Radio frequency ablation equipment needle withdrawing system capable of avoiding scars

Abstract

The invention relates to the field of medical equipment, and discloses a radiofrequency ablation equipment needle withdrawing system capable of avoiding scars. According to the system, a needle position detection device (real-time monitoring depth and speed) and a needle point temperature sensor are integrated on the basis of standard radiofrequency ablation equipment. During needle withdrawing, the radio frequency power is dynamically adjusted according to the needle withdrawing speed (the higher the speed is, the higher the power is); when the needle point depth is smaller than a preset threshold value (close to the body surface), radio frequency output is automatically stopped, and waiting for cooling is prompted; and after the temperature is reduced to be below a safety threshold value, the needle body can be completely pulled out. Through closed-loop control, the needle passage thermal coagulation and tail end cooling process is accurately managed, thermal damage to the skin and subcutaneous tissue is effectively prevented, and scar formation is remarkably reduced.

Description

Technical Field

[0001] The present application relates to the field of medical equipment, and in particular to a needle removal technology for radiofrequency ablation equipment. Background Art

[0002] This section is intended to provide a background or context for understanding the embodiments of the present application and is for reference only. The applicant should not be considered to admit that this section belongs to the prior art that has been disclosed before the filing date of this application.

[0003] Radiofrequency ablation (RFA) is a minimally invasive treatment technique widely used in clinical medicine. This technique delivers radiofrequency (RF) current to the target lesion, using the thermal effect of the current to induce coagulative necrosis of tissue cells, thereby achieving therapeutic results. Due to its minimal invasiveness, rapid recovery, and proven efficacy, RFA plays an important role in the treatment of a variety of diseases, including localized treatment of solid organ tumors such as liver, lung, and kidney tumors, as well as the treatment of certain cardiac arrhythmias (such as atrial fibrillation).

[0004] A typical radiofrequency ablation system usually includes an RF generator and one or more RF ablation needles (abbreviated as "ablation needles"), also often referred to as RF electrodes. The RF generator is responsible for generating RF current of a specific frequency and power. The RF ablation needle is a specially designed puncture needle with an uninsulated active tip at the distal end, which is used to accurately transmit the energy generated by the RF generator to the target tissue. During the treatment process, the operator guides the ablation needle percutaneously or through other puncture routes to the lesion area, activates the RF generator to output energy, and raises the temperature of the tissue around the active tip to reach the preset treatment temperature (usually between 60°C and 100°C) and maintain it for a period of time to ensure sufficient necrosis of the target tissue.

[0005] After completing ablation treatment of the target lesion, the process of removing the ablation needle from the patient's body, also known as needle withdrawal, is a critical step in the entire procedure. Improper handling can cause bleeding along the needle tract or potential tumor cell implantation and metastasis. In clinical practice, needle tract ablation, also known as needle tract cauterization or needle tract coagulation, is often required during needle withdrawal. This is usually achieved by continuously outputting a low-power radiofrequency current while slowly and evenly withdrawing the ablation needle. The goal is to heat and coagulate the needle tract and surrounding tissue, sealing the blood vessels and tissue spaces.

[0006] However, the existing needle tract ablation operation method has certain limitations. During the manual needle withdrawal process, it is difficult for the operator to accurately control the constant needle withdrawal speed. Changes in the needle withdrawal speed may cause uneven heating of different sections of the needle tract. If the needle withdrawal speed is too fast or the radio frequency power is insufficient, it may lead to incomplete coagulation of the needle tract and fail to achieve the expected hemostasis or anti-implantation effect. Conversely, if the needle withdrawal speed is too slow or the radio frequency power is too high, especially when the ablation needle is close to the body surface (such as skin and subcutaneous tissue), excessive heat accumulation may cause excessive thermal damage to normal tissues around the puncture point. This excessive thermal damage close to the body surface is an important reason for the formation of obvious scars on the skin in the puncture point area after surgery, which not only affects the appearance, but may sometimes be accompanied by pain or discomfort.

[0007] Therefore, how to more effectively control the release of radiofrequency energy during the needle withdrawal phase of radiofrequency ablation surgery to ensure that the needle tract is fully and evenly coagulated, while precisely managing the heat release before the ablation needle withdraws from the body surface to minimize thermal damage to the skin and subcutaneous tissue, thereby avoiding or significantly reducing the formation of postoperative scars, is a technical problem that urgently needs to be solved in the current field of radiofrequency ablation equipment. Summary of the Invention

[0008] The purpose of this application is to provide a radiofrequency ablation device needle withdrawal system that avoids scarring and solves the technical problems existing in the prior art.

