Ablation device

Abstract

The invention provides an ablation device, and relates to the technical field of medical instruments, and the ablation device comprises a dipole antenna which is used for radiating microwave energy to a to-be-treated tissue; the dipole antenna comprises a radiation part, a feed-in line, a radiation tube, a choke ring and a protective sleeve, and the radiation part and the choke ring are two poles of the dipole antenna respectively; the far end of the feed-in wire is electrically connected with the near end of the radiation part, the choke ring sleeves the outer side of the feed-in wire, and the choke ring and the radiation part are arranged at an interval along the axial direction; the radiant tube is arranged on the outer side of the feed-in wire in a sleeving manner, and the radiant tube is located between the choke ring and the radiation part; the protective sleeve covers the rear part of the radiation part, the radiation tube and the front part of the choke ring; and the feed-in line, the radiant tube and the protective sleeve can be bent.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to an ablation device. Background Art

[0002] Microwave ablation technology has been widely used in the treatment fields of liver tumors, thyroid nodules, lung nodules, etc. due to its advantages such as minimally invasive, high efficiency, and rapid postoperative recovery. Among them, lung nodules are divided into two treatment methods: percutaneous puncture and endoscopic non-invasive treatment. The so-called endoscopic non-invasive treatment method refers to sending an ablation catheter to the lesion through the treatment channel of a bronchoscope. Since the bronchoscope completely approaches the lesion through the natural body cavity (bronchus) of the human body, the whole process is non-invasive and the postoperative complications are extremely low, which is the future direction of lung nodule treatment.

[0003] Because endoscopic non-invasive treatment of bronchoscopy is to send an ablation catheter through the working forceps channel of the bronchoscope to reach the lesion, and the state of the bronchoscope in the patient's lung is usually multi-stage twisted, so there are extremely high requirements for the overall bending performance and flexibility of the ablation catheter. Secondly, the application of microwave ablation technology in the treatment of lung nodules is later than that of liver tumors. At present, the microwave emission end design of the ablation catheters on the market basically follows the design of the microwave ablation antenna for liver tumors. However, the tissue structure and physical and electrical properties of lung nodules are completely different from those of liver tumors, so the treatment effect is not ideal. For example, the coking area is serious, and the ablation range is insufficient, resulting in residual tumor tissue after surgery. Summary of the Invention

[0004] The purpose of the present invention is to provide an ablation device to alleviate the technical problems of insufficient flexibility and insufficient ablation range of the existing ablation devices.

[0005] An ablation device provided by the present invention includes: a dipole antenna, and the dipole antenna is used to radiate microwave energy to the tissue to be processed;

[0006] The dipole antenna includes a radiation part, a feeding line, a radiation tube, a choke ring, and a protective sleeve. The radiation part and the choke ring are respectively two poles of the dipole antenna;

[0007] The distal end of the feeding line is electrically connected to the proximal end of the radiation part. The choke ring is sleeved outside the feeding line, and the choke ring is axially spaced from the radiation part;

[0008] The radiation tube is sleeved outside the feeding line, and the radiation tube is located between the choke ring and the radiation part;

[0009] The protective sleeve covers the rear part of the radiation part, the radiation tube, and the front part of the choke ring;

[0010] The feeding line, the radiation tube, and the protective sleeve can all be bent.

[0011] Further, the axial length L1 of the radiation part is λ / 4, where,

[0012]

[0013] ε γ is the relative permittivity of the tissue to be ablated, c is the speed of light, and f is the operating frequency of the ablation microwave;

[0014] and / or, the outer diameter r of the radiation part ≤ (φ - 0.2) mm, where, φ is the working forceps channel aperture of the tissue to be processed.

[0015] Further, the choke ring is sleeved outside the feeding line for suppressing the reverse current on the feeding line and optimizing the microwave ablation pattern;

[0016] and / or, the axial length L3 of the choke ring is λ / 4.

[0017] Further, a groove is provided at the axial middle part of the choke ring, and the proximal end port of the protection sleeve is covered in the groove.

