the moment of inertia.

[0014] The beneficial effects of the present invention are: The present invention utilizes a plurality of elastic units to connect a clamping mechanism and a housing for clamping a guide wire, and a sensor is arranged between the housing and the clamping mechanism. When the guide wire is subjected to an external force, it is transmitted to the plurality of elastic units and the sensor respectively through the clamping mechanism. Since the stiffness of the elastic element is much smaller than the stiffness of the sensor, the attenuation ratio of the force at the elastic element is relatively small; and since the sensor is no longer abutted against the clamping mechanism alone, the force actually received by the sensor at this time will also be smaller than the force when the sensor and the clamping mechanism are abutted alone, so the force attenuation value caused by the excessive stiffness of the sensor will also become smaller. Based on the above two aspects, the total attenuation value of the force will be significantly reduced, so that the detection error will be significantly reduced.

[0015] Then, the first position offset of the elastic unit is calculated using the first force detected by the sensor, and a mechanical model for representing the relationship between the position offset of the elastic unit and the force is constructed. The second force of the elastic unit on the clamping mechanism is calculated using the first position offset and the mechanical model; finally, the initial force on the guide wire along the first direction is calculated based on the number of elastic units, the first force and the second force; thus, the specific value of the initial force is obtained through more accurate calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 A partial structural diagram of a master device and / or a slave device of an interventional robot; Figure 2 It is a schematic diagram of the structure when the elastic unit does not produce deformation; Figure 3 It is a schematic diagram of the structure when the elastic unit is deformed; Figure 4 for Figure 3 A partial enlarged view of the middle A; Figure 5 is the structural diagram of the elastic unit; Figure 6 is a flow chart of the detection method; Wherein: 1. Shell; 2. Guide wire; 3. Clamping mechanism; 4. Elastic unit; 5. Sensor. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0019] Please refer to Figure 1 The present invention provides an operation force detection method for an interventional robot, the interventional robot comprising: A master device and a slave device; the master device and / or the slave device comprises: A housing 1 and a clamping mechanism 3 for clamping a guide wire 2; the guide wire 2 extends along a first direction; the clamping mechanism 3 is arranged in the housing 1, and a plurality of elastic units 4 with deformation capability are installed between the clamping mechanism 3 and the housing 1; the extension direction of the elastic unit 4 is perpendicular to the first direction; In this embodiment, there are four elastic units 4, which are respectively connected to four parts of the clamping mechanism 3 and are symmetrically arranged with the guide wire 2 as the symmetry axis, so as to ensure the force balance of the clamping mechanism 3 on both sides of the guide wire 2, and avoid the clamping mechanism 3 from deflecting in direction due to uneven force, causing the guide wire 2 to twist.

[0020] When the guide wire 2 is subjected to an external force along the first direction, the clamping mechanism 3 is driven to shift position along the first direction, so that both ends of the elastic unit 4 are shifted position along the first direction, and the middle part of the elastic unit 4 is deformed; A sensor 5 is also installed in the housing 1 ; the sensor 5 abuts against the clamping mechanism 3 along the first direction, and is used to detect the force between the clamping mechanism 3 and the housing 1 along the first direction.

[0021] It should be noted that, since the clamping mechanism 3 fixes and clamps the guide wire 2, in this embodiment, it is assumed that the guide wire 2 and the clamping mechanism 3 are subjected to forces of equal magnitude and in the same direction.

[0022] Working process: refer to Figure 2-3 When the guide wire 2 is subjected to an external force, the guide wire 2 itself and the clamping mechanism 3 are offset relative to the housing 1 along a first direction; At this time, the plurality of elastic units 4 are acted upon by the clamping mechanism 3 . Since the force is mutual, the clamping mechanism 3 is also acted upon by the elastic units 4 with equal magnitude and opposite direction.

[0023] refer to Figure 4 , the middle part of the elastic unit 4 is bent, and a position offset occurs along the first direction between the end connected to the housing 1 and the end connected to the clamping mechanism 3. The tangent directions of the two ends of the elastic unit 4 are still perpendicular to the first direction.

