Steam ablation treatment method capable of accurately controlling steam injection amount

Abstract

The invention relates to the technical field of tumor ablation, and provides a steam ablation treatment method capable of accurately controlling the steam injection amount, the diameter D (cm) of a target ablation area is input into a control module, mstep, namely the injection steam mass (g), is obtained through the control module according to a dose-effect relation formula, and the injection steam injection amount (g) is calculated according to the obtained injection steam mass. The system has the advantages that the clinically expected ablation effect is converted into controllable engineering parameters, namely the injection time t and the injection steam quality, through experiments and modeling, and it is ensured that in the complex clinical environment, the ablation time t and the injection steam quality can be controlled; the preset dosage can be output reliably, accurately and repeatedly, so that the volume of an ablation lesion is accurate, the ablation boundary is more controllable, the steam energy and the treatment effect are accurately controlled in real time, and the treatment effectiveness and safety are achieved.

Description

Technical Field

[0001] This invention belongs to the field of tumor ablation technology, and specifically relates to a steam ablation treatment method with precise control of steam injection volume. Background Technology

[0002] Traditional tumor ablation works by using physical energy (heat or cold) to destroy local tumor tissue under image guidance. Benign prostatic hyperplasia (BPH) generally occurs after age 40, with an incidence rate exceeding 50% in men over 60 and reaching as high as 83% by age 80. Based on this, it is estimated that there are 84 million BPH patients in my country. Transurethral resection of the prostate (TURP) is an invasive procedure widely used since the 1920s. Steam ablation utilizes an interventional approach to precisely release steam heat onto the target tissue for ablation. Due to the excellent tissue penetration and convection properties of steam water molecules, it can treat solid tumors, cancers, and lesions. It is particularly effective in ablating excess prostate tissue, reducing its size and alleviating pressure on the urethra, thus addressing benign prostatic hyperplasia.

[0003] However, in existing steam ablation treatments, the amount of steam injected relies on experience-based judgment, which can easily lead to incomplete ablation or damage to normal tissues due to dosage deviations. At the same time, the steam injection control is based on experience, which cannot achieve precise injection of the set steam quality, resulting in incomplete ablation or damage to other tissues. Summary of the Invention

[0004] In view of this, the present invention provides a steam ablation treatment method with precise control of steam injection volume. The clinically desired ablation effect is transformed into controllable engineering parameters—injection time t and injection steam mass—through experiments and modeling. This ensures that the preset dose can be reliably, accurately, and repeatedly delivered in complex clinical environments, thereby accurately ablated lesion volume, making the ablation boundary more controllable, and accurately controlling steam energy and treatment effect in real time to achieve treatment effectiveness and safety.

[0005] The technical solution is as follows: A steam ablation treatment method with precise control of steam injection volume, comprising the following steps:

[0006] Step 1: Input the diameter of the target ablation area, D (cm), into the control module. The control module then uses the dose-response formula: m steam That is, the mass of injected steam (g);

[0007] Step 2: Position the injection needle at the target tissue and trigger the 'Treatment Start' button to allow the control module to confirm that the temperature and pressure of the steam generator have reached the preset values;

[0008] Step 3: Based on the injection steam mass obtained in Step 1, the control module starts the liquid injection component to inject the set injection liquid mass into the steam generator through the liquid delivery component. That is, the control module simultaneously opens the injection valve and the high-precision timer. When the preset injection time t is reached, the control module controls the injection valve to close. The injection time t = injection liquid mass m / injection speed v, and the injection liquid mass m = injection steam mass.

[0009] Preferably, in step three, the temperature and pressure of the steam generated by the steam generator are detected in real time by temperature and pressure sensors, and the signals are fed back to the control module. Based on the temperature value, the power of the steam generator is controlled. When the pressure value suddenly rises or falls, the control module shuts off the injection valve and the steam generator.

[0010] Preferably, the control module is equipped with a watchdog timer, which will shut down the injection valve and steam generator when the safe time set by the watchdog timer is reached.

