Physiological index simulator

Abstract

The utility model relates to the technical field of medical equipment, and discloses a physiological index simulator which comprises a signal generation module, a proportion attenuation circuit, a bias superposition circuit and a baseline generation circuit. The signal generation module is used for generating normalized signals of the physiological indexes; the proportional attenuation circuit is connected with the signal generation module and is used for carrying out proportional attenuation operation on the normalized signal to generate an attenuation signal; the baseline generation circuit is used for generating a baseline signal and outputting the baseline signal to the outside; the bias superposition circuit is connected with the proportion attenuation circuit and the baseline generation circuit and is used for superposing the attenuation signal and the baseline signal to generate a superposition signal and outputting the superposition signal to the outside; wherein the superposed signal and the baseline signal are a pair of differential signals of the physiological index. According to the utility model, high-precision simulation waveforms can be provided for measuring equipment.

Description

Technical Field

[0001] This utility model relates to the field of medical equipment technology, specifically to a physiological indicator simulator. Background Technology

[0002] To facilitate the analysis or testing of measurement data from physiological index measuring devices, corresponding analog signals can be generated based on physiological index simulators and connected to the measuring devices. Taking invasive blood pressure (IBP) as an example, current invasive blood pressure simulators typically output electrical signals through a DAC (Digital-to-Analog Converter) and connect to the measuring device. The accuracy of such physiological index simulators depends on the performance of the DAC chip, which can easily lead to poor accuracy of the generated signals. Utility Model Content

[0003] In view of this, the present invention provides a physiological indicator simulator to improve the simulation accuracy of physiological indicator signals.

[0004] In the first aspect, this utility model provides a physiological indicator simulator, including: a signal generation module, a proportional attenuation circuit, a bias superposition circuit, and a baseline generation circuit;

[0005] The signal generation module is used to generate normalized signals of physiological indicators;

[0006] The proportional attenuation circuit is connected to the signal generation module and is used to perform proportional attenuation calculation on the normalized signal to generate an attenuated signal.

[0007] The baseline generation circuit is used to generate a baseline signal and output the baseline signal to the outside.

[0008] The bias superposition circuit is connected to the proportional attenuation circuit and the baseline generation circuit, and is used to superimpose the attenuation signal and the baseline signal to generate a superimposed signal, and output the superimposed signal to the outside; wherein, the superimposed signal and the baseline signal are a pair of differential signals of the physiological index.

[0009] In some optional implementations, the proportional attenuation circuit is used to: perform a proportional attenuation operation on the difference between the normalized signal and a preset reference voltage to generate an attenuated signal;

[0010] The amplitude of the attenuated signal is one or more orders of magnitude smaller than the amplitude of the baseline signal.

[0011] In some alternative implementations, the proportional attenuation circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a first operational amplifier;

[0012] One end of the first resistor is used to connect to the reference voltage, and the other end is connected to the inverting input terminal of the first operational amplifier;

[0013] One end of the second resistor is connected to the signal generation module to obtain the normalized signal; the other end of the second resistor is connected to the non-inverting input of the first operational amplifier.

[0014] One end of the third resistor is connected to the inverting input terminal of the first operational amplifier, and the other end is connected to the output terminal of the first operational amplifier; the output terminal of the first operational amplifier is used to output the attenuation signal.

[0015] One end of the fourth resistor is connected to the non-inverting input of the first operational amplifier, and the other end is grounded.

[0016] Wherein, the first resistor and the second resistor have the same resistance value, the third resistor and the fourth resistor have the same resistance value, and the resistance value of the first resistor is greater than the resistance value of the third resistor.

[0017] In some alternative implementations, the bias superposition circuit includes: a fifth resistor, a sixth resistor, a seventh resistor, and a second operational amplifier;

[0018] One end of the fifth resistor is connected to the output of the proportional attenuation circuit to obtain the attenuation signal; the other end of the fifth resistor is connected to the inverting input of the second operational amplifier.

[0019] One end of the sixth resistor is connected to the output of the baseline generation circuit to obtain the baseline signal; the other end of the sixth resistor is connected to the inverting input of the second operational amplifier.

[0020] One end of the seventh resistor is connected to the inverting input of the second operational amplifier, and the other end is connected to the output of the second operational amplifier; the non-inverting input of the second operational amplifier is grounded, and the output of the second operational amplifier is used to output the superimposed signal.

[0021] In some alternative implementations, the physiological indicator simulator also includes: a zero-calibration circuit;

[0022] The zero-calibration circuit is connected to the bias superposition circuit. The zero-calibration circuit is used to: generate a calibration signal for compensating the superposition signal according to a preset zero-calibration voltage; and superimpose the calibration signal and the superposition signal to generate an adjusted superposition signal.