[0009] The present application discloses a radiofrequency ablation device needle removal system for avoiding scarring, comprising an ablation needle and a radiofrequency generator for providing radiofrequency power to the ablation needle. The device also includes: A needle position detection device, used to detect the depth of the active tip of the ablation needle entering the human body and the movement speed of the ablation needle; a temperature sensor, disposed on the ablation needle, for detecting the temperature of the active tip; and a control device electrically connected to the radio frequency generator, the needle position detection device and the temperature sensor; Wherein, the control device is configured as follows: When the ablation needle is withdrawn, the control device controls the radio frequency power provided to the ablation needle by the radio frequency generator according to the movement speed of the ablation needle detected by the needle position detection device, wherein a higher movement speed of the ablation needle corresponds to a higher radio frequency power; When the depth of the active tip detected by the needle position detection device entering the human body is less than or equal to a predetermined depth threshold, the control device controls the radio frequency generator to stop providing radio frequency power to the ablation needle and issues a prompt message indicating that the needle should be withdrawn and wait for cooling; and After the RF generator stops providing RF power to the ablation needle, when the temperature of the ablation needle detected by the temperature sensor drops below a predetermined temperature threshold, the control device issues a prompt message indicating that the ablation needle can be removed.

[0010] In a preferred example, the control device is also configured to start the cooling system of the ablation needle when the depth of the active tip detected by the needle position detection device entering the body is less than or equal to a predetermined depth threshold, so that the cooling liquid flows into the fluid channel inside the ablation needle to cool the active tip.

[0011] In a preferred embodiment, the needle position detection device includes: A base is fixed on the patient's body surface near the puncture point before the ablation operation, and the base is provided with a channel for the ablation needle to pass through; a first ultra-wideband module, integrated or fixed on the base; a second ultra-wideband module, integrated into or fixed on the handle of the ablation needle; and a processing module, electrically connected to the second ultra-wideband module; The processing module is configured to calculate the depth of the active tip entering the human body and the movement speed of the ablation needle based on the distance information determined by the ultra-wideband radio pulse signals sent and received between the first ultra-wideband module and the second ultra-wideband module.

[0012] In a preferred embodiment, the outer surface of the ablation needle has a periodic texture arranged along the axial direction; The needle position detection device comprises: a base having an internal detection chamber and a coaxial penetration hole for the ablation needle to pass through; an optical lighting component, disposed in the detection chamber and configured to illuminate a textured area on the surface of the ablation needle passing through the penetration hole; At least two photoelectric sensing components installed side by side along the axis of the ablation needle, disposed in the detection chamber, for receiving light reflected from the texture on the surface of the needle body and generating an electrical signal; and The processing circuit is electrically connected to the photoelectric sensing component and is configured to calculate the depth of the active tip entering the human body and the movement speed of the ablation needle according to the electrical signal generated by the photoelectric sensing component.

[0013] In a preferred example, the axial distance between the at least two photoelectric sensing components is set to a non-integer multiple of the period length of the periodic texture.

[0014] In a preferred example, the axial distance between the at least two photoelectric sensing elements is set to be one quarter of the period length of the periodic texture.

[0015] In a preferred example, the control device is configured to control the RF power according to the ablation needle movement speed through a table lookup method, and the control device stores at least one lookup table that defines the ablation needle movement speed interval or speed point and the corresponding RF power value.

[0016] In a preferred example, the control device is configured to control the radio frequency power according to the movement speed of the ablation needle through a mathematical function method, and the control device is programmed to implement a monotonically non-decreasing mathematical function P=f(v), where v is the input movement speed of the ablation needle and P is the output radio frequency power.

[0017] In a preferred embodiment, the control device includes a display screen with a graphical user interface for displaying the depth, the speed, the temperature, the radio frequency power and the prompt information in real time.

[0018] In a preferred example, the prompt information indicating that the needle should be withdrawn and waiting for cooling and the prompt information indicating that the ablation needle can be withdrawn include visual prompt information and / or auditory prompt information.

[0019] In an embodiment of the present application, intelligent, refined closed-loop control of the RF ablation needle withdrawal process is achieved by integrating a needle position detection device (for real-time monitoring of the depth and movement speed of the active tip of the ablation needle), a temperature sensor (for monitoring needle tip temperature), and specific control device logic (this logic adjusts the RF power according to the detected movement speed during needle withdrawal, ensuring that the faster the speed, the higher the power or remains constant; automatically stops RF output and issues a waiting temperature reduction prompt when the needle tip reaches a predetermined shallow depth; and issues a needle withdrawal permission prompt after the temperature has sufficiently decreased). This solution ensures effective thermal coagulation of the entire needle tract to prevent bleeding or tumor spread. It also precisely stops heating at the final stage before the needle tip is about to leave the skin and forces the needle tip to cool to a safe temperature before allowing complete withdrawal. This significantly reduces the risk of postoperative scarring caused by burns to the skin and subcutaneous tissue caused by the high-temperature needle, significantly improving surgical safety and the patient's postoperative recovery quality and aesthetics.

[0020] Furthermore, by configuring the control device to start the ablation needle's own cooling system in addition to stopping the radio frequency power when the control device detects that the active tip depth is less than or equal to a predetermined depth threshold, the cooling process of the active tip can be actively accelerated, shortening the waiting cooling time required after stopping the needle withdrawal, thereby improving the overall efficiency of the operation, and being able to reduce the needle tip temperature more quickly and effectively, further consolidating the effect of preventing thermal damage to superficial tissues.

