Detection circuit of medical instrument hand tool

Abstract

The utility model belongs to the technical field of medical instruments, and particularly relates to a detection circuit of a medical instrument hand tool, which detects whether the medical instrument hand tool is in good contact with a biological tissue or not by utilizing capacitance parameter change generated by an induction point after the medical instrument hand tool is in contact with the biological tissue. The biological tissue contact point can be made into an insulating material to realize electrical isolation, and experimental test results show that the method is high in sensitivity, high in response speed and relatively high in reliability; a medical instrument hand tool on energy source equipment such as laser, radio frequency and ultrasonic equipment is provided with a biological tissue contact detection function, so that accidental injury to a human body or other organisms caused by accidental energy output when the medical instrument hand tool is not aligned with pathological tissues is avoided; a capacitance detection technology is used, a biological tissue detection point is configured on a medical instrument hand tool biological tissue contact surface, stable and reliable biological tissue contact detection is realized through hardware circuit and structure suggestion configuration, and the safety of equipment treatment is improved.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, and specifically relates to a detection circuit for a medical device handpiece. Background Technology

[0002] With the continuous development of medical technology, energy source devices are becoming increasingly widespread in clinical and home settings, not only for medical aesthetics, dentistry, and surgery. As medical needs continue to grow, the clinical use of energy source devices has surged, with applications including plastic surgery, dentistry, gynecology, cancer treatment, general surgery, and urology. Their mechanism of action involves applying energy to the lesion or area requiring treatment. If this energy is applied to normal tissue, it can cause damage and lead to unnecessary risks. Furthermore, if an energy source product unexpectedly outputs energy before reaching the treatment target, it can easily result in medical accidents.

[0003] The commonly used method for detecting biological tissue contact involves using a pair of positive and negative metal electrodes. This approach requires human tissue to have an impedance of approximately 2KΩ-20MΩ. By applying a certain excitation signal to the electrodes, a current is generated between the biological tissue and the positive and negative electrodes when they come into contact with the body. The current signal is collected through a loop, adjusted, and used to detect whether biological tissue contact has occurred. However, this method has the following drawbacks: When the surface of the biological tissue is coated with some auxiliary therapeutic fluids, or when there is sweat or a wound, the impedance of the biological tissue will change. These factors will lead to a wider current threshold range. Also, when in contact with some conductors, the current magnitude may be the same as when in contact with biological tissue, which can easily cause false triggering. Secondly, the electrodes will generate leakage current. Excessive leakage current will reduce the safety performance of the product and may also cause user discomfort. Utility Model Content

[0004] The purpose of this invention is to provide a detection circuit for a medical device handpiece, which uses the change in capacitance parameters generated when biological tissue comes into contact with a sensing point to detect whether the contact with biological tissue is good, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a detection circuit for a medical device handpiece, comprising: a handpiece circuit board, on which are provided:

[0006] A touch detection chip, comprising at least: a touch input terminal for detecting capacitance changes upon contact with biological tissue; an output terminal for outputting the biological tissue contact status signal detected by the touch detection chip; a fixed-focus frame with biological tissue contact detection points connected to the touch input terminal via wires; a connector for connecting the handpiece circuit board to the power source device host to read the handpiece connection status signal, handpiece specification information, and biological tissue contact status signal; and an optocoupler for isolating signal transmission between the output terminal and the microcontroller.

[0007] The microcontroller has: a first input terminal for reading biological tissue contact status signals; and a second input terminal for reading the handpiece connection status.

[0008] Preferably, the fixed-focus frame is covered with an insulating layer.

[0009] Preferably, the touch detection chip further includes: a VDD power supply pin, which is powered by a 5V power supply and filtered by a capacitor; and an AHLB pin, which is grounded so that the output terminal outputs a low level by default.

[0010] Preferably, the touch detection chip further includes a TOG pin, which is grounded so that the output terminal outputs a low level in the default state and outputs a high level when biological tissue comes into contact.

[0011] Preferably, the touch detection chip further includes an LPMB pin, which is connected to a high level to put the touch detection chip into a fast mode.