[0011] Preferably, in step one, before inputting the diameter D (cm) of the target ablation area into the control module, a self-check for steam ablation treatment is performed. The specific steps are as follows:

[0012] Step 1: Initialization and self-test. The control module performs a self-test on the sensors, actuators, and safety circuits of the steam ablation therapy. If a fault occurs, the treatment mode cannot be entered.

[0013] Step 2: Standby mode. The control module starts the liquid injection component to inject a small amount of liquid to be evaporated into the steam generator through the liquid delivery component. Then, the steam generator is controlled to heat the liquid to be evaporated to the saturated steam temperature (~100℃) and maintain it at the set pressure. The indicator light will light up, and the system will enter standby mode.

[0014] Preferably, the control module includes a housing, and an HMI module is disposed inside the housing for interacting with the outside world. The HMI module is electrically connected to a controller MCU for controlling and managing the operation of steam ablation therapy. The controller MCU is electrically connected to a data storage module for storing configuration data and logs. The controller MCU is electrically connected to an interaction module for gas path isolation and cooling components, an interaction module for liquid injection components, an interaction module for steam generator, and a sensor module.

[0015] Preferably, the liquid injection assembly includes a liquid-to-vaporize chamber wall, one end of which is provided with an injection outlet and is sealed and connected to the liquid delivery assembly. A liquid-to-vaporize chamber is formed inside the liquid-to-vaporize chamber wall, and an injection piston is slidably installed in the liquid-to-vaporize chamber. A propulsion mechanism is provided at the end of the injection piston away from the injection outlet to drive the injection piston to slide in a sealed manner along the liquid-to-vaporize chamber.

[0016] Preferably, the liquid injection assembly further includes a fixedly installed movable guide rail, and the injection mechanism is slidably installed on the movable guide rail. The movable guide rail is provided with a limit block to limit the movement of the injection mechanism within the limit stroke of the movable guide rail. The injection mechanism is provided with an injection pressure sensor and an injection speed sensor, and is electrically connected to the controller MCU.

[0017] Preferably, the liquid delivery assembly includes a pipe connector that is sealed and connected to the injection outlet, and the other end of the pipe connector is sealed and connected to the liquid inlet of the steam generator through a liquid delivery conduit. The liquid outlet is equipped with a gas delivery pipe for delivering the gas generated by the steam generator. The end of the gas delivery pipe is provided with a gas outlet device that corresponds to the injection needle.

[0018] Preferably, the steam generator includes a heating chamber, which has a cavity and heating components inside. The cavity is sealed and connected to a liquid delivery conduit through an inlet for the liquid to be vaporized, and to a gas delivery pipe through a liquid vapor outlet on the other side. Multiple temperature sensors and pressure sensors are installed in the cavity and are electrically connected to the controller MCU.

[0019] Preferably, the outer wall of the gas pipeline is fitted with a gas path isolation and cooling assembly. The gas path isolation and cooling assembly includes a cooling isolation cavity fitted on the outer wall of the gas pipeline. A cooling medium inlet is provided at one end of the cooling isolation cavity near the steam generator, and a cooling medium outlet is provided at the other end. Multiple sets of cooling assembly temperature sensors are provided in the cooling isolation cavity and are electrically connected to the controller MCU.

[0020] After adopting the above technical solution, the beneficial effects of the present invention are:

[0021] 1. The desired ablation effect in clinical practice is transformed into controllable engineering parameters—injection time t and injection steam quality—through experiments and modeling. This ensures that the preset dose can be reliably, accurately, and repeatedly delivered in complex clinical environments, thereby precisely controlling the ablation lesion volume, making the ablation boundary more controllable, and accurately controlling steam energy and treatment effect in real time to achieve treatment effectiveness and safety.

