CN113662657A

CN113662657A - Interventional blood vessel cancer embolus ablation medical system with 3D navigation function

Info

Publication number: CN113662657A
Application number: CN202110987935.3A
Authority: CN
Inventors: 苑立波; 杨世泰
Original assignee: Guilin University of Electronic Technology
Current assignee: Guilin University of Electronic Technology
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2021-11-19
Anticipated expiration: 2041-08-26
Also published as: CN113662657B

Abstract

The invention provides an interventional blood vessel cancer embolus ablation medical system with a 3D navigation function, which is characterized in that: the medical system comprises a multi-core optical fiber with a 3D shape sensing function, a multi-core optical fiber connector, a surgical laser light source, a fiber grating demodulator, an optical fiber sleeve and a computer; the multi-core optical fiber comprises three energy transmission fiber cores with annular defects, four single-mode fiber cores and FBG unit arrays distributed on the four single-mode fiber cores; the output end of the multi-core optical fiber connector is provided with seven fiber cores which are respectively and correspondingly connected with the single-mode core and the annular broken fiber core of the multi-core optical fiber, wherein the input ends of the four corresponding single-mode fiber cores are connected with the fiber bragg grating demodulator; the input ends of the other three corresponding annular energy-transmitting fiber cores are connected with an operation light source; optical signals obtained by the fiber grating demodulator are processed by a computer to invert the shape of the multi-core fiber in real time, the position of the fiber probe in the blood vessel is determined, and 3D navigation of the blood vessel in the body is realized. The invention can be used for minimally invasive interventional operation treatment.

Description

Interventional blood vessel cancer embolus ablation medical system with 3D navigation function

Technical Field

The invention relates to an interventional type blood vessel cancer embolus ablation medical system with a 3D navigation function, and belongs to the technical field of medical instruments.

Background

Vascular cancer emboli are common diseases which can appear in all stages of tumor development. For example, portal vein cancer embolus is a common disease in the development process of liver cancer, and is one of the direct causes of death of liver cancer patients, so it is important to discover and remove vascular cancer embolus as soon as possible.

The optical fiber has the advantages of being fine, flexible, biocompatible, safe, reliable and the like, so that the optical fiber type sensor can be effectively embedded into medical instruments such as a needle head, a catheter, an endoscope and the like, and can be inserted into various cavities and channels of a human body to reach a diseased area, realize minimally invasive and accurate detection and treatment, effectively avoid dangerous and painful operation processes such as operation and the like, reduce operation blood loss and shorten postoperative recovery time. The optical fiber shape sensor can dynamically feed back the shape and the position of the medical catheter attached to the optical fiber shape sensor in the human body in real time, so that the optical fiber shape sensor is expected to replace dangerous and expensive X-ray perspective imaging technology in a plurality of minimally invasive interventional therapy operations.

Lasers have been used in the treatment of tumors, such as primary tumors, metastatic tumors, and post-operative recurrent tumors, particularly in patients with tumors that cannot tolerate re-surgery. When tumors such as liver cancer, breast cancer, adrenal gland cancer, osteoid osteoma, pituitary tumor, prostate tumor and the like are treated by laser, a common puncture needle is punctured into a tumor body through skin under the positioning guidance of an image system such as an ultrasonoscope, an X-ray fluoroscopy instrument, a computer-controlled nuclear magnetic resonance instrument and the like, and laser fiber is directly inserted into a treatment part through a common puncture needle tube, so that laser treatment can be carried out. Because the laser treatment has a good killing boundary, the tumor cells can be completely killed by regulation, and the cells outside the ablation area can be prevented from being damaged.

Currently, although multi-core fiber-based shape sensors have been proposed and may potentially be applied to intravascular 3D shape sensing navigation ((ii))

Sonja, et al, three-dimensional guiding enclosing shape sensing for a stereogram system for an endo-vascular and pumping, International journal of computer assisted surgery and surgery,2020,15: 1033. sup. 1042), but the fiber failed to function as a laser surgery treatment. Of course, optical fiber is already a mature medical means scheme as a surgical laser conduction medium, but the existing optical fiber surgical laser conduction optical fiber is generally a simple multimode energy conduction optical fiber and does not have a 3D navigation function.

Disclosure of Invention

The invention aims to provide an interventional type blood vessel cancer embolus ablation medical system with a 3D navigation function.