[0021] Furthermore, by employing a specific needle-position detection device based on ultra-wideband (UWB) technology (comprising a base and a first UWB module fixed near the patient's body surface, a second UWB module fixed to the ablation needle handle, and a processing module that calculates distance and infers depth and speed), a non-contact, high-precision real-time positioning and velocity measurement solution for ablation needles can be achieved. This provides the control system with precise depth and velocity data, and requires no extensive modification to the ablation needle itself (requiring only integration of the module into the handle). It is relatively easy to install and use, and is less susceptible to interference from other factors in the surgical environment (such as fluids and tissue obstructions).

[0022] Furthermore, by creating periodic textures on the outer surface of the ablation needle and using an optical needle-position detection device consisting of a base (with a detection chamber), an optical illumination component, at least two photoelectric sensing components, and processing circuitry, a needle-position detection solution based on optical reading principles can be constructed. By directly reading physical markings on the needle body to precisely track its axial displacement and velocity, very high measurement resolution and accuracy can be achieved, providing reliable input for control algorithms.

[0023] Furthermore, by setting the axial spacing between the two photoelectric sensing elements to a non-integer multiple of the periodic texture, a fixed phase difference is ensured between the reflected light signals received by the two sensors. This specific sensor layout enables the processing circuit to accurately determine the current movement direction of the ablation needle (whether it is being inserted or removed) based on the order of the signal phases.

[0024] Furthermore, by precisely setting the axial spacing between the two photoelectric sensing components to one-quarter of the periodic texture period length (P / 4), an orthogonal signal with a phase difference of approximately 90 degrees can be generated. This not only enables very stable and reliable judgment of the direction of movement, but also facilitates subdivision of the orthogonal signal (such as counting the rising and falling edges of the pulse, or analyzing the phase angle), thereby achieving a higher depth measurement resolution than a single texture period.

[0025] Furthermore, by using a lookup table (LUT) to realize the mapping relationship between the ablation needle movement speed and the radio frequency power in the control device, a simple, efficient and flexible way to implement a speed-power monotonic non-decreasing control strategy can be provided. It has low computational complexity, fast response speed, and allows for convenient customization and adjustment of complex, nonlinear speed-power correspondences according to experimental data or clinical needs.

[0026] Furthermore, by adopting a mathematical function method to realize the mapping relationship between the movement speed of the ablation needle in the control device and the radio frequency power, that is, realizing a monotonic non-decreasing function P=f(v) (where v is the speed and P is the power) in the control program, continuous and smooth power adjustment can be achieved. Compared with the step-like power changes that may be produced by the lookup table method, the function method can make more precise power adjustments according to subtle changes in speed, which helps to achieve a more uniform needle track coagulation effect.

[0027] Furthermore, by equipping the control device with a display screen with a graphical user interface (GUI) for real-time visual display of depth, speed, temperature, current radiofrequency power value and prompt information issued by the system, the human-computer interaction performance of the system can be significantly improved, allowing the operating doctor to clearly understand all key parameters and system status during the needle withdrawal process, enhancing the transparency and controllability of the operation, and improving the convenience and safety of use.

[0028] Furthermore, by stipulating that the prompt messages issued by the system such as "stop withdrawing the needle and wait for cooling" and "the ablation needle can be removed" can be in visual (such as LED light flashing or color change) and / or auditory (such as beeps of different frequencies or rhythms), it can ensure that the operator can receive these key safety instructions in a timely and clear manner. In a noisy or complex lighting operating room environment, the reliability and effectiveness of the prompt information are improved, ensuring that the operator follows a safe needle withdrawal process, thereby ensuring that the ultimate goal of avoiding scars is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a needle withdrawal system for a radiofrequency ablation device for avoiding scarring according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] In the following description, many technical details are provided to help readers better understand this application. However, those skilled in the art will understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented.

[0031] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0032] The embodiment of the present application relates to a radiofrequency ablation device needle removal system that avoids scarring, such as Figure 1 As shown, the radiofrequency ablation device needle removal system for avoiding scarring includes: ablation needle; A radiofrequency generator that provides radiofrequency power to the ablation needle. A needle position detection device is used to detect the depth of the active tip of the ablation needle into the human body and the movement speed of the ablation needle; a temperature sensor, disposed on the ablation needle, for detecting the temperature of the active tip; and a control device electrically connected to the radio frequency generator, the needle position detection device and the temperature sensor; Wherein, the control device is configured as follows: When the ablation needle is withdrawn, the control device controls the radio frequency power provided by the radio frequency generator to the ablation needle according to the movement speed of the ablation needle detected by the needle position detection device, wherein a relatively high ablation needle movement speed corresponds to a relatively high radio frequency power, and a relatively low ablation needle movement speed corresponds to a relatively low radio frequency power; When the depth of the active tip detected by the needle position detection device into the human body is less than or equal to a predetermined depth threshold, the control device controls the radio frequency generator to stop providing radio frequency power to the ablation needle and issues a prompt message indicating that the needle should be withdrawn and wait for cooling; and After the radio frequency generator stops providing radio frequency power to the ablation needle, when the temperature of the ablation needle detected by the temperature sensor drops below a predetermined temperature threshold, the control device issues a prompt message indicating that the ablation needle can be removed.

