FBG miniature beam type three-dimensional force sensor

Abstract

The invention discloses an FBG (Fiber Bragg Grating) miniature beam type three-dimensional force sensor, relates to the technical field of instrument sensing equipment for robot-assisted minimally invasive surgery, and solves the problem that the existing instrument sensing equipment for robot-assisted minimally invasive surgery has defects. Lines and parts used for connecting the surgical instrument and the surgical instrument are located in the body, the optical fibers are bonded to the inner wall of the body through adhesives, one end of each optical fiber is connected with the inner wall of the upper notch, the other end of each optical fiber is connected with the surgical instrument, the structure is compact, and the device can be integrated at the tail end of the minimally invasive surgical instrument; when the upper notch and the lower notch have relative acting force, the FBG gate regions of the optical fibers bonded with the pressure beam region and the shear beam region are caused to deform, the two FBG gate regions generate corresponding central wavelength shift according to the current strain, the corresponding variable quantity can be read by using an FBG demodulator, and then the magnitude of the borne external force is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of instrument sensing equipment for robot-assisted minimally invasive surgery, and in particular to an FBG micro-beam type three-dimensional force sensor. Background Art

[0002] In robot-assisted minimally invasive surgery, the perception and feedback of the robot system on the intraoperative operating force plays an important role in the physician's judgment and control of the surgical operation. At the same time, considering that the sensor should be as close to the measurement area as possible to reduce the system error of the measurement, the position of the sensor should be near the end of the minimally invasive surgical instrument, and researchers have designed many forms of special sensors. According to the different main structures, they can be roughly divided into: straight beam type and spiral beam type. The spiral structure has high sensitivity and is generally used in delicate operations such as ophthalmic surgery, and is designed for one-dimensional force measurement; the straight beam structure has high rigidity and a large measurement range. By adjusting the spatial layout of multiple beams, three-dimensional / six-dimensional force measurement can be obtained, which can be used in minimally invasive surgery in the abdominal cavity, oral cavity and other areas. However, the existing robot-assisted minimally invasive surgery instrument sensor equipment has a complex structure, large volume and mass, and is difficult to integrate at the end of the minimally invasive surgical instrument. At the same time, in order to achieve precise detection, it is mostly made of metal materials, which will produce electromagnetic effects during some surgical processes. Summary of the invention

[0003] In view of the above-mentioned problems of the drawbacks of the existing robot-assisted minimally invasive surgery instrument sensing devices, the object of the present invention is to provide a FBG micro-beam three-dimensional force sensor.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A FBG micro beam type three-dimensional force sensor, comprising: a body 1, the body 1 is a cylindrical structure, and the two ends of the body 1 are respectively provided with an upper notch 12 and a lower notch 17, the upper notch 12 is used to connect with a surgical instrument, the lower notch 17 is used to connect with a surgical instrument, and the lines and components for connecting the surgical instrument and the surgical instrument are located in the body 1; the body 1 comprises: an upper half, a lower half, at least one middle part and at least two force sensing areas; the force sensing area is a shear beam area or a pressure beam area; any two adjacent force sensing areas are connected through an middle part, the force sensing area at the uppermost end is connected to the upper half, and the force sensing area at the lowermost end is connected to the lower half; the upper notch 12 is located in the upper half, and the lower notch 17 is located in the lower half;

[0006] The body 1 is provided with at least one shear beam area and at least one pressure beam area;

[0007] It also includes: optical fiber 2, multiple optical fibers 2 are parallel to the axis of the main body 1, multiple optical fibers 2 are connected to the inner wall of the main body 1, one end of each optical fiber 2 is connected to the inner wall of the upper groove 12, and the other end of each optical fiber 2 is connected to the surgical instrument.

[0008] The above-mentioned FBG micro beam type three-dimensional force sensor, wherein the shear beam area includes: a short pressure beam 13 and a shear beam 14, the shear beam 14 is annular, any two adjacent shear beams 14 are connected by at least two short pressure beams 13, and a plurality of short pressure beams 13 are arranged at equal intervals around the axis of the body 1;

[0009] The shear beam 14 at the uppermost end and the upper half / a middle portion are connected by at least two short pressure beams 13, and the plurality of short pressure beams 13 are arranged at equal intervals around the axis of the body 1;

[0010] The shear beam 14 at the lowermost end and the lower half / another middle part are connected by at least two short pressure beams 13 , and the plurality of short pressure beams 13 are arranged at equal intervals around the axis of the body 1 .