[0022] 2. Multi-stage liquid storage device: The injection component stores the main liquid to be vaporized, and the heating component stores the preheated liquid, reducing the preheating power. At the same time, when switching from ready to heating, the system can quickly heat and vaporize the liquid in the heating component, shorten the gas waiting time, control the liquid output rate at each stage, maintain the amount of liquid used and the total amount of gas per unit time, and achieve precise material control. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a control flowchart of the present invention;

[0025] Figure 2 This is a schematic diagram of the liquid injection assembly of the present invention;

[0026] Figure 3 This is a schematic diagram of the liquid delivery assembly of the present invention;

[0027] Figure 4 This is a schematic diagram of the gas path isolation and cooling assembly of the present invention;

[0028] Figure 5 This is a schematic diagram of the steam generator of the present invention;

[0029] Figure 6 This is a schematic diagram of the control module of the present invention;

[0030] Figure 7 This is a schematic diagram of the structure of the present invention;

[0031] Figure 8 This is a schematic diagram of the propulsion mechanism in Embodiment 3 of the present invention;

[0032] In the diagram, 100 is the liquid injection assembly; 200 is the liquid delivery assembly; 300 is the gas path isolation and cooling assembly; 400 is the steam generator; 500 is the control module; 101 is the wall of the liquid to be vaporized chamber; 102 is the propulsion mechanism; 103 is the injection piston; 104 is the injection pressure sensor; 105 is the propulsion speed sensor; 106 is the injection outlet; 107 is the moving guide rail; 108 is the limit block; 109 is the liquid to be vaporized chamber; 201 is the pipe connector; 202 is the liquid delivery conduit; 203 is the gas delivery pipe; 204 is the gas outlet device; 301 is the cooling medium inlet; 302 is the cooling assembly temperature sensor; and 303 is the cooling isolation... 304. Cooling medium outlet; 401. Liquid to be vaporized inlet; 402. Liquid vapor outlet; 403. Heating chamber; 404. Temperature sensor; 405. Heating component; 406. Cavity; 501. Housing; 502. HMI module; 503. Data storage module; 504. Controller MCU; 505. Gas path isolation and cooling component interaction module; 506. Liquid injection component interaction module; 507. Steam generator interaction module; 1021. Mounting base; 1022. Screw; 1023. Nut; 1024. Drive motor; 1025. Transmission rod; 1026. Transmission plate; 1027. Piston rod; Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 and Figure 7 As shown, a steam ablation treatment method with precise control of steam injection volume includes the following steps:

[0036] Step 1: Input the diameter of the target ablation area, D (cm), into the control module 500. The control module 500 then uses the dose-response relationship formula: m steam That is, the mass of injected steam (g);

[0037] Step 2: Position the injection needle to the target tissue and trigger the 'Treatment Start' button to allow the control module 500 to confirm that the temperature and pressure of the steam generator 400 have reached the preset values;

[0038] Step 3: Based on the injection steam mass obtained in Step 1, the control module 500 starts the liquid injection assembly 100 to inject the set injection liquid mass into the steam generator 400 through the liquid delivery assembly 200. That is, the control module 500 simultaneously opens the injection valve and the high-precision timer. When the preset injection time t is reached, the control module 500 controls the injection valve to close. The injection time t = injection liquid mass m / injection speed v, and the injection liquid mass m = injection steam mass.

[0039] In step three, the temperature and pressure of the steam generated by the steam generator 400 are detected in real time by the temperature sensor 404 and the pressure sensor, and the signal is fed back to the control module 500. Based on the temperature value, the power of the steam generator 400 is controlled. When the pressure value suddenly rises or falls, the control module 500 shuts off the injection valve and the steam generator 400.

