Disposable prostate steam ablation catheter

Abstract

The utility model discloses a disposable prostate steam ablation catheter, and relates to the technical field of medical instruments. In order to solve the problem that a trigger or an actuating mechanism of a prostate steam ablation catheter is easy to cause insensitive triggering and no reaction, the following technical scheme is provided: the prostate steam ablation catheter comprises a handle shell, a catheter body arranged at the front end of the handle shell and an outer sheath arranged at the front end of the catheter body, the handle shell comprises a front shell, and a needle withdrawing button is movably clamped on the front shell; a flushing button is arranged in the needle outlet button, and the flushing button and the needle outlet button achieve control of flushing and needle outlet switch functions in a segmented mode based on the Hall effect. According to the utility model, the risk that a point contact type mechanical switch is easy to wear, loosen and fall off after being used for many times and frequently is avoided, and the sensitivity and the reliability of switch triggering are improved, so that the operation efficiency and the user experience can be improved.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a disposable prostate steam ablation catheter. Background Technology

[0002] Benign prostatic hyperplasia (BPH) is a common disease among middle-aged and elderly men, also known as enlarged prostate. The enlarged gland is located at the bladder neck, causing urinary tract obstruction, leading to urinary frequency and difficulty urinating, severely impacting the patient's quality of life. Symptoms typically appear after age 50, and its incidence is positively correlated with age. Early symptoms can be relieved with medication, while later stages require surgical or minimally invasive ablation procedures. Among various surgical options for this disease, transurethral steam ablation of the prostate is one of the most advanced techniques for treating BPH internationally. During the procedure, sterile steam at 103°C is injected into the target area of ​​the enlarged prostate tissue through a steam delivery needle. This causes the enlarged tissue to gradually lose its activity, eventually leading to apoptosis and necrosis. The necrotic prostate tissue gradually shrinks or sloughs off and is excreted with urine, reducing the volume of the prostate tissue adjacent to the urethra and thus forming a natural urethral passage, thereby relieving urinary tract obstruction.

[0003] Existing prostate steam ablation catheters, such as the steam ablation system disclosed in CN112168329A, mostly use point-contact mechanical switches for their triggers or actuation mechanisms. These switches are at risk of wear, loosening, or even falling off after repeated use, which can lead to insensitive triggering or no response, seriously affecting surgical efficiency and user experience. Utility Model Content

[0004] The purpose of this invention is to provide a disposable prostate steam ablation catheter to solve the problem that the trigger or actuation mechanism of the existing prostate steam ablation catheter is prone to wear, loosening or even falling off after multiple uses, which can easily lead to insensitive triggering or no response.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0006] A disposable prostate vapor ablation catheter includes: a handle housing, a catheter body disposed at the front end of the handle housing, and an outer sheath disposed at the front end of the catheter body. The handle housing includes a front housing, on which a needle ejection button is movably engaged. The needle ejection button has a flushing button inside. The flushing button and the needle ejection button are controlled by segmented flushing and needle ejection functions based on the Hall effect.

[0007] Furthermore, a mounting plate is fixed inside the handle housing, and a PCB circuit board is mounted on the front end of the mounting plate. A Hall sensor is provided at the upper end of the PCB circuit board, and an MCU control module and a steam switch are provided at the lower end of the PCB circuit board.

[0008] Furthermore, a second spring is sleeved at the rear end of the needle dispensing button, and limit blocks that can be movably engaged with the needle dispensing button are provided on both sides of the rear end of the rinsing button. The rinsing button has two slots inside, and a first spring is provided in each slot.

[0009] Furthermore, a limiting post is fitted onto the rear end of the first spring at the upper end, with the front end of the limiting post extending into the groove cavity and the rear end of the limiting post fixed to the mounting plate; a mounting post is fitted onto the rear end of the first spring at the lower end, with the front end of the mounting post also extending into the corresponding groove cavity, and the rear end of the mounting post is fixedly connected to a permanent magnet, with the permanent magnet and the Hall sensor facing each other.

[0010] Furthermore, the handle housing also includes an upper housing and a rear housing.

[0011] Furthermore, the front housing is also equipped with a needle retraction button and a steam button. Above the needle retraction button is an electromagnetic drive assembly, and the steam button is positioned opposite the steam switch.