An interventional blood vessel cancer embolus ablation medical system with a 3D navigation function. As shown in fig. 1, the medical system comprises a multi-core optical fiber 1 with 3D shape sensing function, a multi-core optical fiber connector 4, a surgical laser light source 6, a fiber grating demodulator 5, a fiber sleeve 3 and a computer 9; the multi-core optical fiber comprises three energy transmission fiber cores 1-3 with annular defects, four single-mode fiber cores 1-1 and 1-2, a cladding 1-4 and an FBG unit array 2 distributed on the four single-mode fiber cores; seven fiber cores are arranged at the output end of the multi-core optical fiber connector 4 and are respectively and correspondingly connected with the single-mode core and the annular broken fiber core of the multi-core optical fiber, and the input ends of four corresponding single-mode fiber cores of the multi-core optical fiber connector 4 are connected with the fiber bragg grating demodulator 5 and are used for monitoring the shape of the multi-core optical fiber 1 in real time; the other three input ends of the multi-core optical fiber connector 4 corresponding to the annular broken fiber core are connected with the operation laser light source 6, and the output operation laser is transmitted to the fiber end through the annular broken energy transmission fiber core and is used for ablation of cancer embolus. After optical signals obtained by the fiber grating demodulator are processed by a computer, the shape of the multi-core fiber 1 can be inverted in real time, the position of the fiber probe in a blood vessel is determined, and 3D navigation of the blood vessel in a body is realized.

As shown in fig. 2 and fig. 3(a), three cores 1-1 of the four single-mode cores of the multi-core optical fiber 1 are distributed in a regular triangle, and the other core 1-2 is located in the middle of the optical fiber. Three annular broken fiber cores 1-3 and three single-mode fiber cores 1-1 distributed in a regular triangle are distributed on the same ring.

Optionally, as shown in fig. 3(b), the multi-core fiber has a ring of fluorine-doped low refractive index layers 1-5 outside the four single-mode cores for preventing energy crosstalk between the energy-transmitting core and the single-mode cores.

As shown in fig. 4, the FBG unit array is located on four single-mode fiber cores, four gratings at the same position of each single-mode fiber core are in one group, each group of gratings is prepared by using the same parameter grating mask, and different groups of gratings are prepared by using grating masks with different parameters.

The fiber end of the multi-core fiber is provided with a reflecting cone frustum, and the reflecting cone frustum reflects and focuses the surgical laser in front of the fiber end.

The FBG reflection sensing signals on the four single-mode fiber cores are demodulated by the fiber bragg grating demodulator, and the signals are obtained and processed by the computer to obtain and display the three-dimensional shape distribution of the optical fibers in real time.

The tail end of the single-mode fiber core in the middle of the multi-core fiber is provided with the FBG which is used for monitoring the temperature of a fiber end in real time and monitoring the temperature of a fiber end laser ablation operation area in real time, so that the phenomenon that the local temperature is too high and normal tissues are damaged is prevented.

Since the optical fiber is a special optical fiber, the connection method of each core waveguide is a key problem for whether the optical fiber can be applied. The optical fiber can adopt the following optical fiber fan-in fan-out connector: as shown in fig. 5, a seven-core fiber fan-in fan-out device 4 can be selected to be fusion-spliced with a multi-core fiber 1, one end of the device is connected with seven single-mode fibers 4-2, and the other output end 4-1 is provided with seven single-mode output fiber cores, wherein three of six fiber cores which are distributed in an annular shape are correspondingly matched with three single-mode fiber cores of the multi-core fiber 1 provided by the invention, the other three fiber cores are correspondingly matched with three annular broken fiber cores, and the middle cores are mutually butt-jointed and matched. This enables the fan-in and fan-out connection of the present invention.

Before the medical system works, the shape distribution of a treatment target blood vessel is obtained by using an angiography, a reference coordinate system is established by a computer, and the absolute position of the tail end of the optical fiber in the blood vessel is obtained by feeding back and fusing the shape of the inserted multi-core optical fiber in the coordinate system.

The three annular energy-transmitting fiber cores have larger effective areas, pulse beams with high energy density are transmitted in the three annular energy-transmitting fiber cores, and the operation effect is adjusted by adjusting parameters such as the repetition frequency and the output energy of the operation beams; the three energy transmission fiber cores can inject light in turn, so that the phenomenon that the normal tissue is damaged due to overhigh temperature caused by heat accumulation due to long-time local single-point work is prevented.