[0040] The control module 500 includes a housing 501, and an HMI module 502 is disposed within the housing 501 for interaction with the outside world. The HMI module 502 is electrically connected to a controller MCU 504 for controlling and managing the operation of steam ablation therapy. The controller MCU 504 is electrically connected to a data storage module 503 for storing configuration data and logs. The controller MCU is electrically connected to an interaction module for the gas path isolation and cooling component 300, an interaction module for the liquid injection component 100, an interaction module for the steam generator 400, and a sensor module. The liquid injection component 100 includes a liquid to be vaporized chamber wall 101, one end of which is provided with an injection outlet 106 and is sealed and connected to the liquid delivery component 200. A liquid-to-vaporize chamber 109 is formed within the wall 101. A pusher piston 103 is slidably mounted within this chamber, and a propulsion mechanism 102 is provided at the end of the pusher piston 103 away from the pusher outlet 106. This mechanism drives the pusher piston 103 to slide along the liquid-to-vaporize chamber 109 in a sealed manner. The liquid pusher assembly 100 also includes a fixedly mounted movable guide rail 107, on which the propulsion mechanism 102 is slidably mounted. A limit block 108 is provided on the movable guide rail 107 to limit the movement of the propulsion mechanism 102 within its limit stroke. A pusher pressure sensor 104 and a pusher speed sensor 105 are provided on the pusher mechanism, and they are electrically connected to the controller MCU 504. Liquid delivery assembly 2 The steam generator 400 includes a pipe connector 201 that is sealed and connected to the injection outlet 106. The other end of the pipe connector 201 is sealed and connected to the inlet of the steam generator 400 via a liquid delivery conduit 202. A gas delivery pipe 203 is installed at the outlet for delivering gas generated by the steam generator 400. A gas outlet device 204 is provided at the end of the gas delivery pipe 203, corresponding to the injection needle. Specifically, the gas outlet device 204 is a needle-type gas outlet or a gas nozzle. The steam generator 400 includes a heating chamber 403, inside which is a cavity 406 and a heating element 405. The heating element 405 includes a resistance heating wire or a heating tube (preferably a corrugated tube) for vaporizing the liquid to be vaporized. The cavity 406 is connected to the inlet of the liquid to be vaporized. 401 is sealed and connected to the liquid delivery conduit 202, and the other side is sealed and connected to the gas delivery pipe 203 through the liquid vapor outlet 402. Multiple temperature sensors 404 and pressure sensors are installed in the cavity 406, and are electrically connected to the controller MCU504 respectively. A gas path isolation and cooling assembly 300 is installed on the outer wall of the gas delivery pipe 203. The gas path isolation and cooling assembly 300 includes a cooling isolation cavity 303 installed on the outer wall of the gas delivery pipe 203. A cooling medium inlet 301 is provided at one end of the cooling isolation cavity 303 near the steam generator 400, and a cooling medium outlet 304 is provided at the other end. Multiple sets of cooling assembly temperature sensors 404 and 302 are installed in the cooling isolation cavity 303, and are electrically connected to the controller MCU504.

[0041] Specifically: Preheated liquid is stored in cavity 406. The liquid delivery assembly 200 and the liquid injection assembly 100 are made of materials with low susceptibility to pressure and temperature variations. When steam is generated, causing changes in liquid pressure within the liquid delivery assembly 200 and the liquid injection assembly 100, their volumes remain unchanged. Under the precise liquid velocity control of the control module 500, the steam generator 400 maintains a constant gas pressure output. The propulsion mechanism 102 employs an electric push rod or a hydraulic cylinder.

[0042] In practice: the control module 500 links multiple components to achieve closed-loop control of the entire process from parameter input to safe ablation; before treatment, medical staff input the diameter D of the target ablation area into the control module 500, and the controller MCU504 calls the built-in dose-effect relationship formula to quickly calculate the required injection steam mass, laying a data foundation for precise treatment.

[0043] After positioning the injection needle, the "treatment start" command is triggered. The controller MCU504 immediately verifies whether the temperature and pressure of the steam generator 400 meet the standards to ensure that the initial treatment conditions are compliant. Once the standards are met, the controller MCU504 sends a command to the liquid injection component 100 according to the preset steam quality: the propulsion mechanism 102 drives the injection piston 103 to slide at a constant speed along the moving guide rail 107, and presses the liquid to be vaporized into the liquid delivery conduit 202 at a set speed, while simultaneously opening the injection valve and the high-precision timer.

[0044] After the liquid enters the cavity 406 of the steam generator 400 through the pipeline, the heating element 405 rapidly vaporizes it. The temperature and pressure sensors in the cavity 406 collect data in real time and feed it back to the controller MCU504. The controller MCU504 maintains a stable temperature by adjusting the heating power to ensure the steam generation efficiency. The injection time is precisely calculated by "injection liquid mass / injection speed". When the preset time t is reached, the controller MCU504 immediately closes the injection valve to realize the quantitative control of the steam injection amount.

