Optical fiber guide wire for in-vivo dose measurement

Abstract

The invention discloses an optical fiber guide wire for in-vivo dose measurement, and belongs to the field of close-range radiotherapy. According to the invention, the problem that a tool for detecting the dose of important tissues and organs in a narrow and limited space in a body is lacked in the current close-range radiotherapy operation is solved. The technical key points are as follows: the sensor comprises a main body part and a coating layer (4), the main body part comprises a core shaft (1), a plurality of optical fiber radiation sensors (2) and a stranded wire (3), the plurality of optical fiber radiation sensors (2) are attached to the side wall of the core shaft (1) in an annular array manner, the stranded wire (3) spirally winds the core shaft (1) and the optical fiber radiation sensors (2), and the main body part is packaged by the coating layer (4). The method is used for detecting the dose of important tissues and organs in a narrow and restricted space in a body in close-range radiotherapy. According to the optical fiber guide wire, the optical fiber and the guide wire structure are integrated, the traditional guide wire is endowed with the capability of radiation dose detection, a beneficial tool is provided for dose measurement in a narrow and limited space in a close-range radiotherapy body, and convenience is brought to surgical operation.

Description

Technical Field

[0001] The invention relates to an optical fiber guide wire, in particular to an optical fiber guide wire used for in vivo dose measurement, and belongs to the field of brachytherapy. Background Art

[0002] With the rapid development of science and technology, minimally invasive interventional treatments are becoming more and more popular. Minimally invasive interventional cancer treatments that use radioactive particles implanted in the body for brachytherapy are gradually being promoted and applied. Minimally invasive interventional brachytherapy uses the short-range effectiveness of radioactive particles and the large gradient of surrounding dose distribution to implant them near the tumor or directly into the tumor, thereby killing or inhibiting the growth of the tumor, while ensuring that the dose absorbed by the surrounding important local tissues and organs is small, maximizing the negative effects of radiotherapy. Commonly used radioactive particles in brachytherapy are: 125 I. 103 Pd and 192 Ir, etc. They are small in size, in the shape of rods with a diameter of 0.4-0.8mm and a length of about 4.5mm. They can be implanted in patients after local anesthesia in a minimally invasive surgery. At present, particle implantation in brachytherapy is completed through a particle planning system (TPS), which requires the import of patient tumor images, outlining the tumor location, and using the simulation technology of the planning system to determine the number and location of the particle source. However, for a relatively large tumor, due to the large number of sources and complex locations, it is difficult for doctors to operate accurately, which often leads to deviations between the actual source and the plan, resulting in a large dose to normal tissues, affecting the effect of surgical treatment. Therefore, designing a tool for real-time intraoperative in vivo dose measurement will help improve the surgical efficiency and implementation accuracy of brachytherapy.

[0003] Traditional radiation dose instruments are large in size and have a limited measurement range, making them difficult to be used in confined and narrow spaces in the body. Taking all factors into consideration, designing a guidewire based on a fiber optic radiation sensor will help solve the current dose detection problem in narrow and confined spaces in the body during brachytherapy. Summary of the invention

[0004] In order to overcome the problem of the lack of a dose detection tool for important tissues and organs in a narrow and confined space in the body during current brachytherapy surgery, the present invention provides an optical fiber guidewire for in vivo dose measurement. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0005] The technical solution of the present invention:

[0006] A fiber optic guidewire for in vivo dose measurement comprises a main body and a cladding layer, wherein the main body comprises a core shaft, a plurality of fiber optic radiation sensors, and a twisted wire, wherein a ring array of the plurality of fiber optic radiation sensors is attached to the side wall of the core shaft, the twisted wire is spirally wound around the core shaft and the fiber optic radiation sensors, and the cladding layer encapsulates the main body.

[0007] As a further improvement of the present invention, the core shaft 1 includes a conical body and a cylindrical body connected together, the conical body is made of nickel-titanium alloy material, and the cylindrical body is made of stainless steel material.

[0008] As a further improvement of the present invention, the sensitive end of the optical fiber radiation sensor is coated with a developing point made of barium sulfate, and the front optical fiber of the optical fiber radiation sensor is bent as the core shaft becomes thinner to fit on the side wall of the core shaft.

[0009] As a further improvement of the present invention, the probe of the optical fiber radiation sensor is formed by punching holes at the core of the end face of the PMMA optical fiber, filling the holes with scintillation material, and encapsulating the holes with a flexible resin.

[0010] As a further improvement of the present invention, the cladding layer is made of soft polytetrafluoroethylene material, and a fiber through hole is left at the left end of the cladding layer.

