Microwave ablation needle and microwave ablation therapeutic device

Abstract

The present invention discloses a microwave ablation needle and a microwave ablation therapeutic apparatus. The microwave radiation antenna included in the microwave ablation needle has a unique multi-transmitting ring structure. The radiation structure has a high radiation efficiency. By adjusting the structural parameters of the antenna, the shape and size of the microwave ablation area can be adjusted and improved, which has a high practical value and promotion significance. The high-frequency spike pulse suppression module, coaxial isolation module, and surge protector included in the microwave ablation therapeutic apparatus have the functions of reducing the standing wave ratio and improving the microwave output efficiency, and can also improve the shape and size of the microwave ablation area. The present invention is mainly used in microwave ablation therapy, and can be used to perform ablation therapy on tumors, nodules, and other muscle, fat, blood vessel and other tissues of the human body.

Description

Technical Field

[0001] The invention relates to a medical device for ablating a tumor, in particular to a microwave ablation therapeutic apparatus and a matching microwave ablation needle. Background Art

[0002] Microwave ablation technology is a new technology developed in the past decade. It is a combination of modern medical imaging and microwave technology. Its treatment mechanism is to insert a needle-shaped radiator (called "microwave ablation needle") directly into the tumor tissue under the guidance of B-ultrasound, CT or MRI. The polar molecules and ions in the tumor tissue vibrate violently and rub under the action of the alternating microwave field to generate a large amount of heat, directly heating the tumor tissue, and using the method of thermal coagulation to denature and necrotize the tumor tissue to achieve the purpose of inactivating the tumor tissue. Due to its significant efficacy, simple operation and small wound, it has been increasingly widely used in minimally invasive treatment of solid tumors.

[0003] With the continuous deepening of clinical practice, people have put forward higher and higher requirements for microwave ablation therapeutic devices and microwave ablation needles (microwave radiation antennas). For example: microwave ablation therapeutic devices are required to have stable performance, user-friendly interface, simple operation, and the ability to quickly and accurately display various real-time parameters of the treatment site, and have various safety protection functions; when using microwave ablation needles to insert tumor tissue for treatment, on the one hand, it is hoped that the ablation needle can output stable and large microwave power so that the tumor tissue can be effectively heated, and on the other hand, the needle tube is required to be thinner and thinner so that the damage to blood vessels, nerves and other tissues along the puncture path can be minimized during puncture; it is also required that the shape of the ablation area be as close to a circle as possible, that is, matching the shape of the tumor, so as to achieve the best treatment effect.

[0004] Many microwave ablation therapeutic devices on the market still use microwave sources with magnetron as the core. This type of microwave ablation therapeutic device is large in size, has an operating voltage of up to 4000V, and a lifespan of only 500-1000 hours. Its output power decays severely over time; the CPU used in the central control module is also slow and has poor performance. The outer diameter of the current microwave ablation needle tube is generally about 2.2mm, and its internal microwave transmission part is a rigid (or semi-rigid) coaxial cable, which consists of a metal outer conductor (shielding function), a metal inner conductor (transmitting microwave function) and a plastic insulation layer between the inner and outer conductors. Usually, a section of the metal outer conductor is stripped off at the front end of the coaxial cable, leaving the plastic insulation layer and the metal inner conductor between the inner and outer conductors. The metal inner conductor is connected to the needle tip of the microwave ablation needle, and the needle tip is the microwave radiation end. Since the needle tip of the microwave ablation needle connected to the front end of the rigid coaxial cable is not shielded by the metal outer conductor, the microwave energy can be radiated from it. After the tumor absorbs the microwave, high-temperature ablation will occur, inactivating tumor cells. However, the needle tip as one pole of the antenna has a slender shape, and the microwave field formed by radiation is slender, which makes the shape of the ablation area also slender. In addition, the cross-sectional area of ​​the coaxial cable is proportional to the microwave energy it can carry. Under the condition of a certain microwave frequency, the more microwave energy the microwave ablation needle outputs to the tumor tissue, the larger the range of tissue that can be coagulated. Therefore, in order to increase the range of tumor ablation, it is necessary not only to increase the diameter of the coaxial cable, but also to increase the surface area of ​​the needle tip as the radiating antenna. Practice has shown that the use of thicker microwave ablation needles for clinical puncture will inevitably cause serious damage to blood vessels, nerves or other tissues in the puncture path, and the probability of massive bleeding of tissues and organs will increase, thereby increasing the complexity and danger of surgical operations. Therefore, most of the microwave ablation needles used at home and abroad are less than 2.2 mm in diameter. When the coaxial cable is forced to increase the conduction output power, it will cause excessive current and heat, which may cause the coaxial cable to burn, and may even cause normal tissues around the ablation needle shaft to be burned. Therefore, in addition to taking cooling measures on the needle tip of the microwave ablation needle, it is imperative to improve the radiation efficiency of the microwave antenna through reasonable design.

[0005] The utility model patent with announcement number CN204708984U and name “A high-intensity microwave ablation needle” discloses a water-cooled microwave ablation needle. It is difficult to achieve impedance matching between the radiating antenna and the needle rod in the ceramic needle head. Microwaves will be reflected in the structure, resulting in low radiation efficiency of the microwave antenna. In addition, the ablation area is not spherical, which affects the ablation effect. The invention patent with announcement number CN101711705A and name “Microwave ablation needle and microwave ablation therapeutic device” discloses that the needle tube uses a capillary tube for water circulation cooling. However, the water intake of the capillary tube is too small, and the cooling effect on the needle head is not good. There is also a slot antenna used as a microwave transmitting antenna. Since the antenna area is too small, the transmission efficiency is low, and it is difficult to obtain a satisfactory ablation effect. Summary of the invention

[0006] In view of the above technical defects and shortcomings, the present invention proposes a microwave ablation needle and a microwave ablation therapeutic apparatus used therewith to solve the problem that the traditional microwave radiation antenna has poor ablation effect due to low radiation efficiency.

