A method of needle-out zero self-calibration for a replaceable radio frequency microneedle component
By designing an automatic zero-point detection and calibration circuit inside the radio frequency microneedle device, and using conductive foil and displacement sensors to detect the microneedle exit position, the problem of cumbersome zero-point calibration after replacing the radio frequency microneedle device is solved, the calibration efficiency and accuracy are improved, and the accuracy of the microneedle insertion depth is ensured.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANXI STRONTIUM INTELLIGENT TECH CO LTD
- Filing Date
- 2025-08-28
- Publication Date
- 2026-07-31
AI Technical Summary
After replacing the microneedle components, the zero-point calibration process for existing radio frequency microneedle devices is cumbersome and difficult to guarantee accuracy, affecting the efficiency of device use and the difficulty of operation.
An automatic zero-point detection and calibration circuit is designed inside the handpiece body of the radio frequency microneedle component. A conductive plate is formed by conductive foil, and the position change when the microneedle tip touches the conductive plate is detected by radio frequency current transformer and displacement sensor to achieve self-calibration of the needle exit zero point.
It achieves automated calibration of the zero point of radiofrequency microneedle exit, improves the calibration efficiency and accuracy of the equipment, reduces the difficulty of operation, and ensures the accuracy and repeatability of the depth of microneedle insertion into the skin.
Smart Images
Figure CN120900124B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of radiofrequency cosmetic medical device technology, specifically relating to a method for self-calibrating the needle exit zero point of a replaceable radiofrequency microneedle component. Background Technology
[0002] Radiofrequency microneedles are a type of microneedle-like device widely used in medical and cosmetic fields. They are used to insert microneedles into the subcutaneous dermis for precise depth control down to 0.1mm, allowing for accurate release of radiofrequency energy at that depth. Calibration of the microneedle's exit zero point is crucial for ensuring its accuracy and repeatability. However, in reality, it is difficult to guarantee the consistency of microneedle components during manufacturing, leading to deviations in the exit zero point when the components are installed on surgical instruments. Therefore, zero-point calibration is essential to ensure the accuracy of the microneedle's insertion depth. Current technology uses calipers for visual calibration of the radiofrequency microneedle's exit zero point, a highly specialized and cumbersome process that consumes significant time and manpower, impacting the efficiency of the microneedle device and the smooth progress of experiments. Furthermore, operators often lack the expertise to master current radiofrequency microneedle exit zero-point calibration methods. Therefore, it is highly necessary to develop an automatic zero-point calibration method for microneedles with replaceable radiofrequency microneedle components to improve the calibration efficiency and accuracy of the microneedle device and reduce its ease of use. Summary of the Invention
[0003] To address the difficulty in calibrating the zero-point position of the needle exit after replacing the radiofrequency microneedle component in current radiofrequency surgical handpieces, this invention provides a method for self-calibrating the zero-point position of the needle exit using a replaceable radiofrequency microneedle component.
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0005] A method for self-calibrating the zero point of a replaceable radio frequency microneedle component is disclosed. This method involves designing an automatic zero-point detection and calibration circuit inside the handpiece body on which the microneedle component is installed; forming a conductive plate on the end face of the microneedle component after pressing a conductive foil onto the end face; and achieving self-calibration of the zero point by detecting the value of a displacement sensor when the microneedle changes from an open circuit to a short circuit during its displacement process and touches the conductive plate.
[0006] Furthermore, the automatic zero-point detection and calibration circuit comprises: an RF current transformer, an RF current signal conversion circuit, a voltage amplifier circuit, a comparator, a 16-bit data latch, a 16-bit zero-point data register, and a displacement sensor.
[0007] Furthermore, the radio frequency current transformer is used to collect radio frequency current and achieve electrical isolation between the high-voltage radio frequency circuit and the low-voltage automatic zero-point calibration circuit, ensuring that the low-voltage circuit can work normally without damage; the current ratio of the radio frequency current transformer is between 10:1 and 100:1, and the operating frequency range meets the requirements of 200KHz~10MHz.