[0011] The above-mentioned FBG micro-beam type three-dimensional force sensor, wherein the pressure beam area includes: a long pressure beam 15, a plurality of long pressure beams 15 are arranged at equal intervals around the axis of the main body 1, one end of each long pressure beam 15 is connected to the upper half or a middle part, and the other end of each long pressure beam 15 is connected to the lower half or another middle part.

[0012] The above-mentioned FBG micro beam type three-dimensional force sensor, wherein the number of short pressure beams 13 between any two adjacent shear beams 14, the number of short pressure beams 13 between the uppermost shear beam 14 and the upper half / one middle part, and the number of short pressure beams 13 between the lowermost shear beam 14 and the lower half / another middle part are the same;

[0013] Any short pressure beam 13 on the upper side of each shear beam 14 is arranged in the middle of the two adjacent short pressure beams 13 on the lower side thereof, and the multiple short pressure beams 13 connected above another adjacent shear beam 14 located on the upper side of the shear beam 14 are in the same position as the multiple short pressure beams 13 connected below the shear beam 14.

[0014] In the above-mentioned FBG micro beam type three-dimensional force sensor, the length and width of the multiple short pressure beams 13 in each shear beam area are the same, and the width of the multiple shear beams 14 in each shear beam area is the same.

[0015] In the above-mentioned FBG micro beam type three-dimensional force sensor, the length and width of the multiple long pressure beams 15 in each pressure beam area are the same.

[0016] In the above-mentioned FBG micro beam type three-dimensional force sensor, the multiple short pressure beams 13 in each shear beam area are parallel to the axis of the body 1.

[0017] In the above-mentioned FBG micro beam type three-dimensional force sensor, each optical fiber 2 is located in the middle of the inner side of a plurality of short pressure beams 13 spaced apart along the axial direction in any shear beam area and is located in the middle of the inner side of a long pressure beam 15 in any pressure beam area.

[0018] The above-mentioned FBG micro-beam type three-dimensional force sensor, wherein an upper notch 12 with a reduced outer diameter is provided at the upper end of the upper half, and the outer wall of the upper notch 12 is provided with at least one concave first cut angle plane 11; a lower notch 17 with an increased inner diameter is provided at the lower end of the lower half, and the inner wall of the lower notch 17 is provided with at least one convex second cut angle plane 16.

[0019] The above-mentioned FBG micro beam type three-dimensional force sensor further includes: adhesive 3, and each optical fiber 2 is bonded to the inner walls of the upper half, the lower half and multiple middle parts of the body 1 through the adhesive 3.

[0020] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art:

[0021] (1) In the present invention, the two ends of the body are connected to the surgical instrument and the surgical instrument respectively, the circuits and components for connecting the surgical instrument and the surgical instrument are located in the body, and the multiple optical fibers are bonded to the inner wall of the body by adhesive, one end of each optical fiber is connected to the inner wall of the upper groove, and the other end of the optical fiber is connected to the surgical instrument. The structure is compact and can be integrated into the end of the minimally invasive surgical instrument;

[0022] (2) In the present invention, when relative forces appear between the upper notch and the lower notch, the FBG grating area of ​​the optical fiber bonded to the pressure beam area and the shear beam area will be deformed, and the two parts of the FBG grating area will produce corresponding central wavelength shifts according to the current strain. The corresponding change can be read out using an FBG demodulator, thereby obtaining the magnitude of the external force. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a first structural schematic diagram of an FBG micro beam type three-dimensional force sensor of the present invention.

[0024] Figure 2 This is a second structural schematic diagram of an FBG micro beam type three-dimensional force sensor of the present invention.

[0025] Figure 3 It is a third structural schematic diagram of an FBG micro beam type three-dimensional force sensor of the present invention.