To realize the shape sensing of a single optical fiber and complete the 3D surgical navigation, the measurement tasks of bending and twisting are completed simultaneously. This requires a single fiber with a minimum of three single mode cores. In order to eliminate the systematic deviation and improve the systematic measurement accuracy, a common reference fiber core capable of providing the environmental temperature and the matrix strain is also needed. Therefore, the multi-core optical fiber adopted by the invention comprises four single-mode fiber cores, and the influence of the external environment is eliminated through the differential motion of the three fiber cores in triangular distribution and the central reference fiber core, so that the absolute measurement of bending and torsion is realized.

In order to realize the shape reconstruction operation of the multi-core fiber in the blood vessel based on the curvature information, the wavelength data acquired by the FBG demodulation system is converted into curvature data, and the reconstruction of the three-dimensional structure shape change is realized by utilizing a curvature serialization and reconstruction algorithm.

Because the optical fiber deformation parameters detected by the multi-core optical fiber FBG sensing array are discrete data, the data can be serialized by adopting methods such as linear interpolation, secondary interpolation, B-spline interpolation and the like, and a continuous change function of the curvature and torsion of the optical fiber is obtained: κ(s) and τ(s). Further, according to the continuous change data of curvature and torsion, the three-dimensional space position function of the whole optical fiber sensor is reconstructed

The reconstruction process of this function will be briefly analyzed below.

For the convenience of analysis, only four single-mode cores of the multi-core fiber, on which FBG arrays are written, are analyzed in the process of reconstructing the fiber shape. As shown in FIG. 6, a unit tangent vector along the bending direction of the optical fiber is defined

Unit normal vector along bending direction of optical fiber

And negative normal vector

Here, the

Thus, it is obtained from the Frenet Serley formula:

an important feature of the frenlun-serley equation is that,

and

can be expressed as its integral:

once the various parameters of the multicore optical fiber sensor are calibrated, the initial position is determined (i.e., the

And

known), the spatial position function of the multi-core optical fiber sensor can be obtained by combining the two formulas, and the deformation profile of the sensor is reconstructed:

bending and torsion of the multi-core fiber grating sensing array can be abstracted into a space three-dimensional curve through a Frenet-Serret (Frenet-Serret) formula, the optical fiber is analogized to a linear kirchhoff rod, the optical fiber is uniform in elasticity, symmetrical in structure and uniform in circular section density, and therefore the relation between the framework of the optical fiber in the three-dimensional space and the framework of a natural curve is kept unchanged.

And the continuous variation functions κ(s) and τ(s) of the fiber curvature and twist can be determined by the following method. In the process of detecting the shape of the multi-core fiber FBG sensing array, the whole sensing fiber grating array is changed into a complex curve due to bending and twisting of the multi-core fiber.

According to the geometry of four single mode cores, as shown in fig. 7. The relationship between the strain of the FBG on the core and the fiber curvature is given by:

local curvature of core i is

In the formula of_iFor the strain value of the ith grating, it is given by

The magnitude of each core's local curvature vector depends on its measured strain and radial distance from the center of the fiber, while the vector direction depends on the angular offset of the core. For a four-single mode core fiber, the vector of the curvature vector is defined as

The bending direction is defined as

Interpolating the curvature and bending direction of the whole optical fiber by cubic spline interpolation method for discrete curvature and bending direction, wherein the curvature function is the differential of the bending angle function

κ(s)＝θ′(s) (9)

Once the continuously varying functions κ(s) and τ(s) of fiber curvature and twist are determined, as well as the initial position of the multicore fiber sensor (i.e., the

And

) The three-dimensional shape of the sensing optical fiber in space can be reconstructed by the equations (2) and (3).

The dynamic data obtained by the fiber bragg grating is further converted into a real-time reflection wavelength displacement data set after being demodulated by the high-speed FBG demodulation system. These datasets constitute two-dimensional, three-dimensional and even high-dimensional data fields containing information on the spatial three-dimensional shape of the intervening vessel and its in-vivo temperature distribution.

In order to display the distribution shape of the optical fiber in the blood vessel in real time, it is necessary to display the point coordinate data obtained by the fitting and reconstruction method by means of calculation on a computer screen by the Open GL technique.

As shown in fig. 8, the three-dimensional optical fiber shape is accurately, efficiently and dynamically reconstructed visually by using the spatial coordinate values obtained by the fitting operation of the reconstruction algorithm and the computer graphics processing technique. The data processing flow of the three-dimensional form reconstruction comprises the steps of raw data acquisition, curvature conversion, curvature interpolation, coordinate point fitting, coordinate data fusion, graph rendering and the like, wherein the coordinate data fusion is a key link for realizing a dynamic display effect.