[0011] As a further improvement of the present invention, the number of the optical fiber radiation sensors is 3-5.

[0012] As a further improvement of the present invention, the front end of the conical body extends out of or retracts into the probe of the optical fiber radiation sensor. When the front end of the conical body is retracted into the probe of the optical fiber radiation sensor, the probes of multiple optical fiber radiation sensors are aggregated together.

[0013] As a further improvement of the present invention, the probes of the polymerized optical fiber radiation sensor are bonded and fixed with epoxy resin glue.

[0014] As a further improvement of the present invention, the probe of the adhesively fixed optical fiber radiation sensor is packaged with a smooth end surface.

[0015] As a further improvement of the present invention, the signal transmission end of the optical fiber radiation sensor is connected to the dose display instrument via the optical fiber through hole.

[0016] As a further improvement of the present invention, a cavity is left between the twisted wire and the core shaft for delivering drugs.

[0017] As a further improvement of the present invention, the core shaft is replaced by an optical fiber radiation sensor.

[0018] As a further improvement of the present invention, the conical body is a conical body with a blunt tip.

[0019] The beneficial effects of the present invention are embodied in:

[0020] Compared with the prior art, the present invention designs a fiber optic guidewire for in vivo dose measurement, which is used for detecting the dose of important tissues and organs in narrow and confined spaces in the body during brachytherapy. The fiber optic guidewire integrates the optical fiber and the guidewire structure, giving the traditional guidewire the ability to detect radiation dose, providing a useful tool for dose measurement in narrow and confined spaces in the body during brachytherapy, and bringing convenience to surgical operations. The structure of the fiber optic radiation sensor attached to the core shaft designed by the present invention not only makes the guidewire structure compact and smaller in size, but also leaves a cavity between the stranded wire and the core shaft, so that the guidewire also has the function of delivering drugs. The core diameter of the fiber optic radiation sensor in the present invention can be designed to be 0.125mm, 0.25mm or 0.5mm according to the requirements of the guidewire diameter. Although a smaller core diameter of the fiber optic radiation sensor will lead to a decrease in dose sensitivity, sufficient dose sensitivity can also be guaranteed under a multi-wire bundle design. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of an optical fiber guide wire used for in vivo dose measurement;

[0022] Figure 2 is a schematic diagram of the cross section of the optical fiber guide wire (4 optical fiber radiation sensors);

[0023] Figure 3 is a schematic diagram of the cross section of the optical fiber guide wire (3 optical fiber radiation sensors);

[0024] Figure 4 is a schematic diagram of the cross section of the optical fiber guide wire (5 optical fiber radiation sensors);

[0025] Figure 5 It is a partial schematic diagram of the front end of the optical fiber guide wire.

[0026] In the figure: 1-core, 2-optical fiber radiation sensor, 3-twisted wire, 4-cladding, 5-conical body, 6-probe, 7-optical fiber through hole. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention. It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third" and the like in the specification are only used to distinguish between the various components, elements, steps, etc. in the specification, rather than to represent the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0028] Embodiment 1, combination Figure 1-Figure 5 To illustrate this embodiment, this embodiment provides an optical fiber guidewire for in vivo dose measurement, including a main body portion and a cladding layer 4, wherein the main body portion includes a core shaft 1, a plurality of optical fiber radiation sensors 2, and a twisted wire 3, wherein a plurality of optical fiber radiation sensors 2 are attached to the side wall of the core shaft 1 in a circular array, the twisted wire 3 is spirally wound around the core shaft 1 and the optical fiber radiation sensor 2, and the cladding layer 4 encapsulates the main body portion.

[0029] It should be noted that the dimensions in the illustrated structure are schematic and do not necessarily limit the design scope of the present invention, wherein the diameter of the core shaft 1 can also be designed to be smaller than the core diameter of the optical fiber radiation sensor 2 according to actual design requirements. Even for some application scenarios with less complex pipelines, the core shaft 1 of the optical fiber guide wire in the present invention can be replaced by an optical fiber radiation sensor 2, which can increase the dose sensitivity of the optical fiber guide wire.

[0030] More specifically, the sensitive end of the optical fiber radiation sensor 2 is coated with a developing point 8 made of barium sulfate, and the front optical fiber of the optical fiber radiation sensor 2 is bent as the core shaft 1 becomes thinner to fit on the side wall of the core shaft 1. The core shaft 1 includes a conical body 5 and a cylindrical body connected together, the conical body 5 is made of a nickel-titanium alloy material that is easier to deform, and the cylindrical body is made of a stainless steel material.