[0008] Furthermore, the radio frequency current signal conversion circuit uses a low offset operational amplifier with a bandwidth of over 50MHz to convert 200KHz~10MHz radio frequency AC current into DC voltage.
[0009] Furthermore, the voltage amplification circuit employs a high-voltage slew rate operational amplifier to amplify the voltage from approximately 100mV to 2V. The zero-point self-calibration RF output power is very low; to prevent the microneedle tip from being short-circuited by the conductive foil and burned, the voltage output of the pre-amplifier stage of the microneedle circuit varies around 100mV.
[0010] Furthermore, the comparator is a high-speed comparator with a zero-point calibration threshold voltage of 1.25V. The stored displacement sensor data is triggered when the comparator's output signal generates a falling edge.
[0011] Furthermore, the 16-bit data latch is used to store the displacement values of the sensor; the 16-bit zero-point data register is used to store the displacement sensor values at the zero point of the calibrated working displacement, and the data in this data register is not lost after power failure.
[0012] Furthermore, the displacement sensor: adopts an absolute linear displacement sensor, which is structurally connected to the displacement propulsion mechanism of the microneedle; the displacement sensor's range of 15mm is greater than the maximum displacement stroke of the microneedle of 10mm, and the sensing accuracy is higher than the needle delivery accuracy used in the device by 0.1mm, using 0.05mm; it is used for position feedback of the linear displacement of the microneedle.
[0013] Furthermore, the conductive foil used to form the conductive plate is made of aluminum foil; the thickness of the conductive plate is between 0.05mm and 0.2mm.
[0014] Furthermore, the radio frequency range of the radio frequency microneedle component is 200KHz~10MHz.
[0015] The radio frequency and waveform are completely consistent with the actual radio frequency and waveform of the device, except that the voltage amplitude is very small.
[0016] Principle: During the upward displacement of the radio frequency microneedle, when the tip of the microneedle does not touch the conductive plate, the microneedle is open-circuited, the input voltage of the comparator is much lower than 1.25V, and the comparator output is continuously high-level; when the tip of the microneedle touches the conductive plate, the microneedle is short-circuited, the input voltage of the comparator is higher than 1.25V, and the comparator output voltage immediately reverses to low-level. At this time, the falling edge of the level triggers the data latch to store the displacement value of the displacement sensor at this time. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 Conductive foil is bonded to the front end face of the pinhole of the micro-needle component;
[0019] Figure 2 Zero-point automatic detection and calibration circuit. Detailed Implementation
[0020] To gain a deeper understanding of this invention, we will provide a comprehensive and detailed description. However, this invention has various implementations and is not limited to the specific examples listed herein. These examples are presented to enhance a full understanding of the disclosure of this invention.
[0021] Example 1
[0022] A method for self-calibrating the zero point of a replaceable radio frequency (RF) microneedle component involves designing an automatic zero-point detection and calibration circuit inside the handpiece body where the microneedle component is installed; forming a conductive plate on the end face of the RF microneedle component after pressing a conductive foil onto the end face; and achieving self-calibration of the zero point by detecting when the RF microneedle changes from an open circuit to a short circuit during the needle tip's displacement and touches the conductive plate, triggering and recording the value of a displacement sensor at that position. Figure 1 As shown.
[0023] Furthermore, the automatic zero-point detection and calibration circuit comprises: an RF current transformer, an RF current signal conversion circuit, a voltage amplifier circuit, a comparator, a 16-bit data latch, a 16-bit zero-point data register, and a displacement sensor, as shown below. Figure 2 As shown.
[0024] Furthermore, the radio frequency current transformer is used to collect radio frequency current and achieve electrical isolation between the high-voltage radio frequency circuit and the low-voltage automatic zero-point calibration circuit, ensuring that the low-voltage circuit can work normally without damage; the current ratio of the radio frequency current transformer is between 10:1 and 100:1, and the operating frequency range meets the requirements of 200KHz~10MHz.