[0045] The entire treatment process relies on multiple safety mechanisms: the gas path isolation and cooling component 300 cools the gas delivery tube 203 through the circulation of cooling medium to avoid thermal damage. If the sensor detects a sudden rise or fall in steam pressure or abnormal temperature, the controller MCU504 will immediately trigger emergency protection, shutting down the injection valve and steam generator 400. At the same time, the data storage module 503 records the treatment parameters and equipment status in real time, providing support for treatment traceability, and ultimately achieving safe and precise targeted ablation.

[0046] Specifically: In the calculation of the dose-response relationship formula in step one, when steam condenses into water in tissues, it releases a large amount of latent heat of vaporization, which is the main source of therapeutic energy.

[0047] Calculation formula: Total transferred energy = Sensible heat + Latent heat

[0048] In steam ablation, because the steam temperature (100℃) is much higher than the tissue temperature (37℃), and latent heat accounts for the vast majority (about 80%) of the total energy, latent heat is the dominant factor.

[0049] That is: E≈m×h fg

[0050] E: Total energy transferred (unit: joules J)

[0051] m: Mass of injected steam (unit: grams)

[0052] h_{fg}: Latent heat of vaporization of water (approximately 2257 J / g at 100℃);

[0053] Steam quality is calculated using steam flow rate and injection time, i.e.:

[0054] Steam mass flow rate (unit: g / s)

[0055] t: Injection time (unit: seconds)

[0056] Therefore, the dosage calculation formula is:

[0057] Dose-response model: The functional relationship between energy E and tissue ablation volume, i.e., the dose-response relationship.

[0058] V ablation =f(E,T) tissue ,P injection (Organizational characteristics)

[0059] V ablation Predicted ablation volume (cm²) 3 ),

[0060] T tissue Specific heat capacity, thermal conductivity, and density of tissue types (such as prostatic hyperplasia, uterine fibroids, etc.).

[0061] P injection Injection pressure affects the penetration range and distribution pattern of vapor;

[0062] Tissue characteristics: including tissue homogeneity and blood perfusion (which carries away heat).

[0063] Specifically: The energy released by the injected steam (saturated steam at 100°C) consists of two parts:

[0064] 1. Latent heat (Q) latent ): The energy released when steam condenses into water at 100°C, i.e.:

[0065] Q latent =m steam ×h fg

[0066] Where h fg It is the latent heat of vaporization of water, approximately 2257 g / g;

[0067] 2. Sensible heat (Q) sensible The energy released when 100℃ condensed water is cooled to its final tissue equilibrium temperature (close to 65℃) is:

[0068] Q sensible =m steam ×c water ×ΔT′

[0069] Where c water The specific heat capacity of water is 4.18 J / (g·℃), and ΔT′ is 100℃-65℃=35℃.

[0070] Therefore, the total energy released per gram of steam is:

[0071] E steam_per_gram =h fg +(c water ×ΔT′)

[0072] E steam_per_gram =2257 + (4.18 × 35)

[0073] E steam_per_gram =2257 + 146.3 ≈ 2403.3 J / g

[0074] Conclusion: Injecting 1 gram of steam into the tissue provides 2400 Joules of energy;

[0075] According to the law of conservation of energy: the energy released by vapor = the energy absorbed by tissue.

[0076] m steam ×E steam ×η=m tissue ×c tissue ×ΔT where η is the heat transfer efficiency <1

[0077] Organizational quality m tissue The diameter D (unit: cm) of the spherical ablation volume is converted.

[0078] spherical volume:

[0079] Organizational quality: m tissue =V×ρ, where ρ is the tissue density, approximately equal to 1.05 g / cm³. 3 (Close to water);

[0080] therefore:

[0081]

[0082] Based on the above fundamental principles, parameter calculations will begin:

[0083] 1. Set calculation parameters based on clinical data.

[0084] Water vapor (0.42 mL) is delivered in a 9-second injection and dispersed circumferentially to form an ablation zone with a diameter of 1.5-2.0 cm.