[0024] The sensor is also subjected to the force of the clamping mechanism 3 at the same time, so the sum of the force applied to the sensor and the force applied to the plurality of elastic units 4 is equal to the magnitude of the external force applied to the guide wire 2 .

[0025] Principle introduction: The present invention utilizes a plurality of elastic units 4 to connect a clamping mechanism 3 for clamping a guide wire 2 and a housing 1 , and a sensor 5 is disposed between the housing 1 and the clamping mechanism 3 .

[0026] When the guide wire 2 is subjected to external force, the force is transmitted to the multiple elastic units 4 and the sensor 5 through the clamping mechanism 3. Since the stiffness of the elastic element 4 is much smaller than that of the sensor 5, the attenuation ratio of the force at the elastic element 4 is small.

[0027] Also, because the sensor 5 is no longer in contact with the clamping mechanism 3 alone, the actual force applied to the sensor 5 will be smaller than the force when the sensor 5 is in contact with the clamping mechanism 3 alone. Therefore, the force attenuation value caused by the excessive stiffness of the sensor 5 will also become smaller.

[0028] Based on the above two aspects, the total attenuation value of the force will be significantly reduced, so that the detection error will be significantly reduced.

[0029] Specifically, the configuration and method of the present invention can be applied to the master device or the slave device, or both. The master device can more accurately detect the force provided by the doctor and transmit it to the slave device through an electrical signal, so as to more accurately complete the surgical action; the slave device can more accurately detect the resistance of the guide wire 2 and feed it back to the master device. The doctor can more accurately judge the current surgical situation based on the feedback resistance.

[0030] Based on the above detection method, there is a large difference between the force actually detected by the sensor and the force actually exerted on the guidewire. Therefore, it is necessary to design a corresponding calculation method according to the characteristics of the above detection method.

[0031] refer to Figure 6 , methods include: S1: constructing a force model of the guidewire 2 along the first direction; the force model includes an initial force to be calculated on the guidewire 2 along the first direction, the number of the elastic units 4, a first force generated by the abutment between the sensor 5 and the clamping mechanism 3 to be detected, and a second force generated by the deformation of one elastic unit 4 on the clamping mechanism 3 to be calculated; Furthermore, the force model is shown in Formula 1: Formula 1; in, F a represents the initial force, F 1 represents the first force, F 2 represents the second force, n Indicates the number of the elastic units 4.

[0032] When the structural design of the present invention is installed on the main end device, the initial force represents the driving force exerted on the guide wire 2 at the main end device by the doctor.

[0033] When the structural design of the present invention is installed on a slave device, the initial force represents the resistance from the tissue encountered by the guide wire 2 at the slave device.

[0034] In this embodiment, four elastic units 4 are installed, so when calculating n Substitute 4. The elastic unit 4 uses an elastic reed. Since the elastic unit 4 will be stretched laterally during use, the total length after stretching will be greater than the length of the elastic unit 4 in its natural state.

[0035] Therefore, reference Figure 5 The elastic unit 4 has a bending structure in the middle, which is used to deform when subjected to lateral stretching to extend the total length of the elastic unit 4.

[0036] S2: Using the sensor 5 to detect the first force, and obtaining a specific value of the first force; In this embodiment, the sensor 5 is a pressure sensor.

[0037] S3: calculating a first position offset of the guide wire 2 and the clamping mechanism 3 along the first direction according to the first force; The specific steps include: S3-1: Obtaining the axial stiffness of the sensor 5 along the first direction; S3-2: Calculate the first position offset according to the axial stiffness and the first force.

[0038] Specifically, the axial stiffness can be calculated by formula 5: Formula 5; in, k represents the axial stiffness, A represents the cross-sectional area of ​​the object, E represents Young's modulus, L Indicates the length of an object.

[0039] Specifically, the first position offset can be calculated by formula 6: Formula 6; in, Indicates the first position offset.

