Multi-channel temperature detection circuit and radio frequency treatment device

Abstract

The utility model discloses a multipath temperature detection circuit and a radio frequency treatment device, which are used in the technical field of temperature detection. In the circuit, an excitation source is connected with a common end of a load selection switch; a plurality of channels of the load selection switch are respectively connected with the multi-channel temperature sensor; a plurality of channels of the multi-channel sampling selection switch are correspondingly connected with a plurality of channels of the load selection switch; the common end of the multipath sampling selection switch is connected with the input end of the electric signal detection module, and the output end of the electric signal detection module is connected with the controller. The controller is connected with the gating control end of the load selection switch and the gating control end of the multipath sampling selection switch. According to the multi-channel temperature detection circuit, the temperature value of the multi-channel temperature sensor can be detected only through one multiplexed excitation source and one multiplexed electric signal detection module, multiple excitation sources and multiple electric signal detection modules are not needed, and the cost of the multi-channel temperature detection circuit can be effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of temperature detection technology, and in particular to a multi-channel temperature detection circuit and a radiofrequency therapy device. Background Technology

[0002] In the field of aesthetic medicine, radiofrequency (RF) therapy devices stimulate collagen regeneration in the skin through the thermal effect of radiofrequency current, thereby achieving treatment effects such as skin tightening and wrinkle reduction. To ensure the safety and effectiveness of the treatment, it is usually necessary to monitor the temperature distribution of the skin tissue in the treatment area in real time to prevent local overheating that could lead to burns or insufficient treatment that could affect the results. Especially in multi-point treatment mode, due to the differences in tissue characteristics and heat dissipation conditions at different treatment sites, it is necessary to use multiple temperature detection circuits to simultaneously monitor temperature changes at multiple points.

[0003] In a multi-channel temperature detection circuit, multiple temperature sensors are included. Existing methods require an excitation source to provide excitation to the temperature sensor, and a voltage detector to sample the voltage across the sensor. The resistance of the sensor is then determined based on this voltage value, yielding the temperature reading. Each temperature sensor requires its own excitation source and a separate voltage detector. Since a multi-channel temperature detection circuit includes multiple temperature sensors, it necessitates multiple excitation sources and voltage detectors, increasing its cost. Utility Model Content

[0004] This invention provides a multi-channel temperature detection circuit and a radiofrequency therapy device, which can effectively reduce the cost of the multi-channel temperature detection circuit.

[0005] This utility model provides a multi-channel temperature detection circuit, including: an excitation source, a load selection switch, a load circuit, a multi-channel sampling selection switch, an electrical signal detection module, and a controller;

[0006] The excitation source is connected to the common terminal of the load selection switch; the load circuit includes: multiple temperature sensors, and multiple channels of the load selection switch are respectively connected to the multiple temperature sensors;

[0007] The multiple channels of the multi-channel sampling selection switch are connected to the multiple channels of the load selection switch respectively; the common terminal of the multi-channel sampling selection switch is connected to the input terminal of the electrical signal detection module, and the output terminal of the electrical signal detection module is connected to the controller.

[0008] The controller is connected to the selection control terminal of the load selection switch and the selection control terminal of the multiple sampling selection switch; the controller is used to obtain the electrical signal value of any of the temperature sensors detected by the electrical signal detection module by selecting the channels of the load selection switch and the multiple sampling selection switch, and to determine the temperature value of any of the temperature sensors based on the electrical signal value.

[0009] Furthermore, it also includes: an electrical signal processing module;

[0010] The input terminal of the electrical signal processing module is connected to the common terminal of the multiple sampling selection switch, and the output terminal of the electrical signal processing module is connected to the input terminal of the electrical signal detection module; the electrical signal processing module is used for signal filtering and amplification.

[0011] Furthermore, the load circuit also includes: a precision resistor;

[0012] The multiplexed channels using selection switches are connected to the precision resistor;

[0013] The controller is used to determine the temperature value of any of the temperature sensors based on the electrical signal value detected by the electrical signal detection module and the calibration signal value of the precision resistor.

[0014] Furthermore, the precision resistor includes: a first precision resistor; the electrical signal detection module includes: a voltage detection module;

[0015] The first terminals of the multiple temperature sensors are connected in parallel and then connected in series with the first terminal of the first precision resistor; the multiple channels of the load selection switch are respectively connected to the second terminals of the multiple temperature sensors and the first terminal of the first precision resistor.