[0012] Preferably, the touch detection chip further includes an SM pin, which is grounded to enable the touch detection chip to be in multi-key mode.

[0013] Preferably, the touch detection chip further includes a MOT0 pin, which is grounded so that the longest effective output time of the output terminal is 16 seconds.

[0014] Preferably, the touch detection chip further includes a resistor and a capacitor connected in series between the TPO pin and the fixed-focus frame to improve the anti-static capability of the biological tissue detection circuit.

[0015] Preferably, the touch detection chip further includes: a capacitor connected to the TP0 pin for adjusting the sensitivity of biological tissue contact detection, wherein the capacitance value ranges from 0 to 50 pF.

[0016] Preferably, the detection circuit further includes an EEPROM chip for storing hand tool specification information, wherein the EEPROM chip communicates with the microcontroller via a single bus.

[0017] Technical effects and advantages of this utility model: The detection circuit for a medical device handpiece proposed in this utility model has the following advantages compared with the prior art:

[0018] This invention utilizes the change in capacitance parameters generated when biological tissue comes into contact with a sensing point to detect whether the contact with the biological tissue is good. In addition, the biological tissue contact point can be made of insulating material to achieve electrical isolation. Experiments have verified that it has high sensitivity, fast response speed, and high reliability. By configuring biological tissue contact detection function on medical device handpieces of energy source devices such as lasers, radio frequency, and ultrasound, it avoids accidental energy output when the medical device handpiece is not aligned with the diseased tissue, which could cause accidental damage to the organism. Using capacitive sensing technology, biological detection points are configured on the biological tissue contact surface of the medical device handpiece. Through hardware circuit and structural design, stable and reliable biological tissue contact detection is achieved. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the fixed-focus frame of this utility model;

[0020] Figure 2 This is one of the circuit diagrams for the hand tool circuit of this utility model;

[0021] Figure 3 This is the second circuit diagram of the hand tool circuit of this utility model;

[0022] Figure 4 This is one of the circuit diagrams for the host control circuit of this utility model;

[0023] Figure 5 This is the second circuit diagram of the host control circuit of this utility model;

[0024] Figure 6 This is the third circuit diagram of the host control circuit of this utility model;

[0025] Figure 7 This is the fourth circuit diagram of the host control circuit of this utility model;

[0026] Figure 8 This is the fifth circuit diagram of the host control circuit of this utility model;

[0027] Figure 9 This is the sixth circuit diagram of the host control circuit of this utility model;

[0028] Figure 10 This is the seventh circuit diagram of the host control circuit of this utility model;

[0029] Figure 11 This is the eighth circuit diagram of the host control circuit of this utility model. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The specific embodiments described herein are only used to explain the present utility model and are not intended to limit the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] This utility model provides a detection circuit for a medical device handpiece, including a handpiece circuit board, on which:

[0032] A touch detection chip, comprising at least: a touch input terminal for detecting capacitance changes upon contact with biological tissue; an output terminal for outputting the biological tissue contact status signal detected by the touch detection chip; a fixed-focus frame covered with an insulating layer, on which biological tissue detection points are provided, the biological tissue contact detection points being connected to the touch input terminal via wires; a connector for connecting the handpiece circuit board to the main unit of the energy source device to realize the reading of biological tissue contact status signals, handpiece connection status signals, and handpiece specification information; and an optocoupler for isolating signal transmission between the output terminal and the microcontroller.

[0033] The microcontroller has: a first input terminal for reading biological tissue contact status signals; and a second input terminal for reading the handpiece connection status.

[0034] In a further preferred embodiment, the touch detection chip further includes: a VDD power supply pin, which is powered by a 5V power supply and filtered by a capacitor; and an AHLB pin, which is grounded so that the output terminal outputs a low level by default.

[0035] In a further preferred embodiment, the touch detection chip further includes a TOG pin, which is grounded so that the output terminal outputs a low level in the default state and outputs a high level when biological tissue comes into contact.

[0036] In a further preferred embodiment, the touch detection chip further includes an LPMB pin, which is connected to a high level to put the touch detection chip into a fast mode.