[0025] Furthermore, the radio frequency current signal conversion circuit uses a low offset operational amplifier with a bandwidth of over 50MHz to convert 200KHz~10MHz radio frequency AC current into DC voltage.
[0026] The radio frequency current signal conversion circuit includes resistors R1, R2, R3, R4, R6, and R10; capacitors C1, C2, and C3; diodes D1 and D2; and a first operational amplifier. One end of capacitor C2 and one end of capacitor C1 are connected to the radio frequency current transformer. The other end of capacitor C2 is connected to one end of resistor R1 and one end of resistor R2. The other end of capacitor C1 is connected to the other end of resistor R1, one end of resistor R10, one end of capacitor C3, and port 3 of the first operational amplifier. The other end of capacitor C3 and the other end of resistor R10 are grounded (GND). The other end of resistor R2 is connected to one end of resistor R3, port 2 of the first operational amplifier, and one end of resistor R6. The other end of resistor R3 is connected to one end of resistor R4 and the anode of diode D1. The other end of resistor R6 is connected to the cathode of diode D2. The cathode of diode D1 is connected to port 1 of the first operational amplifier and the anode of diode D2.
[0027] Furthermore, the voltage amplification circuit employs a high-voltage slew rate operational amplifier to amplify the voltage from approximately 100mV to 2V. The zero-point self-calibration RF output power is very low; to prevent the microneedle tip from being short-circuited by the conductive foil and burned, the voltage output of the pre-amplifier stage of the microneedle circuit varies around 100mV.
[0028] The voltage amplification circuit includes a resistor R5, a capacitor C5, and a second operational amplifier; one end of resistor R5, one end of capacitor C5, and port 6 of the second operational amplifier are connected to the other end of resistor 4 (RF current signal conversion circuit); port 5 of the second operational amplifier and the other end of resistor R6 are connected to the cathode of diode D2; port 7 of the second operational amplifier is connected to the other end of resistor R5, the other end of capacitor C5, and one end of resistor 8; the positive power supply port of the second operational amplifier is connected to VCC, and the negative power supply port is grounded (GND).
[0029] Furthermore, the comparator is a high-speed comparator with a zero-point calibration threshold voltage of 1.25V. The stored displacement sensor data is triggered when the comparator's output signal generates a falling edge.
[0030] The comparator includes a resistor R8 and a third operational amplifier. The other end of the resistor R8 is connected to port 3 of the third operational amplifier. Port 2 of the third operational amplifier is connected to a 1.25V voltage. Port 1 of the third operational amplifier is connected to an RF device, a 16-bit data latch, and a 16-bit zero-point data register.
[0031] Furthermore, the 16-bit data latch is used to store the displacement value of the sensor; the 16-bit zero-point data register is used to store the displacement sensor value at the calibrated working displacement zero point, and the data in this data register is not lost after power failure. Both the 16-bit data latch and the 16-bit zero-point data register are connected to the displacement sensor.
[0032] Furthermore, the displacement sensor: adopts an absolute linear displacement sensor, which is structurally connected to the displacement propulsion mechanism of the microneedle; the displacement sensor's range of 15mm is greater than the maximum displacement stroke of the microneedle of 10mm, and the sensing accuracy is higher than the needle delivery accuracy used in the device by 0.1mm, using 0.05mm; it is used for position feedback of the linear displacement of the microneedle.
[0033] Furthermore, the conductive foil used to form the conductive plate is made of aluminum foil; the thickness of the conductive plate is between 0.05mm and 0.2mm.
[0034] Furthermore, the radio frequency range of the radio frequency microneedle component is 200KHz~10MHz.
