Physiological signal zeroing module and electronic equipment

Abstract

The utility model provides a physiological signal zeroing module and electronic equipment, and relates to the technical field of physiological signal calibration. A first group of input ends of the analog switch module are used for connecting a sensor, and a second group of input ends of the analog switch module are connected with the reference signal module; the output end of the analog switch module is connected with the input end of the operational amplification module; the output end of the operational amplification module is connected with the input end of the analog-to-digital conversion module; the output end of the analog-to-digital conversion module is connected with the control module. Wherein the analog switch module can conduct a signal of the reference signal module to the operational amplification module, and the control module can obtain an amplification factor of the operational amplification module according to a signal output by the operational amplification module and the signal of the reference signal module, calibrate the operational amplification module and accurately process a sensor signal according to the amplification factor.

Description

Technical Field

[0001] The present application relates to the technical field of physiological signal calibration, and in particular to a physiological signal zeroing module and an electronic device. Background Art

[0002] Invasive blood pressure monitoring technology can monitor real-time changes in blood pressure. Some monitors may have intracranial pressure monitoring and temperature monitoring functions. The monitor receives sensor signals.

[0003] Since signal processing usually requires analog circuits, temperature drift is an inevitable problem for analog circuits. As the temperature rises, the pressure zero point or temperature zero point will also rise, which will affect the accuracy of signal measurement.

[0004] How to calibrate the analog circuit for processing sensor signals is a technical problem to be solved by this application. Utility Model Content

[0005] The purpose of the present application is to provide a physiological signal zeroing module and an electronic device to calibrate an analog circuit for processing sensor signals.

[0006] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions.

[0007] In a first aspect, an embodiment of the present application provides a physiological signal zeroing module, including a control module, an analog-to-digital conversion module, an operational amplifier module, an analog switch module, and a reference signal module;

[0008] The first group of input ends of the analog switch module is used to connect to the sensor, and the second group of input ends of the analog switch module is connected to the reference signal module; the analog switch module is used to switch different input ends to conduct to the output end;

[0009] The output end of the analog switch module is connected to the input end of the operational amplifier module;

[0010] The output end of the operational amplifier module is connected to the input end of the analog-to-digital conversion module;

[0011] The output end of the analog-to-digital conversion module is connected to the control module;

[0012] The reference signal module is used to provide a reference signal so that the operational amplifier module can be calibrated.

[0013] Optionally, the reference signal module includes a pressure reference signal generating circuit; the pressure reference input terminal of the analog switch module is connected to the pressure reference signal generating circuit;

[0014] The pressure reference signal generating circuit is used to generate a pressure reference signal.

[0015] Optionally, the pressure reference signal generating circuit includes a first voltage divider circuit and a second voltage divider circuit; the first voltage divider circuit is used to generate a first reference pressure signal, and the second voltage divider circuit is used to generate a second reference pressure signal, the first reference pressure signal is a pressure signal corresponding to a minimum pressure value, and the second reference pressure signal is a pressure signal corresponding to a maximum pressure value.

[0016] Optionally, the reference signal module further includes a reference level circuit; the reference level input terminal of the analog switch module is connected to the reference level circuit;

[0017] The reference level circuit is used to provide a short-circuited differential signal so that the operational amplifier module can be calibrated.

[0018] Optionally, the reference signal module includes a temperature reference signal generating circuit; the temperature input terminal of the analog switch module is connected to the temperature reference signal generating circuit;

[0019] The temperature reference signal generating circuit is used for generating a temperature reference signal.

[0020] Optionally, the temperature reference signal generating circuit includes a first thermistor and a second thermistor; the physiological signal zeroing module also includes a constant current source;

[0021] The analog switch module includes a differential signal analog switch;

[0022] The first output end of the differential signal analog switch is connected to the constant current source;

[0023] The second output end of the differential signal analog switch is connected to the input end of the operational amplifier module;

[0024] The first group of differential input terminals of the differential signal simulation switch is connected to the first terminal of the first thermistor, and the second terminal of the first thermistor is grounded;

[0025] The second group of differential input terminals of the differential signal simulation switch is connected to the first terminal of the second thermistor, and the second terminal of the second thermistor is grounded.