[0023] In some optional implementations, the zero-calibration circuit includes: an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a third operational amplifier, and a fourth operational amplifier;

[0024] One end of the eighth resistor is used to connect to the reference voltage, and the other end is connected to the inverting input terminal of the third operational amplifier;

[0025] One end of the ninth resistor is used to connect to the zero-calibration voltage, and the other end is connected to the non-inverting input terminal of the third operational amplifier;

[0026] One end of the tenth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end is connected to the output terminal of the third operational amplifier; the output terminal of the third operational amplifier is used to output the calibration signal.

[0027] One end of the eleventh resistor is connected to the non-inverting input of the third operational amplifier, and the other end is grounded;

[0028] One end of the twelfth resistor is connected to the output of the bias superposition circuit to obtain the superposition signal; the other end of the twelfth resistor is connected to the inverting input of the fourth operational amplifier.

[0029] One end of the thirteenth resistor is connected to the output terminal of the third operational amplifier, and the other end is connected to the inverting input terminal of the fourth operational amplifier;

[0030] One end of the fourteenth resistor is connected to the inverting input terminal of the fourth operational amplifier, and the other end is connected to the output terminal of the fourth operational amplifier.

[0031] The non-inverting input terminal of the fourth operational amplifier (U4) is grounded, and the output terminal of the fourth operational amplifier outputs the adjusted superimposed signal through the fifteenth resistor;

[0032] The eighth resistor has the same resistance value as the ninth resistor, the tenth resistor has the same resistance value as the eleventh resistor, and the resistance value of the eighth resistor is greater than that of the tenth resistor.

[0033] In some alternative implementations, the input of the baseline generation circuit is used to connect to an external measuring device to receive the power supply voltage from the measuring device to the physiological index sensor.

[0034] The baseline generation circuit is used to: divide the supply voltage and generate a baseline signal based on the divided supply voltage.

[0035] In some alternative implementations, the baseline generation circuit includes: a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, and a fifth operational amplifier;

[0036] One end of the sixteenth resistor is used to receive the power supply voltage from the measuring device to the physiological index sensor, and the other end is grounded through the seventeenth resistor;

[0037] The connection node between the sixteenth resistor and the seventeenth resistor is connected to the non-inverting input terminal of the fifth operational amplifier; the inverting input terminal of the fifth operational amplifier is connected to the output terminal of the fifth operational amplifier.

[0038] One end of the eighteenth resistor is connected to the output of the fifth operational amplifier, and the other end is used to output the baseline signal.

[0039] In some optional implementations, the signal generation module includes an input module, an output module, a controller, and a digital-to-analog converter;

[0040] The input module is connected to the controller and is used to transmit the waveform parameters of the input physiological indicators to the controller.

[0041] The controller is used to generate a normalized signal in the form of an analog signal based on the waveform parameters of the physiological indicators;

[0042] The digital-to-analog converter is connected to the controller and is used to convert the normalized signal in digital form into an analog signal and transmit it to the proportional attenuation circuit.

[0043] The output module is connected to the controller and is used to output the waveform parameters of the physiological indicators and / or the simulation results of the physiological indicator simulator.

[0044] In some alternative implementations, the physiological parameter simulator is an invasive blood pressure simulator.

[0045] The physiological indicator simulator provided by this utility model generates an invariant baseline signal based on a baseline generation circuit for differential signal physiological indicator signals, and attenuates the changing part of the signal based on a proportional attenuation circuit to obtain a higher precision attenuated signal. The baseline signal and the attenuated signal are then superimposed by a bias superposition circuit. The resulting superimposed signal and the baseline signal are output as a pair of differential signals of physiological indicators to the measuring device, enabling the measuring device to determine the corresponding physiological indicator waveform based on the attenuated normalized signal, thereby providing the measuring device with a high precision simulated waveform. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this utility model, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of a physiological indicator simulator according to an embodiment of the present invention;

[0048] Figure 2 This is another structural schematic diagram of the physiological indicator simulator according to an embodiment of the present utility model;

[0049] Figure 3 This is a schematic diagram of the proportional attenuation circuit according to an embodiment of the present utility model;

[0050] Figure 4 This is a schematic diagram of the bias superposition circuit according to an embodiment of the present utility model;

[0051] Figure 5 This is a schematic diagram of a zero-calibration circuit according to an embodiment of the present utility model;

[0052] Figure 6 This is a schematic diagram of a baseline generation circuit according to an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of a process for simulating IBP signals based on a physiological index simulator according to an embodiment of the present invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] 10. Signal generation module; 20. Proportional attenuation circuit; 30. Bias superposition circuit; 40. Baseline generation circuit; 50. Zeroing circuit; 101. Input module; 102. Output module; 103. Controller; 104. Digital-to-analog converter;

[0056] R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; R12, twelfth resistor; R13, thirteenth resistor; R14, fourteenth resistor; R15, fifteenth resistor; R16, sixteenth resistor; R17, seventeenth resistor; R18, eighteenth resistor; U1, first operational amplifier; U2, second operational amplifier; U3, third operational amplifier; U4, fourth operational amplifier; U5, fifth operational amplifier. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0058] In the description of this utility model, it should be understood that the terms indicating orientation or positional relationship, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0060] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 according to the specific circumstances.

