CN110354366B - Force sensing guide wire for CTO interventional therapy - Google Patents

Abstract

The invention relates to a force sensing guide wire for CTO interventional therapy, which comprises a wire core, an optical fiber and a plurality of FBG sensors, wherein a plurality of grooves are formed in the outer surface of the wire core, the optical fiber is arranged in the grooves, the plurality of FBG sensors are arranged in the optical fiber, the wire core comprises a plurality of detection sections, three vertexes of each three FBG sensors which are in an equilateral triangle shape are distributed on one detection section, the FBG sensors are mutually parallel, and the radial direction of each FBG sensor and the radial direction of the wire core form an inclination angle. Compared with the prior art, the invention can realize accurate stress detection of the guide wire at the guide wire operation end, and form tactile feedback.

Description

A force-sensing guidewire for CTO interventional treatment

Technical Field

The present invention relates to the field of medical devices, and in particular to a force-sensing guidewire for CTO interventional treatment.

Background Art

Chronic total occlusion (CTO) lesions are known as the "last bastion" in the field of coronary intervention because of their low success rate and high complication rate in percutaneous coronary intervention (PCI). Data show that the average lesion success rate of interventional treatment of CTO lesions is currently 75.1% (62-85%), and the vast majority of CTO intervention failures are due to the inability to pass the guidewire through the lesion to reach the distal end of the blood vessel. During the operation, the operator determines whether the guidewire is running in the true lumen of the blood vessel by observing the shape of the guidewire and the tiny tactile feedback on the hand. The tactile feedback generated at the end of the guidewire is different for different lesions, which is an important basis for doctors to adjust the wire feeding strategy. This step requires a lot of experience accumulation, but it is still easy to make mistakes.

At the same time, the existing percutaneous coronary intervention (PCI) surgical robot CorPath can achieve the same effect as conventional manual PCI surgery, can meet the needs of PCI surgery for simple lesions, reduce the radiation damage to doctors during interventional treatment, and have a very positive impact on interventional treatment. However, the surgical robot is still unable to handle complex lesions, such as CTO surgery, due to the lack of sufficient tactile feedback information. For example, the invention patent application with publication number CN106659394A discloses a guidewire with sensors, the type and layout of which are only for strengthening the strength of the guidewire, and cannot provide accurate tactile feedback such as torsion information. Therefore, there is an urgent need to build real and fine tactile feedback at the operating end of the guidewire.

Summary of the invention

The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a force-sensing guidewire for CTO interventional treatment.

The purpose of the present invention can be achieved by the following technical solutions:

A force-sensing guidewire for CTO interventional treatment comprises a wire core, an optical fiber and a plurality of FBG sensors, wherein the outer surface of the wire core is provided with a plurality of grooves, the optical fiber is arranged in the grooves, the plurality of FBG sensors are arranged in the optical fiber, the wire core comprises a plurality of detection sections, and the three vertices of every three FBG sensors forming an equilateral triangle are distributed on a detection section, the FBG sensors are parallel to each other and the radial direction of the FBG sensor forms an inclination angle with the radial direction of the wire core.

Furthermore, the multiple grooves are spiral grooves, and the optical fiber is spirally wound on the core in the grooves.

Furthermore, the grooves on the outer surface of the wire core are three step-like grooves of the same shape, each groove is provided with a vertical section and an inclined section at intervals, and the FBG sensor is provided in the inclined section of each groove.

Furthermore, the multiple detection sections are evenly distributed on the wire core.

Furthermore, the guide wire is longer than 15 cm.

Furthermore, the diameter of the wire core is 0.35-0.37 mm.

Furthermore, the diameter of the groove is 0.08-0.125 mm.

Furthermore, the wire core is made of stainless steel or nickel-titanium alloy.

Furthermore, a hemispherical end point is provided at the top of the wire core.

Compared with the prior art, the present invention has the following advantages:

1. The present invention decomposes the strain of each FBG sensor on the same detection section into the axial and tangential directions of the guidewire through the layout of the FBG sensor on the guidewire, and then sequentially establishes the guidewire curvature and sensor (group) strain model and the guidewire force and curvature model according to the geometric relationship, and derives the sensor (group) strain and force model, and realizes accurate force detection of the guidewire by solving the mathematical model composed of differential equations and boundary conditions to form tactile feedback.

2. The present invention adopts FBG sensors to realize the arrangement of sensors on micro-sized guide wires. FBG optical fiber sensors have the advantages of extremely high sensitivity and accuracy, small size, flexibility, and integration of sensing and transmission, and are very suitable for integration into guide wires. At the same time, the inherent safety, anti-electromagnetic interference, and corrosion resistance of optical fiber sensors enable them to be used normally in radiation environments and vascular environments.

3. The optical fiber is arranged on the core in the form of a spiral groove, which is convenient for preparing the groove and embedding the optical fiber for installation; when the optical fiber is arranged in a stepped form, the length of the embedded optical fiber can be greatly shortened, reducing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of the first embodiment.

FIG2 is a schematic structural diagram of the FBG sensor layout on the same detection cross section after the wire core diameter is enlarged.

FIG3 is a cross-sectional schematic diagram of the layout of FBG sensors on the same detection section.

FIG4a is a schematic diagram of the analysis of the modeling principle.

FIG4 b is a schematic diagram of the analysis of the modeling principle.

FIG5 is a schematic diagram of the structure of the second embodiment.

Figure numerals: 1. Silk core, 2. Optical fiber, 3. FBG sensor, 4. Groove, 5. Detection section, 6. End point.