The coordinate data fusion mainly aims to fuse the relative coordinate values of all points on the optical fiber and the blood vessel into a unified coordinate system to form a unified and complete model structure coordinate point set. The processing procedure of coordinate point fusion is as follows:

(1) by angiography, a fixed coordinate system of the vascularised structure is established.

(2) The coordinate value of each characteristic point in the whole optical fiber structure fixed coordinate system is determined by establishing a transformation relation between the coordinate system where each optical fiber grating sensing point is located and the fixed coordinate system and unifying the relative coordinates of each characteristic point reconstructed in the independent coordinate system of each optical fiber grating sensing point into the fixed coordinate system according to the transformation relation.

(3) And finally, fusing the coordinates of each unit under a fixed coordinate system to realize coordinate point reconstruction, thereby realizing the real-time reconstruction of the optical fiber shape and completing the intravascular 3D surgical navigation.

Compared with the prior art, the invention has the following remarkable improvements:

(1) by adopting the special multi-core optical fiber, the operation beam conduction function and the 3D operation navigation function are integrated into the same optical fiber, the device is small and flexible, and the device is particularly suitable for interventional operation in blood vessels.

(2) The FBG array that distributes on the optic fibre can be used to intervene the distributed measurement of temperature at internal different positions, acquires distributed temperature sign parameter, and the fine end of middle core has FBG, can be used for monitoring the local temperature of operation point and feed back the operation effect.

(3) The fiber cores of the three annular breaks have large mode field areas, can transmit laser with larger power, and are used as beam transmission channels for interventional laser ablation treatment in blood vessels.

(4) The fiber end of the optical fiber is precisely ground and processed to prepare a cone frustum structure, so that the surgical laser transmitted in the fiber core with three annular defects is reflected and focused, and the energy density of the surgical laser is further improved.

Drawings

Fig. 1 is a block diagram of an interventional vascular cancer embolus ablation medical system with 3D navigation functionality.

FIG. 2 is a multi-core optical fiber for interventional ablation procedures with an array of FBGs in the fiber, the amplification zone being an end-face structural view of the fiber.

Fig. 3 is an end view of two multifunctional optical fibers for interventional ablation procedures, wherein fig. 3(b) differs from fig. 3(a) in that the outer circles of the 4 single-mode cores are added with low-refractive-index spacer layers.

Fig. 4 is a three-dimensional structural view of a multicore fiber in which a fiber grating array is distributed in groups on 4 single-mode cores.

FIG. 5 is a block diagram of a fan-in fan-out connector for a multifunctional optical fiber for use in interventional ablation procedures.

Fig. 6 is a schematic diagram of a multicore fiber for shape reconstruction.

Fig. 7 is a flow chart of a three-dimensional shape sensing real-time dynamic display of a multifunctional optical fiber for interventional ablation procedures.

Fig. 8 is a structural diagram of a multicore optical fiber with a cone frustum structure at the fiber end for an intravascular laser ablation treatment system.

Detailed Description

The invention is further illustrated below with reference to specific examples.

Example 1: can be used for the ablation treatment of cancer embolus in blood vessel.

The blood vessel to be operated of the patient is firstly subjected to intravascular radiography to obtain the actual spatial distribution of the blood vessel. An absolute coordinate system is established on the computer.

Then, the puncture needle is punctured to a proper blood vessel position, the puncture needle core is drawn out, and a guide wire is inserted to the top end of the puncture needle tube along the puncture needle tube; the puncture needle tube is pulled out and the multi-core optical fiber is inserted.

And opening the fiber grating demodulator, monitoring the dynamic shape of the multi-core fiber on a monitor of a computer, and judging the advancing condition and the current position of the fiber end in the blood vessel according to the matching degree of the shape of the multi-core fiber and the angiography blood vessel. According to such 3D navigation, the advancing direction of the optical fiber is adjusted until the end of the optical fiber reaches the cancer embolus of the patient.

And opening a surgical laser light source, injecting laser beams into the three energy transmission fiber cores with annular defects through the multi-core optical fiber connector, monitoring the reflection wavelength of the grating at the end of the middle core fiber obtained by the fiber grating demodulator, and monitoring the local temperature of the fiber end.

The operation effect is improved by adjusting the pulse intensity and the pulse period of the operation laser light source.