[0016] The controller is specifically used to determine the temperature value of any of the temperature sensors based on the first voltage value of the first precision resistor detected by the voltage detection module and the second voltage value of any of the temperature sensors connected in series with the first precision resistor.

[0017] Furthermore, the excitation source is a constant current excitation source, and the controller is also used to calibrate the voltage value detected by the voltage detection module based on the first voltage value of the first precision resistor.

[0018] Furthermore, the excitation source is a constant current excitation source, and the precision resistor further includes: a second precision resistor;

[0019] The first end of the second precision resistor is connected to one channel of the load selection switch and one channel of the multiple sampling selection switch, and the second end of the second precision resistor is connected in series with the first end of the first precision resistor.

[0020] The controller is also used to calibrate the voltage value transmitted by the voltage detection module based on the third voltage value of the second precision resistor and the first precision resistor connected in series, which is detected by the voltage detection module.

[0021] Furthermore, the excitation source is a constant current excitation source, which is composed of a transistor and an operational amplifier, or a constant current excitation circuit composed of transistors.

[0022] Furthermore, the load circuit also includes: a first inductor, a first capacitor, and a second capacitor;

[0023] The first end of the multiple temperature sensors is connected to one end of the first inductor and one end of the first capacitor;

[0024] The other end of the first inductor is connected to one end of the second capacitor and the first end of the first precision resistor;

[0025] The other end of the first capacitor, the other end of the second capacitor, and the second end of the first precision resistor are grounded.

[0026] Furthermore, both the load selection switch and the multi-channel sampling selection switch are multi-channel analog switches, and the number of channels of the multi-channel analog switch is greater than the number of the multiple temperature sensors.

[0027] Furthermore, the temperature sensor is an NTC thermistor or a silicon-based thermistor.

[0028] This utility model also provides a radiofrequency therapy device, including: the multi-channel temperature detection circuit described above, wherein the temperature detection points of the multi-channel temperature detectors in the multi-channel temperature detection circuit are set at the treatment points of multiple radiofrequency electrodes; the controller of the multi-channel temperature detection circuit is further used to determine whether the radiofrequency electrodes are in place based on the electrical signal values ​​detected by the electrical signal detection module in the multi-channel temperature detection circuit.

[0029] As can be seen from the above technical solutions, this utility model has the following advantages:

[0030] In the multi-channel temperature detection circuit of this utility model, the excitation source is connected to the common terminal of the load selection switch; multiple channels of the load selection switch are respectively connected to multiple temperature sensors; multiple channels of the multi-channel sampling selection switch are correspondingly connected to multiple channels of the load selection switch; the common terminal of the multi-channel sampling selection switch is connected to the input terminal of the electrical signal detection module, and the output terminal of the electrical signal detection module is connected to the controller; the controller is connected to the selection control terminal of the load selection switch and the selection control terminal of the multi-channel sampling selection switch; the controller is used to obtain the electrical signal value of any temperature sensor detected by the electrical signal detection module by selecting the channels of the load selection switch and the multi-channel sampling selection switch, and determine the temperature value of any temperature sensor based on the electrical signal value.

[0031] As can be seen, in this utility model, the controller can reuse the excitation source to provide excitation for multiple temperature sensors by selecting the channel of the load selection switch; and the controller can reuse the electrical signal detection module to detect the voltage value of multiple temperature sensors by selecting the channel of the multi-channel sampling selection switch. In the multi-channel temperature detection circuit, only one reused excitation source and one reused electrical signal detection module are needed to detect the temperature value of multiple temperature sensors, without the need for multiple excitation sources and multiple electrical signal detection modules, which can effectively reduce the cost of the multi-channel temperature detection circuit. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0033] Figure 1 This is a structural block diagram of a multi-channel temperature detection circuit disclosed in this utility model;

[0034] Figure 2 This is a structural block diagram of another multi-channel temperature detection circuit disclosed in this utility model;

[0035] Figure 3 This is a circuit diagram of a multi-channel temperature detection circuit disclosed in this utility model;

[0036] Figure 4 This is a circuit diagram of a constant current excitation source disclosed in this utility model;

[0037] Figure 5 This is a schematic diagram of a filter circuit disclosed in this utility model;