[0026] Figure 4It is a front view of an FBG micro beam type three-dimensional force sensor of the present invention.

[0027] Figure 5 yes Figure 4 A cross-sectional view of the FBG micro beam three-dimensional force sensor is shown.

[0028] Figure 6 yes Figure 5 A local enlarged view of the FBG micro-beam three-dimensional force sensor shown.

[0029] Figure 7 It is a side view of an FBG micro beam type three-dimensional force sensor of the present invention.

[0030] Figure 8 It is a top view of an FBG micro beam type three-dimensional force sensor of the present invention.

[0031] Fig. 9 yes Figure 8 A cross-sectional view of the FBG micro beam three-dimensional force sensor is shown.

[0032] In the accompanying drawings: 1, body; 2, optical fiber; 3, adhesive; 11, first cutting angle plane; 12, upper notch; 13, short pressure beam; 14, shear beam; 15, long pressure beam; 16, second cutting angle plane; 17, lower notch. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0034] Please refer to Figures 1 to 9 As shown, a FBG micro beam type three-dimensional force sensor is shown, which includes: a body 1, the body 1 is a cylindrical structure, and the two ends of the body 1 are respectively provided with an upper notch 12 and a lower notch 17, the upper notch 12 is used to connect with the surgical instrument, and the lower notch 17 is used to connect with the surgical instrument, and the lines and components for connecting the surgical instrument and the surgical instrument are located in the body 1; the body 1 includes: an upper half, a lower half, at least one middle part and at least two force sensing areas; the force sensing area is a shear beam area or a pressure beam area; any two adjacent force sensing areas are connected through an middle part, the force sensing area at the uppermost end is connected to the upper half, and the force sensing area at the lowermost end is connected to the lower half; the upper notch 12 is located in the upper half, and the lower notch 17 is located in the lower half;

[0035] The body 1 is provided with at least one shear beam area and at least one pressure beam area;

[0036] It also includes: optical fiber 2, multiple optical fibers 2 are parallel to the axis of the main body 1, multiple optical fibers 2 are connected to the inner wall of the main body 1, one end of each optical fiber 2 is connected to the inner wall of the upper groove 12, and the other end of each optical fiber 2 is connected to the surgical instrument.

[0037] Further, in a preferred embodiment, the shear beam area includes: a short pressure beam 13 and a shear beam 14, the shear beam 14 is annular, any two adjacent shear beams 14 are connected by at least two short pressure beams 13, and a plurality of short pressure beams 13 are arranged at equal intervals around the axis of the body 1;

[0038] The shear beam 14 at the uppermost end and the upper half / a middle portion are connected by at least two short pressure beams 13, and the plurality of short pressure beams 13 are arranged at equal intervals around the axis of the body 1;

[0039] The shear beam 14 at the lowermost end and the lower half / another middle part are connected by at least two short pressure beams 13 , and the plurality of short pressure beams 13 are arranged at equal intervals around the axis of the body 1 .

[0040] Further, in a preferred embodiment, the pressure beam area includes: a long pressure beam 15, a plurality of long pressure beams 15 are arranged at equal intervals around the axis of the main body 1, one end of each long pressure beam 15 is connected to the upper half or a middle part, and the other end of each long pressure beam 15 is connected to the lower half or another middle part.

[0041] Further, in a preferred embodiment, the number of short pressure beams 13 between any two adjacent shear beams 14, the number of short pressure beams 13 between the uppermost shear beam 14 and the upper half / one middle part, and the number of short pressure beams 13 between the lowermost shear beam 14 and the lower half / another middle part are the same;

[0042] Any short pressure beam 13 on the upper side of each shear beam 14 is arranged in the middle of the two adjacent short pressure beams 13 on the lower side thereof, and the multiple short pressure beams 13 connected above another adjacent shear beam 14 located on the upper side of the shear beam 14 are in the same position as the multiple short pressure beams 13 connected below the shear beam 14.

[0043] Furthermore, in a preferred embodiment, the lengths and widths of the multiple short pressure beams 13 in each shear beam area are the same, and the widths of the multiple shear beams 14 in each shear beam area are the same.