[0026] Optionally, the constant current source is generated by a precision operational amplifier.

[0027] Optionally, the reference signal module includes a pressure reference signal generating circuit and a temperature reference signal generating circuit;

[0028] The analog switch module includes a pressure signal analog switch and a temperature signal analog switch; the physiological signal zeroing module also includes a switching analog switch, and the switching analog switch is used to switch the pressure signal and the temperature signal to the analog-to-digital conversion module;

[0029] The operational amplifier module includes a pressure signal amplifier module and a temperature signal amplifier module;

[0030] The pressure reference input terminal of the pressure signal analog switch is connected to the pressure reference signal generating circuit; the temperature input terminal of the temperature signal analog switch is connected to the temperature reference signal generating circuit;

[0031] The pressure reference signal generating circuit is used to generate a pressure reference signal; the temperature reference signal generating circuit is used to generate a temperature reference signal;

[0032] The output end of the pressure signal simulation switch is connected to the input end of the pressure signal amplification module; the output end of the temperature signal simulation switch is connected to the input end of the temperature signal amplification module;

[0033] The output end of the pressure signal amplifying module is connected to the first group of input ends of the switching analog switch, the output end of the temperature signal amplifying module is connected to the second group of input ends of the switching analog switch, and the output end of the switching analog switch is connected to the analog-to-digital conversion module.

[0034] Optionally, the physiological signal zeroing module further includes an electrostatic protection circuit, which is connected to a connection interface between the physiological signal zeroing module and the sensor, and is used for electrostatic protection at the interface.

[0035] In a second aspect, an embodiment of the present application provides an electronic device, comprising the physiological signal zeroing module of the first aspect.

[0036] Compared with the prior art, this application has the following beneficial effects:

[0037] In the physiological signal zeroing module provided in the embodiment of the present application, the analog switch module can conduct the signal of the reference signal module to the operational amplifier module, and the control module can obtain the amplification factor of the operational amplifier module based on the signal output by the operational amplifier module and the signal of the reference signal module, so that the sensor signal can be accurately processed according to the amplification factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of a physiological signal zeroing module provided in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of a physiological signal zeroing module for processing a pressure sensor signal provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram of a physiological signal zeroing module with a voltage divider circuit provided in an embodiment of the present application;

[0042] Figure 4 A schematic diagram of a pressure reference signal generating circuit provided in an embodiment of the present application;

[0043] Figure 5 A schematic diagram of a physiological signal zeroing module with a reference level circuit provided in an embodiment of the present application;

[0044] Figure 6 A schematic diagram of a physiological signal zeroing module for processing a temperature sensor signal provided in an embodiment of the present application;

[0045] Figure 7 A schematic diagram of a physiological signal zeroing module with a thermistor provided in an embodiment of the present application;

[0046] Figure 8 A schematic diagram of a precision operational amplifier generating a constant current source provided in an embodiment of the present application;

[0047] Fig. 9 A schematic diagram of a temperature reference signal generating circuit composed of four thermistors and a differential signal analog switch provided in an embodiment of the present application;

[0048] Fig.10 A schematic diagram of a physiological signal zeroing module for processing pressure sensor signals and temperature sensor signals provided in an embodiment of the present application;

[0049] Fig.11 A schematic diagram of a physiological signal zeroing module with an interface electrostatic protection function provided in an embodiment of the present application;

[0050] Fig.12 A schematic diagram of an interface electrostatic protection circuit provided in an embodiment of the present application;

[0051] Fig.13 A schematic diagram of an electronic device with a display screen and a key module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described in the drawings here can be arranged and designed in various different configurations.

[0053] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0054] In the description of this application, it should be noted that relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium.

[0055] The present application embodiment provides a physiological signal zeroing module, such as Figure 1 ,The physiological signal zeroing module includes a control module, an analog-to-digital conversion module, an operational amplifier module, an analog switch module and a reference signal module.