[0038] Figure 6 This is a schematic diagram of the structure of a radiofrequency therapy device disclosed in this utility model. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present application, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0040] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] In a multi-channel temperature detection circuit, multiple temperature sensors are included. Existing methods require an excitation source to provide excitation to the temperature sensor and a voltage detector to sample the voltage across the sensor. The resistance of the temperature sensor is then determined based on the voltage value to obtain the temperature value. Each temperature sensor requires its own excitation source and a separate voltage detector. Since a multi-channel temperature detection circuit includes multiple temperature sensors, it requires multiple excitation sources and multiple voltage detectors, increasing its cost. Therefore, this invention discloses a multi-channel temperature detection circuit that effectively reduces its cost. Figure 1 As shown, the details are as follows:

[0043] The multi-channel temperature detection circuit of this utility model includes: an excitation source 101, a load selection switch 102, a load circuit 103, a multi-channel sampling selection switch 104, an electrical signal detection module 105, and a controller 106. The excitation source 101 can be a constant current excitation source or a constant voltage excitation source, which is not specifically limited here; preferably, the excitation source is a constant current excitation source, and temperature detection is performed through a constant current drive method. Compared with a constant voltage excitation source, this avoids the self-heating effect or sensitivity deviation of constant voltage drive affecting the detection error.

[0044] The excitation source 101 is connected to the common terminal of the load selection switch 102. The load circuit 103 includes a multi-channel temperature sensor. This temperature sensor is a thermistor, which can be an NTC thermistor (negative temperature coefficient thermistor) or a silicon-based thermistor; the specific type is not limited here. Compared with using thermocouples for temperature detection, this thermistor has higher detection accuracy and can reduce the detection error caused by the temperature sensor itself. Multiple channels of the load selection switch 102 are respectively connected to the multi-channel temperature sensor; that is, the load selection switch 102 includes multiple channels, and each temperature sensor is connected to one channel of the load selection switch 102. The load selection switch 102 can select the channel connected to the temperature sensor, that is, connect the common terminal of the load selection switch 102 and the corresponding channel, so that the excitation source 101 connected to the common terminal provides excitation to the temperature sensor corresponding to the selected channel, thereby realizing the multiplexing of the excitation source 101 connected to the common terminal of the load selection switch 102 to provide excitation for the multi-channel temperature sensor.

[0045] It is understood that the load selection switch 102 can be an analog switch, a MOSFET, or a transistor; the specific type is not limited here. The number of switches in the load selection switch is greater than the number of multiple temperature sensors. If the load selection switch is a multiple analog switch, the number of channels in the multiple analog switch is greater than the number of multiple temperature sensors. The number of channels in the multiple analog switch can be 3 or 8, or even more than 8; the specific type is not limited here. For example, it can be an 8-to-1 analog switch or a 16-to-1 analog switch.

[0046] The multiplexer 103 is similar to the load selector 102, and its specific characteristics are not limited here. Multiple channels of the multiplexer 103 are connected to corresponding channels of the load selector; that is, each temperature sensor is also connected to one channel of the multiplexer 103. The common terminal of the multiplexer 103 is connected to the input terminal of the electrical signal detection module 105, and the output terminal of the electrical signal detection module 105 is connected to the controller 106. In other words, the multiplexer 103 can select the channel connected to the temperature sensor, i.e., connect the common terminal of the multiplexer 103 to the corresponding channel, so that the electrical signal detection module 105 connected to the common terminal samples and detects the electrical signal value of the selected channel's temperature sensor.

[0047] The controller 106 is connected to the gating control terminal of the load selection switch 102 and the gating control terminal of the multiplexing selection switch 104. That is, the controller 106 can send gating signals to the gating control terminals of the load selection switch 102 and the multiplexing selection switch 104 to select one channel of the load selection switch 102 and one channel of the multiplexing selection switch 104. It can be understood that the controller 106 can send the same gating signal to the load selection switch 102 and the multiplexing selection switch 104 to select the channel connected to the same load (same temperature sensor) on the load selection switch 102 and the multiplexing selection switch 104. The load selection switch 102 provides excitation to any one temperature sensor, and the multiplexing selection switch 104 selects the any one temperature sensor so that the electrical signal detection module samples the electrical signal value of the any one temperature sensor, so as to realize the multiplexing electrical signal detection module to detect the electrical signal values ​​of multiple temperature sensors. The controller receives the electrical signal value from any temperature sensor detected by the electrical signal detection module and determines the temperature value of that sensor based on the electrical signal value. It can be understood that this electrical signal detection module can be a voltage detection module or a current detection module, with the corresponding electrical signal value being either a voltage or current value. The temperature value of the sensor can be determined based on either the voltage or current value. For example, if the electrical signal detection module is a voltage detection module, the voltage value can be divided by the excitation current value provided by the excitation source to obtain the resistance value of any temperature sensor. The temperature value corresponding to this resistance value can then be obtained by looking up a table, thus obtaining the temperature value of any given temperature sensor and enabling temperature detection from multiple temperature sensors.

