Compound optical navigation puncture positioning needle and needle tip pose detection method

Abstract

The present application belongs to the technical field of medical devices, and discloses a puncture positioning needle with composite optical navigation and a needle tip pose detection method. The puncture positioning needle comprises an inner needle tube and an outer needle tube. The inner needle tube is coaxially arranged in the outer needle tube. The top end of the inner needle tube is a needle tip, and the tail end is a needle tail. The outer needle tube has an optical navigation marker frame outside. An external optical navigation camera obtains a reference position through the optical navigation marker frame. The inner needle tube has a multi-core optical fiber inside. The multi-core optical fiber is connected to an external optical fiber deformation sensing control system. The optical fiber deformation sensing control system calculates the bending curvature and direction of the inner needle tube according to the reference position and the signal fed back by the multi-core optical fiber, and then calculates the pose of the needle tip. The present application uses the deformation information of the optical fiber deformation sensor to fit the deformation of the needle shaft, so as to calculate the actual position of the needle tip according to the reference position of the optical navigation marker frame. The measured position is more accurate and is not affected by the magnetic field. The structure is simple and has strong applicability.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a composite optical navigation puncture positioning needle and a needle tip posture detection method. Background Art

[0002] An existing puncture positioning needle consists of an outer needle tube, an outer needle holder, an inner needle tube coaxial with the outer needle tube, and an inner needle holder. When puncturing a lesion in the human body, it is necessary to locate the position of the needle tip to provide real-time feedback on the accuracy of the puncture of the lesion. After the puncture positioning needle accurately reaches the lesion, the inner needle tube is pulled out and the biopsy needle is inserted into the outer needle tube for sampling. Existing puncture biopsy needle positioning navigation mostly uses a single optical navigation or electromagnetic navigation. Among them, the implementation method of optical navigation is to set a number of optical tracking balls at the end of the puncture biopsy needle, track the positions of these optical tracking balls by an optical navigation camera, and then obtain the position information of the end of the biopsy needle in space, and then infer the position information of the tip in space based on the structural information from the tip to the end when the biopsy needle is produced. This method is calculated under the ideal state that the puncture biopsy needle shaft does not deform. The puncture biopsy needle often deforms after entering the human tissue. Therefore, the ideal tip position calculated based on the position of the puncture biopsy needle end is inaccurate. Although electromagnetic navigation can directly integrate the electromagnetic sensor into the tip of the outer tube of the puncture biopsy needle to directly obtain the position information of the tip of the puncture biopsy needle and the measurement results are accurate, the working range of electromagnetic navigation is smaller than that of optical navigation and is easily affected by nearby magnetic fields and metals, resulting in limited use. Summary of the Invention

[0003] The purpose of the present invention is to provide a composite optical navigation puncture positioning needle and a needle tip posture detection method to solve the above technical problems.

[0004] To solve the above technical problems, the specific technical solutions of the present invention for a composite optical navigation puncture positioning needle and needle tip posture detection method are as follows:

[0005] A composite optical navigation puncture positioning needle includes a needle rod, and the needle rod includes an inner needle tube and an outer needle tube. The inner and outer needle tubes are hollow inside, and the inner needle tube is sleeved in the outer needle tube and coaxially arranged with the outer needle tube. The top of the inner needle tube is a needle tip, and the end is a needle tail. The outside of the outer needle tube is provided with an optical navigation marker frame, and an external optical navigation camera obtains the needle rod reference position through the optical navigation marker frame. The inner and outer needle tubes puncture into the lesion site together, and the inner needle tube has a multi-core optical fiber inside, and the multi-core optical fiber is connected to an external optical fiber deformation sensing control system. The optical fiber deformation sensing control system calculates the bending curvature and direction of the inner needle tube according to the signal fed back by the optical fiber deformation sensor, and then can calculate the position of the needle tip according to the reference position of the optical navigation marker frame.

[0006] Further, the multi-core optical fiber in the inner needle tube is fixedly arranged relative to the inner needle tube.