[0007] The technical implementation scheme of the present invention is as follows:

[0008] A microwave ablation needle comprises: an ablation needle, an ablation needle tube, a coaxial cable, a tail box, a microwave cable connector, a water inlet connector and a water outlet connector; the front end of the ablation needle tube is connected to the ablation needle, and the end of the ablation needle tube enters the tail box; the coaxial cable runs through the ablation needle tube, and the end of the coaxial cable is electrically connected to the microwave cable connector in the tail box; the microwave cable connector, the water inlet connector and the water outlet connector are all arranged on the tail box.

[0009] Furthermore, the microwave ablation needle also includes: a metal body, which is at the front end of the coaxial cable and electrically connected to the inner conductor of the coaxial cable; two metal rings parallel to each other and surrounding the coaxial cable are installed on the insulating layer of a section of the coaxial cable close to the metal body, respectively called a front ring and a rear ring, the front ring is close to the metal body and electrically connected to the metal body, and the rear ring is electrically connected to the rear outer conductor of the coaxial cable through a wire; a microwave radiation antenna composed of the front ring, the rear ring, and the metal body is placed in the ablation needle, and microwaves are emitted outward from the microwave radiation antenna composed of the metal body, the front ring, and the rear ring.

[0010] The microwave ablation needle described in the present invention is a microwave radiation antenna composed of a metal body and at least two metal rings with a multi-emitting ring structure, which greatly improves the radiation efficiency under the same conditions and without increasing the diameter of the coaxial cable, and the ablation area is larger, thereby improving the ablation effect and avoiding the problem of the coaxial cable being forced to increase the output power and causing easy overheating and burning; at the same time, by adjusting the width of the front ring and the rear ring, the spacing between the front ring and the rear ring, and the spacing between the rear ring and the rear outer conductor of the coaxial cable, the shape and size of the ablation area can be adjusted and changed, further improving the ablation effect without increasing the diameter of the coaxial cable and the surface area of ​​the ablation needle, avoiding damage to blood vessels, nerves or other tissues in the puncture path as much as possible, and reducing the complexity and risk of surgical operations; the microwave radiation antenna is simple to manufacture, ingeniously conceived, and has high practical value and promotion significance.

[0011] Furthermore, a mode of multiple metal rings can be used in the microwave radiation antenna: a third or multiple metal rings are installed between the front ring and the rear ring; the multiple metal ring mode is implemented as follows: two or more sections of the outer conductor of the coaxial cable are removed from the coaxial cable to form multiple metal rings composed of outer conductors and parallel to each other, or a section of the outer conductor of the coaxial cable is stripped off, and multiple metal rings are mounted on the insulating layer of the coaxial cable. According to needs, the middle ring can be electrically connected to the front ring or the rear ring.

[0012] Other methods such as corrosion can also be used to produce a microwave radiation antenna with a double transmitting ring structure.

[0013] Furthermore, the width of the front ring of the microwave radiation antenna is 1.0 to 12.5 mm, and the optimal value is 1.5 mm to 6.5 mm; the width of the rear ring is 1.5 to 12.5 mm, and the optimal value is between 4.0 mm and 9.8 mm; the spacing between the front ring and the rear ring is 0.5 to 13 mm, and the optimal value is between 1.5 mm and 5.0 mm; the spacing between the rear ring and the rear outer conductor of the coaxial cable is 1.0 to 32 mm, and the optimal value is between 6.5 mm and 18 mm.

[0014] The distance between the rear ring and the rear outer conductor of the coaxial cable should be as large as possible, greater than 6 mm, so as to reduce the electric field influence of the outer conductor on the microwave radiation antenna, and also improve and adjust the shape of the ablation area.

[0015] Furthermore, the widths of the front ring and the rear ring are equal, and the microwave radiation antenna produces a spherical or ellipsoidal ablation area; the widths of the front ring and the rear ring are unequal, and the microwave radiation antenna produces a spindle-shaped or teardrop-shaped ablation area; the size and shape of the ablation area can be adjusted by adjusting the spacing between the front ring and the rear ring and the spacing between the rear ring and the rear outer conductor of the coaxial cable.

[0016] The microwave ablation needles on the market basically emit microwaves from windows and gaps, while the present invention mainly emits microwaves through a microwave radiation antenna composed of a metal ball, a front ring and a rear ring. Compared with other products on the market, the present invention greatly improves the radiation efficiency of the microwave radiation antenna, and the transmission power under the same conditions can be greater, and the ablation area is larger. Another advantage of the microwave radiation antenna is that the shape and size of the ablation area can be easily changed by adjusting the front ring width W1, the rear ring width W2, the spacing D1 between the front and rear rings, and the spacing D2 between the rear ring and the rear outer conductor of the coaxial cable in the radiation antenna.

[0017] Furthermore, the metal body is a metal ball, a metal ellipsoid or a metal body of other shapes whose diameter is the same as the outer diameter of the coaxial cable; or the metal body is a metal ball, a metal ellipsoid or a metal body of other shapes whose diameter is different from the outer diameter of the coaxial cable; the ratio of the diameter of the metal body to the outer diameter of the inner conductor of the coaxial cable is 0.5:1 to 3:1, preferably 0.8:1 to 1.5:1; this ratio facilitates welding the metal body, the inner conductor and the frontmost conductive ring together.

[0018] Furthermore, the ablation needle is made of high-temperature resistant non-metallic material, and the microwave radiation antenna is coaxially arranged in the central symmetrical hole of the ablation needle; the microwave radiation antenna is coaxially arranged in the central symmetrical hole of the ablation needle; a front isolation ring made of metal material is provided at the connection between the tail of the ablation needle and the ablation needle tube, the front isolation ring surrounds the coaxial cable with the outer conductor stripped, is in close contact with the insulation layer of the coaxial cable, and is electrically connected to the inner needle tube; a rear isolation ring made of metal material is provided at the connection between the tail box and the ablation needle tube, the rear isolation ring surrounds the outer needle tube, and is electrically connected to the outer needle tube.