[0061] Furthermore, to better illustrate this utility model, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this utility model can be implemented even without certain specific details. In some instances, methods, means, and elements well-known to those skilled in the art have not been described in detail, in order to highlight the main points of this utility model.

[0062] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0063] This utility model embodiment provides a physiological indicator simulator, see [link / reference]. Figure 1 As shown, the physiological index simulator includes: a signal generation module 10, a proportional attenuation circuit 20, a bias superposition circuit 30, and a baseline generation circuit 40.

[0064] The signal generation module 10 is used to generate normalized signals of physiological indicators.

[0065] The proportional attenuation circuit 20 is connected to the signal generation module 10 and is used to perform proportional attenuation calculation on the normalized signal to generate an attenuated signal.

[0066] The baseline generation circuit 40 is used to generate a baseline signal and output the baseline signal to the outside.

[0067] The bias superposition circuit 30 is connected to the proportional attenuation circuit 20 and the baseline generation circuit 40. It is used to superimpose the attenuation signal and the baseline signal to generate a superimposed signal and output the superimposed signal to the outside. The superimposed signal and the baseline signal are a pair of differential signals of physiological indicators.

[0068] In this embodiment, the waveform of the physiological indicator is divided into two parts: a constant baseline and a varying waveform. The characteristics of the physiological indicator are mainly reflected in the varying waveform. Since invasive blood pressure and other physiological indicators are represented in the form of differential signals, this embodiment generates two signals in the differential signal form of the physiological indicator to simulate the waveform of the physiological indicator and improve the simulation accuracy.

[0069] Specifically, the baseline generation circuit 40 generates an invariant baseline portion, i.e., a baseline signal, and outputs this baseline signal. This physiological indicator simulator is typically connected to a corresponding physiological indicator measurement device; for example, when simulating the generation of invasive blood pressure and pulse signals, a corresponding invasive blood pressure measurement device can be connected. The baseline generation circuit 40 can be connected to the measurement device to output the baseline signal to it; wherein the baseline signal is one signal in a pair of differential signals.

[0070] Furthermore, the signal generation module 10 normalizes the waveforms of the physiological indicators to obtain a signal representing the changing portion of the waveform, i.e., a normalized signal. For example, the signal generation module 10 can pre-record multiple normalized waveforms of the physiological indicators, and select one to use as needed when simulation is required; alternatively, it can adaptively generate suitable normalized waveforms based on relevant parameters input by the user. Generating normalized waveforms is a mature technology, and this embodiment will not elaborate on it.

[0071] The proportional attenuation circuit 20 is connected to the signal generation module 10. It can acquire the normalized signal generated by the signal generation module 10, and then perform proportional attenuation calculations on it to obtain the attenuated normalized signal, i.e., the attenuated signal. As the name suggests, proportional attenuation is to attenuate (reduce) the signal amplitude by a certain proportion, thereby representing the normalized signal with a smaller amplitude and improving the accuracy of the normalized signal. For example, the proportional attenuation circuit 20 can attenuate the normalized signal to 1 / 10, 1 / 100, etc., depending on the actual situation.

[0072] Compared to related technologies that generate electrical signals via a DAC, in order to ensure signal accuracy, such as using a DAC to generate a signal at the millivolt level, the DAC needs to have extremely high resolution. However, in this embodiment, a baseline signal with a larger amplitude (e.g., at the volt level) can be generated based on the baseline generation circuit 40, and then the baseline signal can be reduced to a smaller level (e.g., at the millivolt level) using the proportional attenuation circuit 20. This reduces the resolution requirement of the DAC, which is equivalent to improving the accuracy of the millivolt signal.

[0073] In addition, such as Figure 1 As shown, the bias superposition circuit 30 is connected to the proportional attenuation circuit 20 to obtain the attenuation signal; and the bias superposition circuit 30 is also connected to the baseline generation circuit 40 to obtain the baseline signal.

[0074] The bias superposition circuit 30 superimposes the attenuation signal and the baseline signal to generate a superimposed signal, which is the sum of the attenuation signal and the baseline signal. Similar to the baseline generation circuit 40, the bias superposition circuit 30 can also output the superimposed signal, for example, to an external measuring device. The output superimposed signal is the other signal in a pair of differential signals.

[0075] For the measuring device connected to the physiological index simulator, it can acquire a pair of differential signals that represent the waveform of the physiological index. Taking invasive blood pressure as an example, the measuring device can acquire the differential signals of invasive blood pressure generated by the physiological index simulator, namely IBP+ and IBP-, where IBP- is the baseline signal and IBP+ is the superimposed signal. The measuring device determines the measured physiological index based on the difference between IBP+ and IBP-, that is, it performs the measurement based on the attenuated normalized signal (attenuated signal), which has higher accuracy.