[0085] Mass of injected steam: 0.42g

[0086] Ablation zone diameter: 1.5-2.0cm (take the median value of 1.75cm for calculation)

[0087] Ablation zone shape: sphere (clinical approximation)

[0088] Tissue density: 1.05 g / cm³ 3 (Similar to prostate tissue)

[0089] 2. Calculation of ablated tissue quality

[0090] Formula for the volume of a sphere:

[0091] For a sphere with a diameter of 1.75cm:

[0092]

[0093] Corresponding organizational quality:

[0094] m tissue =V×ρ=2.805×1.05=2.945g

[0095] Conclusion: 0.42g of steam produced the ablation of approximately 2.945g of tissue.

[0096] 3. Energy efficiency calculation

[0097] A. Total energy carried by steam:

[0098] Latent heat: 2257 J / g

[0099] Sensible heat (100℃→65℃): 4.18 J / g·℃ × 35℃ = 146.3 J / g

[0100] Total energy per gram of steam: 2257 + 146.3 = 2403.3 J / g

[0101] Total energy of 0.42g steam:

[0102] E total =0.42 × 2403.3 = 1009.4 J

[0103] B. Energy required for tissue heating:

[0104] The tissue was heated from 37°C to 65°C (ΔT = 28°C):

[0105] E tissue =m tissue ×c×ΔT=2.945×4.18×28=344.7J

[0106] C. Energy efficiency factor:

[0107]

[0108] The actual energy utilization efficiency is approximately 34.1%, with about 66% of the energy lost through blood flow and surrounding tissues.

[0109] 4. Derivation of the dose-response relationship formula

[0110] According to the principle of conservation of energy:

[0111]

[0112] Substituting η = 0.341:

[0113]

[0114] 819.0×m steam =64.4×D 3

[0115]

[0116] D 3 =12.72×m steam

[0117] The dose-response relationship formula is derived as follows:

[0118]

[0119] in:

[0120] D = Diameter of the ablation zone (cm)

[0121] m steam = Mass of injected steam (g)

[0122] 5. The relationship between steam mass and ablation diameter is based on the formula D = (12.72 × m). steam ) 1 / 3 calculate:

[0123]

[0124]

[0125] 6. Clinical significance and validation

[0126] Formula verification:

[0127] For the measured data points (0.42g→1.75cm), the calculated diameter range was consistent with the predicted range of 1.5-2.0cm observed in clinical practice.

[0128] Clinical application guidance:

[0129] Dosage selection: Clinicians can calculate the required steam mass by working backwards from the target ablation size.

[0130] For example, to obtain an ablation diameter of 2.0 cm:

[0131]

[0132] Safety considerations: This model is based on normal prostate tissue. For different tissue types (such as tissues with a high degree of fibrosis), the efficiency factor η may need to be adjusted.

[0133] Treatment planning: The total treatment dose and injection sites can be calculated based on the prostate volume and the desired ablation ratio.

[0134] Example 2

[0135] Based on Embodiment 1, the control module 500 is equipped with a watchdog timer. When the safe time set by the watchdog timer is reached, the injection valve and the steam generator 400 will be shut down.

[0136] Before inputting the diameter D (cm) of the target ablation area into the control module 500 in step one, a self-check for steam ablation treatment is performed. The specific steps are as follows:

[0137] Step 1: Initialization and self-test. The control module 500 performs a self-test on the sensors, actuators, and safety circuits of the steam ablation therapy. If a fault occurs, the treatment mode cannot be entered.

[0138] Step 2: Standby mode. The control module 500 starts the liquid injection component 100 to inject a small amount of liquid to be evaporated into the steam generator 400 through the liquid delivery component 200. Then, the steam generator 400 is controlled to heat the liquid to be evaporated to the saturated steam temperature (100°C) and maintain it at the set pressure. The indicator light is on, and the system enters the standby mode.

[0139] In actual operation: the control module 500 has a built-in watchdog timer. If the preset action is not completed within the timeout period, the injection valve and generator will be shut down immediately. The gas cooling component cools the gas delivery tube 203 through medium circulation to prevent thermal damage. When the pressure or temperature is abnormal, the controller MCU504 triggers an emergency shutdown. The data storage module 503 records parameters and equipment status in real time. With multiple safeguards, the system can not only achieve precise control of the steam injection volume, but also ensure that the entire treatment process is safe and controllable, and ultimately achieve the goal of targeted ablation.