[0019] The front isolation ring is made of metal material and has microwave isolation function. The front isolation ring surrounds the coaxial cable with the outer conductor stripped and is in close contact with the insulation layer of the coaxial cable. At the same time, the front isolation ring is electrically connected to the inner needle tube of the ablation needle tube. The front isolation ring mainly isolates and blocks the reverse electromagnetic waves reflected from the microwave radiation antenna along the coaxial cable to reduce the standing wave ratio. In addition, the front isolation ring also has the function of improving the shape of the ablation area. The rear isolation ring is also made of metal material and has microwave isolation function. The rear isolation ring surrounds the outer needle tube of the ablation needle tube and is electrically connected to the outer needle tube. The rear isolation ring mainly isolates and blocks the reverse electromagnetic waves reflected along the outer and inner needle tubes, as well as the residual reverse electromagnetic waves reflected from the microwave radiation antenna along the coaxial cable. The design of the front and rear isolation rings greatly reduces the standing wave ratio, improves the radiation efficiency of the antenna, and improves the ablation shape. Furthermore, the front and rear isolation rings reduce useless microwave leakage and increase the safety of the microwave ablation needle.

[0020] Furthermore, the ablation needle tube includes an inner needle tube, and an outer needle tube coaxially sleeved outside the inner needle tube; the coaxial cable is arranged in the inner needle tube, and a first gap is reserved between the coaxial cable and the inner needle tube, and a second gap is reserved between the inner needle tube and the outer needle tube; a water outlet hole is opened on the inner needle tube close to the ablation needle, and the first gap and the second gap are connected through the water outlet hole; the inner cavity of the tail box is divided into a water inlet cavity and a water outlet cavity, and a channel gasket is provided on the partition wall between the water inlet cavity and the water outlet cavity, the ends of the inner needle tube and the coaxial cable pass through the channel gasket and extend into the water inlet cavity, and the end of the outer needle tube extends into the water outlet cavity; the water inlet joint, the water inlet cavity, the first gap, the second gap, the water outlet cavity, and the water outlet joint are connected to each other, and the microwave cable joint is provided on the tail box corresponding to the water inlet cavity.

[0021] A circular hole matching the outer needle tube of the ablation needle is provided at the connection between the tail box and the ablation needle tube. The outer needle tube of the ablation needle can pass through the circular hole to enter the water outlet cavity. A metal channel gasket is provided on the rear wall of the water outlet cavity. The center of the metal channel gasket has a circular hole matching the inner needle tube of the ablation needle. The inner needle tube of the ablation needle passes through the circular hole from the water outlet cavity to enter the water inlet cavity. The end face of the tail of the outer needle tube of the ablation needle is located in the water outlet cavity. The cooling water flows into the first gap through the water inlet joint, cools the coaxial cable, and then flows into the second gap through the water outlet hole. After returning to the water outlet cavity, it flows out through the water outlet joint. Compared with the capillary, the first gap as the water inlet channel has a large water inlet volume, and the second gap as the water outlet channel has a large water outlet volume, which improves the flow rate and flow volume of the cooling water in the ablation needle tube, improves the cooling effect on the coaxial cable, the ablation needle and the needle rod, and avoids the damage of the ablation needle and the ablation needle rod to the surrounding normal tissue due to overheating.

[0022] The present invention also provides a microwave ablation therapeutic apparatus, comprising: the microwave ablation needle as described above.

[0023] Furthermore, the microwave ablation therapeutic device also includes a central control module, a circulating water cooling system, a microwave source and a coaxial isolation module. The central control module is electrically connected to the microwave source and the circulating water cooling system, respectively; the microwave cable connector of the microwave ablation needle is electrically connected to the microwave source through the coaxial isolation module, and the water inlet connector of the microwave ablation needle is connected to the circulating water cooling system.

[0024] The central control module controls the microwave source to output microwave energy, and the microwave energy is transmitted to the microwave cable connector on the ablation needle tail box via the microwave coaxial cable, and then transmitted to the microwave radiation antenna by the coaxial cable after entering the tail box, and then radiated microwave energy to the patient's lesion site for heating and ablation. The microwave radiation antenna adopts a multi-emitting ring structure to improve the radiation efficiency, thereby improving the ablation effect; the cooling water in the circulating water cooling system flows into the water inlet cavity of the tail box through the water inlet connector, and then flows into the first gap to cool the coaxial cable. After cooling, it flows into the second gap from the water outlet hole close to the ablation needle, and finally flows out through the water outlet connector. The water inlet channel and water outlet channel formed by the first gap and the second gap have a large water flow rate and a fast water flow rate, thereby improving the cooling effect on the coaxial cable and the ablation needle. The coaxial isolation module is a microwave one-way device. Microwaves transmitted in the forward direction can pass smoothly with reduced attenuation, while microwaves transmitted in the reverse direction are blocked, which greatly reduces microwave reflection, lowers the standing wave ratio of the microwave output circuit, protects the microwave devices in the microwave source, and enhances the reliability of the therapeutic device; at the same time, it improves the microwave output efficiency and improves the size and roundness of the ablation area.

[0025] Furthermore, the microwave ablation therapeutic device also includes a surge protection module and a high-frequency peak pulse suppression module. The input end of the surge protection module is connected to an external power supply, the output end of the surge protection module is connected to the input end of the high-frequency peak pulse suppression module, and the output end of the high-frequency peak pulse suppression module is connected to the power module of the therapeutic device.

[0026] The surge protection module and the high-frequency spike pulse suppression module are installed at the mains power input of the microwave ablation therapeutic device. The surge protection module can suppress instantaneous overvoltage, indirect lightning and direct lightning, avoiding damage to the therapeutic device due to impact, and improving safety and anti-interference capabilities; the high-frequency spike pulse suppression module can resist and eliminate the fast transient pulse groups in the mains power circuit, ensuring that the equipment works stably without interference.

[0027] Furthermore, the microwave therapeutic apparatus also includes a first temperature measuring probe and a second temperature measuring probe electrically connected to the central control module. The first temperature measuring probe is arranged in the ablation needle tube to detect the temperature of the ablation needle tube, and the second temperature measuring probe is used to detect the temperature of the ablation site during treatment.

[0028] The first temperature measuring probe and the second temperature measuring probe both use platinum resistance as temperature sensing elements, which have good linearity, high precision and low aging.

[0029] Furthermore, the microwave source is a solid-state microwave source with an LDMOS device as its core.