[0048] As can be seen, in this utility model, the controller can reuse the excitation source to provide excitation for multiple temperature sensors by selecting the channel of the load selection switch; and the controller can reuse the electrical signal detection module to detect the electrical signal values ​​of multiple temperature sensors by selecting the channel of the multi-channel sampling selection switch. In the multi-channel temperature detection circuit, only one reused excitation source and one reused electrical signal detection module are needed to detect the temperature values ​​of multiple temperature sensors, without the need for multiple excitation sources and multiple electrical signal detection modules, which can effectively reduce the cost of the multi-channel temperature detection circuit.

[0049] Furthermore, in existing multi-channel temperature detection circuits, the signal from each temperature sensor requires filtering and amplification by a subsequent circuit before signal detection. Since a multi-channel temperature detection circuit contains multiple temperature sensors, multiple subsequent circuits are needed, further increasing the cost. However, the utility model, by using a multiplexed electrical signal processing module, can further reduce the cost of the multi-channel temperature detection circuit, specifically as follows: Figure 2 As shown:

[0050] In this invention, the multi-channel temperature detection circuit further includes an electrical signal processing module 107, which filters and amplifies the signal to improve its accuracy. The input terminal of the electrical signal processing module 107 is connected to the common terminal of the multi-channel sampling selection switch 104, and the output terminal of the electrical signal processing module 107 is connected to the input terminal of the electrical signal detection module 105. Therefore, by reusing a single electrical signal processing module 107, the electrical signals from the multiple temperature sensors transmitted through the common terminal of the multi-channel sampling selection switch 104 are filtered and amplified without requiring multiple subsequent circuits, further reducing the cost of the multi-channel temperature detection circuit.

[0051] Furthermore, to accurately detect the temperature value of the temperature sensor, the load circuit 103 also includes: a precision resistor; this precision resistor has a known resistance value, and the resistance value of the precision resistor is pre-stored in the controller; a channel of the multi-channel sampling selection switch 104 is connected to the precision resistor; it is understood that the load selection switch 102 and the multi-channel sampling selection switch 104 use other channels to connect to the precision resistor, and these other channels are channels other than those connected to the multi-channel temperature sensors. The controller 106 is used to determine the temperature value of any temperature sensor based on the electrical signal value of any temperature sensor detected by the electrical signal detection module and the calibration signal value of the precision resistor. It is understood that in this invention, the electrical signals of the multi-channel temperature sensors and the calibration signals of the precision resistor can both be multiplexed using a single electrical signal processing module for filtering and amplification, and a single electrical signal detection module can be multiplexed for signal detection, reducing the cost of the multi-channel temperature detection circuit.

[0052] Specifically, the precision resistor includes a first precision resistor; the electrical signal detection module includes a voltage detection module, which can be a Hall voltage sensor or an analog-to-digital converter (ADC), the specifics of which are not limited here. The first terminals of the multiple temperature sensors are connected in parallel and then in series with the first terminal of the first precision resistor, and the second terminal of the first precision resistor is grounded. Multiple channels of the load selection switch 102 are respectively connected to the second terminals of the multiple temperature sensors and the first terminal of the first precision resistor; that is, the load selection switch 102 includes multiple channels, the second terminal of each temperature sensor is connected to one channel of the load selection switch 102, and the first terminal of the first precision resistor is connected to one channel of the load selection switch 102. It can be understood that the second terminal of each temperature sensor and the first terminal of the first precision resistor are respectively connected to different channels of the load selection switch 102. The load selection switch 102 can select the channel connected to the temperature sensor or the channel connected to the first precision resistor, that is, connect the common terminal of the load selection switch 102 and the corresponding channel, so that the excitation source 101 connected to the common terminal provides excitation to the selected channel; such as providing excitation to any temperature sensor or the first precision resistor. Meanwhile, the first end of the first precision resistor is connected to one channel of the multiple sampling selection switch 103. The multiple sampling selection switch 103 can select the channel, so that the first precision resistor is connected to the voltage detection module 105 of the common terminal of the multiple sampling selection switch 103.