[0018] Further, the axial length L2 of the radiation tube is λ / 4 - 3λ / 4.

[0019] Further, the ablation device further includes a catheter body and a handle. The distal end of the catheter body is connected to the choke ring, and the proximal end of the catheter body is connected to the distal end of the handle;

[0020] A coolant circulation mechanism is provided on the handle; a water supply pipe is provided inside the catheter body, and the feeding line passes through the water supply pipe.

[0021] Further, the coolant circulation mechanism includes a water inlet chamber, a water outlet chamber, a water inlet pipe, and a water outlet pipe. The water inlet chamber communicates with the water inlet pipe, and the water outlet chamber communicates with the water outlet pipe;

[0022] The catheter body further includes a support pipe. The water supply pipe is located inside the support pipe, and the two are spaced apart radially to form a first cavity; the water supply pipe and the feeding line are spaced apart radially to form a second cavity, and the first cavity and the second cavity communicate at the proximal end face of the choke ring;

[0023] The water inlet chamber communicates with the second cavity; the water outlet chamber communicates with the first cavity.

[0024] Further, the proximal side of the choke ring is filled with a sealing medium.

[0025] Further, a length scale is provided on the outer wall of the catheter body along its axis.

[0026] The present invention has at least the following advantages or beneficial effects:

[0027] The ablation device provided by the present invention includes: a dipole antenna, which is used to radiate microwave energy to the tissue to be treated; the dipole antenna includes a radiation part, a feeding line, a radiation tube, a choke ring and a protective sleeve, and the radiation part and the choke ring are respectively two poles of the dipole antenna; the distal end of the feeding line is electrically connected to the proximal end of the radiation part, the choke ring is sleeved outside the feeding line, and the choke ring and the radiation part are axially spaced apart; the radiation tube is sleeved outside the feeding line, and the radiation tube is located between the choke ring and the radiation part; the protective sleeve covers the rear part of the radiation part, the radiation tube and the front part of the choke ring; the feeding line, the radiation tube and the protective sleeve are all bendable.

[0028] First of all, the middle part of the dipole antenna is flexible and can be freely bent, and can pass through the channels of most endoscopes, and finally reach most lesions for ablation treatment, solving the problem of clinical visibility but inaccessibility. Based on the dipole antenna theory, the radiation part and the choke ring are respectively two poles evolved from the dipole antenna. Since the radiation tubes between the radiation part and the choke ring can all radiate microwave energy into the tissue, the ablation range is increased, and the problem of insufficient ablation range caused by factors such as coking of conventional microwave ablation antennas is completely solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 Schematic diagram of the ablation device provided by the embodiment of the present invention;

[0031] Figure 2 Cross-sectional view of the dipole antenna of the ablation device provided by the embodiment of the present invention (in the freely bent state);

[0032] Figure 3 For Figure 2 Partial enlarged view of position A in

[0033] Figure 4 For Figure 2 Partial enlarged view of position B in

[0034] Figure 5 For Figure 2 Cross-sectional view in the C-C direction of

[0035] Figure 6 is Figure 2 a sectional view in the D - D direction in

[0036] Figure 7 a sectional view (in the straight state) of the dipole antenna of the ablation device provided by the embodiment of the present invention;

[0037] Figure 8 an internal view of the handle of the ablation device provided by the embodiment of the present invention;

[0038] Figure 9 is Figure 8 a partial enlarged view at the E position in

[0039] Icon: 1 - radiation part; 2 - protective sleeve; 3 - radiation tube;

[0040] 4 - feed line; 401 - inner conductor; 402 - dielectric layer; 403 - outer conductor;

[0041] 5 - choke ring; 501 - groove; 61 - water supply pipe; 62 - water inlet cavity; 63 - water outlet cavity; 64 - water inlet pipe; 65 - water outlet pipe; 66 - RF connector; 67 - first cavity; 68 - second cavity;

[0042] 7 - radiation medium; 8 - sealing medium; 9 - support tube;

[0043] 100 - dipole antenna; 200 - catheter body; 210 - scale; 300 - handle. Detailed implementation manners

[0044] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0046] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0047] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0048] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0049] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] As Figure 1 shown, the ablation device includes a dipole antenna 100, a catheter body 200, and a handle 300. The dipole antenna 100 is the part that radiates microwave energy to the tissue to be treated. The catheter body 200 connects the dipole antenna 100 and the handle 300, and the handle 300 is the holding part of the ablation device.