[0012] Furthermore, the inner part of the outer sheath contains a puncture needle and the endoscope tube.

[0013] Furthermore, a rinsing box is provided inside the handle housing.

[0014] This utility model has the following beneficial effects:

[0015] This invention relates to a prostate steam ablation catheter. By setting a permanent magnet on the flushing needle dispensing button and correspondingly setting a linear Hall sensor on the PCB circuit board to detect the distance between the sensor and the permanent magnet and convert it into an electrical signal, the MCU controls the flushing and needle dispensing switching functions in segments according to the electrical signal. This avoids the risk of wear, loosening and falling off of point-contact mechanical switches after repeated and frequent use, and improves the sensitivity and reliability of the switch triggering, thereby improving surgical efficiency and user experience. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the disposable prostate vapor ablation catheter of this utility model;

[0017] Figure 2 This is an enlarged view of the internal structure of the flushing needle button of the disposable prostate steam ablation catheter of this utility model;

[0018] Figure 3 This is an enlarged view of the internal structure of the flushing needle outlet button of the disposable prostate steam ablation catheter of this utility model.

[0019] Figure 4 This is a schematic diagram of the flushing needle dispensing button structure of the disposable prostate steam ablation catheter of this utility model;

[0020] Figures 1 to 4The reference numerals in the accompanying drawings represent: handle housing 1, mounting plate 11, endoscope 12, flushing box 13, PCB circuit board 14, upper housing 15, front housing 16, needle retraction button 161, steam button 162, flushing button 163, first spring 1631, second spring 1632, limit post 1633, needle extension button 164, steam switch 165, mounting post 166, permanent magnet 167, rear housing 17, catheter body 2, outer sheath 3, puncture needle 4, endoscope tube 5, electromagnetic drive assembly 6, Hall sensor 7, and MCU control module 8. Detailed Implementation

[0021] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] Please refer to Figure 1-2 This invention provides a disposable prostate steam ablation catheter. The catheter adopts a modular design, consisting of a handle housing assembly, a catheter body assembly, an outer sheath assembly, and an internal control system. The handle housing assembly includes a front housing 16, an upper housing 15, and a rear housing 17, which are ultrasonically welded to form a sealed cavity. The surface of the front housing 16 integrates a needle retraction button 161, a steam button 162, and a composite needle withdrawal / rinsing button assembly. Each button is axially positioned with the housing via guide posts. The internal mounting plate 11 is made of medical-grade polycarbonate and is fixed to the middle section of the housing with four M1.2 screws. Its front end is equipped with a double-layer PCB circuit board 14, with a Hall sensor array 7 on the upper layer and an integrated MCU control module 8 and a steam switch 165 on the lower layer.

[0023] The needle eject button 164 and the flush button 163 adopt a nested mechanical structure. The outer wall of the needle eject button has four guide ribs that cooperate with the sliding groove of the front housing, and a stepped hole is opened inside to accommodate the flush button. The rear end of the flush button 163 is symmetrically equipped with limiting blocks, which achieve radial limiting through the dovetail groove of the inner wall of the needle eject button via a T-shaped guide rail. The button assembly is equipped with a dual spring system: the first spring 1631 in the upper cavity (0.3mm wire diameter, 8 effective turns) is sleeved on the limiting post 1633, and the rear end of the post is embedded in the positioning hole of the mounting plate; the first spring in the lower cavity (of the same specifications) is sleeved on the mounting post 166, and the rear end of the post is bonded to the permanent magnet 167 with epoxy resin. The permanent magnet is made of neodymium iron boron material with nickel plating on the surface. Its magnetic field strength is gradient distributed along the axial direction, forming a sensing range of 0.5-3mm with the Hall sensor 7.

[0024] The electromagnetic drive assembly 6 is mounted on the front end of the upper housing and consists of a coil frame, a permanent magnet drive rod, and a return spring. The coil frame is 3D printed using PEEK material, with 200 turns of enameled wire wound on its surface to form an 8mm diameter solenoid structure. The front end of the permanent magnet drive rod is hinged to the puncture needle connecting rod via a pin, and the rod body has an annular groove that cooperates with the housing guide post for guidance. When the MCU control module 8 outputs a positive pulse, the coil generates a magnetic field with the same polarity as the permanent magnet, pushing the drive rod forward 12mm; a reverse pulse generates a magnetic field with opposite polarity, and the drive rod retracts under the action of the return spring.