[0033] The ablation needle of a radiofrequency ablation device, also often called a radiofrequency electrode, is designed to precisely direct radiofrequency current into the target tissue area, generating heat that causes tissue coagulation and necrosis while protecting surrounding non-target tissue. Its structure typically includes the following key components: Needle body: This is the main part of the needle, a long, rod-shaped structure typically made of a rigid and biocompatible metal such as medical-grade stainless steel. It is used to penetrate tissue and reach the target ablation area. The needle body's diameter (often expressed in gauge, such as 17G and 18G) and length vary depending on the clinical application (e.g., liver, lung, kidney, bone tumor, or cardiac ablation).

[0034] Insulation: Most of the outer surface of the needle is covered with an electrically insulating, high-temperature resistant material (e.g., a polymer coating such as PEEK, Teflon / PTFE, or polyimide). The insulation layer is used to confine the RF current to a specific area of ​​the needle tip, preventing it from burning non-target tissue (e.g., skin, muscle, or the needle tract) along the needle path, and concentrating the energy on the target area.

[0035] The active tip / exposed electrode is located at the distal end of the ablation needle and is the portion of the needle not covered by the insulation. This is where the RF current actually flows into the tissue and is the core region responsible for generating the thermal effect that causes tissue ablation. The length and shape of the active tip influence the size and morphology of the ablation lesion. Common shapes range from a few millimeters to several centimeters. Shapes can be simple cylindrical, conical, or more complex "shovel-like" to optimize energy distribution for specific applications.

[0036] Internal Wire: The internal wire that extends from the needle shaft / connector to the active tip and is responsible for conducting the RF current generated by the RF generator to the active tip.

[0037] Handle (or "needle handle"): Located at the proximal end of the ablation needle (the end held by the operator), it provides a grip and manipulation area. It also contains a standard or dedicated connector for connecting to the output cable of the RF generator to transmit RF energy and possible sensor signals.

[0038] Temperature sensor: A temperature sensor (e.g., thermocouple) is embedded within or near the active tip to monitor the temperature of the ablation area in real time, providing feedback to the physician and helping control the ablation process. This ensures that the target temperature (typically 60-100°C) is reached for effective tissue destruction while avoiding overheating (e.g., exceeding 105-110°C) that can lead to tissue carbonization and steam explosion, compromising energy transmission and safety. The signal is transmitted back to the RF generator via internal wiring.

[0039] Cooling system: Some RF ablation needles (called "cold circulation" or "irrigated" electrodes) are designed with internal fluid channels. During the ablation process, cooling fluid (such as saline) circulates through these channels to cool the electrode tip. This prevents excessive electrode surface temperature from causing tissue carbonization and a sharp increase in impedance, thereby allowing higher power output, longer ablation times, and the creation of larger ablation lesions. The cooling system requires additional tubing connected to the irrigation pump.

[0040] A higher needle withdrawal speed corresponding to a higher RF power describes a strategy in the operation of an RF ablation device when withdrawing the needle (pulling the ablation needle out of the body). That is, the control device adjusts the output power of the RF generator according to the real-time detected moving speed of the ablation needle. In other words, there is a basically positive correlation between the needle withdrawal speed and the RF power. When the operator pulls out the ablation needle at a faster speed, the control device will instruct the RF generator to output a higher power; conversely, when the needle withdrawal speed is slower, the output power will be correspondingly lower. This means that as the needle withdrawal speed v increases, the corresponding RF power P either increases or at least remains unchanged, and there will be no situation where the speed increases while the power decreases. Expressed in mathematical terms, if the needle withdrawal speed v1 > v2, then the corresponding power P1 ≥ P2. This monotonicity ensures the consistency and predictability of the control logic.

[0041] The purpose of such a design is usually to ensure that when the needle body moves quickly and the time acting on a certain tissue path is shortened, by increasing the energy output rate (power), sufficient thermal effects are applied to the tissue on this path to achieve the expected coagulation or ablation effect, so as to form a uniform and continuous ablation zone along the entire needle withdrawal path. This is of great significance for closing the needle tract, preventing bleeding or tumor cell dissemination along the needle tract, and finally achieving the goal of reducing scars through subsequent precise control (such as finally stopping heating and waiting for cooling).

[0042] The control device can achieve this monotonic non-decreasing mapping relationship between speed and power in various ways. The following are several common technical means: Lookup Table (LUT): One or more tables are pre-stored in the memory of the control device. These tables define different needle withdrawal speed intervals (or specific speed points) and the corresponding RF power values. The control device real-time obtains the speed value measured by the needle position detection device, then looks up the interval where this speed value is located or the closest speed point in the preset table, and reads the corresponding power setting value, instructing the RF generator to output according to this power.