[0040] S4: constructing a mechanical model of the elastic unit 4; the mechanical model is used to represent the relationship between the force exerted by one of the elastic units 4 on the clamping mechanism 3 and the positional displacement when the two ends of one of the elastic units 4 are displaced along the first direction; Furthermore, the step of constructing the mechanical model of the elastic unit 4 includes: S4-1: constructing a deformation coordination equation group of the elastic unit 4; The deformation coordination equation group is used to represent the load when the elastic unit 4 is deformed in various directions; the deformation coordination equation group contains unknown load displacement parameters and generalized displacement parameters; Among them, the load displacement parameters include δ 11 To δ 33 ; δ 11 , δ 12 , δ 13 They represent the displacement along the X1 direction when X1, X2, and X3 act as unit displacements separately; δ 21 , δ 22 , δ 23 They represent the displacement along the X2 direction when X1, X2, and X3 act as unit displacements separately; δ 31 , δ 32 , δ 33 They represent the displacement along the X3 direction when X1, X2, and X3 act as unit displacements separately; The calculation method for X1 and X2 is: the deflection in this direction is longer than the rod, and there is no displacement in the X3 direction, so it is 0.

[0041] Among them, the generalized displacement parameters include Δ 1c To Δ 3c , respectively: The rotation angle of elastic unit 4 in the X1 direction under unit displacement; The rotation angle of the elastic unit 4 in the X2 direction under the unit displacement; Displacement of elastic unit 4 in the X3 direction under unit displacement; The load displacement parameter includes the displacements of the elastic unit 4 in various directions when it is subjected to various loads; the generalized displacement parameter includes the generalized displacements corresponding to the loads in various directions; Furthermore, the step of constructing the deformation coordination equation group of the elastic unit 4 includes: S4-1-1: defining deformation parameters of the elastic unit 4; The deformation parameters include: first position offset parameters of the two ends of the elastic unit 4 along the first direction, second position offset parameters of the two ends of the elastic unit 4 perpendicular to the first direction, and deflection angles of the ends of the elastic unit 4 connected to the housing 1 and the ends connected to the clamping mechanism 3 when the elastic unit 4 is deformed; The deflection angle includes the deflection angle caused by deformation of the connection end between the elastic unit 4 and the housing 1 , and the deflection angle caused by deformation of the connection end between the elastic unit 4 and the clamping mechanism 3 .

[0042] S4-1-2: Obtaining an initial deformation coordination equation group; the initial deformation coordination equation group includes the deformation parameters; Among them, the initial deformation coordination equations represent the general formula for an elastic object to produce various types of deformations in various directions.

[0043] S4-1-3: Set the second position offset parameter and the deflection angle in the initial deformation coordination equation group to zero respectively, to obtain the deformation coordination equation group.

[0044] Based on the structural design provided by the present invention, the four elastic elements 4 are symmetrically arranged with the guide wire 2 as the symmetry axis, so they will not be offset in the position perpendicular to the first direction, that is, the second position offset parameter is equal to 0. Moreover, according to the description of the working process above: the tangent directions of the two ends of the elastic unit 4 are still perpendicular to the first direction; the deflection angles of the two ends of the elastic unit 4 are also 0 respectively.

[0045] Thus, the deformation coordination equations are obtained, as shown in Formula 2: Formula 2: in, represents the deflection angle caused by deformation of the connection end of the elastic unit 4 and the housing 1, represents the deflection angle caused by deformation of the connection end between the elastic unit 4 and the clamping mechanism 3, represents the second position offset parameter, to Both represent load displacement parameters, to All represent load parameters, to Both represent generalized displacement parameters.

[0046] In Formula 2, the first equation indicates that the deflection angle generated by the deformation of the end portion of the elastic unit 4 connected to the housing 1 under the action of loads in all directions is equal to 0; The second equation indicates that the deflection angle generated by the deformation of the end portion of the elastic unit 4 connected to the clamping mechanism 3 under the action of loads in all directions is equal to 0; The third equation indicates that the position offset of the elastic unit 4 along the direction perpendicular to the first direction is 0 under the action of loads in various directions.