[0025] The steam generating assembly is integrated on the back of the mounting plate and consists of a metal coil (316L stainless steel, 0.8mm inner diameter, 50mm length), a high-frequency insulated wire (PTFE insulation, 0.2mm wire diameter), and a temperature sensor. The coil adopts a three-dimensional spiral structure with heating wire evenly wound on its surface and is fixed to the mounting plate by a ceramic bracket. When the steam button is triggered, the MCU control module 8 controls the solid-state relay to conduct, and the high-frequency power supply outputs 200kHz AC power, causing the coil to heat up to 120°C within 5 seconds to generate steam. The temperature sensor uses a negative temperature coefficient thermistor, which automatically cuts off the power supply when the temperature exceeds 130°C.

[0026] The irrigation system consists of an irrigation box 13, silicone irrigation tubing, and a one-way valve. The irrigation box has a dual-chamber structure: the main chamber has a volume of 5 ml and is pre-filled with physiological saline; the secondary chamber integrates a 0.22 μm hydrophobic filter membrane. When the irrigation button is triggered, the change in the magnetic field strength of the permanent magnet causes the Hall sensor 7 to output a linear voltage signal of 0.5-4.5V. After sampling by the ADC module, the MCU control module 8 controls the micro-pump to output irrigation fluid at three flow rates (5 ml / min, 15 ml / min, and 30 ml / min), which is then used to irrigate the tissue through the micropores on the side wall of the endoscope tube 5.

[0027] The outer sheath assembly 3 adopts a double-layer structure, with an outer layer of polyetheretherketone tubing (outer diameter 3.2 mm, inner diameter 2.8 mm) and an inner layer inlaid with a polyimide heat insulation sleeve. The puncture needle 4 is made of shape memory alloy material, with a 0.3 mm steam nozzle at the tip and a hydrophilic coating on the needle body surface. The endoscope tube 5 is integrated into the central axis of the outer sheath, with a 30-degree field-of-view lens at the front end and connected to the fiber optic bundle at the rear end via an FC interface.

[0028] The assembly process of the conduit is as follows: First, the PCB circuit board 14 is installed on the mounting plate 11 using positioning pins. After the components are soldered, a vacuum leak test is performed. The steam generator coil is inserted into the mounting hole, thermal grease is injected, and the cap is tightened. The permanent magnet rod of the electromagnetic drive assembly 6 is installed into the guide groove of the upper housing and the enameled wire is connected to the PCB pad. The permanent magnet 167 of the flushing button assembly is aligned with the Hall sensor 7, and the spring preload is adjusted to make the initial gap 2mm. Finally, the outer sheath assembly is connected to the conduit body through a Luer connector, and the overall encapsulation is completed in a clean environment.

[0029] In terms of electromagnetic compatibility design, a copper foil shielding layer is installed inside the handle, the Hall sensor 7 circuit uses twisted-pair cable transmission, and a π-type filter network is added to the power supply circuit. The software control employs a redundancy check algorithm, requiring three verification checks for each operation command to prevent false triggering. The steam generation system has a pressure monitoring function; heating automatically stops when the internal pressure of the conduit exceeds 20 kPa to prevent tissue damage.

[0030] The clinical procedure is as follows: The operator inserts a catheter into the prostate via the urethra and uses an endoscope to observe and locate the lesion; the first stage of the flushing button is pressed, and the MCU control module 8 detects a 1.5V threshold voltage and starts low-speed flushing; the button is pressed continuously until the second stage triggers a 3.5V signal, and the electromagnetic drive component 6 pushes the puncture needle to extend 2mm into the tissue; after releasing the button, the puncture needle remains locked, and the steam button is pressed to generate steam for ablation; after ablation is completed, the needle retraction button is pressed again, and the electromagnetic component retracts in the opposite direction; finally, a second flush is performed to remove tissue debris.