[0076] The physiological indicator simulator provided in this embodiment generates an invariant baseline signal based on the baseline generation circuit 40 for physiological indicator signals in differential signal form, and attenuates the changing part of the signal based on the proportional attenuation circuit 20 to obtain a higher precision attenuated signal. The baseline signal and the attenuated signal are then superimposed by the bias superposition circuit. The generated superimposed signal and the baseline signal are output as a pair of differential signals of physiological indicators to the measuring device, so that the measuring device can determine the corresponding physiological indicator waveform based on the attenuated normalized signal, thereby providing the measuring device with a high precision simulated waveform.

[0077] In some alternative implementations, such as Figure 2 As shown, the signal generation module 10 specifically includes an input module 101, an output module 102, a controller 103, and a digital-to-analog converter 104.

[0078] The input module 101 is connected to the controller 103 and is used to transmit the waveform parameters of the input physiological indicators to the controller 103. The user can input waveform parameters of physiological indicators through the input module 101; for example, these waveform parameters may include the pulse rate, amplitude, and artery / vein selection of invasive blood pressure and pulse. The input module 101 may include physical buttons.

[0079] The controller 103 is used to generate a normalized signal in analog signal form based on the waveform parameters of physiological indicators. The generation of the corresponding normalized waveform based on the waveform parameters by the controller 103 is a mature technology, and will not be described in detail in this embodiment. Adaptively generating the corresponding normalized signal based on the waveform parameters input by the user can meet various user needs and is applicable to various scenarios.

[0080] The digital-to-analog converter 104 is connected to the controller 103 and is used to convert a normalized signal in digital form into an analog signal and transmit it to the proportional attenuation circuit 20. The digital-to-analog converter 104 can provide a normalized signal in analog form to the proportional attenuation circuit 20 for processing by subsequent circuits. The amplitude of the normalized signal output by the digital-to-analog converter 104 is generally in the volt range; for example, the amplitude of the normalized signal is 1V to 10V.

[0081] Output module 102 is connected to controller 103 and is used to output waveform parameters of physiological indicators and / or simulation results from the physiological indicator simulator. Specifically, when the user inputs corresponding waveform parameters based on input module 101, output module 102 can output those waveform parameters so that the user can verify the correctness of the input parameters. Furthermore, output module 102 can also display the simulation results from the physiological indicator simulator. For example, the simulation results can be a normalized signal, or they can include the final generated superimposed signal and baseline signal, depending on actual needs.

[0082] For example, the output module 102 can be a display screen to show relevant information to the user. It is understood that the input module 101 and the output module 102 can also be integrated into devices with input and output functions such as touch screens, and this embodiment does not limit this.

[0083] Optionally, such as Figure 2 As shown, the physiological index simulator also includes a zero-calibration circuit 50; the zero-calibration circuit 50 is connected to the bias superposition circuit 30 and is used to adjust the zero point of the superposition signal and output the adjusted superposition signal to the outside.

[0084] In this embodiment, the superimposed signal generated by the bias superimposed circuit 30 is zero-point calibrated by the back-end zero-calibration circuit 50 to achieve zero-point adjustment. The final output superimposed signal is the adjusted superimposed signal, which can provide a zero-point calibration signal to external measuring equipment, thereby ensuring the accuracy of the differential signal when it is 0.

[0085] In some alternative implementations, since invasive blood pressure signals are differential signals based on baseline voltages, they can be positive or negative; while the signal generation module 10 may only generate positive signals. For example, the signal output by the digital-to-analog converter 104 is generally positive. In order to more accurately simulate differential signals, the proportional attenuation circuit 20 is used to perform proportional attenuation calculation on the difference between the normalized signal and the preset reference voltage to generate an attenuated signal.

[0086] The amplitude of the attenuation signal can be one or more orders of magnitude smaller than the amplitude of the baseline signal.

[0087] In this embodiment, a reference voltage is preset, the proportional attenuation circuit 20 determines the difference between the normalized signal and the preset reference voltage, and performs proportional attenuation operation on the difference, thereby generating an attenuation signal that can be positive or negative, so that the attenuation signal can accurately represent the differential signal of physiological indicators.

[0088] Typically, the input signal needs to be biased by 1 / 2, so the reference voltage can be half of the normalized signal's maximum value. For example, if the maximum input signal value is 5V, then the reference voltage is 2.5V.

[0089] Furthermore, the amplitude of the attenuated signal is smaller than the amplitude of the baseline signal, and the difference between the two amplitudes is at least one order of magnitude; for example, the amplitude of the attenuated signal is at least 1 / 10 of the amplitude of the baseline signal. For example, the amplitude of the baseline signal is 1V to 10V, while the amplitude of the attenuated signal can be less than or equal to 100mV. This proportional attenuation circuit 20 can output a millivolt-level attenuated signal, improving signal accuracy without requiring a high-resolution DAC.