[0044] Furthermore, in a preferred embodiment, the length and width of the plurality of long pressure beams 15 in each pressure beam zone are the same.

[0045] Furthermore, in a preferred embodiment, the multiple short pressure beams 13 in each shear beam area are parallel to the axis of the body 1 .

[0046] Furthermore, in a preferred embodiment, each optical fiber 2 is located at the inner middle of a plurality of short pressure beams 13 spaced apart along the axial direction in any shear beam zone and is located at the inner middle of a long pressure beam 15 in any pressure beam zone.

[0047] Furthermore, in a preferred embodiment, an upper notch 12 with a reduced outer diameter is provided at the upper end of the upper half, and the outer wall of the upper notch 12 is provided with at least one concave first cutting angle plane 11; a lower notch 17 with an increased inner diameter is provided at the lower end of the lower half, and the inner wall of the lower notch 17 is provided with at least one convex second cutting angle plane 16.

[0048] Furthermore, in a preferred embodiment, it further comprises: adhesive 3 , and each optical fiber 2 is bonded to the inner walls of the upper half, the lower half and multiple middle parts of the body 1 through the adhesive 3 .

[0049] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation and protection scope of the present invention.

[0050] The present invention also has the following implementation modes based on the above:

[0051] In a further embodiment of the present invention, see Figures 1 to 9 Two force sensing areas are provided on the main body 1, one force sensing area is a shear beam area, and the other force sensing area is a pressure beam area; the shear beam area is connected to the upper part, the pressure beam area is connected to the lower part, and the shear beam area and the pressure beam area are connected through an intermediate part.

[0052] In a further embodiment of the present invention, see Figures 1 to 9 , the number of optical fibers 2 selected is 4; three shear beams 14 are provided in the shear beam area, any two adjacent shear beams 14 are connected by two short pressure beams 13, the shear beam 14 at the top and the upper half are connected by two short pressure beams 13, and the shear beam 14 at the bottom and the middle part are connected by two short pressure beams 13, see Figure 4 , 5 , 8 and 9, the angle between the planes where any two adjacent groups of short pressure beams 13 are located is 90 degrees and both pass through the axis of the main body 1, the planes where the two groups of short pressure beams 13 are spaced apart are the same plane, and each optical fiber 2 is located in the middle of the inner side of the two short pressure beams 13 spaced apart.

[0053] In a further embodiment of the present invention, see Figure 4 , 5 , 8 and 9, the pressure beam area is provided with four long pressure beams 15, and each long pressure beam 15 is located outside an optical fiber 2.

[0054] In a further embodiment of the present invention, see Figure 5 , 6, 7 and 9, one end of each optical fiber 2 is connected to the inner wall of the upper slot 12, and the other end of each optical fiber 2 is connected to the surgical instrument, and multiple optical fibers 2 are bonded to the inner wall of the body 1 by adhesive 3, and the bonding points of each optical fiber 2 are respectively located on the inner wall of the upper slot 12, between the shear beam area and the pressure beam area, and between the pressure beam area and the lower slot 17.

[0055] In a further embodiment of the present invention, the main body 1 produces a slight local deformation when subjected to an external force. The structure of the main body 1 includes an upper slot 12, a lower slot 17 and a force sensing area. A through hole is provided in the central area extending from the upper slot 12 to the lower slot 17 to adjust the stiffness of the force sensing area, and is used to bond the optical fiber 2 and accommodate other components during use.

[0056] In a further embodiment of the present invention, the upper slot 12 and the lower slot 17, the outer cylindrical surface of the upper slot 12 is provided with a first angled plane 11 as a positioning reference, and the inner cylindrical surface of the lower slot 17 is provided with a second angled plane 16 as a positioning reference. During use, this part of the structure has little deformation and can be approximated as a rigid body, thereby avoiding relative rotation between the main body 1 and surgical instruments and surgical tools to affect the detection data.