[0037] In a further preferred embodiment, the touch detection chip further includes an SM pin, which is grounded to enable the touch detection chip to be in a multi-key mode.

[0038] In a further preferred embodiment, the touch detection chip further includes a MOT0 pin, which is grounded so that the longest effective output time of the output terminal is 16 seconds.

[0039] In a further preferred embodiment, the touch detection chip further includes a resistor and a capacitor connected in series between the TPO pin and the fixed-focus frame to improve the anti-static capability of the biological tissue detection circuit.

[0040] In a further preferred embodiment, the touch detection chip further includes: a capacitor connected to the TP0 pin for adjusting the sensitivity of biological tissue contact detection, wherein the capacitance value ranges from 0 to 50 pF.

[0041] In a further preferred embodiment, the detection circuit further includes an EEPROM chip for storing hand tool specification information, wherein the EEPROM chip communicates with the microcontroller via a single bus.

[0042] The following will be a detailed explanation with reference to the accompanying drawings:

[0043] like Figures 1-11 As shown, the medical device handpiece needs to integrate a single-point biological tissue contact detection function. It contains a handpiece circuit board 11. The control signal of the handpiece circuit board 11 is connected to the host of the power source device through the connector 10 to realize the reading of biological tissue contact status signal, handpiece connection status signal and handpiece specification information.

[0044] The biological tissue contact state detection sensor signal is connected to the fixed-focus frame 13 via wire 12. This sensor collects the change in capacitance when the biological tissue contacts the detection point on the fixed-focus frame. The fixed-focus frame 13 is made of conductive material, and the wire 12 can be directly soldered to it (or fixed in other ways). Once the biological tissue contacts the fixed-focus frame 13, biological tissue detection can be achieved. Preferably, the fixed-focus frame 13 is covered with an insulating material to achieve electrical insulation without affecting the biological tissue contact detection. This not only improves the system's safety but also its stability (enhancing antistatic capabilities, etc.).

[0045] In this embodiment, the biological tissue contact detection circuit uses the Tontek TTP224C-BSBN touch detection chip based on the capacitive sensing principle. Other models or brands of touch chips with the same function can also be used. This chip provides four independent touch input terminals TP0-TP3 and corresponding output terminals TPQ0-TPQ3. The touch input terminals are used to detect the capacitance change when biological tissue is in contact. After being processed internally by the touch detection chip, the signal is converted into a status signal and output by the output terminal. It can meet the needs of up to four detection points and is compatible with various hand tools.

[0046] In this embodiment, the handpiece uses one biological tissue detection point, so the touch input terminal TP0 and the output terminal TPQ0 are actually used. The touch detection chip output mode needs to be CMOS output by default, with a low level by default, and a high level when touching biological tissue. The touch detection chip's 6-pin VDD is powered by a 5V power supply in this example. Two capacitors, C2 and C1, are used for filtering to eliminate high-frequency noise and prevent interference and parasitic oscillations introduced by the power supply.

[0047] Pin 5 AHLB is used to select whether the output is active high or low. When connected to high, the output is high by default. When grounded, the output is low by default. In this embodiment, the output is low by default, so it is grounded.

[0048] Pin 7 (TOG) is used for output state inversion selection. The default state is low level, meaning that the output terminal outputs a low level when not in contact with biological tissue and a high level when in contact with biological tissue. When the TOG pin is connected to a high level, the output state of the output terminal inverts once every time it contacts biological tissue. In this embodiment, it is configured to the default state, and the output state does not need to invert when not in contact with biological tissue.

[0049] Pin 8 (LPMB) is used for low-power or fast mode selection. A low level indicates low-power mode. In this embodiment, fast mode is used, so a high level is applied. Pin 12 (SM) is used to configure single-key or multi-key output selection. In multi-key mode, when two or more touch points TPQ0-TPQ3 are touched, TP0-TPQ3 can simultaneously output the status of each touch detection point. In single-key mode, TP0-TPQ3 can only output one at a time. When one of the TPQ0-TPQ3 detection points is detected to be touched, the other three touch points are invalid.