[0047] S4-2: Obtain specific values ​​of the load displacement parameter and the generalized displacement parameter; Specifically, the load displacement parameter is calculated using a graph multiplication method; the graph multiplication method is a prior art, and the specific principle will not be described in detail.

[0048] In this embodiment, the specific expression of the load displacement parameter is referred to Formula 7; The specific value of the generalized displacement parameter refers to Formula 8; Formula 7; Formula 8; in, E represents the Young's modulus of elastic element 4, I represents the moment of inertia, l It represents the length of the elastic unit 4 in the natural state.

[0049] S4-3: Calculate the load parameters of the elastic unit 4 according to the load displacement parameters, the generalized displacement parameters and the deformation coordination equations; the load parameters include the loads borne by the elastic unit 4 in various directions; Specifically, the specific expression of the load parameter refers to Formula 9; Formula nine.

[0050] S4-4: Obtaining a force balance equation of the elastic unit 4; Furthermore, the force balance equation is shown in Formula 3: Formula 3; in, represents the resultant force on the elastic unit 4 along its own extension direction, represents the resultant force on the elastic unit 4 along the first direction, represents the resultant force on the end portion where the elastic unit 4 is connected to the housing 1; represents the force on the elastic unit 4 along its own extension direction, represents the force of the elastic unit 4 along the first direction, represents the second force, to All represent load parameters, l Represents the length S4-5 of the elastic unit 4 in the natural state: the mechanical model is calculated according to the load parameter and the force balance equation.

[0051] Furthermore, the mechanical model is shown in Formula 4: Formula 4; in, F 2 represents the second force, Indicates the first position offset.

[0052] S5: Calculate the first position offset generated by the two ends of the elastic unit 4 along the first direction according to the first position offset and the mechanical model. When the elastic unit 4 exerts a force on the clamping mechanism 3, the second force is obtained. F The specific value of 2; S6: Substitute the second force and the first force into the force model to calculate the initial force F a .

[0053] The present invention uses the first force detected by the sensor to calculate the first position offset of the elastic unit, and constructs a mechanical model for representing the relationship between the position offset of the elastic unit and the force. The second force of the elastic unit on the clamping mechanism is calculated using the first position offset and the mechanical model; finally, the initial force on the guide wire along the first direction is calculated based on the number of elastic units, the first force and the second force; thus, the specific value of the initial force is obtained through more accurate calculation.

[0054] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) to form a technical solution.

Claims

1. A method for detecting the operating force of an interventional robot, characterized in that: Interventional robots include: A master device and a slave device; the master device and / or the slave device comprises: A housing (1) and a clamping mechanism (3) for clamping a guide wire (2); the guide wire (2) extends along a first direction; the clamping mechanism (3) is arranged in the housing (1), and a plurality of elastic units (4) with deformation capability are installed between the clamping mechanism (3) and the housing (1); the extension direction of the elastic unit (4) is perpendicular to the first direction; When the guide wire (2) is subjected to an external force in the first direction, the clamping mechanism (3) is driven to shift position in the first direction, causing both ends of the elastic unit (4) to shift position in the first direction and causing the middle of the elastic unit (4) to deform; A sensor (5) is also installed in the housing (1); the sensor (5) abuts against the clamping mechanism (3) along the first direction, and is used to detect the force acting between the clamping mechanism (3) and the housing (1) along the first direction; Methods include: S1: constructing a force model of the guide wire (2) along the first direction; the force model includes an initial force to be calculated on the guide wire (2) along the first direction, the number of the elastic units (4), a first force to be detected generated by the abutment between the sensor (5) and the clamping mechanism (3), and a second force to be calculated generated by the deformation of one of the elastic units (4) on the clamping mechanism (3); S2: using the sensor (5) to detect the first acting force and obtain a specific value of the first acting force; S3: calculating, according to the first acting force, a first position offset of the guide wire (2) and the clamping mechanism (3) along the first direction; S4: constructing a mechanical model of the elastic unit (4); the mechanical model is used to represent the relationship between the force exerted by the elastic unit (4) on the clamping mechanism (3) and the positional displacement when the two ends of the elastic unit (4) are displaced along the first direction; S5: Calculating, based on the first position offset and the mechanical model, the magnitude of the force exerted by one of the elastic units (4) on the clamping mechanism (3) when the two ends of one of the elastic units (4) generate the first position offset along the first direction, and obtaining a specific value of the second force; S6: Substitute the second force and the first force into the force model to calculate the initial force.