[0090] Optionally, Figure 3 A schematic diagram of a proportional attenuation circuit 20 is shown, such as... Figure 3 As shown, the proportional attenuation circuit 20 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a first operational amplifier U1. For example... Figure 3 As shown, the second resistor R2 and the fourth resistor R4 can be connected in parallel with a filter capacitor to ensure the stability of the output signal.

[0091] One end of the first resistor R1 is used to connect to the reference voltage REF_signal, and the other end is connected to the inverting input of the first operational amplifier U1.

[0092] One end of the second resistor R2 is connected to the signal generation module 10 to obtain the normalized signal IBP_signal; the other end of the second resistor R2 is connected to the non-inverting input of the first operational amplifier U1.

[0093] One end of the third resistor R3 is connected to the inverting input of the first operational amplifier U1, and the other end is connected to the output of the first operational amplifier U1; the output of the first operational amplifier U1 is used to output the attenuation signal IBP_signal_weak.

[0094] One end of the fourth resistor R4 is connected to the non-inverting input of the first operational amplifier U1, and the other end is grounded. The first resistor R1 has the same resistance as the second resistor R2, and the third resistor R3 has the same resistance as the fourth resistor R4. The resistance of the first resistor R1 is greater than the resistance of the third resistor R3.

[0095] In this embodiment, the proportional attenuation circuit 20 is a subtractor built based on the first operational amplifier U1, which can bias the normalized signal IBP_signal based on the reference voltage REF_signal; and the resistance value of the first resistor R1 is greater than the resistance value of the third resistor R3, thereby achieving signal attenuation. Specifically, the amplitude of the generated attenuated signal IBP_signal_weak can be attenuated to the original R3 / R1.

[0096] For example, if the resistance of the first resistor R1 is one hundred times the resistance of the third resistor R3, then the amplitude of the attenuated signal IBP_signal_weak is 1 / 100 of the previous normalized signal IBP_signal. If the range of the normalized signal IBP_signal is 0 to 5V, then the range of the attenuated signal IBP_signal_weak is ±25mV.

[0097] Optionally, Figure 4 A schematic diagram of the bias superposition circuit 30 is shown, such as... Figure 4 As shown, the bias superposition circuit 30 includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a second operational amplifier U2. The seventh resistor R7 can also be connected in parallel with a filter capacitor.

[0098] One end of the fifth resistor R5 is connected to the output of the proportional attenuation circuit 20 to obtain the attenuation signal IBP_signal_weak; the other end of the fifth resistor R5 is connected to the inverting input of the second operational amplifier U2.

[0099] One end of the sixth resistor R6 is connected to the output of the baseline generation circuit 40 to obtain the baseline signal IBP-; the other end of the sixth resistor R6 is connected to the inverting input of the second operational amplifier U2.

[0100] One end of the seventh resistor R7 is connected to the inverting input of the second operational amplifier U2, and the other end is connected to the output of the second operational amplifier U2; the non-inverting input of the second operational amplifier U2 is grounded, and the output of the second operational amplifier U2 is used to output the superimposed signal IBP_su.

[0101] In this embodiment, the bias superposition circuit 30 is an inverting adder implemented based on the second operational amplifier U2, which superimposes the attenuated signal IBP_signal_weak onto the baseline signal IBP- to generate the corresponding superimposed signal IBP_su. The fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 have the same resistance value to ensure that the generated superimposed signal IBP_su is the sum of the attenuated signal IBP_signal_weak and the baseline signal IBP-.

[0102] Alternatively, such as Figure 4 As shown, one end of the sixth resistor R6 used to acquire the baseline signal IBP- can also be connected to the first adjustment resistor Ra, and the other end of the first adjustment resistor Ra is grounded.

[0103] In this embodiment, if the superimposed signal IBP_su from the bias superposition circuit 30 is directly output as one of the differential signals, since the superimposed signal is generated based on the second operational amplifier U2, its output impedance is provided by the operational amplifier and can generally reach over 100K ohms. Traditional simulators typically use resistor dividers for output, and the simulator's output impedance depends on the size of the divider resistors. In this embodiment, the impedance is provided by the operational amplifier, which can increase the output impedance and help reduce signal loss.

[0104] In some alternative implementations, the zeroing circuit 50 is used to: generate a calibration signal for compensating the superimposed signal based on a preset zeroing voltage; and superimpose the calibration signal and the superimposed signal to generate an adjusted superimposed signal.

[0105] In this embodiment, a zero-calibration voltage is preset. This zero-calibration voltage is used to normalize the voltage value in the superimposed signal when the superimposed signal should be 0. Specifically, a corresponding calibration signal is generated based on this zero-calibration voltage, and the calibration signal is further superimposed on the superimposed signal generated by the bias superimposition circuit 30, thereby realizing the zero-calibration of the superimposed signal. This allows for fine adjustment of the signal zero point. Using the calibrated superimposed signal (i.e., the adjusted superimposed signal) as one of the output differential signals ensures the accuracy of the differential signal when it is 0.