[0050] This embodiment requires each channel to output independently at the same time, so a multi-key mode is selected for grounding. Pin 11 (OD) is used to configure open-drain output. When low, it is an open-drain output; when high, it is a CMOS output. The default is high. In this embodiment, it is a CMOS output, so it is not connected and is configured as the default state.

[0051] Pin 10 (VSS) is the chip ground, and pin 9 (MOT0) is used to select the longest valid output time for the touch detection point. When grounded, the maximum output time is 16 seconds; when connected to a high level, the output time is infinite. In this embodiment, both are applicable, so it is connected to a low level.

[0052] Pins TP0-TP3 are led out to pads TK1-TK4 respectively. Pads TK1-TK4 are used to... Figure 1 The wire shown is led out and connected to the biological tissue detection point on the fixed-focus frame 13. The wire 11 can also be connected to the touch detection point using a flexible circuit board (FPC), etc.

[0053] Preferably, the circuits between TP0-TP3 and TK1-TK4 can be connected in series with resistors R2, R3, R4, R5 and capacitors C15, C16, C17, and C18, which can greatly improve the anti-static capability of the biological tissue detection circuit.

[0054] In addition, capacitors C13, C14, C11, and C12 can be connected to TP0-TP3 respectively to adjust the sensitivity of biological tissue contact detection. The sensitivity is highest when C13, C14, C11, and C12 are not connected. The larger the capacitance values ​​of C13, C14, C11, and C12, the lower the sensitivity. The capacitance adjustment range for C13, C14, C11, and C12 is 0-50pF. The output terminals TPQ0-TPQ3 are led out through terminal P1 and connected to… Figure 3 The main unit connects to the terminal block for data acquisition and control.

[0055] This embodiment uses single-point biological tissue contact detection, so TPQ0 is used as an example for illustration, configuring the TPQ0 connection. Figure 1 The fixed-focus frame 13 of the medical device handpiece, when the biological tissue is not in contact with the fixed-focus frame 13, TPQ0 outputs a low level; when the biological tissue is in contact with the fixed-focus frame 13, TPQ0 outputs a high level. Its output status is isolated by optocoupler U1 and then sent to the SKIN_CHK1 pin of microcontroller (MCU) U2 for reading. When undetected biological tissue is in contact with the fixed-focus frame 13, the TPQ0 of the touch detection chip U5 outputs a low level, the LED at the input terminal of optocoupler U1 does not light up, the output terminal is open, and pin 4 of optocoupler U1 is equipped with a pull-up circuit. With R9 in place, the SKIN_CHK1 pin of the microcontroller (MCU) U2 reads a high level. When the detected biological tissue contacts the fixed-focus frame 13, the TPQ0 output of the touch detection chip U5 is high, the LED at the input of the optocoupler U1 lights up, and the output is turned on. At this time, the SKIN_CHK1 pin of the microcontroller (MCU) U2 reads a low level. Thus, the contact status of the biological tissue is read. Similarly, when other specifications require multi-point biological tissue contact detection, it is the same as single-point biological tissue contact detection.

[0056] The handpiece circuit board 11 also integrates a handpiece connection status and handpiece specification information reading circuit. Pin 5 of the handpiece end connector P1 is connected to GND, and pin 5 of the host end connector P2 is used to transmit the handpiece connection status. After isolation by optocoupler U6, the data is sent to the HANLE_TOOL_CHK pin of the microcontroller (MCU) U2 for reading. The specific implementation method is as follows:

[0057] When the handpiece is not connected, pin 5 of the host connector P2 is connected to pin 1 of the optocoupler U6. Pin 1 is pulled up by resistor R6, the LED at the input of optocoupler U6 lights up, the output of optocoupler is turned on, and the HANLE_TOOL_CHK pin of microcontroller (MCU) U2 reads a low level.