[0031] It should be noted that the design of the tapered body 5 is to increase the force transmission effect in the guidewire twisting operation, achieve a greater bending and jumping effect at the front end, play a stronger selection ability in complex paths, and facilitate the operator to better complete the operation. In addition, the thinner end design of the tapered body 5 is also to enable it to pass through a narrower channel, and the design of the imaging point behind the optical fiber sensitive end is to ensure that the sensor sensitive end is accurately positioned with less radiation scattering.

[0032] More specifically, the probe 6 of the optical fiber radiation sensor 2 is formed by drilling a hole at the core of the end face of a PMMA optical fiber, filling it with scintillation material, and encapsulating it with a flexible resin.

[0033] It is worth mentioning that the end face punching shape of the optical fiber radiation sensor 2 can be designed to be a cylindrical shape with a flat bottom or a cylindrical shape with a raised bottom. The cylindrical hole with a raised bottom can improve the light coupling efficiency, which is beneficial to the improvement of the dose sensitivity of the optical fiber radiation sensor 2. However, since the diameter of the optical fiber core is too small, it is difficult to process the cylindrical hole with a raised bottom. For dose measurement where the dose sensitivity requirement is not very strict, an optical fiber with a cylindrical hole structure with a flat bottom can be used. In addition, the scintillating material filled in the optical fiber hole can be, but is not limited to, Gd 2 O 2S:Tb, because this scintillating material has high light yield and stable physical and chemical properties.

[0034] More specifically: the diameter of the stranded wire 3 changes with the diameter of the mandrel 1, and gradually decreases at the front end of the mandrel. At the same time, the diameter of the stranded wire 3 itself also gradually becomes thinner at the front end of the mandrel.

[0035] It should be pointed out that the design of the stranded wire 3 is an important part of the guidewire, which can ensure that the guidewire changes its twisting state under the adjustment of the operator to achieve path selection in a complex channel. The winding diameter of the stranded wire 3 and the diameter of the stranded wire 3 itself in the present invention are designed on the one hand to fit the compactness of the overall design of the guidewire, and on the other hand to improve the efficiency of mechanical transmission and the operability of the guidewire application.

[0036] More specifically: the coating layer 4 is made of polymer materials such as soft polytetrafluoroethylene, and a fiber through hole 7 is left at the left end of the coating layer 4. The signal transmission end of the optical fiber radiation sensor 2 is connected to the dose display instrument through the fiber through hole 7.

[0037] It should be noted that the soft polytetrafluoroethylene coating 4 provides a soft surface for the optical fiber guide wire, preventing the guide wire from piercing or abrading the patient's tissue in the body. The optical fiber radiation sensor 2 used is a scintillation detector, which needs to detect the scintillation light excited by the scintillation material after photoelectric conversion. Commonly used photoelectric detection devices include photomultiplier tubes or silicon photodiodes. The dose display in all embodiments of the present invention uses photomultiplier tubes and counters as photoelectric detection devices, and the communication module and display screen are based on the single-chip microcomputer system of stm32.

[0038] The present embodiment provides an optical fiber guide wire for in vivo dose measurement, the core of which is to use an optical fiber radiation sensor 2 as the main body of the guide wire, and to bundle it with a twisted wire 3, and finally to encapsulate it with a polytetrafluoroethylene coating 4. The optical fiber guide wire realizes the traditional minimally invasive intervention function and the latest dose detection in a confined narrow space in the body with a compact integrated structure. The present embodiment uses the twisted wire 3 to wrap around the optical fiber radiation sensor 2 and the core shaft 1 to leave a cavity structure inside the guide wire, giving the guide wire an additional delivery function.

[0039] Example 2: Based on Example 1, this example describes in detail some possible other implementation methods of improving the optical fiber guide wire structure. Its overall structure and implementation method are basically the same as those of Example 1, with only some different designs made locally. The relevant introduction is as follows:

[0040] like Figure 1 and Figure 5As shown, in this embodiment, a fiber optic guidewire is used for in vivo dose measurement, and the front end of the conical body 5 protrudes out or retracts into the probe 6 of the optical fiber radiation sensor 2, that is, the positional relationship between the front end of the conical body 5 and the probe 6 can not only be that the front end of the conical body 5 is longer than the probe 6 of the optical fiber radiation sensor, but also that the front end of the conical body 5 is shorter and the probe 6 of the optical fiber radiation sensor is longer.