[0007] Further, the multi-core optical fiber runs through the whole inner needle tube from the needle tip to the needle tail of the inner needle tube, and is connected to an external optical fiber deformation sensing control system through a fiber cold joint led out from the needle tail of the inner needle tube, the multi-core optical fiber from the needle tip to the needle tail of the inner needle tube is provided with a fiber deformation sensor composed of a plurality of Bragg gratings, and the fiber deformation sensing control system calculates the bending curvature and direction information of the inner needle tube according to different wavelengths reflected by the plurality of Bragg gratings.

[0008] Further, the multi-core optical fiber from the needle tail of the inner needle tube to the fiber deformation sensing control system is a multi-core optical fiber without deformation sensing capability of Bragg gratings.

[0009] Further, the outer wall of the needle tail of the outer needle tube is provided with a mounting position marker, and an optical navigation marker frame is clamped and fixed at the mounting position marker on the outer wall of the needle tail of the outer needle tube, and the mounting position marker is aligned with the last Bragg grating of the needle tail of the inner needle tube.

[0010] Further, the optical navigation marker frame is provided with at least three optical navigation markers capable of reflecting light.

[0011] Further, the end of the outer needle tube is fixedly connected with one end of a hollow outer needle holder, the other end of the outer needle holder is provided with an internal thread, the end of the inner needle tube is fixedly connected with a hollow inner needle holder, the inner needle holder is provided with an external thread matched with the internal thread of the outer needle holder, the inner needle tube penetrates into the inner needle tube and is coaxially arranged with the outer needle tube, and the inner needle holder at the end of the inner needle tube is fixedly connected with the outer needle holder of the outer needle tube by screwing; the inner needle holder is provided with a fixed clamping ring, and the fixed clamping ring is used for fixing the multi-core optical fiber.

[0012] Further, the fiber deformation sensor in the inner needle tube is wrapped with a cladding layer having a lower refractive index than the optical fiber, the cladding layer is coated with a coating layer, and the coating layer is fixedly connected with the inner wall of the inner needle tube by potting glue, and the potting glue is used for fixing the fiber deformation sensor and the inner needle tube.

[0013] Further, the multi-core optical fiber is a seven-core optical fiber MCF, each optical fiber core has different temperature and strain response sensitivity, the Bragg grating is a Bragg grating FBG, the wavelength of each Bragg grating is different, the length L1 of each Bragg grating is 0.5-1.5 cm, the wavelength falls within 1500-1600 nm, and the wavelength spacing between the Bragg gratings is 5-20 nm; the interval between each Bragg grating is a deformation interval L2, and the length of L2 is 0.5-2 cm.

[0014] The application further discloses a needle tip pose detection method, which comprises the following steps:

[0015] Step 1: The optical navigation camera obtains the pose matrix of the optical navigation marker frame in the optical navigation camera coordinate system space based on the optical marker on the optical navigation marker frame Where R0 is a 3x3 rotation matrix and T0 is a 3x1 translation vector;

[0016] Step 2: The bent and deformed tip position is approximately represented by a plurality of straight line segments of length L3 rotated by a certain angle, where L3 = L1 + L2, where L1 is the length of a single Bragg grating 51, and L2 is the interval between two adjacent Bragg gratings 51 in the deformed portion.

[0017] Step 3: Use N0, N1, N2…Nj to represent j+1 adjacent straight line segments to approximate the bending of the puncture needle. The end of Nj is the location of the needle tip, and the end of N0 is the location of the optical navigation marker. The length of each line segment is composed of L3.

[0018] Step 4: Obtain the relative posture matrix A1 of N1 relative to N0, the relative posture matrix A2 of N2 relative to N1, ..., the relative posture matrix Aj of Nj relative to Nj-1, and then obtain the relative posture matrix A of the end of Nj relative to the end of N0 t :

[0019] A t =A1*A2*……*A j

[0020] Finally, the relative attitude matrix At of the needle tip relative to the optical navigation marker frame is obtained;

[0021] Step 5: The needle tip position is obtained by the following formula:

[0022] A x =A t *A0.