[0030] The microwave source can withstand 100% reflected power, has standing wave, overcurrent and over-temperature protection functions, and has low microwave leakage, which can meet radiation safety standards.

[0031] Furthermore, the microwave source housing is provided with power measurement and control terminals to facilitate connection with a computer and a single-chip microcomputer.

[0032] Furthermore, the central control module includes a display screen, which is a touch graphic display screen that integrates display and touch control.

[0033] Furthermore, the circulating water cooling system drives the cooling water by the peristaltic pump to reach the water inlet connector on the ablation needle tail box through the water pipe, enters the water inlet cavity through the connector, and then flows along the first gap of the ablation needle tube to the needle head, flows out from the water outlet hole on the inner needle tube of the ablation needle located at the needle head to the second gap, and flows back to the water outlet cavity along the second gap. The water outlet connector is connected to the water outlet cavity. After the cooling water is discharged from the water outlet connector, it returns to the cooling water source along the reflux water pipe to form a cycle.

[0034] The panel of the microwave ablation therapeutic apparatus is provided with a microwave output terminal and two input terminals of the temperature measuring probes. The microwave output terminal can be connected to the microwave cable connector on the microwave ablation needle tail box through a microwave coaxial cable.

[0035] Beneficial Effects

[0036] Compared with the prior art, the microwave ablation needle and microwave ablation therapeutic apparatus provided by the present invention greatly improve the radiation efficiency without increasing the diameter of the coaxial cable through a microwave radiation antenna with a multi-transmitting ring structure composed of double (or multiple) metal rings and a metal body, thereby improving the ablation effect and avoiding the problem of the coaxial cable being easily heated and burned due to forced increase in output power; at the same time, by adjusting the width of the double rings, the spacing between the front ring and the rear ring, and the spacing between the rear ring and the rear outer conductor of the coaxial cable, the shape and size of the ablation area can be adjusted and changed, further improving the ablation effect without increasing the diameter of the coaxial cable and the surface area of ​​the ablation needle, avoiding damage to blood vessels, nerves or other tissues in the puncture path as much as possible, and reducing the complexity and risk of surgical operations; the microwave radiation antenna is exquisitely designed, simple to manufacture, and has high practical value and promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 is a schematic structural diagram of a microwave ablation needle in an embodiment of the present invention;

[0039] Figure 2 is a schematic structural diagram of a microwave radiation antenna in an embodiment of the present invention;

[0040] Figure 3 is a structural block diagram of a microwave ablation therapeutic apparatus according to an embodiment of the present invention;

[0041] Figure 4 is an appearance diagram of a microwave ablation therapeutic apparatus according to an embodiment of the present invention;

[0042] Among them, 1-tail box, 2-water inlet cavity, 3-channel gasket, 4-water outlet cavity, 5-outer needle tube, 6-inner needle tube, 7-coaxial cable, 8-microwave radiation antenna, 9-ablation needle, 10-water inlet connector, 11-water outlet connector, 12-microwave cable connector, 13-coupling sleeve, 14-rear isolation ring, 15-metal body, 16-front ring, 17-rear ring, 18-insulating layer, 19-wire, 20-inner conductor, 21-rear outer conductor, 22-casing, 23-peristaltic pump, 24-touch display screen, 25-operation panel, 26-cursor adjustment knob, 27-parameter adjustment knob, 28-microwave output socket, 29-first temperature probe socket, 30-second temperature probe socket, 31-power switch, 32-water outlet, 33-front isolation ring. DETAILED DESCRIPTION

[0043] like Figure 1 and Figure 2As shown, a microwave ablation needle provided by the present invention comprises an ablation needle 9, an ablation needle tube, a coaxial cable 7, a tail box 1, a microwave cable joint 12, a water inlet joint 10, a water outlet joint 11 and a metal body 15. The metal body 15 is electrically connected to the inner conductor 20 at the front end of the coaxial cable 7 (connected by electric welding), and a front ring 16 and a rear ring 17 are arranged in parallel on the coaxial cable 7 close to the metal body 15; the front ring 16 is close to the metal body 15 and electrically connected to the metal body 15 (connected by electric welding), and the rear ring 17 is electrically connected to the rear outer conductor 21 of the coaxial cable 7 through a wire 19; the microwave radiation antenna 8 composed of the front ring 16, the rear ring 17 and the metal body 15 is coaxially placed in the central symmetrical hole of the ablation needle 9. The front end of the ablation needle tube is connected to the ablation needle 9. The ablation needle tube includes an inner needle tube 6 and an outer needle tube 5 coaxially sleeved outside the inner needle tube 6; the coaxial cable 7 runs through the inner needle tube 6, and a first gap is retained between the coaxial cable 7 and the inner needle tube 6, and a second gap is retained between the inner needle tube 6 and the outer needle tube 5; a water outlet hole 32 is opened on the inner needle tube 6 near the ablation needle 9; the inner cavity of the tail box 1 is divided into a water inlet cavity 2 and a water outlet cavity 4, and a channel gasket 3 is installed on the partition wall between the water inlet cavity 2 and the water outlet cavity 4, the ends of the inner needle tube 6 and the coaxial cable 7 pass through the channel gasket 3 and extend into the water inlet cavity 2, and the end of the outer needle tube 5 extends into the water outlet cavity 4; the water inlet connector 10, the water inlet cavity 2, the first gap, the second gap, the water outlet cavity 4, and the water outlet connector 11 are interconnected; the microwave cable connector 12 is connected to the end of the coaxial cable 7 through a coupling sleeve 13, and the microwave cable connector 12 is arranged on the tail box 1 corresponding to the water inlet cavity 2.