[0056] like Figure 1 , the connection relationship is as follows: the first group of input ends of the analog switch module is used to connect the sensor, and the second group of input ends of the analog switch module is connected to the reference signal module; the analog switch module is used to switch different input ends to the output end; the output end of the analog switch module is connected to the input end of the operational amplifier module; the output end of the operational amplifier module is connected to the input end of the analog-to-digital conversion module; the output end of the analog-to-digital conversion module is connected to the control module;

[0057] The reference signal module is used to provide a reference signal so that the operational amplifier module can be calibrated. Because the analog switch module can conduct the signal of the reference signal module to the operational amplifier module, the control module can obtain the amplification factor of the operational amplifier module according to the signal output by the operational amplifier module and the signal of the reference signal module, that is, calibrate the operational amplifier module, and then accurately process the sensor signal according to the amplification factor.

[0058] The reference signal module may include a pressure reference signal generating circuit, such as Figure 2 The pressure reference input end of the analog switch module is connected to the pressure reference signal generating circuit, and the pressure reference signal generating circuit is used to generate a pressure reference signal. The pressure signal can be a differential signal, so each line of the analog switch module input in the figure represents two signals, and the analog switch module outputs two signals to the differential operational amplifier.

[0059] The pressure reference signal generating circuit may include a first voltage dividing circuit and a second voltage dividing circuit, such as Figure 3 , the first voltage divider circuit is used to generate a first reference pressure signal, the second voltage divider circuit is used to generate a second reference pressure signal, the first reference pressure signal is a pressure signal corresponding to the minimum pressure value, and the second reference pressure signal is a pressure signal corresponding to the maximum pressure value. Figure 4 The first reference pressure signal represents 0 mmHg pressure, and the second reference pressure signal represents 100 mmHg pressure. The 0 mmHg pressure signal can be a 0V differential signal under the same node, including P_0 mmHg+ and P_0 mmHg-, and the 100 mmHg pressure signal includes P_100 mmHg+ and P_100 mmHg-, which can be generated by multiple voltage-dividing resistors, and the resistors therein are fine-tuned to obtain accurate voltage division.

[0060] You can also set a reference level circuit, such as Figure 5 The reference signal module also includes a reference level circuit, and the reference level input end of the analog switch module is connected to the reference level circuit, and the reference level circuit is used to provide a short-circuited differential signal so that the operational amplifier module can be calibrated. The reference level circuit can use an operational amplifier, and divide the 2.5V voltage through two resistors at the same-direction input end to generate a 1V voltage signal (REF1V+), and use this signal as the reference level of the differential signal amplifier. The two ends of the differential signal amplifier are simultaneously connected to the 1V voltage signal, that is, a short circuit is obtained to obtain a 0V differential signal.

[0061] The reference signal module may include a temperature reference signal generating circuit, such as Figure 6 The temperature input end of the analog switch module is connected to the temperature reference signal generating circuit, and the temperature reference signal generating circuit is used to generate a temperature reference signal.

[0062] like Figure 7 The temperature reference signal generating circuit may include a first thermistor and a second thermistor. The physiological signal zeroing module also includes a constant current source; the constant current source is generated by a precision operational amplifier, such as Figure 8 , CC is the constant current source output. The analog switch module includes a differential signal analog switch, which has the following connection relationship:

[0063] The first output end of the differential signal analog switch is connected to the constant current source; the second output end of the differential signal analog switch is connected to the input end of the operational amplifier module; the first group of differential input ends of the differential signal analog switch is connected to the first end of the first thermistor, and the second end of the first thermistor is grounded; the second group of differential input ends of the differential signal analog switch is connected to the first end of the second thermistor, and the second end of the second thermistor is grounded.

[0064] Fig. 9 The embodiment of a temperature reference signal generating circuit composed of four thermistors and a differential signal analog switch D13 is shown. The constant current source CC can form four loops with the four thermistors R89, R58, R59, and R62 respectively. Since the voltage signal generated by the thermistor is linearly related to the temperature, two points determine a straight line. When the linear equation of the thermistor needs to be calibrated, the parameters of the linear equation y=kx+b can be obtained based on two of the thermistors.