[0035] Example 2
[0036] A method for self-calibrating the zero point of microneedle exit with replaceable radio frequency microneedle components, comprising the following steps:
[0037] Step 1: Replace the radio frequency microneedle component in the radio frequency device;
[0038] Step 2: The device detects the new radio frequency microneedle component and initiates energy output and needle ejection step;
[0039] Step 3: Continuous output of radio frequency micro-energy;
[0040] Step 4: Push the RF microneedle step-out needle at a step speed of 0.05mm / ms;
[0041] Step 5: When the microneedle touches the conductive plate, it triggers the latching of the displacement sensor value into the data latch;
[0042] Step 6: Store the stored displacement data values into the zero-point data register;
[0043] Step 7: Notify the RF device that the needle zero point calibration is complete.
[0044] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.
Claims
1. A method of needle-out zero self-calibration of a replaceable radio frequency microneedle component, characterized by, An automatic zero-point detection and calibration circuit is designed inside the main body of the handpiece on which the microneedle component is installed; a conductive plate is formed on the end face of the pin hole of the radio frequency microneedle component after a conductive foil is pressed onto the end face; the zero-point self-calibration method is achieved by triggering the value of the displacement sensor at the position when the radio frequency microneedle changes from an open circuit to a short circuit when it touches the conductive plate during the needle tip's displacement process. The automatic zero-point detection and calibration circuit comprises: an RF current transformer, an RF current signal conversion circuit, a voltage amplifier circuit, a comparator, a 16-bit data latch, a 16-bit zero-point data register, and a displacement sensor. The radio frequency current transformer is used to collect radio frequency current and achieve electrical isolation between the high-voltage radio frequency circuit and the low-voltage automatic zero-point calibration circuit, ensuring that the low-voltage circuit can work normally without damage; the current ratio of the radio frequency current transformer is between 10:1 and 100:1, and the operating frequency range meets the requirements of 200KHz~10MHz.
2. The method of claim 1, wherein, The radio frequency current signal conversion circuit uses a low offset operational amplifier with a bandwidth of over 50MHz to convert 200KHz~10MHz radio frequency AC current into DC voltage.
3. The method for self-calibrating the needle exit zero point of a replaceable radio frequency microneedle component according to claim 1, characterized in that, The voltage amplification circuit uses a high-voltage slew rate operational amplifier to amplify a voltage of approximately 100mV to 2V.
4. The method for self-calibrating the needle exit zero point of a replaceable radio frequency microneedle component according to claim 1, characterized in that, The comparator is a high-speed comparator with a zero-point calibration threshold voltage of 1.25V; when the comparator's output signal generates a falling edge, it triggers the stored displacement sensor data.
5. The method for self-calibrating the needle exit zero point of a replaceable radio frequency microneedle component according to claim 1, characterized in that, The 16-bit data latch is used to latch the displacement value of the sensor; the 16-bit zero-point data register is used to store the displacement sensor value at the zero point of the calibrated working displacement, and the data in the data register is not lost after power failure.
6. The method for self-calibrating the needle exit zero point of a replaceable radio frequency microneedle component according to claim 1, characterized in that, Displacement sensor: An absolute linear displacement sensor is used, which is structurally connected to the displacement propulsion mechanism of the microneedle; the displacement sensor's range of 15mm is greater than the maximum displacement stroke of the microneedle of 10mm, and the sensing accuracy is higher than the needle delivery accuracy of the device by 0.1mm, using 0.05mm; it is used for position feedback of the linear displacement of the microneedle.
7. The method for self-calibrating the zero point of a replaceable radio frequency microneedle component according to claim 1, characterized in that, The conductive foil used to form the conductive plate is made of aluminum foil; the thickness of the conductive plate is between 0.05 mm and 0.2 mm.
8. The method for self-calibrating the needle exit zero point of a replaceable radio frequency microneedle component according to claim 1, characterized in that, The radio frequency range of the radio frequency microneedle component is 200KHz~10MHz.