[0106] Optionally, Figure 5 A schematic diagram of a zero-calibration circuit 50 is shown, such as... Figure 5 As shown, the zero-calibration circuit 50 includes: an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a third operational amplifier U3, and a fourth operational amplifier U4. Among these, the tenth resistor R10, the eleventh resistor R11, and the fourteenth resistor R14 can also be connected in parallel with filter capacitors.

[0107] One end of the eighth resistor R8 is connected to the reference voltage REF_signal, and the other end is connected to the inverting input of the third operational amplifier U3; one end of the ninth resistor R9 is connected to the zero-calibration voltage True_Up_IBP, and the other end is connected to the non-inverting input of the third operational amplifier U3; one end of the tenth resistor R10 is connected to the inverting input of the third operational amplifier U3, and the other end is connected to the output of the third operational amplifier U3; the output of the third operational amplifier U3 is used to output the calibration signal; one end of the eleventh resistor R11 is connected to the non-inverting input of the third operational amplifier U3, and the other end is grounded.

[0108] Among them, the eighth resistor R8 and the ninth resistor R9 have the same resistance value, the tenth resistor R10 and the eleventh resistor R11 have the same resistance value, and the resistance value of the eighth resistor R8 is greater than the resistance value of the tenth resistor R10.

[0109] One end of the twelfth resistor R12 is connected to the output of the bias superposition circuit 30 to obtain the superposition signal IBP_su; the other end of the twelfth resistor R12 is connected to the inverting input of the fourth operational amplifier U4; one end of the thirteenth resistor R13 is connected to the output of the third operational amplifier U3, and the other end is connected to the inverting input of the fourth operational amplifier U4; one end of the fourteenth resistor R14 is connected to the inverting input of the fourth operational amplifier U4, and the other end is connected to the output of the fourth operational amplifier U4; the non-inverting input of the fourth operational amplifier U4 is grounded, and the output of the fourth operational amplifier U4 outputs the adjusted superposition signal IBP+ through the fifteenth resistor R15.

[0110] Among them, the twelfth resistor R12, the thirteenth resistor R13, and the fourteenth resistor R14 have the same resistance value.

[0111] In this embodiment, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, and the third operational amplifier U3 of the zero-calibration circuit 50 serve as calibration signal generators, and their working principle is the same as described above. Figure 3 The proportional attenuation circuit 20 shown operates on the same principle. The reference voltage REF_signal input to the eighth resistor R8 is the same as the reference voltage REF_signal input to the proportional attenuation circuit 20.

[0112] Furthermore, the twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, and the fourth operational amplifier U4 form an inverting adder, which, together with... Figure 4 The bias superposition circuit 30 shown operates on the same principle, also superimposing two signals, that is, superimposing the calibration signal onto the original superposition signal IBP_su to complete the signal zero-point calibration. In addition, the end of the thirteenth resistor R13 used to obtain the calibration signal (that is, the output terminal of the third operational amplifier U3) can also be connected to the second adjustment resistor Rb.

[0113] In this embodiment, at the zero point of the normalized signal IBP_signal, which is the position where the voltage value is the reference voltage REF_signal, after processing by the proportional attenuation circuit 20, due to resistance errors and other reasons, the voltage value of the final attenuated signal at the zero point will not be zero, thus causing a zero-point error in the superimposed signal IBP_su. This embodiment pre-sets a zero-calibration voltage True_Up_IBP, and generates a suitable calibration signal based on this voltage to perform zero-calibration on the superimposed signal IBP_su, ensuring the accuracy of the voltage value at the zero point.

[0114] In some alternative implementations, such as Figure 2 As shown, the input terminal of the baseline generation circuit 40 is used to connect to an external measuring device to receive the power supply voltage from the measuring device to the physiological index sensor. The baseline generation circuit 40 is used to: divide the power supply voltage and generate a baseline signal based on the divided power supply voltage.

[0115] When simulating the waveforms of physiological indicators, the power supply voltage for the corresponding sensors is typically provided by the measuring equipment. However, traditional simulators generally use the reference voltage of a DAC chip as the signal center voltage. Since DAC chips typically have low voltage ratings, this limits their compatibility range. Consequently, traditional simulators are generally only compatible with one type of power input, resulting in poor compatibility with measuring equipment.

[0116] In this embodiment, the baseline generation circuit 40 takes the power supply voltage of the measuring device to the physiological index sensor (e.g., IBP sensor) as input and generates a corresponding baseline signal based on the power supply voltage. Since the subsequent baseline signal is a type of differential signal, regardless of the magnitude of the power supply voltage, the measuring device can accurately determine the waveform of the corresponding physiological index based on the differential signal, thereby simulating the physiological index. It can be applied to a variety of measuring devices and has strong compatibility.

[0117] Among them, such as Figure 2 As shown, in order to ensure the consistency of the baseline signal IBP-, the baseline generation circuit 40 needs to share a common ground with the external measurement equipment.

[0118] Optionally, Figure 6 A schematic diagram of the baseline generation circuit 40 is shown, such as... Figure 6 As shown, the baseline generation circuit 40 includes: a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, and a fifth operational amplifier U5.