[0065] The physiological signal zeroing module can also have the function of processing both temperature signal and pressure signal, such as Fig.10 :

[0066] The reference signal module may include a pressure reference signal generating circuit and a temperature reference signal generating circuit. The pressure reference signal generating circuit is used to generate a pressure reference signal; and the temperature reference signal generating circuit is used to generate a temperature reference signal.

[0067] The analog switch module includes a pressure signal analog switch and a temperature signal analog switch; the physiological signal zeroing module also includes a switching analog switch, and the switching analog switch is used to switch the pressure signal and the temperature signal to the analog-to-digital conversion module;

[0068] The operational amplifier module includes a pressure signal amplifier module and a temperature signal amplifier module.

[0069] Has the following connection relationship:

[0070] The pressure reference input terminal of the pressure signal analog switch is connected to the pressure reference signal generating circuit; the temperature input terminal of the temperature signal analog switch is connected to the temperature reference signal generating circuit;

[0071] The output end of the pressure signal simulation switch is connected to the input end of the pressure signal amplification module; the output end of the temperature signal simulation switch is connected to the input end of the temperature signal amplification module;

[0072] The output end of the pressure signal amplifying module is connected to the first group of input ends of the switching analog switch, the output end of the temperature signal amplifying module is connected to the second group of input ends of the switching analog switch, and the output end of the switching analog switch is connected to the analog switch module.

[0073] The physiological signal zeroing module may further include an electrostatic protection circuit, which is connected to the connection interface between the physiological signal zeroing module and the sensor, and is used for electrostatic protection at the interface. Fig.11 , the electrostatic protection circuit can be connected to the pressure sensor interface or the temperature sensor interface. Fig.12 An example of an electrostatic protection circuit is given, in which SIN+ and SIN- are used as differential signals of the sensor input. ESD protection devices (model: BAV99) are connected and symmetrical RC filters can be added on both sides to suppress the common-mode signal coming from the input interface. The output signals are VIN+ and VIN-.

[0074] Based on the above embodiments, an embodiment of the present application further provides an electronic device, and the electronic device includes the above physiological signal zeroing module.

[0075] The electronic device may include a display screen, and the control module controls the display screen to display the sensor reading. Fig.13 The control module can control the display screen to display the reading of the temperature sensor, and can also control the display screen to display the reading of the pressure sensor. The electronic device can also include a key module, such as Fig.13 The control module receives the signal from the key module and can switch the display of different data or display data at different times.

[0076] Electronic devices can also include microcontroller peripheral modules, for example: microcontroller MCU as a control module, microcontroller peripheral circuits are composed of power supply, clock, reset, debugging, and communication circuits to form a basic hardware system. The power supply is provided by 5 dry batteries to provide 6V power, which is provided to the core of the MCU after being stepped down by a high-precision linear power supply, and is also provided to the analog power supply part of the MCU after being isolated by inductors and capacitors. The clock uses a 32MHz crystal resonator. The reset uses a watchdog reset, the debugging uses SWD to burn the program, and the communication is carried out with the outside world through the SPI interface provided inside the MCU.

[0077] In general, the present application proposes a physiological signal zeroing module and an electronic device. The electronic device can simultaneously have the functions of data acquisition, button function, display, and sensor zeroing. The electronic device is equivalent to a miniature monitor and can be used for intracranial pressure and temperature monitoring. A calibration module is arranged inside the electronic device to realize calibration of the internal amplifier.

[0078] The above-described device and system embodiments are merely illustrative, and some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. A person of ordinary skill in the art may understand and implement the present embodiment without creative effort.