Example 2: the fiber end is provided with an intravascular thrombus ablation system with a frustum structure.

As shown in fig. 8, one end of a multi-core fiber 1 is connected with a seven-core fiber fan-in fan-out device 4, wherein the input ends corresponding to three annular broken fiber cores are connected with an operation laser light source 6, and the input ends corresponding to four single-mode fiber cores of the multi-core fiber 1 are connected with a four-channel fiber grating demodulation system 5, so that the system can realize the real-time shape reconstruction of the multi-core fiber through the wavelength reflected by a grating array 2 on the multi-core fiber 1. The other end of the multi-core optical fiber 1 can be inserted into the optical fiber ferrule 3, and the shape of the multi-core optical fiber 1 reconstructed after the optical fiber is inserted into the optical fiber ferrule 3 can be regarded as the shape of the optical fiber ferrule. The fiber end of the multi-core optical fiber 1 is precisely ground to obtain a symmetrical reflecting cone frustum structure 10, the frustum structure 10 can reflect and gather the surgical laser 7 transmitted in three damaged fiber cores, so that a high-energy-density small-size focusing light spot 11 is formed at the fiber end and is used for ablating thrombus in blood vessels, minimally invasive interventional treatment of thrombus in blood vessels is realized, and the Bragg grating 8 on the middle core of the fiber end can also be used for monitoring the temperature of laser heating ablation and preventing overhigh temperature and damage to blood vessels.

In the description and drawings, there have been disclosed typical embodiments of the invention. The invention is not limited to these exemplary embodiments. Specific terms are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth.

Claims

1. An interventional blood vessel cancer embolus ablation medical system with a 3D navigation function is characterized in that: the medical system comprises a multi-core optical fiber with a 3D shape sensing function, a multi-core optical fiber connector, a surgical laser light source, a fiber grating demodulator, an optical fiber sleeve and a computer; the multi-core optical fiber comprises three energy transmission fiber cores with annular defects, four single-mode fiber cores and FBG unit arrays distributed on the four single-mode fiber cores; seven fiber cores are arranged at the output end of the multi-core optical fiber connector and are respectively and correspondingly connected with the single-mode core and the annular broken fiber core of the multi-core optical fiber, and the input ends of four corresponding single-mode fiber cores of the multi-core optical fiber connector are connected with the fiber bragg grating demodulator; the input ends of the other three corresponding annular broken energy transmission fiber cores of the multi-core optical fiber connector are connected with an operation laser light source; after being processed by a computer, the optical signal obtained by the fiber grating demodulator can invert the shape of the multi-core fiber in real time, determine the position of the fiber probe in the blood vessel and realize 3D navigation of the blood vessel in vivo.

2. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: three of the four single-mode fiber cores of the multi-core fiber are distributed in a regular triangle, and the other fiber core is positioned in the middle of the fiber.

3. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: three annular energy-transmission broken fiber cores of the multi-core fiber and three single-mode fiber cores distributed in a regular triangle are distributed on the same ring.

4. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: and a circle of fluorine-doped low-refractive index layers are arranged outside the four single-mode fiber cores of the multi-core fiber.

5. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: the FBG unit array is positioned on four single-mode fiber cores, each group of gratings is prepared by grating masks with the same parameters, and the gratings of different groups are prepared by grating masks with different parameters.

6. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: the fiber end of the multi-core fiber is provided with a reflecting cone frustum, and the reflecting cone frustum reflects and focuses the surgical laser in front of the fiber end.

7. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: the FBG reflection sensing signals on the four single-mode fiber cores are demodulated by the fiber bragg grating demodulator, and the signals are obtained and processed by the computer to obtain and display the three-dimensional shape distribution of the optical fibers in real time.

8. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: and the tail end of the single-mode fiber core in the middle of the multi-core fiber is provided with an FBG (fiber Bragg Grating) for monitoring the temperature of the fiber end in real time.

9. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: before the medical system works, the shape distribution of a treatment target blood vessel is obtained through angiography, a reference coordinate system is established through a computer, and the shape feedback of the inserted multi-core optical fiber is fused in the coordinate system to obtain the absolute position of the tail end of the multi-core optical fiber in the blood vessel.

10. The interventional blood vessel cancer embolus ablation medical system with 3D navigation function of claim 1, which is characterized in that: the operation light transmitted in the three annular energy-transmitting fiber cores is a pulse light beam with high energy density, and the three energy-transmitting fiber cores can inject light in turn.