[0044] The microwave ablation needle also includes a front isolation ring 33 and a rear isolation ring 14. The front isolation ring 33 is arranged at the connection between the ablation needle tube and the ablation needle head 9, and the rear isolation ring 14 is arranged at the connection between the tail box 1 and the ablation needle tube. The front isolation ring 33 is made of metal material and has a microwave isolation function. The front isolation ring 33 surrounds the coaxial cable 7 with the outer conductor stripped off and is in close contact with the insulating layer 18 of the coaxial cable. At the same time, the front isolation ring 33 is electrically connected to the inner needle tube 6 of the ablation needle tube; the front isolation ring 33 mainly isolates and blocks the reverse electromagnetic waves reflected from the microwave radiation antenna 8 along the coaxial cable 7 to reduce the standing wave ratio. In addition, the front isolation ring 33 also has the function of improving the ablation shape. The rear isolation ring 14 is also made of metal material and has microwave isolation function. The rear isolation ring 14 surrounds the outer needle tube 5 of the ablation needle tube and is electrically connected to the outer needle tube 5; the rear isolation ring 14 mainly isolates and blocks the reverse electromagnetic waves reflected back along the outer needle tube 5 and the inner needle tube 6, as well as the residual reverse electromagnetic waves reflected back from the microwave radiation antenna 8 along the coaxial cable 7. The design of the front and rear isolation rings greatly reduces the standing wave ratio, improves the radiation efficiency of the antenna, and improves the ablation shape; further, the front and rear isolation rings reduce useless microwave leakage and increase the safety of the microwave ablation needle.

[0045] There are many ways to set the metal ring in the microwave antenna. For example, two sections of the outer conductor of the coaxial cable 7 are removed to form a front ring 16 and a rear ring 17 (such as Figure 2 As shown), or strip off a section of the outer conductor of the coaxial cable, and set the front ring 16 and the rear ring 17 on the insulation layer 18 of the coaxial cable.

[0046] The microwave radiation antenna 8 composed of the front ring 16, the rear ring 17 and the metal body 15 has a double-emitting ring structure, which greatly improves the radiation efficiency without increasing the diameter of the coaxial cable, thereby improving the ablation effect. At the same time, the width of the front ring 16 and the rear ring 17, the spacing between the front ring 16 and the rear ring 17, and the spacing between the rear ring 17 and the rear outer conductor 21 of the coaxial cable can be adjusted and changed. The shape and size of the ablation area can be adjusted and changed. When the widths of the front ring 16 and the rear ring 17 are equal, the microwave radiation antenna 8 produces a spherical or ellipsoidal ablation area; when the widths of the front ring 16 and the rear ring 17 are not equal, the microwave radiation antenna 8 produces a spindle-shaped or water drop-shaped ablation area; by adjusting the spacing between the front ring 16 and the rear ring 17, and the spacing between the rear ring 17 and the rear outer conductor 21 of the coaxial cable, the length of the short axis and the long axis of the ablation area can be adjusted, thereby achieving the adjustment of the size of the ablation area.

[0047] Assuming that the width of the front ring 16 is W1, the width of the rear ring 17 is W2, the spacing between the front ring 16 and the rear ring 17 is D1, and the spacing between the rear ring 17 and the rear coaxial cable outer conductor 21 is D2, then the preferred range of W1 is 1.5 to 6.5 mm, the preferred range of W2 is 4 to 9.8 mm, the preferred range of D1 is 1.5 to 5.0 mm, and the preferred range of D2 is 6.5 to 18 mm.

[0048] 1. Preferred embodiment of microwave ablation needle:

[0049] The core of the microwave ablation needle is the microwave radiation antenna at the needle tip. Depending on the size and shape of the area to be ablated, Figure 3 According to the values ​​of the outer needle tube diameter d, W1, W2, D1, and D2, various corresponding microwave radiation antennas are designed, as shown in Table 1 below. Table 1 shows the parameters of two preferred groups of microwave ablation needles:

[0050]

[0051] By changing d, D1, D2, W1, and W2, microwave ablation needles of various specifications can be manufactured to adapt to various shapes of areas to be ablated.

[0052] The outer needle tubes of the two ablation needles in the above table embodiment are respectively made of medical stainless steel tubes with diameters of 1.6mm and 1.8mm, and the needle is made of ceramic material. When a medical stainless steel tube with a diameter of 1.8mm is used as the outer needle tube, the method for making the microwave radiation antenna located in the central symmetrical hole of the needle is: using a semi-rigid coaxial cable with an outer diameter of 1.19mm, welding a copper metal ball with a diameter of about 1.2mm at the front end of the coaxial cable, and cutting the coaxial cable close to the metal ball to retain a section of the outer conductor with a width of 6mm. This section of the outer conductor constitutes the front ring of the microwave radiation antenna, and the metal ball is connected to the front ring by electric welding. The same method is used to make the rear ring at a distance of 4mm from the front ring. The width of the rear ring is 6mm, and the outer conductor between the front ring and the rear ring is completely removed to expose the insulating layer. The outer conductor of 16mm is removed from the back of the rear ring, so that the distance between the rear ring and the rear outer conductor of the coaxial cable is 16mm. Finally, a metal wire with a length slightly greater than 16mm is used to weld the rear ring and the rear outer conductor of the coaxial cable. The composite antenna part (microwave radiation antenna) is installed in the needle, and the tail of the needle is equipped with a front isolation ring made of metal material with microwave isolation function. The tail of the front isolation ring is made into a cone shape, and the front isolation ring surrounds the coaxial cable with the outer conductor stripped, and is in close contact with the insulation layer of the coaxial cable. At the same time, it is electrically connected to the inner needle tube. In this way, the metal ball, the front ring and the rear ring constitute a microwave radiation antenna. The microwaves radiated by the microwave radiation antenna are confined to the surrounding space of the front ring and the rear ring, which can obtain a satisfactory ablation area and good radiation efficiency, and it is easy to adjust the ablation shape. The front isolation ring isolates and blocks the reverse electromagnetic waves reflected back from the microwave radiation antenna along the microwave cable, reducing the standing wave ratio. In addition, the front isolation ring also improves the ablation shape.

[0053] In this embodiment, the metal body can be a metal ball, a metal ellipsoid, or a metal body of other shapes whose diameter or cross-sectional area is the same as the outer diameter or cross-sectional area of ​​the coaxial cable, or a metal ball, a metal ellipsoid, or a metal body of other shapes whose diameter or cross-sectional area is different from the outer diameter or cross-sectional area of ​​the coaxial cable; the ratio of the diameter or cross-sectional area of ​​the metal body to the outer diameter of the coaxial cable is 0.5:1 to 3:1, preferably 0.8:1 to 1.5:1.