[0053] Specifically, the controller 103 is used to determine the temperature value of any temperature sensor based on the first voltage value of the first precision resistor detected by the voltage detection module 105 and the second voltage value of any temperature sensor connected in series with the first precision resistor. The first voltage value can be the voltage value of the first precision resistor to ground, and the second voltage value can be the voltage value of any temperature sensor connected in series with the first precision resistor to ground.

[0054] Specifically, the controller 106 is used to obtain the first voltage value of the first precision resistor detected by the voltage detection module 105 and the second voltage value of any temperature sensor connected in series with the first precision resistor by selecting the channels of the load selection switch 102 and the multiple sampling selection switch 104. It can be understood that the controller 106 can select the channel connected to the first precision resistor in the load selection switch 102 and the multiple sampling selection switch 104 to obtain the first voltage value of the first precision resistor; and select the channel connected to any temperature sensor in the load selection switch 102 and the multiple sampling selection switch 104 to obtain the second voltage value of any temperature sensor connected in series with the first precision resistor. The temperature value of any temperature sensor is determined based on the first voltage value and the second voltage value. That is, the controller can obtain the current value of the excitation current transmitted by the excitation source based on the first voltage value and the resistance value of the first precision resistor; obtain the resistance value of any temperature sensor based on the second voltage value and the current value; and obtain the temperature value of any temperature sensor by looking up the correspondence between resistance value and temperature value in a table or curve fitting formula. By using the resistance value of the first precision resistor, the current value of the excitation current transmitted by the excitation source can be accurately obtained. Based on the second voltage value and the current value, the temperature value of any temperature sensor can be obtained; thus, the temperature value of the temperature sensor can be accurately detected.

[0055] In one feasible approach, existing methods typically assign a separate excitation source to each temperature sensor to drive its operation. This requires multiple excitation sources for the multi-channel temperature detection circuit, increasing its complexity, cost, and resulting in poor temperature detection consistency. However, in this invention, the multi-channel temperature detection circuit uses only one constant current excitation source to detect the temperature values ​​of multiple temperature sensors. This simplifies the multi-channel temperature detection circuit, reduces its cost, and improves temperature detection consistency.

[0056] Furthermore, the following will combine Figure 3 The multi-channel temperature detection circuit of this application is described below. The multi-channel temperature detection circuit includes: an excitation source 101, a load selection switch 102, a load circuit 103, a multi-channel sampling selection switch 104, and an electrical signal processing module 107.

[0057] In a multi-channel temperature detection circuit, the entire circuit can be powered by the power supply VCC. The excitation source can be a constant current source; this constant current source can be composed of transistors and operational amplifiers, or a constant current excitation circuit composed of transistors, without specific limitations. The transistor can be a bipolar transistor or a MOSFET; that is, the constant current source can be a combination of an operational amplifier and a bipolar transistor / MOSFET, or it can use only a bipolar transistor, only a MOSFET, or a combination of a bipolar transistor and a MOSFET, without specific limitations here.

[0058] For example, the constant current excitation source 101 includes: a reference voltage module, a PNP transistor Q1, and an operational amplifier U2A; the positive input terminal of the operational amplifier U2A is connected to the power supply VCC after being grounded and filtered by capacitor C3, and the negative input terminal of the operational amplifier U2A is grounded; the reference voltage module is connected to the non-inverting input terminal of the operational amplifier U2A, and the reference voltage module includes: resistor R6, resistor R7, and capacitor C4, which provides a reference voltage for the operational amplifier U2A by dividing the power supply VCC; the inverting input terminal of the operational amplifier U2A is connected to the emitter of the PNP transistor Q1, and the emitter of the PNP transistor Q1 is connected to the power supply VCC via resistor R4; the output terminal of the operational amplifier U2A is connected to the base of the PNP transistor Q1 via resistor R5, and the collector of the PNP transistor Q1 is connected to the common terminal X of the load selection switch 102.