DETAILED DESCRIPTION

The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

Embodiment 1

As shown in FIGS. 1 to 3 , this embodiment provides a force-sensing guidewire for CTO interventional treatment, including a wire core 1, an optical fiber 2, and a plurality of FBG sensors 3. The wire core 1 is provided with multiple grooves 4 on the outer surface, the optical fiber 2 is arranged in the grooves 4, and the multiple FBG sensors 3 are arranged in the optical fiber 2. The wire core 1 includes multiple detection sections 5, and the detection sections 5 are evenly distributed on the wire core 1. Every three FBG sensors 3 are distributed on the detection section 5 in the form of three vertices of an equilateral triangle, the FBG sensors 3 are parallel to each other, and the radial direction of the FBG sensors 3 and the radial direction of the wire core 1 form an inclination angle. The multiple grooves 4 are spiral grooves, and the optical fiber 2 is coiled on the wire core 1 in the grooves. A hemispherical end point 6 is provided at the top of the wire core 1. The guidewire length is generally greater than 15 cm, and in this embodiment it is 30 cm. The force-sensing functional area is distributed in the 15-20 cm area of the guidewire head end. The diameter of the wire core is generally 0.35 to 0.37 mm, and in this embodiment it is 0.35 mm. The diameter of the groove is generally 0.08-0.125 mm, and is 0.08 mm in this embodiment. The wire core is made of stainless steel.

The working principle of this embodiment is:

As shown in Fig. 4a and Fig. 4b, the cross section where the FBG sensor is located is selected to establish a local coordinate system, in which the position of the FBG sensor r _s and the curvature u _xy of the guide wire in the plane are defined (u _x and u _y are the curvature decompositions of the x-axis and y-axis of the coordinate system, respectively);

A relationship model between curvature and strain of three sensors in the same detection section is established, and the curvature and torsion values of the guidewire are obtained by solving the simultaneous equations of the sensor group.

Because the effective strain measurement range of the FBG sensor is within 1%, that is, ε _a and ε _t are both small values (<0:01), the following equation holds true:

ε _l ≈w ₁ ε _a +w ₂ ε _t

w ₁ ＝h ² /l ² w ₂ ＝2πrh/l ²

ε _a , ε _t , ε _l are the axial, shear and total strains of the helical fiber segment respectively; h is the pitch; l is the length of the helical fiber segment; r is the length from the center of the fiber cut surface to the center of the guide wire;

And the following equation holds true in the coordinate system constructed above:

in:

They represent the decomposition of the guidewire pre-bending in the coordinate axes x, y, and z directions respectively;

_rs and _αs are the position vector and direction angle of the FBG sensor in the coordinate system, respectively.

Then the curvature and torque of the guide wire bending can be obtained by solving the following equation:

i represents the index number of each FBG sensor in the same detection cross section.

Embodiment 2

As shown in FIG. 5 , FIG. 2 and FIG. 3 , the present embodiment provides a force-sensing guidewire for CTO interventional treatment, comprising a wire core 1, an optical fiber 2 and a plurality of FBG sensors 3. The wire core 1 is provided with a plurality of grooves 4 on the outer surface, the optical fiber 2 is arranged in the grooves 4, and the plurality of FBG sensors 3 are arranged in the optical fiber 2. The wire core 1 includes a plurality of detection sections 5, and the detection sections 5 are evenly distributed on the wire core 1. Every three FBG sensors 3 are distributed on the detection section 5 in the form of three vertices of an equilateral triangle, the FBG sensors 3 are parallel to each other, and the radial direction of the FBG sensors 3 and the radial direction of the wire core 1 form an inclination angle. The grooves 4 on the outer surface of the wire core are three step-like grooves of the same shape, each groove is arranged with a vertical section and an inclined section at intervals, and the FBG sensor is arranged in the inclined section of each groove. The optical fiber 2 is coiled on the wire core 1 in the groove. A hemispherical end point 6 is provided at the top of the wire core 1.

The length of the guide wire is generally 15 to 20 cm, and in this embodiment it is 20 cm. The diameter of the wire core is generally 0.35 to 0.37 mm, and in this embodiment it is 0.37 mm. The diameter of the groove is generally 0.08 to 0.125 mm, and in this embodiment it is 0.125 mm. The wire core is made of nickel-titanium alloy.

The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims (6)

1. The utility model provides a force sensing guide wire for CTO interventional therapy, includes silk core (1), optic fibre (2) and a plurality of FBG sensor (3), the surface of silk core (1) is equipped with multichannel recess (4), optic fibre (2) set up in recess (4), a plurality of FBG sensor (3) set up in optic fibre (2), characterized in that includes a plurality of detection cross-section (5) on silk core (1), every three FBG sensor (3) are on a detection cross-section (5) with equilateral triangle's three summit distribution, are parallel to each other between FBG sensor (3) and the radial of FBG sensor (3) and silk core (1) radially form the inclination;

The multi-channel grooves (4) are spiral grooves, and the optical fibers (2) are spirally wound on the wire core (1) in the grooves, or: the grooves (4) on the outer surface of the wire core are three similar-step-shaped grooves with the same shape, each groove is formed by a vertical section and an inclined section at intervals, and the FBG sensor (3) is arranged in the inclined section of each groove;

the detection sections (5) are uniformly distributed on the wire core (1).

2. The force sensing guidewire for CTO intervention of claim 1, wherein the guidewire length is greater than 15cm.

3. The force sensing guide wire for CTO intervention according to claim 1, wherein the diameter of the wire core (1) is 0.35-0.37 mm.

4. The force sensing guide wire for CTO intervention according to claim 1, wherein the diameter of the groove (4) is 0.08-0.125 mm.

5. A force sensing guidewire for CTO intervention according to claim 1, wherein the wire core (1) is of stainless steel or nitinol.

6. The force sensing guide wire for CTO interventional therapy according to claim 1, wherein the tip of the wire core (1) is provided with a hemispherical end point (6).