[0054] In this embodiment, the channel gasket 3 is a metal pad, and a first circular hole matching the diameter of the inner needle tube 6 is opened on the metal pad. The first circular hole is used for the inner needle tube 6 and the coaxial cable to extend into the water inlet chamber 2, and the end of the outer needle tube 5 is located in the water outlet chamber 4. A second circular hole matching the diameter of the outer needle tube 5 is provided at the connection portion of the ablation needle tube and the tail box 1, and the second circular hole is used for the outer needle tube 5 to extend into the water outlet chamber 4. A rear isolation ring 14 is also sleeved on the connection portion, and the rear isolation ring 14 can isolate the reflected wave, block the reverse electromagnetic wave, and reduce the standing wave ratio. The rear isolation ring 14 is made of metal material and has a microwave isolation function. The diameter of the rear isolation ring 14 is designed to be 1.8 mm, and its tail is made into a cone shape and installed around the outer needle tube 5. The rear isolation ring 14 isolates and blocks the reverse electromagnetic waves reflected back along the outer needle tube 5 and the inner needle tube 6, as well as the residual reverse electromagnetic waves reflected back from the microwave radiation antenna along the coaxial cable. The rear isolation ring 14 further reduces the standing wave ratio and improves the radiation efficiency. In addition, the rear isolation ring 14 reduces useless microwave leakage and increases safety.

[0055] 2. Microwave Ablation Therapy Device

[0056] Figure 3 It is a structural block diagram of the microwave ablation therapeutic apparatus of the present invention. The microwave ablation therapeutic apparatus includes a central control module, a power module, a circulating water cooling system, a microwave source, a coaxial isolation module, a surge protection module, a high-frequency spike pulse suppression module, a first temperature measuring probe, a second temperature measuring probe, and a microwave ablation needle as described in this embodiment. The central control module is electrically connected to the power module, the water pump in the circulating water cooling system, the microwave source, and the first temperature measuring probe and the second temperature measuring probe respectively; the input end of the surge protection module is connected to the external power supply, the output end of the surge protection module is connected to the input end of the high-frequency spike pulse suppression module, and the output end of the high-frequency spike pulse suppression module is connected to the power module; the output end of the microwave source is connected to the input end of the coaxial isolation module, and the output end of the coaxial isolation module is connected to the microwave cable connector of the microwave ablation needle through a microwave coaxial cable; the water outlet of the circulating water cooling system is connected to the water inlet connector of the microwave ablation needle through a pipeline; the first temperature measuring probe is arranged in the ablation needle tube for detecting the temperature of the ablation needle tube, and the second temperature measuring probe is used to detect the temperature of the ablation site during treatment.

[0057] The specific working process of the present invention is as follows:

[0058] The central control module, power module, microwave source, coaxial isolation module, surge protection module and high-frequency spike pulse suppression module are arranged in the casing 22, the peristaltic pump 23 is arranged on the side of the casing 22, and there is also an operation panel 25 on the front of the casing 22. The operation panel 25 is provided with a touch display screen 24, a microwave output socket 28, a first temperature probe socket 29, a second temperature probe socket 30, a cursor adjustment knob 26, a parameter adjustment knob 27 and a power switch.

[0059] like Figure 4 , connect the microwave ablation therapeutic device and the microwave ablation needle: insert one end of the microwave coaxial cable plug into the microwave output socket 28 on the ablation therapeutic device panel 25, and insert the other end into the microwave cable connector 12 on the ablation needle tail box.

[0060] Check the cooling water pipe passing through the peristaltic pump 23, and insert the cooling water inlet and outlet pipes into the cooling water source.

[0061] Press the power switch on the back of the instrument to turn on the power of the therapeutic device. At this time, the cooling water flows driven by the peristaltic pump 23, reaches the water inlet chamber 2 on the ablation needle tail box through the second pipeline, and then flows into the first gap to cool the coaxial cable. After cooling, it flows into the second gap from the water outlet hole close to the ablation needle, flows out through the water outlet joint, and finally flows back to the cooling water tank through the third pipeline.

[0062] Double-click the "One-key test needle" button on the touch screen 24 to check the connection status of the microwave ablation needle. If the connection is not good and the standing wave ratio exceeds the standard, an error prompt will be given on the interface; insert the microwave ablation needle into the patient's treatment area and place the second temperature measuring probe at the area where the temperature needs to be monitored; press the "Start treatment" button on the touch screen 24 to enter the treatment interface, rotate the parameter adjustment and return knob 27, and the cursor movement and confirmation knob 26 to set the treatment power, total treatment time, and temperature control temperature respectively. After the settings are completed, press the "Start" button on the touch screen 24 to start the microwave ablation treatment. At this time, the microwave is output by the microwave output socket 28, transmitted to the microwave cable connector on the ablation needle tail box through the microwave coaxial cable, and then transmitted to the microwave antenna of the ablation needle tip through the ultra-thin semi-rigid coaxial cable passing through the inner needle tube of the ablation needle. The microwave radiation antenna radiates microwave energy outward to efficiently heat the lesion area. When the set treatment time is reached, the device can automatically stop the microwave power output and the treatment ends.

[0063] The microwave source is a solid-state microwave source with LDMOS devices as the core, and is designed with fully enclosed anti-electromagnetic interference, with a rated output microwave power of 200W. The solid-state microwave source is equipped with a circulator and a passive load to eliminate microwave reflection and reduce the standing wave ratio, and can withstand 100% reflected power; the microwave frequency stability output by the solid-state microwave source is controlled by PLL+VCO, and has standing wave, overcurrent, overtemperature and other protection functions, and the microwave leakage is small, which can meet the radiation safety standards. The bottom side of the solid-state microwave source can be equipped with an n-type microwave socket, the top is equipped with a cooling fan, and the bottom is also equipped with a power measurement and power control signal terminal, the signal level is 0-5V, and the microwave output power can be measured and adjusted by the central control module. The volume of the microwave source is: 200 (L) X120 (W) X150 (H). In this embodiment, the specific model of the microwave source is WSPS-433-200M.