[0059] It is understandable that the PNP transistor Q1 in the constant current excitation source 101 can be replaced by an NPN transistor, PMOS transistor, or NMOS transistor; no specific limitation is made here. Figure 4 As shown, the constant current excitation source includes: a reference voltage module, an operational amplifier, and an NPN transistor Q2.

[0060] Figure 3 In this circuit, the load selection switch 102 is an 8-to-1 analog switch with 8 channels (X0 to X7). Three selection control terminals (A, B, C) are connected to the controller. The controller sends three selection signals (CS0, CS1, CS2) to these terminals to select a specific channel. The common terminal X and the enable terminal INH are grounded. The power supply terminal VDD is filtered by capacitor C5 to input the power supply voltage, and the power supply terminals VEE and VSS are grounded. The load circuit 103 includes multiple temperature sensors and precision resistors. Temperature sensors are connected between ports RT1-6 and RT_COM. CAL0 is connected to the first precision resistor R1, and CAL1 is connected to the second precision resistors (R2 and R3). The second precision resistors R2 and R3 are connected in parallel and then in series with the first precision resistor R1. The structure of the multi-channel sampling selection switch 104 and its connection to the load circuit 103 are similar to those of the load selection switch 102, and will not be described in detail here.

[0061] The load circuit 103 further includes: a first inductor L1, a first capacitor C1, and a second capacitor C2; the first terminal (RT_COM) of the multi-channel temperature sensor is connected to one end of the first inductor L1 and one end of the first capacitor C1; the other end of the first inductor L1 is connected to one end of the second capacitor C2 and the first terminal of the first precision resistor R1; the other ends of the first capacitor C1, the other ends of the second capacitor C2, and the second terminal of the first precision resistor R1 are grounded. It can be understood that the first inductor L1, the first capacitor C1, and the second capacitor C2 in the load circuit 103 can form an LC filter circuit to filter the signal provided by the excitation source 101.

[0062] The electrical signal processing module 107 includes a filter amplifier circuit. The input of the filter amplifier circuit is connected to the common terminal X of the multiplexer 104, and the output of the filter amplifier circuit is connected to the input of the analog-to-digital converter (ADC). The output of the ADC is connected to the controller. The filter amplifier circuit performs low-pass filtering and high-frequency suppression on the analog voltage signal (i.e., temperature signal) at the common terminal X of the multiplexer 104, enhancing the circuit's anti-interference capability, and amplifies the analog voltage signal. The ADC performs analog-to-digital conversion on the analog voltage signal and outputs a digital voltage signal to the controller. The controller obtains the resistance value corresponding to the temperature sensor based on the digital voltage signal to obtain the temperature value of the temperature sensor. The filter amplifier circuit includes resistors R8, R9, and R10, capacitors C7, C8, and C9, and an operational amplifier. The amplification factor can be set using resistors R6 and R7.

[0063] The temperature detection process of the multi-channel temperature detection circuit is as follows: the controller selects channel X7 (i.e., CAL0) connected to the first precision resistor R1 in the load selection switch 102 and the multi-channel sampling switch 104, and obtains the first voltage value Ucal0 of the first precision resistor through the voltage detection module; the controller selects channel connected to any temperature sensor in the load selection switch 102 and the multi-channel sampling switch 104, and obtains the second voltage value Urtn of any temperature sensor connected in series with the first precision resistor; the controller can obtain the resistance value RTn of any temperature sensor based on the formula RTn=(Urtn-Ucal0)*R1 / Ucal0, and then obtain the temperature value of any temperature sensor.

[0064] Furthermore, the multi-channel temperature detection circuit can also be equipped with a front-end filtering circuit, such as... Figure 5As shown, it includes: capacitors C10, C11, C12, and C13; inductors L2 and L3; and diodes D1, D2, and D3. A temperature sensor is connected between RT1-2 and RT_COM. Port J1 is connected to the channel of the multi-channel sampling switch. This front-end filtering circuit can filter two temperature sensors simultaneously, using a π-type filter to remove interference signals and reduce detection errors.

[0065] Furthermore, when the excitation source is a constant current excitation source, if the ambient temperature of the multi-channel temperature detection circuit changes, the excitation current value output by the constant current excitation source will differ from the theoretical current value due to the influence of temperature drift, which will affect the accuracy of temperature detection. Therefore, in this invention, it is necessary to calibrate the error of the constant current excitation source to ensure the accuracy of temperature detection.