[0043] Example: Speed range (0, v1] -> Power P1 Speed range (v1, v2] -> Power P2 Speed range (v2, v3] -> Power P3 ... Where v1 < v2 < v3... and P!≤ P2 ≤ P3..., which ensures monotonicity. The table can be precisely set according to experimental data or simulation results, and can achieve various forms of monotonic relationships such as piecewise constant or piecewise linear.

[0044] Mathematical function / formula method: A mathematical function P = f(v) is programmed into the control unit, where v is the input needle withdrawal velocity and P is the output RF power. Function f is designed to be monotonically non-decreasing. The control unit measures the velocity v and directly substitutes this into the function to calculate the required power P, which is then used to control the RF generator output. This method offers the advantage of continuous and smooth power regulation.

[0045] Example: Linear function: P = a × v + b, where a is a non-negative constant (a ≥ 0) and b is the base power or intercept. When a > 0, power increases linearly with speed.

[0046] Piecewise function: You can define different monotonic functions for different speed ranges.

[0047] Or other forms of monotonic functions (such as nonlinear functions).

[0048] Optionally, in one embodiment, the control device is further configured to activate the ablation needle's cooling system when the depth of the active tip detected by the needle position detection device into the body is less than or equal to a predetermined depth threshold, causing cooling liquid to flow into the fluid channel within the ablation needle to cool the active tip. The predetermined depth threshold can be set based on different patient conditions or physician experience, for example, 2-4 mm.

[0049] Optionally, in one embodiment, the needle position detection device includes: a base, a first UWB module, a second UWB module and a processing module.

[0050] The base is fixed to the patient's body surface near the puncture point before the ablation procedure. Its position remains stable relative to the patient's body during the needle withdrawal process. The base is provided with a channel through which the ablation needle can pass. During the ablation and needle withdrawal procedures, the ablation needle slides axially relative to the base. The base can be made of medical-grade engineering plastic injection molding. A first UWB module is integrated or fixed on a base.

[0051] The second UWB module is integrated into or fixed on the handle of the ablation needle.

[0052] The processing module is electrically connected to the second UWB module and performs calculation, control and communication functions. The processing module can be integrated or fixed on the handle of the ablation needle, or it can be set outside the handle (for example, close to the control device).

[0053] The first and second UWB modules perform high-precision, real-time distance measurement by sending and receiving UWB radio pulse signals. Because the base remains relatively fixed during surgery (for example, it can be considered to represent the reference plane of the skin surface or puncture entrance), while the handle moves as the operator moves the ablation needle, changes in the straight-line distance between the first and second UWB modules (or its projection along the axial direction of the ablation needle) directly reflect the displacement of the ablation needle relative to the base.

[0054] The processing module can perform a calibration before system initialization or operation. For example, when the active tip of the ablation needle just contacts the skin surface, the distance d0 between the two UWB modules is recorded. During subsequent insertion and withdrawal, the needle position detection device measures the distance d(t) between the two UWB modules in real time. The depth D(t) of the active tip within the human body can then be calculated as D(t) = f(d(t) − d0), where f is a conversion function. In the simplest case (assuming the needle's motion axis is aligned or nearly aligned with the UWB ranging direction), the depth can be approximately assumed to be D(t) ≈ d(t) − d0 or D(t) ≈ d0 − d(t) (depending on the specific layout of the UWB modules and the definition of distance). This depth information is transmitted to the control device.

[0055] In addition to calculating the continuous depth data D(t) according to the signal from the second UWB module, the processing module can also calculate the continuous depth data D(t) by continuously sampling the time points t1, t2, ..., t n The corresponding depth values ​​D(t1), D(t2), ..., D(t n ) is processed, and the control device can calculate the motion speed V(t) of the ablation needle. For example, the instantaneous speed can be calculated using the differential method. , where i is the sampling point number. The processing module outputs the depth data D(t) and velocity information V(t) to the control device for power regulation.

[0056] In this embodiment, the needle position detection device uses UWB technology to precisely measure the relative position between the base (reference point) and the ablation needle handle (moving point), and from this, calculates the insertion depth and movement speed of the active tip. This information is provided to the control device, enabling it to adjust the RF power based on speed during needle withdrawal, stop power output and issue a prompt when a predetermined depth threshold is reached, and, combined with temperature sensor information, determine the final timing of needle removal, effectively avoiding scarring caused by needle tract burns.

[0057] Optionally, in another embodiment, the needle position detection device includes: Ablation needle body with periodic texture: The outer surface of the ablation needle's outer tube (or its rigid portion) is laser-marked (or ink-printed) with a uniform, light-and-dark ring-shaped or strip-shaped texture with a fixed period length P (e.g., P = 1 mm) along its axial direction in the area where depth monitoring is required. This texture produces periodically varying reflective properties under illumination.