[0031] This design achieves contactless operation sensing through the Hall effect, avoiding the contact wear problems of traditional mechanical switches. The nonlinear response characteristics of the permanent magnet and sensor can accurately distinguish subtle changes in operating force. The dual-spring system ensures the reliability of button reset and clearly distinguishes the two stages of travel through different stiffnesses. The electromagnetic drive mechanism eliminates the mechanical wear of traditional motors, and combined with the elastic deformation characteristics of the shape memory alloy puncture needle, it achieves millimeter-level precise positioning. The steam generation component uses high-frequency induction heating technology, which has a faster response speed and higher thermal efficiency compared to resistance wire heating.

[0032] For sterilization, the catheters are sterilized using ethylene oxide, and all electronic components are pre-vacuum sealed. Packaging consists of medical dialysis paper and a blister tray, with an included humidity indicator card. Shelf life verification tests show that under storage conditions conforming to GB / T 19633-2005 standards, the product performance can be maintained for more than 24 months.

[0033] In vitro simulation tests verified that the catheter achieves a needle insertion accuracy of ±0.1mm, steam temperature fluctuations are controlled within ±3℃, and the flushing system flow rate error is less than 5%. Animal experiments show that under 30W power output conditions, the single ablation volume is 0.5-1.2cm³, and the thermal damage range to surrounding tissue is less than 2mm. The electromagnetic drive component 6 has undergone 2000 cycle tests, with a displacement attenuation rate of less than 3%, meeting the requirements for single clinical use.

[0034] In summary, this utility model, through innovative electromechanical coupling design, organically combines precision sensor technology, electromagnetic drive technology, and minimally invasive interventional devices. While ensuring functional integrity, it significantly improves operational accuracy and system reliability, providing a new technical solution for prostate thermal steam ablation therapy.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A disposable prostate steam ablation catheter characterized by, include: The handle housing (1), the catheter body (2) disposed at the front end of the handle housing (1), and the outer sheath (3) disposed at the front end of the catheter body (2) are provided. The handle housing (1) includes a front housing (16), on which a needle ejection button (164) is movably attached. The needle ejection button (164) is provided with a flushing button (163) inside. The flushing button (163) and the needle ejection button (164) are controlled by segmented flushing and needle ejection switching functions based on the Hall effect.

2. The disposable prostate steam ablation catheter of claim 1, wherein, The handle housing (1) is fixed with an installation plate (11). A PCB circuit board (14) is installed on the front end of the installation plate (11). A Hall sensor (7) is provided on the upper end of the PCB circuit board (14). An MCU control module (8) and a steam switch (165) are provided on the lower end of the PCB circuit board (14).

3. The disposable prostate steam ablation catheter of claim 2, wherein, The rear end of the needle dispensing button (164) is fitted with a second spring (1632), and the rear ends of the flushing button (163) are provided with limiting blocks that can be movably engaged with the needle dispensing button (164). The flushing button (163) has two slots inside, and each slot is provided with a first spring (1631).

4. The disposable prostate steam ablation catheter of claim 3, wherein, A limiting post (1633) is sleeved on the rear end of the first spring (1631) at the upper end. The front end of the limiting post (1633) extends into the groove cavity, and the rear end of the limiting post (1633) is fixed on the mounting plate (11). A mounting post (166) is sleeved on the rear end of the first spring (1631) at the lower end. The front end of the mounting post (166) also extends into the corresponding groove cavity. The rear end of the mounting post (166) is fixedly connected to a permanent magnet (167). The permanent magnet (167) is positioned opposite the Hall sensor (7).

5. The disposable prostate steam ablation catheter of claim 1 wherein, The handle housing (1) also includes an upper housing (15) and a rear housing (17).

6. The disposable prostate steam ablation catheter of claim 2, wherein, The front housing (16) is also provided with a needle retraction button (161) and a steam button (162). An electromagnetic drive assembly (6) is provided above the needle retraction button (161), and the steam button (162) is arranged opposite to the steam switch (165).

7. The disposable prostate steam ablation catheter of claim 1, wherein, The outer sheath (3) contains a puncture needle (4) and the endoscope tube (5) of the endoscope (12).

8. The disposable prostate steam ablation catheter of claim 1, wherein, The handle housing (1) is provided with a rinsing box (13).

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