[0079] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A physiological signal zeroing module, characterized in that: It includes a control module, an analog-to-digital conversion module, an operational amplifier module, an analog switch module and a reference signal module; The first group of input ends of the analog switch module is used to connect to the sensor, and the second group of input ends of the analog switch module is connected to the reference signal module; the analog switch module is used to switch different input ends to conduct to the output end; The output end of the analog switch module is connected to the input end of the operational amplifier module; The output end of the operational amplifier module is connected to the input end of the analog-to-digital conversion module; The output end of the analog-to-digital conversion module is connected to the control module; The reference signal module is used to provide a reference signal so that the operational amplifier module can be calibrated.

2. The physiological signal zeroing module according to claim 1, characterized in that: The reference signal module includes a pressure reference signal generating circuit; the pressure reference input end of the analog switch module is connected to the pressure reference signal generating circuit; The pressure reference signal generating circuit is used to generate a pressure reference signal.

3. The physiological signal zeroing module according to claim 2, characterized in that: The pressure reference signal generating circuit includes a first voltage divider circuit and a second voltage divider circuit; the first voltage divider circuit is used to generate a first reference pressure signal, and the second voltage divider circuit is used to generate a second reference pressure signal, the first reference pressure signal is a pressure signal corresponding to a minimum pressure value, and the second reference pressure signal is a pressure signal corresponding to a maximum pressure value.

4. The physiological signal zeroing module according to claim 3, characterized in that: The reference signal module further includes a reference level circuit; the reference level input terminal of the analog switch module is connected to the reference level circuit; The reference level circuit is used to provide a short-circuited differential signal so that the operational amplifier module can be calibrated.

5. The physiological signal zeroing module according to claim 1, characterized in that: The reference signal module includes a temperature reference signal generating circuit; the temperature input end of the analog switch module is connected to the temperature reference signal generating circuit; The temperature reference signal generating circuit is used for generating a temperature reference signal.

6. The physiological signal zeroing module according to claim 5, characterized in that: The temperature reference signal generating circuit includes a first thermistor and a second thermistor; the physiological signal zeroing module also includes a constant current source; The analog switch module includes a differential signal analog switch; The first output end of the differential signal analog switch is connected to the constant current source; The second output end of the differential signal analog switch is connected to the input end of the operational amplifier module; The first group of differential input terminals of the differential signal simulation switch is connected to the first terminal of the first thermistor, and the second terminal of the first thermistor is grounded; The second group of differential input terminals of the differential signal simulation switch is connected to the first terminal of the second thermistor, and the second terminal of the second thermistor is grounded.

7. The physiological signal zeroing module according to claim 6, characterized in that: The constant current source is generated by a precision operational amplifier.

8. The physiological signal zeroing module according to claim 1, characterized in that: The reference signal module includes a pressure reference signal generating circuit and a temperature reference signal generating circuit; The analog switch module includes a pressure signal analog switch and a temperature signal analog switch; the physiological signal zeroing module also includes a switching analog switch, and the switching analog switch is used to switch the pressure signal and the temperature signal to the analog-to-digital conversion module; The operational amplifier module includes a pressure signal amplifier module and a temperature signal amplifier module; The pressure reference input terminal of the pressure signal analog switch is connected to the pressure reference signal generating circuit; the temperature input terminal of the temperature signal analog switch is connected to the temperature reference signal generating circuit; The pressure reference signal generating circuit is used to generate a pressure reference signal; The temperature reference signal generating circuit is used to generate a temperature reference signal; The output end of the pressure signal simulation switch is connected to the input end of the pressure signal amplification module; the output end of the temperature signal simulation switch is connected to the input end of the temperature signal amplification module; The output end of the pressure signal amplifying module is connected to the first group of input ends of the switching analog switch, the output end of the temperature signal amplifying module is connected to the second group of input ends of the switching analog switch, and the output end of the switching analog switch is connected to the analog-to-digital conversion module.

9. The physiological signal zeroing module according to claim 1, characterized in that: The physiological signal zeroing module further includes an electrostatic protection circuit, which is connected to a connection interface between the physiological signal zeroing module and the sensor, and is used for electrostatic protection at the interface.

10. An electronic device, characterized in that: It comprises a display screen and the physiological signal zeroing module according to any one of claims 1 to 9, wherein the control module controls the display screen to display the sensor reading.

Images