[0140] Before treatment begins, an initial self-check is performed: the control module 500 conducts a comprehensive check of sensors, actuators, and safety circuits. In case of a fault, the treatment mode is locked. After the self-check passes, it enters standby mode: the liquid injection component 100 injects a small amount of liquid into the steam generator 400. The generator heats the liquid to 100°C saturated steam temperature and maintains the set pressure. When the indicator light illuminates, standby mode is complete. Then, medical staff input the diameter D of the target area. The control module 500 transmits the data to the controller MCU504. The controller MCU504 calls the dose-effect formula to calculate the required steam mass, laying the foundation for precise treatment.

[0141] Example 3

[0142] Based on any of the above embodiments, such as Figure 8 As shown, the propulsion mechanism includes two symmetrical mounting seats fixedly installed. A screw is rotatably installed between the two mounting seats. A drive motor is mounted on one of the mounting seats via bolts and nuts, and is connected to the end of the screw via gear transmission. When the drive motor is started, it drives the screw to rotate through gear transmission. The propulsion speed sensor is mounted on the drive motor and is electrically connected to the controller of the drive motor. A nut is threaded onto the screw. A transmission rod is slidably mounted on the other mounting seat. The mounting seat has a sliding hole through which the transmission rod slides. The transmission rod is fixedly connected to the side wall of the nut. A transmission plate is fixedly mounted on the other end of the transmission rod. A piston rod is mounted on the transmission plate via bolts and nuts. The piston rod is connected and fixed to the piston plate. The propulsion pressure sensor is mounted on the piston plate and is in contact with the internal liquid. The propulsion pressure sensor is a waterproof sensor or is waterproofed. The propulsion pressure sensor is electrically connected to the controller of the drive motor.

[0143] In actual operation: The drive motor is started and drives the screw to rotate through gear transmission. The screw drives the nut and transmission rod to move synchronously along the sliding hole on the mounting base. The speed of the drive motor is controlled by the propulsion speed sensor, thereby controlling the propulsion speed of the transmission rod. The transmission rod drives the transmission plate and piston rod to move synchronously, which in turn drives the piston plate to move, realizing the injection function. Pressure changes are detected in real time by the propulsion pressure sensor.

[0144] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A method of steam ablation therapy with precise control of the amount of steam injected, characterized in that, The method comprises the following steps: Step one: input the diameter of target ablation area: D (cm) into the control module (500), and obtain m by the control module (500) according to the dose-effect relationship formula: m = D / 2 steam , that is, the injection steam mass (g); Step two: positioning the injection needle to the target tissue, confirming the temperature and pressure of the steam generator (400) reaching the preset value by triggering the "treatment start" button; Step three: according to the injection steam quality obtained in step one, starting the liquid bolus assembly (100) to inject a set injection liquid quality into the steam generator (400) through the liquid delivery assembly (200) by the control module (500), that is, opening the injection valve and the high-precision timer at the same time by the control module (500), and when the preset injection time t is reached, the control module (500) controls the injection valve to close, wherein the injection time t = injection liquid quality m / injection speed v, and the injection liquid quality m = injection steam quality.

2. The method of claim 1, wherein the amount of vapor injected is precisely controlled. In step three, the temperature and pressure of the steam generated by the steam generator (400) are detected in real time by the temperature sensor (404) and the pressure sensor, and the signals are fed back to the control module (500), and the power of the steam generator (400) is controlled according to the temperature value; when the pressure value suddenly rises or falls, the control module (500) closes the injection valve and the steam generator (400).

3. The method of claim 1, wherein the amount of vapor injected is precisely controlled. The watchdog timer is arranged in the control module (500), and the injection valve and the steam generator (400) will be closed when the safety time set by the watchdog timer is reached.