[0064] The circulating water cooling system includes a cooling water tank, a peristaltic pump and a pipeline. The outlet pipe of the cooling water tank is the first pipeline. The first pipeline passes through the peristaltic pump and is connected to the water inlet joint of the microwave ablation needle. The water inlet pipe of the cooling water tank is connected to the water outlet joint of the microwave ablation needle through the second pipeline. The refluxed water flows back to the cooling water tank through the water outlet joint and the second pipeline to form a cycle and save water resources. In this embodiment, the cooling water is ice saline, the water pump is a peristaltic pump, and the specific model of the peristaltic pump is YZ25B.

[0065] The high-frequency spike pulse suppression module adopts a design scheme that combines filtering and absorption. The filter circuit is designed with high-voltage resistant resistors, capacitors and inductors. When the high-frequency spike pulse reaches the filter circuit, it will be blocked or filtered out. For absorption, ferrite cores are directly used. These ferrite cores are put on the cables. When interference signals such as high-frequency spike pulses pass through the cables, the ferrite will absorb these interference signals and convert the absorbed electromagnetic energy into heat energy for consumption. The high-frequency spike pulse suppression module is also designed and manufactured with an all-metal enclosure, and the volume is: 100 (L)X75 (W)X25 (H). The high-frequency spike pulse suppression module improves the working stability of the microwave ablation device. The high-frequency spike pulse suppression module can also choose the general model sold on the market. In this embodiment, the specific model of the high-frequency spike pulse suppression module is JY-3*2*2.5.

[0066] The coaxial isolation module is composed of ferrite columns arranged in a parallel plate waveguide. The material of the parallel plate is a metal aluminum plate. Microwaves can only pass through the coaxial isolation module in the forward direction of the waveguide, and the microwaves transmitted in the reverse direction will be absorbed by the ferrites arranged in the waveguide. The selected ferrite has a strong absorption for microwaves with a microwave source operating frequency of 2.45GHz. The coaxial isolation module is a microwave unidirectional device. The microwaves transmitted in the forward direction can pass smoothly with reduced attenuation, while the microwaves transmitted in the reverse direction are blocked, which greatly reduces microwave reflection, reduces the standing wave ratio of the microwave output circuit, protects the microwave devices in the microwave source, and enhances the reliability of the therapeutic device; at the same time, it improves the microwave output efficiency and improves the size and roundness of the ablation area. The coaxial isolation module can be processed into a microwave device with a volume of 90 (L) X60 (W) X30 (H), and a BNC high-frequency socket is installed at the front and back for input and output connection. In this embodiment, the coaxial isolation module uses a coaxial isolator of model TG2126C. Microwaves can only pass through the coaxial isolator in the forward direction, and microwaves transmitted in the reverse direction will be absorbed by the ferrite arranged in the waveguide of the coaxial isolator.

[0067] The surge protection module is composed of a discharge gap, a gas-filled discharge tube, a varistor, a suppression diode, a choke coil and other electronic components, and the functions of these components are different. The discharge gap is composed of two metal rods exposed to the air with a certain gap, one of which is connected to the power phase line or neutral line (N) of the device to be protected, and the other is connected to the ground wire (PE). When the instantaneous overvoltage strikes, the gap is broken down, and part of the overvoltage charge is introduced into the earth, avoiding the voltage increase on the protected device. The gas-filled discharge tube is composed of a pair of cold cathode plates separated from each other and encapsulated in a glass tube or ceramic tube filled with a certain inert gas (Ar). The varistor is a metal oxide semiconductor nonlinear resistor with ZnO as the main component. When the voltage across it reaches a certain value, the resistor is very sensitive to voltage. The suppression diode has a clamping voltage limiting function. It works in the reverse breakdown region and has the advantages of low clamping voltage and fast action response. It is used as a final protection element here. The choke coil is composed of two coils of the same size and number of turns symmetrically wound on the same ferrite toroidal core. It is used to suppress common-mode interference signals (such as lightning interference) in balanced lines. The function of the surge protection module is to limit the instantaneous overvoltage that penetrates into the power line and signal transmission line to the voltage range that the microwave ablation device can withstand, or to discharge the strong lightning current into the ground to protect the microwave ablation device from damage due to impact. The surge protection module can also choose a general model sold on the market. In this embodiment, the specific model of the surge protection module is AM-10 / 350.

[0068] The present invention provides a microwave ablation needle and a matching microwave ablation therapeutic apparatus, and is described through the above embodiments. However, it should be understood that there are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. The present invention is not limited to the above embodiments. According to the principle of the present invention, more variations and modifications can be made, and these variations and modifications should also be regarded as the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the claims of the present invention.

Claims

1. A microwave ablation needle, characterized in that: include: An ablation needle (9), an ablation needle tube, a coaxial cable (7), a tail box (1), a microwave cable connector (12), a water inlet connector (10), and a water outlet connector (11); the front end of the ablation needle tube is connected to the ablation needle (9), and the rear end of the ablation needle tube enters the tail box (1); the coaxial cable (7) runs through the ablation needle tube, and the rear end of the coaxial cable (7) is electrically connected to the microwave cable connector (12) in the tail box (1); the microwave cable connector (12), the water inlet connector (10), and the water outlet connector (11) are all arranged on the tail box (1); The microwave ablation needle further comprises: a metal body (15), the metal body (15) being mounted at the front end of the coaxial cable (7) and being electrically connected to the inner conductor (20) of the coaxial cable; two metal rings parallel to each other being mounted on the insulating layer (18) of the coaxial cable (7) near the metal body (15), respectively referred to as a front ring (16) and a rear ring (17); the front ring (16) being close to the metal body (15) and being electrically connected to the metal body (15), and the rear ring (17) being electrically connected to the rear outer conductor (21) of the coaxial cable via a wire (19); a microwave radiation antenna (8) formed by the front ring (16), the rear ring (17) and the metal body (15) being coaxially arranged in the central symmetrical hole of the ablation needle (9), and microwaves being emitted outward from the microwave radiation antenna (8) formed by the metal body (15), the front ring (16) and the rear ring (17).