[0041] It should be noted that, for the structure in Example 1, the front end of the conical body 5 is longer than the probe 6 of the optical fiber sensor, which is mainly to cope with complex channel environments. Since the front end of the conical body 5 is more flexible and plastic, it can have better curved path selection capabilities. In this embodiment, the probe of the optical fiber radiation sensor is designed to be longer, which is aimed at application scenarios with lower channel environment complexity. At this time, the probes 6 of multiple optical fiber radiation sensors are aggregated together, the position is more compact, and there is no front end of the conical body 5 in the middle, which reduces the impact on the radiation dose. Therefore, under this embodiment, the radiation dose accuracy of the optical fiber guide wire is higher and the sensitivity is stronger.

[0042] It should be noted that the probes 6 of the polymerized optical fiber radiation sensors need to be bonded and fixed with epoxy resin glue to avoid the inconsistent movement of the multiple optical fiber radiation sensors 2 in the pipeline affecting the measurement effect, and the probes 6 of the bonded and fixed optical fiber radiation sensors are packaged with a smooth end face, which avoids hard contact between the guide wire and the body tissue and prevents puncture of the patient.

[0043] In addition, if Figure 2 – Figure 4 As shown, an optical fiber guide wire for in vivo dose measurement may also have other structural forms, such as: 3 to 5 optical fiber radiation sensors 2 may be used, and they are symmetrically distributed around the core shaft 1.

[0044] It should be noted that the selection of the number of optical fiber radiation sensors 2 will affect the flexibility of the optical fiber guide wire, the sensitivity of dose detection, and the size of the cavity. When more optical fiber radiation sensors 2 are used, the force transmission performance of the optical fiber guide wire will be reduced, and the size of the cavity between the strand 3 and the core shaft 1 will be reduced, but the dose sensitivity of the optical fiber guide wire can be improved.

[0045] The embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present application shall be included in the scope of protection of the present application.

Claims

1. An optical fiber guide wire for in vivo dose measurement, characterized in that: The invention comprises a main body and a cladding layer (4), wherein the main body comprises a core shaft (1), a plurality of optical fiber radiation sensors (2), and a twisted wire (3), wherein the plurality of optical fiber radiation sensors (2) are attached to the side wall of the core shaft (1) in an annular array, the twisted wire (3) is spirally wound around the core shaft (1) and the optical fiber radiation sensor (2), and the cladding layer (4) encapsulates the main body.

2. The optical fiber guide wire for in vivo dose measurement according to claim 1, characterized in that: The core shaft (1) comprises a conical body (5) and a cylindrical body connected together, the conical body (5) is a conical body with a blunt tip and is made of a nickel-titanium alloy material, and the cylindrical body is made of a stainless steel material.

3. The optical fiber guide wire for in vivo dose measurement according to claim 2, characterized in that: The rear side of the sensitive end of the optical fiber radiation sensor (2) is coated with a developing point (8) made of barium sulfate, and the front optical fiber of the optical fiber radiation sensor (2) is bent as the core shaft (1) becomes thinner so as to fit on the side wall of the core shaft (1).

4. The optical fiber guide wire for in vivo dose measurement according to claim 3, characterized in that: The probe (6) of the optical fiber radiation sensor (2) is formed by drilling a hole at the core of the end face of a PMMA optical fiber, filling it with scintillation material, and encapsulating it with a flexible resin.

5. The optical fiber guide wire for in vivo dose measurement according to claim 4, characterized in that: The cladding layer (4) is made of soft polytetrafluoroethylene material, and a fiber through hole (7) is left at the left end of the cladding layer (4); the number of the fiber optic radiation sensors (2) is 3-5.

6. An optical fiber guidewire for in vivo dose measurement according to any one of claims 2 to 5, characterized in that: The front end of the conical body (5) extends out of or retracts into the probe (6) of the optical fiber radiation sensor (2); when the front end of the conical body (5) is retracted into the probe (6) of the optical fiber radiation sensor (2), the probes (6) of the multiple optical fiber radiation sensors are aggregated together.

7. The optical fiber guide wire for in vivo dose measurement according to claim 6, characterized in that: The probes (6) of the polymerized optical fiber radiation sensor are bonded and fixed using epoxy resin glue; and the bonded and fixed probes (6) of the optical fiber radiation sensor are packaged with a smooth end face.

8. The optical fiber guide wire for in vivo dose measurement according to claim 1, characterized in that: The signal transmission end of the optical fiber radiation sensor (2) is connected to the dose display instrument via the optical fiber through hole (7).

9. The optical fiber guide wire for in vivo dose measurement according to claim 1, characterized in that: A cavity is left between the twisted wire (3) and the core shaft (1) for delivering medicine.

10. The optical fiber guide wire for in vivo dose measurement according to claim 1, characterized in that: The core shaft (1) is replaced by an optical fiber radiation sensor (2).

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