[0058] The motion detection unit further includes a base, an optical lighting component, an optical lighting component and a processing circuit. The base is injection-molded from medical-grade opaque engineering plastic, forming a detection chamber that is virtually completely shielded from ambient light. Coaxial holes are located at each end of the base, slightly larger than the outer diameter of the ablation needle. This allows for smooth and free axial movement of the needle while effectively blocking external light from entering the detection chamber. The base can be secured to the human body surface by adhesive or other means.

[0059] The optical lighting component is fixed with one or more infrared LEDs on the inner wall of the detection chamber. The light beam is focused near the central axis of the penetration hole through appropriate design (such as using a microlens) to continuously illuminate the textured area on the surface of the passing ablation needle.

[0060] The photoelectric sensing component consists of at least two photosensors mounted side by side within the detection chamber, near the illumination area and along the axis of the ablation needle. The sensitive areas of these two sensors are aligned with the needle surface to receive light reflected from the needle surface texture. The axial spacing L between the two sensors is precisely set to a non-integer multiple of the texture period P, preferably P / 4, to generate orthogonal signals with a phase difference of approximately 90 degrees, facilitating motion direction determination. A light barrier can be placed between the two sensors to reduce crosstalk.

[0061] The processing circuit includes: a signal conditioning circuit for amplifying and filtering the weak signal from the photodiode; a distance determination component (for example, a microcontroller (MCU)) responsible for processing the signals from the two sensors to obtain depth and speed; and an interface circuit for transmitting the processing results (depth and speed) to the needle withdrawal system control device through a wired connection.

[0062] The reset button is provided on the base and is used to manually set the current ablation needle position as the zero point reference for depth calculation.

[0063] The working principle of the needle position detection device is as follows Depth measurement: 1. Fixing and Initialization: The mobile detection unit is fixed through a specific structure (for example, the thread at one end of the base penetration hole matches the vascular sheath interface, or it is fixed to the skin puncture point using medical tape). When the active tip of the ablation needle first contacts the skin surface or reaches the preset reference depth, the operator presses the reset button or sends a command through the main control system, and the processing unit resets the internal cumulative displacement counter to zero, which is defined as the depth zero point.

[0064] 2. Signal Generation: As the ablation needle moves axially, light and dark patterns on its surface alternately pass through the detection areas of two photodiodes. Due to the different reflectivities of these patterns, the intensity of the reflected light received by the two photodiodes varies periodically, generating a periodic electrical signal that approximates a sine wave or square wave. Due to the spatial positional difference between the two sensors (L = P / 4), their output signals exhibit a phase difference of approximately 90 degrees.

[0065] 3. Direction Determination and Counting: The processing unit (MCU or dedicated circuit) analyzes the two phase-shifted signals in real time. By determining which signal leads or lags in phase, it can determine whether the ablation needle is advancing (inserting) or retreating (withdrawing). Simultaneously, it accurately counts the number of complete cycles of one signal (or both signals combined).

[0066] 4. Depth Calculation: Each time the signal completes a full cycle, the ablation needle moves by one texture cycle length, P (e.g., 1 mm). The processing unit calculates the total displacement of the ablation needle relative to zero based on the detected direction of motion (addition for forward movement and subtraction for backward movement) and the accumulated number of cycles, N: Depth = N × P. Subdividing the signal phase allows for even higher-precision measurements of less than one cycle.

[0067] Speed ​​measurement: 1. Real-time depth acquisition: The processing unit updates and stores the current depth value Depth(t) at a fixed high frequency (for example, every 10ms), where t represents time.

[0068] 2. Difference Calculation: By comparing the current depth value, Depth(t), with the depth value at the previous sampling moment, Depth(t-Δt), the displacement change within the time interval Δt is calculated. Velocity V = [Depth(t) - Depth(t-Δt)] / Δt. This velocity value is the average motion speed of the ablation needle during that time period and can be roughly considered the instantaneous velocity.

[0069] Optionally, in one embodiment, the core of the control device is a microcontroller unit (MCU).

[0070] The control device includes a microcontroller, an input interface circuit, an output interface circuit, a memory and a power management unit. The MCU is responsible for receiving signals from various sensors, executing control algorithms, and outputting control instructions.

[0071] The input interface circuit is used to connect to the needle position detection device. Depending on the output signal type of the needle position detection device (e.g., digital pulse signal, analog voltage signal, or data sent via a serial communication interface such as SPI / I2C), the corresponding interface circuit (e.g., a digital I / O port, an analog input port with an analog-to-digital converter (ADC), or a serial communication interface) is configured. The MCU processes these signals to calculate the real-time depth of the active tip of the ablation needle into the body and the needle's movement speed (e.g., by time-differentiating the position information to obtain the speed). The input interface circuit is also used to connect to the temperature sensor. Depending on the output type of the temperature sensor (e.g., analog voltage, resistance change, or digital signal such as I2C / SPI), the corresponding interface circuit (e.g., an analog input port with an ADC, or a digital communication interface) is configured to allow the MCU to read temperature data.