[0023] The composite optical navigation puncture positioning needle and needle tip posture detection method of the present invention have the following advantages: the present invention passes a multi-core optical fiber through the needle tip to the needle tail, and the multi-core optical fiber from the needle tip to the needle tail is provided with a plurality of Bragg gratings for monitoring optical fiber deformation, and calculates the deformation information of different parts of the needle rod with the different wavelengths reflected by each Bragg grating, and then calculates the posture of the needle tip according to the reference position of the optical navigation marker frame and the deformation information of the inner needle tube. The present invention takes into account the deformation of the needle rod after entering the human body, and uses the deformation information of the optical fiber deformation sensor to fit the deformation of the needle rod, thereby inferring the actual posture of the needle tip according to the reference position of the optical navigation marker frame, and measuring the position more accurately. The optical fiber deformation sensor is not affected by the magnetic field, and when used on the thermal energy ablation needle, it also has a temperature measurement function, integrating temperature measurement and positioning, with a simple structure and strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the external structure of the composite optical navigation puncture needle positioning needle of the present invention;

[0025] Figure 2 This is a schematic diagram of the outer needle tube structure of the puncture needle positioning needle of the present invention;

[0026] Figure 3 Schematic diagram of the inner needle tube structure of the puncture needle positioning needle of the present invention;

[0027] Figure 4 Schematic diagram of the structure of the optical fiber deformation sensor of the present invention;

[0028] Figure 5 Schematic diagram of the grating position structure of the optical fiber deformation sensor of the present invention;

[0029] Figure 6 This is a schematic diagram of the present invention using adjacent straight line segments to approximately simulate the curved structure of a puncture needle;

[0030] Figure 7 Schematic diagram of the needle tip posture matrix of the present invention;

[0031] Explanation of the marks in the figure: 1. Needle rod; 11. Inner needle tube; 12. Outer needle tube; 121. Installation position mark; 13. Outer needle seat; 14. Inner needle seat; 141. Fixed clamp; 2. Optical navigation mark holder; 21. Optical navigation mark; 4. Fiber optic cold joint; 5. Fiber optic deformation sensor; 51. Bragg grating; 6. Cladding; 7. Coating layer; 8. Potting glue. DETAILED DESCRIPTION

[0032] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of a composite optical navigation puncture positioning needle and a needle tip posture detection method of the present invention in conjunction with the accompanying drawings.

[0033] like Figure 1-3As shown, a composite optical navigation puncture positioning needle of the present invention includes a needle rod 1, which includes an inner needle tube 11 and an outer needle tube 12. The inner needle tube 11 and the outer needle tube 12 are hollow inside. The end of the outer needle tube 12 is fixedly connected to one end of the hollow outer needle seat 13. The other end of the outer needle seat 13 has an internal thread. The end of the inner needle tube 11 is fixedly connected to the hollow inner needle seat 14. The inner needle seat 14 has an external thread that matches the internal thread of the outer needle seat 13. The inner needle tube 11 penetrates the outer needle seat 13 and enters the interior of the outer needle tube 12. It is coaxially arranged with the outer needle tube 12. The inner needle seat 14 at the end of the inner needle tube 11 is threadedly fixedly connected to the outer needle seat 13 of the outer needle tube 12. The top of the inner needle tube 11 is a needle tip, exposed outside the outer needle tube 12, used for puncture, and the end is a needle tail. The inner needle seat 14 has a fixing ring 141, which is used to fix the optical fiber deformation sensor 5. The multi-core optical fiber penetrates the inner needle tube 11 from the needle tip to the needle tail, and is led out through the fixed clamp 141 of the inner needle seat 14 and connected to the external optical fiber deformation sensing control system through the optical fiber cold connector 4. The fixed clamp 141 is used to fix the multi-core optical fiber. The outer wall of the needle tail of the outer needle tube 12 has an installation position mark 121. The optical navigation marker frame 2 is clamped and fixed at the installation position mark 121 on the outer wall of the needle tail of the outer needle tube 12. The optical navigation marker frame 2 is provided with at least three reflective optical navigation markers 21. The optical navigation markers 21 are reflective stickers or reflective balls. The external optical navigation camera obtains the reference position of the needle rod 1 through the optical navigation marker frame 2. The multi-core optical fiber is fixed relative to the inner needle tube 11. The portion of the multi-core optical fiber from the end of the inner needle tube 11 to the needle tip is a fiber optic deformation sensor 5 composed of multiple Bragg gratings 51. The fiber optic deformation sensing control system calculates the deformation information of the inner needle tube 11 (including the bending curvature and direction of the inner needle tube 11) based on the different wavelengths reflected by the multiple Bragg gratings 51, and then calculates the position of the needle tip based on the reference position of the optical navigation marker frame 2 and the deformation information of the needle rod 1. The portion from the end of the inner needle tube 11 to the fiber optic deformation sensing control system is an ordinary multi-core optical fiber without Bragg gratings and deformation sensing capability. Therefore, the bending of this portion will not be detected during actual operation.