[0066] The controller is also used to calibrate the voltage value detected by the voltage detection module based on the first voltage value of the first precision resistor. Specifically, the controller can determine the actual current value of the constant current excitation source based on the first voltage value Ucal0 of the first precision resistor; and calibrate the voltage value detected by the voltage detection module based on the current difference between the actual current value and the target current value of the constant current excitation source under a preset environment. The target current value under the preset environment can be the current value output by the constant current excitation source at a temperature of 25 degrees Celsius or 28 degrees Celsius. The calibration process can be as follows: if the current difference is greater than 0, the voltage value detected by the voltage detection module is increased accordingly; if the current difference is less than 0, the voltage value detected by the voltage detection module is decreased accordingly. By calibrating the voltage value detected by the voltage detection module using the current difference between the actual current value and the target current value, the error of the constant current excitation source can be calibrated, ensuring the accuracy of temperature detection.

[0067] Furthermore, in this invention, the precision resistor also includes a second precision resistor (R2 in parallel with R3), which can be used to calibrate the error of the constant current excitation source using the first precision resistor R1 and the second precision resistor (R2 in parallel with R3). Specifically, the first end of the second precision resistor is connected to one channel X6 of the load selection switch and one channel X6 of the multiplexer selection switch, and the second end of the second precision resistor is connected in series with the first end of the first precision resistor R1. The controller is also used to select the channel X7 connected to the second precision resistor in the load selection switch 102 and the multiplexer selection switch 104 to obtain the third voltage value Ucal1 detected by the voltage detection module; this third voltage value is the voltage value after the first precision resistor and the second precision resistor are connected in series.

[0068] The controller can calibrate the voltage value transmitted by the voltage detection module based on this third voltage value. Specifically, the actual current value of the constant current excitation source is determined based on the first and third voltage values; that is, the first current value can be determined based on the first voltage value and the resistance value of the first precision resistor, and the second current value can be determined based on the third voltage value and the resistance value of the first and second precision resistors connected in series. The average of the first and second current values ​​is then used to obtain the actual current value of the constant current excitation source. The voltage value transmitted by the voltage detection module is calibrated based on the current difference between the actual current value and the target current value of the constant current excitation source under a preset environment. The actual current value of the constant current excitation source can be accurately obtained using these two voltage values, thus accurately calibrating the error of the constant current excitation source.

[0069] This utility model also provides a radiofrequency therapy device, including: the aforementioned multi-channel temperature detection circuit, wherein the temperature detection points of the multi-channel temperature detectors in the multi-channel temperature detection circuit are set at the treatment points of multiple radiofrequency electrodes, and the multi-channel temperature detection circuit is used to detect the temperature at the treatment points of the multiple radiofrequency electrodes. Figure 6 As shown, the radiofrequency therapy device includes: a switching power supply, a main controller, a radiofrequency power supply, a display touch, a multi-channel temperature detection circuit, and radiofrequency electrodes; wherein the switching power supply supplies power to the main controller and the radiofrequency power supply; the display touch communicates with the main controller to realize human-computer interaction; the main controller controls the multi-channel temperature detection circuit to detect the temperature of the treatment points of multiple radiofrequency electrodes in real time.

[0070] Furthermore, in radiofrequency therapy devices, when detecting the presence of radiofrequency electrodes, corresponding presence signal lines are often set on the radiofrequency electrodes. However, radiofrequency therapy devices have multiple radiofrequency electrodes, requiring multiple presence signal lines, increasing the cost of the device. In this invention, a reset electrical signal detection module can be used to detect the presence of multiple radiofrequency electrodes, effectively saving costs. Specifically, the controller of the multi-channel temperature detection circuit determines whether the radiofrequency electrode is in place based on the electrical signal values ​​detected by the electrical signal detection module in the multi-channel temperature detection circuit. It is understood that the multi-channel temperature sensors are used to detect the treatment point of the radiofrequency electrode. When the radiofrequency electrode is in place, the radiofrequency current output by the electrode heats the treatment point, causing the temperature at the treatment point to rise. The presence of the radiofrequency electrode can be determined based on the signal range of the electrical signal value detected by the electrical signal detection module, such as the voltage range of the voltage value between the temperature sensor and the first precision resistor in series. By multiplexing the electrical signal detection module to detect the presence of multiple radiofrequency electrodes, the presence signal lines in the radiofrequency therapy device are effectively eliminated, saving costs.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A multiplexed temperature sensing circuit, comprising: The application relates to a temperature sensor detection device. The device comprises an excitation source, a load selection switch, a load circuit, a multi-channel sampling selection switch, an electric signal detection module and a controller. The excitation source is connected to the common terminal of the load selection switch. The load circuit comprises a plurality of temperature sensors, and a plurality of channels of the load selection switch are respectively connected to the plurality of temperature sensors. A plurality of channels of the multi-channel sampling selection switch are correspondingly connected to a plurality of channels of the load selection switch.