[0058] When the handpiece is connected to the host, pin 5 of the host connector P2 is connected to pin 1 of the optocoupler U6 and connected to GND. The LED at the input of the optocoupler U6 does not light up, and the output is not conducting. Pin 4 is pulled up through resistor R7. At this time, the HANLE_TOOL_CHK pin of the microcontroller (MCU) U2 reads a high level, thus realizing the reading of the handpiece connection status.

[0059] Hand tool specification information reading circuit, such as Figure 1 As shown, the ADI / MAXIM DS2431 single-bus EEPROM chip U7, with a storage capacity of 1Kbit, is used to store handheld device specification information. It allows data and power to share a single line. A pull-up resistor R10 on pin 2 of the data line powers the chip. The single-bus signal is transmitted to pin 7 of the host connector P2 via pin 7 of connector P1. To ensure the reliability of single-bus data transmission and the system's anti-interference capability, an ADI DS9503ESD protection diode D3 is configured on the data line to improve the system's anti-static capability and isolate the single-bus from the host side. The specific isolation scheme is as follows:

[0060] Using ADI's DS2480B data conversion chip U8, the single bus is converted into a serial port. Then, using ADI's ADUM1201 U20 digital isolation chip, the serial port data is isolated and connected to the USART1_RX and USART1_TX of the microcontroller (MCU) U2 for communication, which enables the reading of tool specification information.

[0061] In summary, this invention utilizes the change in capacitance parameters generated when biological tissue comes into contact with a sensing point to detect whether the contact with the biological tissue is good. Furthermore, the biological tissue contact point can be made of insulating material to achieve electrical isolation. Experimental verification shows high sensitivity, fast response speed, and high reliability. By configuring biological tissue contact detection functionality on medical device handpieces of energy source devices such as lasers, radio frequency devices, and ultrasound devices, accidental energy output when the medical device handpiece is not aligned with the diseased tissue can be avoided, preventing accidental harm to the living organism. Using capacitive sensing technology, a human detection point is configured on the biological tissue contact surface of the medical device handpiece, and through hardware circuit and structural design, stable and reliable biological tissue contact detection is achieved.

[0062] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A detection circuit for a medical device handpiece, characterized in that, include: The handpiece circuit board has the following features: A touch detection chip, wherein the touch detection chip comprises at least: The touch input terminal is used to detect changes in capacitance when biological tissue comes into contact with it. The output terminal is used to output the biological tissue contact status signal detected by the touch detection chip; A fixed-focus frame is provided with a biological tissue contact detection point, which is connected to the touch input terminal via a wire. A connector is used to connect the handpiece circuit board to the main unit of the energy source device to enable the reading of handpiece connection status signals, handpiece specification information, and biological tissue contact status signals; An optocoupler is used to isolate signal transmission between the output terminal and the microcontroller. A microcontroller, the microcontroller having: The first input terminal used to read the contact status signal of biological tissue; The second input terminal is used to read the connection status of the handpiece.

2. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The fixed-focus frame is covered with an insulating layer.

3. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: The VDD power supply pin is powered by a 5V power supply and uses a capacitor for filtering. The AHLB pin is grounded so that the output terminal outputs a low level by default.

4. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: The TOG pin is grounded so that the output terminal outputs a low level by default and a high level when in contact with biological tissue.

5. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: The LPMB pin is connected to a high level to put the touch detection chip into fast mode.

6. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: The SM pin is grounded to enable the touch detection chip to be in multi-key mode.

7. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: The MOT0 pin is grounded so that the longest effective output time of the output terminal is 16 seconds.

8. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: A resistor and a capacitor are connected in series between the TP0 pin and the fixed-focus frame to improve the anti-static capability of the biological tissue detection circuit.

9. The detection circuit of a medical device handpiece according to claim 1, characterized in that, The touch detection chip also includes: A capacitor is connected to the TP0 pin to adjust the sensitivity of biological tissue contact detection. The capacitance value of the capacitor ranges from 0 to 50 pF.

10. The detection circuit for a medical device handpiece according to claim 1, characterized in that, The detection circuit further includes: An EEPROM chip is used to store hand tool specification information. The EEPROM chip communicates with the microcontroller via a single bus.

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