[0034] like Figure 4 As shown, the optical fiber deformation sensor 5 within the inner needle tube 11 is wrapped with a cladding 6 having a lower refractive index than the optical fiber. Cladding 6 is preferably a glass sheath cladding. Cladding 6 is then coated with a coating 7, preferably a Teflon coating, to further protect the cladding. Potting adhesive 8 is used to secure the outer surface of coating 7 to the inner wall of the inner needle tube 11. Potting adhesive 8 secures the optical fiber deformation sensor 5 to the inner needle tube 11. Therefore, the bending information of the optical fiber deformation sensor 5 reflects the bending information of the inner needle tube 11, including the bending direction and degree. Because moisture significantly affects the interior of the optical fiber, epoxy resin X280 is used as the potting adhesive to both secure and protect the optical fiber.

[0035] like Figure 5 As shown, the multi-core optical fiber is a seven-core optical fiber MCF. Each optical fiber core has different temperature and deformation response sensitivities. When each optical fiber core is subjected to temperature and deformation, it will cause the reflection wavelength of the fiber Bragg grating 51 to move, thereby reflecting the size of the deformation. The Bragg grating 51 is a Bragg grating FBG. Figure 5 As shown, multiple Bragg gratings 51 are distributed between the tip and the tail of the needle. The wavelength of each Bragg grating 51 is different to identify the deformation information at different positions. The length L1 of each Bragg grating 51 is 0.5 to 1.5 cm, the wavelength falls between 1500 and 1600 nm, the reflection wavelength spacing between each other is 5 to 20 nm, and the interval between each Bragg grating 51 is the deformation spacing distance L2, and the length of L2 is 0.5 cm to 2 cm.

[0036] When the middle portion of the inner needle tube 11 is deformed by force inside the human body, causing the internal fiber optic deformation sensor 5 to deform accordingly, the strain response sensitivity coefficients of different optical fiber cores at the same position inside the inner needle tube 11 are different, resulting in slightly different reflection wavelengths measured by the external fiber optic sensing control system. The external fiber optic sensing control system uses the data measured by each optical fiber core to establish multiple equations or factory-calibrated data to determine the degree and direction of bending. Since the fiber optic deformation sensor 5 and the inner needle tube 11 inside the inner needle tube 11 are fastened together by potting glue, the deformation information of the fiber optic deformation sensor 5 can be used to obtain the deformation information of the inner needle tube 11. Combined with the reference position obtained by the optical navigation marker, the true position of the needle tip in the human body can be obtained based on the correspondence between the reference position and the needle tip structure.

[0037] Example:

[0038] The outer needle tube 12 is 18G in diameter, and the inner needle tube 11 is 17G in diameter. The outer needle tube 12 and the inner needle tube 11 can be coaxially inserted and locked according to the conventional puncture needle design. A Bragg grating 51 with a length of 1 cm is set 1 mm away from the needle tip. The central reflection wavelength of the Bragg grating 51 is 1500 nm. A deformed Bragg grating 51 with a length of 1 cm is set at intervals of 1 cm. The central reflection wavelength of the Bragg grating is 1520 nm. Then, Bragg gratings 51 with wavelengths of 1540 nm, 1560 nm, and 1580 nm are set in sequence at intervals of 1 cm, 2 cm, and 3 cm, respectively. The length from the needle tip to the last Bragg grating 51 is 11 cm. After the outer needle tube 12 and the inner needle tube 11 are inserted and locked, the last Bragg grating 51 corresponds to the installation position mark 121 on the outer wall of the outer needle tube 12. This position is the starting installation position of the optical navigation marker frame 2.