[0057] In a further embodiment of the present invention, the force sensing area is provided with a pressure beam area and a shear beam area, and the pressure beam area responds to both axial load and lateral load but is smaller than the shear beam area. Figures 1 to 9 As shown, four optical fibers 2 are selected, four long pressure beams 15 of equal length and cross-section are distributed at intervals of 90 degrees, the axis of the shear beam 14 located at any cross-section is annular, the shear beam 14 located at the uppermost end and the upper half of the body 1, between two adjacent shear beams 14, and between the shear beam 14 located at the lowermost end and the lower half of the body 1 are all connected by two short pressure beams 13 spaced 180 degrees apart, and the angle between the planes where two adjacent groups of short pressure beams 13 are located is 90 degrees and both pass through the axis of the force sensing area.

[0058] In a further embodiment of the present invention, the optical fiber 2 has two FBG grating regions with different central wavelengths, and their lengths correspond to the lengths of the pressure beam region and the shear beam region, respectively. The four optical fibers 2 are bonded to the inner surface of the body 1 using an adhesive 3, and the two FBG grating regions should correspond to the pressure beam region and the shear beam region in the axial direction and the circumferential direction, respectively, and the adhesive should be evenly coated.

[0059] In a further embodiment of the present invention, the bonding points of each optical fiber 2 are respectively located on the inner wall of the upper slot 12, between the shear beam area and the pressure beam area, and between the pressure beam area and the lower slot 17. The portion from the bonding point of the optical fiber 2 located on the inner wall of the upper slot 12 to its bonding point located between the shear beam area and the pressure beam area is a section of the FBG grating area corresponding to the length of the pressure beam area. The portion from the bonding point of the optical fiber 2 located between the shear beam area and the pressure beam area to its bonding point located between the pressure beam area and the lower slot 17 is another section of the FBG grating area corresponding to the length of the shear beam area.

[0060] In a further embodiment of the present invention, during the bonding process, care should be taken to maintain the pre-tightening of both ends of the optical fiber 2, and the direction of the optical fiber 2 should be parallel to the axial direction of the body 1 to avoid bonding adjacent shear beams 14 together. After bonding, the excess optical fiber 2 should be removed.

[0061] In a further embodiment of the present invention, since the change of the central wavelength of the FBG grating area is affected by two factors, strain and temperature, in order to avoid the influence of temperature changes on the sensor, the change of the central wavelength of the FBG grating area of ​​the four optical fibers 2 located in the pressure beam area should be the actual reading minus the average value of the four readings, and the change of the central wavelength of the FBG grating area of ​​the four optical fibers 2 located in the shear beam area should be the actual reading minus the average value of the four readings.

[0062] In a further embodiment of the present invention, when relative forces appear between the upper notch 12 and the lower notch 17, the FBG grating area of ​​the optical fiber 2 bonded to the pressure beam area and the shear beam area will be deformed, wherein the two FBG grating areas of the optical fiber 2 produce corresponding central wavelength shifts according to the current strain, and the corresponding changes can be read out using an FBG demodulator to obtain the magnitude of the external force.

[0063] In a further embodiment of the present invention, both ends of the main body 1 are respectively connected to surgical instruments and surgical instruments, the lines and components for connecting the surgical instruments and surgical instruments are located inside the main body 1, and multiple optical fibers 2 are bonded to the inner wall of the main body 1 by adhesive 3, and one end of each optical fiber 2 is connected to the inner wall of the upper groove 12, and one end of each optical fiber 2 is connected to the surgical instrument. The structure is compact and can be integrated at the end of the minimally invasive surgical instrument.

[0064] In a further embodiment of the present invention, the body 1 is made of a non-metallic material that does not generate electromagnetic effects, preferably ABS or photosensitive resin.

[0065] In a further embodiment of the present invention, the specific structures of the outer cylindrical surface of the upper notch 12 and the inner cylindrical surface of the lower notch 17 can be designed according to actual size and structure so as to be suitable for a variety of surgical instruments.