[0051] As Figure 7 shown, the dipole antenna 100 is a multi-segment structure, including a radiation part 1 (the first segment), a feeding line 4, a radiation tube 3 (the second segment), a choke ring 5 (the third segment), and a protective sleeve 2. According to the theory of the dipole antenna 100, the radiation part 1 is a pole of the dipole antenna 100, and the axial length L1 of the radiation part 1 is related to the wavelength λ of the microwave in the tissue (such as lung tissue).

[0052] The microwave propagates in different human tissues, and the wavelength λ is calculated by the formula:

[0053]

[0054] Where is the wavelength in free space, εγ is the relative permittivity of the tissue, c is the speed of light (3x10 8 m / s), and f is the frequency.

[0055] According to the above formula, the wavelength λ of microwaves at a frequency of 2.45 GHz (ε γ which can be obtained through experiments) in different human tissues is as follows:

[0056] Table 2

[0057] Wavelength (cm) of 2.45G microwaves in different human tissues

[0058] Human organs Liver Lung (not inflated) Lung (inflated) Thyroid gland Wavelength λ 1.86 2.12 2.69 1.9－2.1

[0059] By referring to relevant literature, the wavelength of microwaves with a frequency of 2.45 GHz in lung tissue (inflated) is approximately 2.69 cm. According to λ / 4, the axial length L1 of the radiation part 1 is calculated to be 6.7 mm.

[0060] The outer diameter of the radiation part 1 is related to the aperture φ of the working forceps channel of the endoscope, and the outer diameter of the radiation part 1 ≤ φ - 0.2 mm. In this embodiment, a bronchus with a currently common working forceps channel of 2 mm on the market is selected, and the outer diameter of the radiation part 1 can be set to 1.6 mm.

[0061] As Figure 2 - Figure 4 shown, the feeding line 4 includes an inner conductor 401, a dielectric layer 402, and an outer conductor 403 arranged in sequence from the inside out. In this embodiment, a flexible radio frequency transmission line is selected. Its inner conductor 401 and dielectric layer 402 penetrate into the inside of the radiation part 1. The end face hole of the radiation part 1 is a stepped structure. The inner conductor 401 extends in 4 mm, and the inner conductor 401 and the radiation part 1 are reliably electrically connected through processes such as welding and crimping. The dielectric layer 402 then penetrates into the radiation part 1. A radiation medium 7 is filled between the dielectric layer 402 and the radiation part 1. According to practice, this filling medium can be a high-temperature resistant glue (with a relative permittivity of 2 - 3 at 2.45 GHz) or other medical materials.

[0062] As Figure 7 shown, a radiation tube 3 is sleeved outside the outer conductor 403. According to data calculation and multiple verifications, when the axial length L2 of the radiation tube 3 is λ / 4 - 3λ / 4, experiments prove that this structural dimension can achieve an ideal ablation range and at the same time the coking area is small. Since this embodiment selects lung tissue as the ablation tissue, therefore, the axial length of the radiation tube 3 in this embodiment can be designed to be 12 mm. In terms of material selection, polytetrafluoroethylene can be selected, and this type of material has outstanding characteristics in terms of temperature resistance and relative permittivity.

[0063] As Figure 5 and Figure 6As shown, the choke ring 5 is mounted on the outer conductor 403, and its main function is to choke the reverse current on the outer conductor 403 and alleviate the reverse heating problem of the dipole antenna 100. Its axial length L3 is also 1 / 4 of the wavelength λ of microwaves in lung tissue, which is set to 6.5 mm in this embodiment.