[0119] One end of the sixteenth resistor R16 is used to receive the power supply voltage IBP_SENSOR from the physiological index sensor of the measuring device, and the other end is grounded through the seventeenth resistor R17.

[0120] The connection point between the sixteenth resistor R16 and the seventeenth resistor R17 is connected to the non-inverting input of the fifth operational amplifier U5; the inverting input of the fifth operational amplifier U5 is connected to the output of the fifth operational amplifier U5; one end of the eighteenth resistor R18 is connected to the output of the fifth operational amplifier U5, and the other end is used to output the baseline signal IBP-.

[0121] In this embodiment, IBP_SENSOR is the power supply voltage of the physiological index sensor provided by the measuring device. Common voltages include 2V, 5V, 10V, and 16V. This power supply voltage IBP_SENSOR is divided by resistors R16 (sixteenth resistor) and R17 (seventeenth resistor) and then output through operational amplifier U5. It is compatible with the maximum input voltage of operational amplifier U5, which can generally reach around 20V depending on the op-amp selection. This allows the baseline generation circuit 40 to meet the input of various common voltage types of sensors, such as 2V, 5V, 10V, and 16V, providing a wide power supply voltage range and compatibility with various measuring devices.

[0122] Among them, the sixteenth resistor R16 and the seventeenth resistor R17 can have the same resistance value, so that the output baseline signal IBP- is half of the supply voltage IBP_SENSOR.

[0123] Furthermore, in the case of the superimposed signal IBP+ after being adjusted by the zeroing circuit 50, it is specifically output by the fourth operational amplifier U4 and the fifth operational amplifier U5 in the baseline generation circuit 40 as a differential signal. The output impedance of the physiological index simulator is provided by the operational amplifier, which is generally above 100K ohms according to the selection of the operational amplifier, which can ensure that the output impedance meets the requirements.

[0124] Optionally, the physiological indicator to be simulated can be invasive blood pressure, and correspondingly, the physiological indicator simulator is an invasive blood pressure simulator.

[0125] Taking invasive blood pressure as an example of a physiological indicator, the invasive blood pressure waveform, i.e., the IBP signal, can be simulated based on the simulator of this physiological indicator (i.e., the invasive blood pressure simulator). Figure 7 A schematic diagram of a process for simulating IBP signals based on this physiological index simulator is shown.

[0126] like Figure 7 As shown, the invasive blood pressure waveform simulation parameters that need to be set can be set based on the input module 101, including pulse rate, specific artery and vein selection, etc., and connected to the corresponding measurement device, i.e., invasive blood pressure measurement device.

[0127] After the parameters are set, the controller 103 controls the digital-to-analog converter 104 to output a normalized pulse waveform of the target amplitude. Then, the normalized signal is attenuated to the target amplitude by the proportional attenuation circuit 20, thus generating the pulse signal, which is the attenuated signal. The baseline generation circuit 40 shares a ground with the invasive blood pressure measurement device and receives the IBP sensor power supply voltage from the invasive blood pressure measurement device. The baseline generation circuit 40 divides the sensor power supply voltage (e.g., attenuates it by half) to obtain the reference signal IBP-, which is output back to the invasive blood pressure measurement device. It also outputs the reference signal IBP- to the bias superposition circuit 30. The bias superposition circuit 30 superimposes the signals from the proportional attenuation circuit 20 and the baseline generation circuit 40 and outputs them to the zeroing circuit 50. The zeroing circuit 50 compensates for the signal, generates the signal IBP+, and outputs it to the invasive blood pressure measurement device, thereby completing the simulation of invasive blood pressure.

[0128] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations should all be covered within the protection scope of the present invention.

Claims

1. A physiological indicator simulator, characterized in that, include: The signal generation module (10), the proportional attenuation circuit (20), the bias superposition circuit (30), and the baseline generation circuit (40) are included. The signal generation module (10) is used to generate normalized signals of physiological indicators; The proportional attenuation circuit (20) is connected to the signal generation module (10) and is used to perform proportional attenuation calculation on the normalized signal to generate an attenuated signal; The baseline generation circuit (40) is used to generate a baseline signal and output the baseline signal to the outside. The bias superposition circuit (30) is connected to the proportional attenuation circuit (20) and the baseline generation circuit (40) to superimpose the attenuation signal and the baseline signal to generate a superimposed signal and output the superimposed signal to the outside; wherein the superimposed signal and the baseline signal are a pair of differential signals of the physiological index.

2. The physiological indicator simulator according to claim 1, characterized in that, The proportional attenuation circuit (20) is used for: A proportional attenuation calculation is performed on the difference between the normalized signal and the preset reference voltage to generate an attenuated signal; The amplitude of the attenuated signal is one or more orders of magnitude smaller than the amplitude of the baseline signal.