[0039] The optical navigation camera obtains the pose matrix of the optical navigation marker frame 2 in the optical camera coordinate system space according to the optical marker on the optical navigation marker frame 2 wherein R0 is a 3x3 rotation matrix, T0 is a 3x1 translation vector, since the length of the Bragg grating of the puncture positioning needle is L1 of 1 cm, the interval between adjacent deformed Bragg gratings is L2, thus the pose of the needle tip after bending and deformation can be approximated by rotating a number of straight line segments with a length of L3 (L3=L1+L2) by a certain angle, wherein N0, N1, N2, …, Nj represent j+1 adjacent straight line segments for approximating the bending of the puncture needle, the end of Nj is the position of the needle tip, and the end of N0 is the position of the optical navigation marker frame 2, and the length of each line segment is composed of L1+L2; as shown in Figure 6 Fig. 2, N0, N1, N2 are three adjacent straight line segments for approximating the bending of the puncture needle, the end of N2 is the position of the needle tip, and the end of N0 is the position of the optical navigation marker frame 2.

[0040] Since the optical fiber sensing control system can obtain the deformation information of the Bragg grating of each deformed part, the relative attitude matrix A1 of N1 relative to N0, the relative attitude matrix A2 of N2 relative to N1, …, the relative attitude matrix A j of Nj relative to Nj-1, and the relative attitude matrix A t of the end of Nj relative to the end of N0 are obtained, and are expressed as:

[0041] A t =A1*A2*……*A i

[0042] Taking two segments as an example:

[0043] A t =A1*A2

[0044] The relative attitude matrix A t of the needle tip relative to the optical navigation marker frame 2 can be finally obtained, as shown in Figure 7 .

[0045] Then the new needle tip pose can be obtained by the following formula

[0046] A x =A t *A0.

[0047] In use, firstly, the inner needle tube 11 is inserted into the outer needle tube 12, and the inner needle seat 14 at the end of the inner needle tube 11 is threadedly fixedly connected with the outer needle seat 13 of the outer needle tube 12. In puncture, the inner needle tube 11 and the outer needle tube 12 are inserted into the lesion tissue of the human body together, the optical navigation camera obtains the reference position according to the optical mark on the optical navigation mark frame 2 on the outer needle tube 12, and the optical fiber deformation sensing control system obtains the deformation information of the inner needle tube 11 according to the optical deformation sensor 5 in the inner needle tube 11, so as to calculate the pose of the needle tip. The puncture process is real-time monitored and tracked to the pose of the needle tip until the puncture positioning needle accurately reaches the lesion tissue position. After puncture, the inner needle tube 11 is taken out from the outer needle tube 12, and the biopsy needle is inserted into the outer needle tube 12 to perform the conventional sampling biopsy on the lesion site.

[0048] It can be understood that the present application is described by some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to the features and embodiments without departing from the spirit and scope of the present application. In addition, under the teaching of the present application, the features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the scope of protection of the present application.