[0064] A groove 501 is designed in the axial middle portion of the choke ring 5 , and the proximal end port of the protection sleeve 2 is covered in the groove 501 of the choke ring 5 to prevent the axial slip of the protection sleeve 2 .

[0065] The protective sleeve 2 covers the rear part of the radiating part 1, the radiating tube 3, and the choke ring 5 (a heat shrink process may be used in the actual production process), and its main function is to protect the dipole antenna 100 and prevent the dipole antenna 100 from being damaged under extreme operation.

[0066] like Figure 8 and Figure 9 As shown, the catheter body 200 receives the dipole antenna 100 and the handle 300. According to the bronchoscope working channel (2mm) selected in this embodiment, its outer diameter is set to 1.6mm. It is a nested structure. The innermost part is a part of the feed line 4, the middle is the water supply pipe 61, and the outermost part is the support pipe 9. The wall thickness of the water supply pipe 61 is ≤0.05mm, and its inner and outer diameters must comply with the following formula:

[0067]

[0068] in, are the inner diameter and outer diameter of the water supply pipe 61, is the inner diameter of the support tube 9-1, is the outer diameter of the feed line 4.

[0069] like Figure 7 As shown, the protective sleeve 2 and the support tube 9 can be a two-stage structure or an integrated structure. In order to ensure the microwave radiation efficiency of the dipole antenna 100, the wall thickness of the protective sleeve 2 should be ≤0.05mm; at the same time, in order to ensure the structural characteristics of the support tube 9, the wall thickness should be between 0.05mm and 0.15mm. Therefore, if it is an integrated design, it needs to be a double-walled structure with a thin distal wall (≤0.05mm) and a thick proximal wall (0.05mm-0.15mm). Specifically, the protective sleeve 2 and the support tube 9 in this embodiment are of an integrated design (thin front section and thick rear section), the inner wall of the protective sleeve 2 is tightly fitted with the outer wall of the radiation tube 3, and the wall thickness of the protective sleeve 2 is selected as 0.03mm in this embodiment; the support tube 9 is selected as 0.1mm.

[0070] The proximal end of the choke ring 5 is filled with a sealing medium 8, which may be a high-temperature medical glue.

[0071] The catheter body 200 is provided with a length scale 210. The starting position of the first scale 210 of the scale 210 can be the length L4 = l + 30 mm to the distal end of the catheter body 200, where l is the length of the working channel of the endoscope. According to the length of the working channels of commonly used bronchoscopes on the market at present, in this embodiment, it is set as: L4 = 730 mm.

[0072] The handle 300 is a holding component of the ablation catheter, and a coolant circulation mechanism and a radio frequency connector 66 are designed inside it.

[0073] The coolant circulation mechanism is designed with double cavities in the front and rear. The front and rear double cavities are the water inlet cavity 62 and the water outlet cavity 63 respectively. The water inlet cavity 62 communicates with the water inlet pipe 64, and the water outlet cavity 63 communicates with the water outlet pipe 65. The path of the water circulation is: the cooling water enters the water inlet cavity 62 from the water inlet pipe 64, then enters the second cavity 68 between the feeding line 4 and the water supply pipe 61, and finally flows back into the water supply pipe 61 between the choke ring 5 and the support pipe 9 at the end face of the choke ring 5, and finally flows back to the water outlet cavity 63 and finally flows out of the pipe through the water outlet pipe 65 to achieve the cooling effect.

[0074] The radio frequency connector 66 is fixed on the handle 300 and connected to the feeding line 4.