[0072] The output interface circuit is used to control the RF generator. The MCU generates control signals (e.g., analog voltage signals, PWM pulse-width modulation signals, or digital commands sent via UART / SPI) to the RF generator to precisely adjust its output power. The amplitude or parameters of the control signal correspond to the required RF power calculated based on the speed of the ablation needle. The output interface circuit is also used to drive prompt information. The MCU is connected to user interface elements such as light-emitting diodes (LEDs), buzzers, or small speakers. By controlling the status of these elements (e.g., lighting up an LED of a specific color, emitting a sound of a specific frequency or pattern), prompts such as "Stop withdrawing the needle and wait for cooling" and "The ablation needle can be removed" are issued.

[0073] Memory includes program memory (such as Flash) for storing control algorithm firmware and data memory (such as RAM) for runtime data processing. Non-volatile memory (such as EEPROM or Flash) can be used to store preset parameters, such as predetermined depth thresholds, predetermined temperature thresholds, and speed-power relationship data (for example, lookup tables or function parameters).

[0074] The power management unit provides stable power to the entire control device.

[0075] The firmware running inside the MCU consists of the following main modules: Signal acquisition and processing module: Periodically reads data from the needle position detection device and temperature sensor, and performs necessary filtering, conversion and calculation to obtain real-time depth, speed and temperature values.

[0076] Control decision module: During the needle withdrawal phase, the target RF power is calculated based on the real-time detected ablation needle movement speed according to a preset mapping relationship (for example, a piecewise function stored in a lookup table or a continuous function P=f(v), where P is the RF power, v is the speed, and f(v) is a monotonically increasing function), and a corresponding control signal is generated and sent to the RF generator.

[0077] Continuously monitor the depth of the active tip of the ablation needle. Once the depth is detected to be less than or equal to a predetermined depth threshold (e.g., 2 mm subcutaneously), immediately set the control signal to the RF generator to the "stop output" state (e.g., output 0V analog voltage or send a command of 0 power), and trigger the "stop needle withdrawal and wait for cooling" prompt (e.g., illuminate a yellow LED and emit a short beep).

[0078] After the RF power is turned off, the temperature sensor reading is continuously monitored. When the temperature is detected to drop below a predetermined temperature threshold (e.g., 45°C), a prompt indicating that the ablation needle can be removed is triggered (e.g., a green LED is lit and a long beep is emitted).

[0079] User interface management module: controls the actions of prompt elements such as LEDs and buzzers.

[0080] Alternatively, in another embodiment, the control device is a more complex embedded system, possibly integrated into a medical console with a graphical user interface (GUI).

[0081] The control device includes: Microprocessor (MPU) or high-performance MCU: has stronger processing power and can support operating systems and graphical interfaces.

[0082] Memory: Larger RAM and Flash / hard disk for running the operating system, applications, and storing data.

[0083] Input / output interface: Similar to the previous embodiment, but can include more standard interfaces (such as USB, Ethernet) for data transmission or system expansion.

[0084] Display: Such as an LCD or OLED touchscreen, used to show real-time status information (depth, speed, temperature, power, system prompts) and may allow limited user interaction (for example, confirming prompts).

[0085] Speaker: Used to issue clearer voice prompts or prompts with different tones.

[0086] A microprocessor (MPU) or high-performance MCU runs an embedded operating system (e.g., Linux, RTOS). The control application not only implements the core control logic of the MCU in the previous embodiments, but also includes: a graphical user interface (GUI) driver that updates the numerical or graphical representation of the ablation needle depth, speed, temperature, and current RF power level on the display in real time; prompt information display that clearly displays messages such as "Please stop withdrawing the needle and wait for the needle to cool down" and "The needle has cooled and can be safely removed" on the screen in text or icon form, possibly accompanied by an audio prompt; a parameter configuration interface (optional) that may allow authorized users (e.g., doctors or technicians) to view or adjust preset depth and temperature thresholds within a certain range (this should be handled with caution to ensure safety); and a data logging function (optional) that can record key parameters (speed, depth, temperature, and power curve) during each operation for subsequent analysis or quality control.

[0087] Optionally, in another embodiment, the control device may use a MCU and an FPGA (Field-Programmable Gate Array) in combination.

[0088] The control device includes: an MCU, which is responsible for high-level decision-making logic, user interface, and communication with the RF generator; an FPGA, which is specifically used to process signals from the needle position detection device at high speed and in real time, accurately calculate instantaneous speed and depth, and may directly implement a fast lookup table (LUT) or complex calculation of speed-power. The FPGA transmits the processed speed and depth information to the MCU; other interfaces and memories are similar to those before.

[0089] FPGAs can process high-speed sensor signals with extremely low latency, making them particularly advantageous for pin-position detection requiring rapid response (e.g., detection based on optical encoders or high-frequency sensors). Computationally intensive or time-critical tasks (such as high-speed differential operations and complex filtering algorithms) can be offloaded to the FPGA, reducing the burden on the MCU and improving the overall system response speed and stability.

[0090] It should be noted that, in this application, relational terms such as first and second are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. Without further restriction, an element defined by the phrase "comprising a" does not exclude the presence of other identical elements in the process, method, article, or device comprising the element. In this application, if it is mentioned that an action is performed according to a certain element, it means that the action is performed at least according to that element, including two situations: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "multiple," and "multiple" include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.