4. The method of claim 1, wherein the amount of vapor injected is precisely controlled. Before inputting the diameter of the target ablation area D (cm) into the control module (500) in step one, self-checking of the steam ablation treatment is performed, and the specific steps are as follows: Step one: initialization and self-checking, self-checking of the sensors, actuators and safety circuits of the steam ablation treatment by the control module (500), if a fault occurs, the treatment mode cannot be entered; Step two: standby mode, a small amount of evaporation liquid is injected into the steam generator (400) by the liquid bolus assembly (100) through the liquid delivery assembly (200) by the control module (500), and then the evaporation liquid is heated to the saturated steam temperature (~100℃) by the steam generator (400), and maintained at a set pressure state, the indicator light is on, and the standby state is entered.

5. The method of claim 1-4, wherein the amount of vapor injected is precisely controlled. The control module (500) comprises a shell (501), and the shell (501) is provided with an HMI module (502) for interaction with the outside world, the HMI module (502) is electrically connected with a controller MCU (504) for controlling and managing the operation of the steam ablation treatment, the controller MCU (504) is electrically connected with a data storage module (503) for configuring data and storing log data, and the control MCU is electrically connected with an air path isolation and cooling assembly (300) interaction module, a liquid bolus assembly (100) interaction module, a steam generator (400) interaction module and a sensor module.

6. The method of claim 5, wherein the amount of vapor injected is precisely controlled. The liquid bolus assembly (100) comprises a to-be-gasified liquid cavity wall (101), one end of the to-be-gasified liquid cavity wall (101) is provided with a bolus outlet (106) and is in sealed communication with a liquid delivery assembly (200), a to-be-gasified liquid cavity (109) is formed in the to-be-gasified liquid cavity wall (101), a bolus piston (103) is sealingly and slidably arranged in the to-be-gasified liquid cavity (109), and the bolus piston (103) is provided with a propulsion mechanism (102) at an end away from the bolus outlet (106) for driving the bolus piston (103) to sealingly slide along the to-be-gasified liquid cavity (109).

7. The method of claim 6, wherein the amount of vapor injected is precisely controlled. The liquid bolus assembly (100) further comprises a fixedly-installed moving guide rail (107), and the propulsion mechanism (102) is slidably arranged on the moving guide rail (107), the moving guide rail (107) is provided with a limiting block (108) for limiting the movement of the propulsion mechanism (102) within a limiting stroke along the moving guide rail (107), the bolus mechanism is provided with a bolus pressure sensor (104) and a propulsion speed sensor (105) and is electrically connected with a controller MCU (504).

8. The method of claim 6, wherein the amount of vapor injected is precisely controlled. The liquid delivery assembly (200) comprises a pipeline connecting head (201) in sealed communication with the bolus outlet (106), the other end of the pipeline connecting head (201) is in sealed communication with a liquid inlet of a steam generator (400) through a liquid delivery conduit (202), and a gas delivery pipe (203) is arranged at a liquid outlet for delivering gas generated by the steam generator (400), an end of the gas delivery pipe (203) is provided with an air outlet device (204) corresponding to the injection needle.

9. The method of claim 8, wherein the amount of vapor injected is precisely controlled. The steam generator (400) comprises a heating box body (403), the heating box body (403) is internally provided with a cavity (406) and a heating component (405), the cavity (406) is in sealed communication with the liquid delivery conduit (202) through a to-be-gasified liquid inlet (401) and is in sealed communication with the gas delivery pipe (203) through a liquid vapor outlet (402) on the other side, a plurality of temperature sensors (404) and pressure sensors are arranged in the cavity (406) and are electrically connected with the controller MCU (504) respectively.

10. The method of claim 9, wherein the amount of vapor injected is precisely controlled. The outer wall of the gas delivery pipe (203) is sleeved with a gas path isolation and cooling assembly (300), the gas path isolation and cooling assembly (300) comprises a cooling isolation cavity (303) sleeved on the outer wall of the gas delivery pipe (203), one end of the cooling isolation cavity (303) close to the steam generator (400) is provided with a cooling medium inlet (301), and the other end is provided with a cooling medium outlet (304), a plurality of cooling assembly temperature sensors (302) are arranged in the cooling isolation cavity (303) and are electrically connected with the controller MCU (504).

Images