Claims

1. A method for detecting the tip position of a composite optical navigation puncture positioning needle, the composite optical navigation puncture positioning needle comprising a needle shaft (1), the needle shaft (1) comprising an inner needle tube (11) and an outer needle tube (12), the inner needle tube (11) and the outer needle tube (12) being hollow, the inner needle tube (11) being sleeved inside the outer needle tube (12) and being coaxially arranged with the outer needle tube (12), the top end of the inner needle tube (11) being a needle tip and the bottom end being a needle tail, the outer needle tube (12) being provided with an optical navigation marker frame (2) on the outside, and the outer needle tube (12) being provided with a needle tip. The optical navigation camera obtains the reference position of the needle rod (1) through the optical navigation marker frame (2), and the inner needle tube (11) and the outer needle tube (12) are configured to puncture into the lesion site together. The inner needle tube (11) has a multi-core optical fiber, and the multi-core optical fiber is connected to an external optical fiber deformation sensing control system. The optical fiber deformation sensing control system calculates the bending curvature and direction of the inner needle tube (11) based on the reference position of the optical navigation marker frame (2) and the signal fed back by the multi-core optical fiber, and then calculates the position of the needle tip; the inner needle tube ( The multi-core optical fiber in the inner needle tube (11) is fixedly arranged relative to the inner needle tube (11); the multi-core optical fiber runs through the entire inner needle tube (11) from the needle tip to the needle tail of the inner needle tube (11), and is led out from the needle tail of the inner needle tube (11) and connected to an external optical fiber deformation sensing control system through an optical fiber cold joint (4); the multi-core optical fiber from the needle tip to the needle tail of the inner needle tube (11) is an optical fiber deformation sensor (5) composed of multiple Bragg gratings (51), and the optical fiber deformation sensing control system is based on the uneven reflection of the multiple Bragg gratings (51). The bending curvature and direction information of the inner needle tube (11) are calculated at the same wavelength; the portion from the needle tail to the optical fiber deformation sensing control system is a multi-core optical fiber with no deformation sensing capability and no Bragg grating; the outer wall of the needle tail of the outer needle tube (12) is provided with an installation position mark (121), and the optical navigation mark frame (2) is clamped and fixed at the installation position mark (121) on the outer wall of the needle tail of the outer needle tube (12), and the installation position mark (121) is aligned with the last Bragg grating (51) of the needle tail of the inner needle tube (11); it is characterized in that The method for detecting the needle tip posture comprises the following steps: Step 1: The optical navigation camera obtains the pose matrix of the optical navigation marker frame (2) in the optical navigation camera coordinate system space according to the optical marker on the optical navigation marker frame (2). ,in is a 3x3 rotation matrix, is a 3x1 translation vector; Step 2: The position of the needle tip after bending deformation is approximately represented by a plurality of straight line segments of length L3 rotated by a certain angle, where L3=L1+L2, L1 is the length of a single Bragg grating (51), and L2 is the interval between two adjacent Bragg gratings (51) of the deformed part; Step 3: Use N0, N1, N2...Nj to represent j+1 adjacent straight line segments to approximate the bending of the puncture needle. The end of Nj is the location of the needle tip, and the end of N0 is the location of the optical navigation marker frame (2). The length of each line segment is composed of L3. Step 4: Obtain the relative posture matrix A1 of N1 relative to N0, the relative posture matrix A2 of N2 relative to N1, ..., the relative posture matrix A of Nj relative to Nj-1 j , and then get the relative posture matrix of the Nj terminal relative to the N0 terminal : ， Finally, the relative attitude matrix of the needle tip relative to the optical navigation marker frame (2) is obtained ; Step 4: The needle tip position is obtained by the following formula: 。 2. The method according to claim 1, characterized in that The optical navigation marker frame (2) is provided with at least three reflective optical navigation markers (21).

3. The method according to claim 1, characterized in that The end of the outer needle tube (12) is fixedly connected to one end of the hollow outer needle seat (13), and the other end of the outer needle seat (13) has an internal thread. The end of the inner needle tube (11) is fixedly connected to the hollow inner needle seat (14), and the inner needle seat (14) has an external thread that matches the internal thread of the outer needle seat (13). The inner needle tube (11) penetrates the outer needle seat (13) and enters the interior of the outer needle tube (12), and is coaxially arranged with the outer needle tube (12). The inner needle seat (14) at the end of the inner needle tube (11) is threadedly fixedly connected to the outer needle seat (13) of the outer needle tube (12); a fixing clamp (141) is provided inside the inner needle seat (14), and the fixing clamp (141) is used to fix the optical fiber deformation sensor (5).

4. The method according to claim 1, wherein The optical fiber deformation sensor (5) in the inner needle tube (11) is wrapped with a cladding (6) having a lower refractive index than the optical fiber, the cladding (6) is coated with a coating layer (7), and the coating layer (7) is sealed and fixed to the inner wall of the inner needle tube (11) with a potting glue (8), and the potting glue (8) is used to fix the optical fiber deformation sensor (5) and the inner needle tube (11).

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