[0091] This specification includes combinations of the various embodiments described herein. Separate references to an embodiment (e.g., "one embodiment," "some embodiments," or "preferred embodiment") do not necessarily refer to the same embodiment; however, these embodiments are not mutually exclusive unless indicated as such or clear to one skilled in the art. It should be noted that the word "or" is used in this specification in a non-exclusive sense unless the context clearly indicates or requires otherwise.

[0092] All documents mentioned in this application are considered to be included in their entirety in the disclosure of this application so that they can be used as a basis for modification when necessary. In addition, it should be understood that after reading the contents of this application, those skilled in the art may make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A radiofrequency ablation device needle removal system for preventing scarring, comprising an ablation needle and a radiofrequency generator for providing radiofrequency power to the ablation needle, characterized in that: The device further comprises: A needle position detection device, used to detect the depth of the active tip of the ablation needle entering the human body and the movement speed of the ablation needle; a temperature sensor, disposed on the ablation needle, for detecting the temperature of the active tip; and a control device electrically connected to the radio frequency generator, the needle position detection device and the temperature sensor; Wherein, the control device is configured as follows: When the ablation needle is withdrawn, the control device controls the radio frequency power provided to the ablation needle by the radio frequency generator according to the movement speed of the ablation needle detected by the needle position detection device, wherein a higher movement speed of the ablation needle corresponds to a higher radio frequency power; When the depth of the active tip detected by the needle position detection device entering the human body is less than or equal to a predetermined depth threshold, the control device controls the radio frequency generator to stop providing radio frequency power to the ablation needle and issues a prompt message indicating that the needle should be withdrawn and wait for cooling; and After the RF generator stops providing RF power to the ablation needle, when the temperature of the ablation needle detected by the temperature sensor drops below a predetermined temperature threshold, the control device issues a prompt message indicating that the ablation needle can be removed.

2. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 1, characterized in that: The control device is also configured to start the cooling system of the ablation needle when the depth of the active tip detected by the needle position detection device into the body is less than or equal to a predetermined depth threshold, so that the cooling liquid flows into the fluid channel inside the ablation needle to cool the active tip.

3. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 1, characterized in that: The needle position detection device comprises: A base is fixed on the patient's body surface near the puncture point before the ablation operation, and the base is provided with a channel for the ablation needle to pass through; a first ultra-wideband module, integrated or fixed on the base; a second ultra-wideband module, integrated into or fixed on the handle of the ablation needle; and a processing module, electrically connected to the second ultra-wideband module; The processing module is configured to calculate the depth of the active tip entering the human body and the movement speed of the ablation needle based on the distance information determined by the ultra-wideband radio pulse signals sent and received between the first ultra-wideband module and the second ultra-wideband module.

4. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 1, characterized in that: The outer surface of the ablation needle has a periodic texture arranged along the axial direction; The needle position detection device comprises: a base having an internal detection chamber and a coaxial penetration hole for the ablation needle to pass through; an optical lighting component, disposed in the detection chamber and configured to illuminate a textured area on the surface of the ablation needle passing through the penetration hole; At least two photoelectric sensing components installed side by side along the axis of the ablation needle, disposed in the detection chamber, for receiving light reflected from the texture on the surface of the needle body and generating an electrical signal; and The processing circuit is electrically connected to the photoelectric sensing component and is configured to calculate the depth of the active tip entering the human body and the movement speed of the ablation needle according to the electrical signal generated by the photoelectric sensing component.

5. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 4, characterized in that: The axial distance between the at least two photoelectric sensing elements is set to be a non-integer multiple of the period length of the periodic texture.

6. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 5, characterized in that: The axial spacing between the at least two photoelectric sensing elements is set to be a quarter of the period length of the periodic texture.

7. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 1, characterized in that: The control device is configured to control the radio frequency power according to the ablation needle movement speed by a table lookup method, and the control device stores at least one lookup table defining ablation needle movement speed intervals or speed points and corresponding radio frequency power values.

8. The radiofrequency ablation device needle removal system for avoiding scarring according to claim 1, characterized in that: The control device is configured to control the radio frequency power according to the ablation needle movement speed through a mathematical function method. The control device is programmed to implement a monotonically non-decreasing mathematical function P=f(v), where v is the input ablation needle movement speed and P is the output radio frequency power.

9. The radiofrequency ablation device needle removal system for avoiding scarring according to any one of claims 1 to 8, characterized in that: The control device includes a display screen with a graphical user interface, which is used to display the depth, the speed, the temperature, the radio frequency power and the prompt information in real time.

10. The radiofrequency ablation device needle removal system for avoiding scarring according to any one of claims 1 to 8, characterized in that: The prompt information indicating that the needle should be withdrawn and the time should be waited for cooling, and the prompt information indicating that the ablation needle can be withdrawn, include visual prompt information and / or auditory prompt information.

Images