[0075] To sum up, there are mainly two innovation points in the ablation device in this embodiment:

[0076] (1) Based on the theory of the dipole antenna 100, a kind of overall flexible design is adopted, and the dipole antenna 100 can also be freely bent. The radiation part 1 and the choke ring 5 of the dipole antenna 100 are respectively the two poles evolved from the dipole antenna 100, and their structural dimensions are consistent with the wavelength of the microwave in the treatment tissue. Since the part (radiation tube 3) between the radiation part 1 and the choke ring 5 can radiate microwave energy into the tissue, the maximum ablation range can reach more than 3 cm, completely solving the problem of insufficient ablation range caused by factors such as coking in conventional microwave ablation antennas;

[0077] (2) The dipole antenna 100 is designed with a multi-segment structure (currently all are single-end structures), which are respectively the radiation part 1 (the first segment), the choke ring 5 (the third segment) and the radiation tube 3 (the second segment) between the two. And the radiation tube 3 is a flexible structure. The multi-segment structure + the flexible structure of the radiation tube 3 can ensure that the dipole antenna 100 of this ablation catheter can pass through the vast majority of the endoscope channels and finally reach the vast majority of the lesions for ablation treatment, solving the problem of being visible but not reachable clinically.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ablation device, characterized in that, Comprising: A dipole antenna (100) for radiating microwave energy to the tissue to be treated; The dipole antenna (100) includes a radiation part (1), a feeding line (4), a radiation tube (3), a choke ring (5) and a protective sleeve (2), and the radiation part (1) and the choke ring (5) are respectively two poles of the dipole antenna (100); The distal end of the feeding line (4) is electrically connected to the proximal end of the radiation part (1), the choke ring (5) is sleeved on the outside of the feeding line (4), and the choke ring (5) is axially spaced from the radiation part (1); The radiation tube (3) is sleeved on the outside of the feeding line (4), and the radiation tube (3) is located between the choke ring (5) and the radiation part (1); The protective sleeve (2) covers the rear part of the radiation part (1), the radiation tube (3) and the front part of the choke ring (5); The feeding line (4), the radiation tube (3) and the protective sleeve (2) are all bendable.

2. The ablation device according to claim 1, wherein, The axial length L1 of the radiation part (1) is λ / 4, where ε γ is the relative permittivity of the tissue to be ablated, c is the speed of light, and f is the operating frequency of the ablation microwave; and / or, the outer diameter r of the radiation part (1) ≤ (φ - 0.2) mm, where is the working forceps channel aperture of the tissue to be treated.

3. The ablation device according to claim 2, wherein The choke ring (5) is sleeved on the outside of the feeding line (4) for suppressing the reverse current on the feeding line (4); And / or, the axial length L3 of the choke ring (5) is λ / 4.

4. The ablation device according to claim 1, characterized in that, A groove (501) is provided at the axial middle part of the choke ring (5), and the proximal end port of the protective sleeve (2) is covered on the groove (501).

5. The ablation device according to claim 1, wherein The axial length L2 of the radiation tube (3) is λ / 4 - 3λ / 4.

6. The ablation device according to claim 2, wherein, The ablation device further includes a catheter body (200) and a handle (300), the distal end of the catheter body (200) is connected to the choke ring (5), and the proximal end of the catheter body (200) is connected to the distal end of the handle (300); A coolant circulation mechanism is provided on the handle (300); a water supply pipe (61) is provided in the catheter body (200), and the feeding line (4) passes through the water supply pipe (61).

7. The ablation device according to claim 6, characterized in that, The coolant circulation mechanism includes a water inlet chamber (62), a water outlet chamber (63), a water inlet pipe (64) and a water outlet pipe (65), the water inlet chamber (62) communicates with the water inlet pipe (64), and the water outlet chamber (63) communicates with the water outlet pipe (65); The catheter body (200) further includes a support tube (9), the water supply pipe (61) is located inside the support tube (9), and the two are spaced apart radially to form a first cavity (67); the water supply pipe (61) and the feeding line (4) are spaced apart radially to form a second cavity (68), and the first cavity (67) and the second cavity (68) communicate at the proximal end face of the choke ring (5); The water inlet chamber (62) communicates with the second cavity (68); the water outlet chamber (63) communicates with the first cavity (67).

8. The ablation device according to claim 6, wherein A sealing medium (8) is filled on one side of the proximal end of the choke ring (5).

9. The ablation device according to claim 6, wherein, A length scale (210) arranged along the axis is provided on the outer wall of the catheter body (200).

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