2. The method for detecting the operating force of an interventional robot according to claim 1, characterized in that: The force model is shown in Formula 1: Formula 1; in, F a represents the initial force, F 1 represents the first force, F 2 represents the second force, n Indicates the number of the elastic units (4).

3. The method for detecting the operating force of an interventional robot according to claim 1, characterized in that: Calculating a first position offset of the guide wire (2) and the clamping mechanism (3) along the first direction according to the first acting force comprises: S3-1: Obtaining the axial stiffness of the sensor (5) along the first direction; S3-2: Calculate the first position offset according to the axial stiffness and the first force.

4. The method for detecting the operating force of an interventional robot according to claim 1, characterized in that: Constructing a mechanical model of the elastic unit (4) includes: S4-1: constructing a deformation coordination equation group of the elastic unit (4); the deformation coordination equation group is used to represent the load when the elastic unit (4) is deformed in various directions; the deformation coordination equation group contains unknown load displacement parameters and generalized displacement parameters; the load displacement parameters include the displacements generated in various directions when the elastic unit (4) is subjected to various loads; the generalized displacement parameters include the generalized displacements corresponding to the loads in various directions; S4-2: Obtain specific values ​​of the load displacement parameter and the generalized displacement parameter; S4-3: Calculating the load parameters of the elastic unit (4) according to the load displacement parameter, the generalized displacement parameter and the deformation coordination equation group; the load parameters include the loads borne by the elastic unit (4) in various directions; S4-4: Obtaining a force balance equation of the elastic unit (4); S4-5: Calculate the mechanical model according to the load parameters and the force balance equation.

5. The method for detecting the operating force of an interventional robot according to claim 4, characterized in that: The deformation coordination equations of the elastic unit (4) are constructed, including: S4-1-1: defining deformation parameters of the elastic unit (4); the deformation parameters include: first position offset parameters of the two ends of the elastic unit (4) along the first direction, second position offset parameters of the two ends of the elastic unit (4) perpendicular to the first direction, and deflection angles of the ends of the elastic unit (4) connected to the housing (1) and the ends connected to the clamping mechanism (3) when the elastic unit (4) is deformed; S4-1-2: Obtaining an initial deformation coordination equation group; the initial deformation coordination equation group includes the deformation parameters; S4-1-3: Set the second position offset parameter and the deflection angle in the initial deformation coordination equation group to zero respectively, to obtain the deformation coordination equation group.

6. The method for detecting the operating force of an interventional robot according to claim 5, characterized in that: The deformation coordination equations are shown in Formula 2: Formula 2: in, represents the deflection angle caused by deformation of the connection end of the elastic unit (4) and the housing (1), represents the deflection angle caused by deformation of the connection end of the elastic unit (4) and the clamping mechanism (3), represents the second position offset parameter, to Both represent load displacement parameters, to All represent load parameters, to Both represent generalized displacement parameters.

7. The method for detecting the operating force of an interventional robot according to claim 4, characterized in that: The force balance equation is shown in Formula 3: Formula 3; in, represents the resultant force on the elastic unit (4) along its own extension direction, represents the resultant force on the elastic unit (4) along the first direction, represents the resultant force acting on the end portion where the elastic unit (4) is connected to the housing (1); represents the force on the elastic unit (4) along its own extension direction, represents the force on the elastic unit (4) along the first direction, represents the second force, to All represent load parameters, l represents the length of the elastic unit (4) in its natural state.

8. The method for detecting the operating force of an interventional robot according to claim 7, characterized in that: The mechanical model is shown in Formula 4: Formula 4; in, F 2 represents the second force, Indicates the first position offset; E represents the Young's modulus of the elastic element (4), I Represents the moment of inertia.

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