[0066] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A FBG micro beam type three-dimensional force sensor, characterized in that: include: The body (1) is a cylindrical structure, and an upper notch (12) and a lower notch (17) are respectively provided at two ends of the body (1), the upper notch (12) is used to connect with a surgical instrument, and the lower notch (17) is used to connect with a surgical instrument, and the circuits and components used to connect the surgical instrument and the surgical instrument are located inside the body (1); The body (1) comprises: an upper half, a lower half, at least one middle part and at least two force sensing areas; the force sensing area is a shear beam area or a pressure beam area; any two adjacent force sensing areas are connected through a middle part, the force sensing area at the uppermost end is connected to the upper half, and the force sensing area at the lowermost end is connected to the lower half; the upper notch (12) is located in the upper half, and the lower notch (17) is located in the lower half; The body (1) is provided with at least one shear beam area and at least one pressure beam area; It also includes: optical fibers (2), wherein the plurality of optical fibers (2) are parallel to the axis of the body (1), the plurality of optical fibers (2) are connected to the inner wall of the body (1), one end of each optical fiber (2) is connected to the inner wall of the upper notch (12), and the other end of each optical fiber (2) is connected to a surgical instrument.

2. The FBG micro beam type three-dimensional force sensor according to claim 1, characterized in that: The shear beam area comprises: a short pressure beam (13) and a shear beam (14); the shear beam (14) is ring-shaped; any two adjacent shear beams (14) are connected by at least two short pressure beams (13); and a plurality of short pressure beams (13) are arranged at equal intervals around the axis of the body (1); The shear beam (14) at the uppermost end and the upper half / a middle part are connected by at least two short pressure beams (13), and the plurality of short pressure beams (13) are arranged at equal intervals around the axis of the body (1); The shear beam (14) at the lowest end and the lower half / another middle part are connected by at least two short pressure beams (13), and a plurality of short pressure beams (13) are arranged at equal intervals around the axis of the body (1).

3. The FBG micro beam type three-dimensional force sensor according to claim 2, characterized in that: The pressure beam area comprises: a long pressure beam (15), a plurality of long pressure beams (15) are arranged at equal intervals around the axis of the body (1), one end of each long pressure beam (15) is connected to the upper half or a middle part, and the other end of each long pressure beam (15) is connected to the lower half or another middle part.

4. The FBG micro beam type three-dimensional force sensor according to claim 2, characterized in that: The number of short pressure beams (13) between any two adjacent shear beams (14), the number of short pressure beams (13) between the uppermost shear beam (14) and the upper half / one middle part, and the number of short pressure beams (13) between the lowermost shear beam (14) and the lower half / another middle part are the same; Any short pressure beam (13) on the upper side of each shear beam (14) is arranged in the middle of two adjacent short pressure beams (13) on the lower side thereof, and the positions of the multiple short pressure beams (13) connected above another adjacent shear beam (14) located on the upper side of the shear beam (14) and the multiple short pressure beams (13) connected below the shear beam (14) are the same.

5. The FBG micro beam type three-dimensional force sensor according to claim 2, characterized in that: The length and width of the multiple short pressure beams (13) in each shear beam area are the same, and the width of the multiple shear beams (14) in each shear beam area is the same.

6. The FBG micro beam type three-dimensional force sensor according to claim 3, characterized in that: The length and width of the plurality of long pressure beams (15) in each pressure beam zone are the same.

7. The FBG micro beam type three-dimensional force sensor according to claim 3, characterized in that: The multiple short pressure beams (13) in each shear beam area are parallel to the axis of the body (1).

8. The FBG micro beam type three-dimensional force sensor according to claim 7, characterized in that: Each optical fiber (2) is located at the inner middle of a plurality of short pressure beams (13) spaced apart along the axial direction in any shear beam area and at the inner middle of a long pressure beam (15) in any pressure beam area.

9. The FBG micro beam type three-dimensional force sensor according to claim 1, characterized in that: An upper notch (12) with a reduced outer diameter is provided at the upper end of the upper half, and at least one first indented cutting angle plane (11) is provided on the outer wall of the upper notch (12); a lower notch (17) with an increased inner diameter is provided at the lower end of the lower half, and at least one second convex cutting angle plane (16) is provided on the inner wall of the lower notch (17).

10. The FBG micro beam type three-dimensional force sensor according to claim 1, characterized in that: Also includes: Adhesive (3), each optical fiber (2) is bonded to the inner walls of the upper half, the lower half and multiple middle parts of the body (1) by adhesive (3).

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