2. The multi-channel temperature sensing circuit of claim 1, wherein, The common terminal of the multi-channel sampling selection switch is connected to the input terminal of the electric signal detection module, and the output terminal of the electric signal detection module is connected to the controller. The controller is connected to the gating control terminals of the load selection switch and the multi-channel sampling selection switch. The controller is used for obtaining the electric signal value of any temperature sensor detected by the electric signal detection module by gating the channels of the load selection switch and the multi-channel sampling selection switch, and determining the temperature value of any temperature sensor based on the electric signal value.

3. The multi-channel temperature sensing circuit of claim 1, wherein, The device further comprises an electric signal processing module. The input terminal of the electric signal processing module is connected to the common terminal of the multi-channel sampling selection switch, and the output terminal of the electric signal processing module is connected to the input terminal of the electric signal detection module. The electric signal processing module is used for filtering and amplifying the signal.

4. The multi-channel temperature sensing circuit of claim 3, wherein, The load circuit further comprises a precision resistor. The channels of the multi-channel sampling selection switch are connected to the precision resistor. The controller is used for determining the temperature value of any temperature sensor based on the electric signal value of any temperature sensor detected by the electric signal detection module and the calibration signal value of the precision resistor.

5. The multi-channel temperature sensing circuit of claim 4, wherein, The precision resistor comprises a first precision resistor, and the electric signal detection module comprises a voltage detection module.

6. The multi-channel temperature sensing circuit of claim 4, wherein, The first terminals of the plurality of temperature sensors are connected in parallel and then connected in series to the first terminal of the first precision resistor. The controller is specifically used for determining the temperature value of any temperature sensor based on the first voltage value of the first precision resistor detected by the voltage detection module and the second voltage value of any temperature sensor and the first precision resistor in series. The excitation source is a constant current excitation source.

7. The multi-channel temperature sensing circuit of claim 4, wherein, The excitation source is a constant current excitation source. The precision resistor further comprises a second precision resistor. The first terminal of the second precision resistor is connected to one channel of the load selection switch and one channel of the multi-channel sampling selection switch, and the second terminal of the second precision resistor is connected in series to the first terminal of the first precision resistor. The controller is further used for calibrating the voltage value transmitted by the voltage detection module based on the third voltage value of the second precision resistor and the first precision resistor in series detected by the voltage detection module. The load circuit further comprises a first inductor, a first capacitor and a second capacitor. The first end of the plurality of temperature sensors is connected with one end of the first inductor and one end of the first capacitor; The other end of the first inductor is connected with one end of the second capacitor and the first end of the first precision resistor; The other end of the first capacitor, the other end of the second capacitor and the second end of the first precision resistor are grounded.

8. The multi-channel temperature sensing circuit of claim 1, wherein, The excitation source is a constant current excitation source, which is composed of a transistor and an operational amplifier, or a constant current excitation circuit composed of a transistor.

9. The multi-channel temperature sensing circuit of claim 1, wherein, The load selection switch and the multi-channel sampling selection switch are both multi-channel analog switches, and the number of channels of the multi-channel analog switches is greater than the number of the plurality of temperature sensors.

10. A radio frequency treatment device, characterized by The application further discloses a multi-channel temperature detection circuit and a radio frequency electrode system. The multi-channel temperature detection circuit according to any one of claims 1 to 9, wherein the temperature detection points of the plurality of temperature detectors are arranged at treatment points of a plurality of radio frequency electrodes. The controller of the multi-channel temperature detection circuit is further configured to determine whether the radio frequency electrodes are in place based on the electrical signal value detected by the electrical signal detection module.

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