2. A microwave ablation needle according to claim 1, characterized in that: The microwave radiation antenna (8) is configured as a multi-metal ring mode: a third or more metal rings are installed between the front ring (16) and the rear ring (17); the multi-metal ring mode is implemented by removing two or more sections of the outer conductor of the coaxial cable (7) on the coaxial cable (7) to form a plurality of metal rings composed of the outer conductor, or stripping a section of the outer conductor of the coaxial cable (7) and fitting a plurality of metal rings on the insulating layer (18) of the coaxial cable (7); and the middle metal ring is electrically connected to the front ring (16) or the rear ring (17) as required.

3. A microwave ablation needle as claimed in claim 1, characterized in that: The width of the front ring (16) of the microwave radiation antenna (8) is 1.0 to 12.5 mm; the width of the rear ring (17) is 1.5 to 12.5 mm; the spacing between the front ring (16) and the rear ring (17) is 0.5 to 13 mm; and the spacing between the rear ring (17) and the rear outer conductor (21) of the coaxial cable (7) is 1.0 to 32 mm.

4. A microwave ablation needle as claimed in claim 3, characterized in that: The width of the front ring (16) of the microwave radiation antenna (8) is 1.5 mm to 6.5 mm; the width of the rear ring (17) is 4.0 mm to 9.8 mm; the spacing between the front ring (16) and the rear ring (17) is 1.5 mm to 5 mm; and the spacing between the rear ring (17) and the rear outer conductor (21) of the coaxial cable (7) is 6.5 mm to 18 mm.

5. The microwave ablation needle according to claim 3, characterized in that: The widths of the front ring (16) and the rear ring (17) are equal, and the microwave radiation antenna (8) generates a spherical or ellipsoidal ablation area; the widths of the front ring (16) and the rear ring (17) are unequal, and the microwave radiation antenna (8) generates a spindle-shaped or teardrop-shaped ablation area; the distance between the front ring (16) and the rear ring (17) and the distance between the rear ring (17) and the rear outer conductor (21) of the coaxial cable (7) are adjusted to adjust the lengths of the short axis and the long axis of the ablation area shape, thereby adjusting the size and shape of the ablation area.

6. The microwave ablation needle according to claim 1, characterized in that: The metal body (15) is a metal ball or metal ellipsoid whose diameter is the same as the outer diameter of the coaxial cable; or the metal body (15) is a metal ball or metal ellipsoid whose diameter is different from the outer diameter of the coaxial cable; the ratio of the diameter of the metal body (15) to the outer diameter of the coaxial cable is in the range of 3:1 to 0.5:

1.

7. A microwave ablation needle as claimed in claim 6, characterized in that: The ratio of the diameter of the metal body (15) to the outer diameter of the coaxial cable is in the range of 0.8:1 to 1.5:

1.

8. The microwave ablation needle according to claim 1, characterized in that: The ablation needle (9) is made of a high-temperature resistant non-metallic material; a front isolating ring (33) made of a metal material is provided at the connection between the tail of the ablation needle (9) and the ablation needle tube, the front isolating ring surrounds the coaxial cable (7) with the outer conductor stripped, is in close contact with the insulating layer (18) of the coaxial cable, and is electrically connected to the inner needle tube (6); a rear isolating ring (14) made of a metal material is provided at the connection between the tail box (1) and the ablation needle tube, the rear isolating ring (14) surrounds the outer needle tube (5), and is electrically connected to the outer needle tube (5).

9. A microwave ablation needle according to any one of claims 1 to 8, characterized in that: The ablation needle tube comprises an inner needle tube (6) and an outer needle tube (5) coaxially sleeved outside the inner needle tube (6); the coaxial cable (7) is arranged in the inner needle tube (6), and a first gap is retained between the coaxial cable (7) and the inner needle tube (6), and a second gap is retained between the inner needle tube (6) and the outer needle tube (5); a water outlet hole (32) is opened on the inner needle tube (6) near the ablation needle head (9); the first gap and the second gap are connected through the water outlet hole (32) on the inner needle tube (6); the inner cavity of the tail box (1) is divided into a water inlet cavity (2) and a water outlet chamber (4), a channel gasket (3) is provided on a partition wall between the water inlet chamber (2) and the water outlet chamber (4), the ends of the inner needle tube (6) and the coaxial cable (7) pass through the channel gasket (3) and extend into the water inlet chamber (2), and the end of the outer needle tube (5) extends into the water outlet chamber (4); the water inlet joint (10), the water inlet chamber (2), the first gap, the second gap, the water outlet chamber (4) and the water outlet joint (11) are interconnected, and the microwave cable joint (12) is provided on a tail box (1) corresponding to the water inlet chamber (2).

10. A microwave ablation therapeutic apparatus, characterized in that: The microwave ablation therapeutic apparatus comprises: a microwave ablation needle as described in any one of claims 1-9.

11. A microwave ablation therapeutic apparatus as claimed in claim 10, characterized in that: It also includes a central control module, a circulating water cooling system, a microwave source and a coaxial isolation module. The central control module is electrically connected to the microwave source and the circulating water cooling system respectively; the microwave cable connector (12) of the microwave ablation needle is electrically connected to the microwave source via the coaxial isolation module, and the water inlet connector (10) of the microwave ablation needle is connected to the circulating water cooling system.

12. A microwave ablation therapeutic apparatus as claimed in claim 11, characterized in that: It also includes a surge protection module and a high-frequency spike pulse suppression module. The input end of the surge protection module is connected to an external power supply, the output end of the surge protection module is connected to the input end of the high-frequency spike pulse suppression module, and the output end of the high-frequency spike pulse suppression module is connected to the power module of the therapeutic device.

13. A microwave ablation therapeutic apparatus as claimed in claim 12, characterized in that: It also includes a first temperature measuring probe and a second temperature measuring probe electrically connected to the central control module. The first temperature measuring probe is arranged in the ablation needle tube to detect the temperature of the ablation needle tube, and the second temperature measuring probe is used to detect the temperature of the ablation site during treatment.

14. The microwave ablation therapeutic apparatus according to claim 11, characterized in that: The microwave source is a solid-state microwave source with an LDMOS device as its core.

Images