3. The physiological indicator simulator according to claim 2, characterized in that, The proportional attenuation circuit (20) includes: a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), and a first operational amplifier (U1); One end of the first resistor (R1) is used to connect to the reference voltage, and the other end is connected to the inverting input terminal of the first operational amplifier (U1); One end of the second resistor (R2) is used to connect to the signal generation module (10) to obtain the normalized signal; the other end of the second resistor (R2) is connected to the non-inverting input terminal of the first operational amplifier (U1); One end of the third resistor (R3) is connected to the inverting input terminal of the first operational amplifier (U1), and the other end is connected to the output terminal of the first operational amplifier (U1); the output terminal of the first operational amplifier (U1) is used to output the attenuation signal; One end of the fourth resistor (R4) is connected to the non-inverting input terminal of the first operational amplifier (U1), and the other end is grounded; Wherein, the first resistor (R1) and the second resistor (R2) have the same resistance value, the third resistor (R3) and the fourth resistor (R4) have the same resistance value, and the resistance value of the first resistor (R1) is greater than the resistance value of the third resistor (R3).

4. The physiological indicator simulator according to claim 1, characterized in that, The bias superposition circuit (30) includes: a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7), and a second operational amplifier (U2); One end of the fifth resistor (R5) is connected to the output of the proportional attenuation circuit (20) to obtain the attenuation signal; the other end of the fifth resistor (R5) is connected to the inverting input of the second operational amplifier (U2); One end of the sixth resistor (R6) is connected to the output of the baseline generation circuit (40) to obtain the baseline signal; the other end of the sixth resistor (R6) is connected to the inverting input of the second operational amplifier (U2); One end of the seventh resistor (R7) is connected to the inverting input of the second operational amplifier (U2), and the other end is connected to the output of the second operational amplifier (U2); the non-inverting input of the second operational amplifier (U2) is grounded, and the output of the second operational amplifier (U2) is used to output the superimposed signal.

5. The physiological indicator simulator according to any one of claims 1 to 4, characterized in that, Also includes: Zeroing circuit (50); The zero-calibration circuit (50) is connected to the bias superposition circuit (30). The zero-calibration circuit (50) is used to: generate a calibration signal for compensating the superposition signal according to a preset zero-calibration voltage; and superimpose the calibration signal and the superposition signal to generate an adjusted superposition signal.

6. The physiological indicator simulator according to claim 5, characterized in that, The zero-calibration circuit (50) includes: an eighth resistor (R8), a ninth resistor (R9), a tenth resistor (R10), an eleventh resistor (R11), a twelfth resistor (R12), a thirteenth resistor (R13), a fourteenth resistor (R14), a fifteenth resistor (R15), a third operational amplifier (U3), and a fourth operational amplifier (U4); One end of the eighth resistor (R8) is used to connect to the reference voltage, and the other end is connected to the inverting input terminal of the third operational amplifier (U3); One end of the ninth resistor (R9) is used to connect to the zero-calibration voltage, and the other end is connected to the non-inverting input terminal of the third operational amplifier (U3); One end of the tenth resistor (R10) is connected to the inverting input terminal of the third operational amplifier (U3), and the other end is connected to the output terminal of the third operational amplifier (U3); the output terminal of the third operational amplifier (U3) is used to output the calibration signal; One end of the eleventh resistor (R11) is connected to the non-inverting input terminal of the third operational amplifier (U3), and the other end is grounded; One end of the twelfth resistor (R12) is connected to the output of the bias superposition circuit (30) to obtain the superposition signal; the other end of the twelfth resistor (R12) is connected to the inverting input of the fourth operational amplifier (U4); One end of the thirteenth resistor (R13) is connected to the output terminal of the third operational amplifier (U3), and the other end is connected to the inverting input terminal of the fourth operational amplifier (U4); One end of the fourteenth resistor (R14) is connected to the inverting input terminal of the fourth operational amplifier (U4), and the other end is connected to the output terminal of the fourth operational amplifier (U4). The non-inverting input terminal of the fourth operational amplifier (U4) is grounded, and the output terminal of the fourth operational amplifier (U4) outputs the adjusted superimposed signal through the fifteenth resistor (R15). The eighth resistor (R8) has the same resistance value as the ninth resistor (R9), the tenth resistor (R10) has the same resistance value as the eleventh resistor (R11), and the resistance value of the eighth resistor (R8) is greater than the resistance value of the tenth resistor (R10).

7. The physiological indicator simulator according to claim 1, characterized in that, The input terminal of the baseline generation circuit (40) is used to connect to an external measuring device to receive the power supply voltage from the measuring device to the physiological index sensor; The baseline generation circuit (40) is used to: divide the power supply voltage and generate a baseline signal based on the divided power supply voltage.

8. The physiological indicator simulator according to claim 7, characterized in that, The baseline generation circuit (40) includes: a sixteenth resistor (R16), a seventeenth resistor (R17), an eighteenth resistor (R18), and a fifth operational amplifier (U5); One end of the sixteenth resistor (R16) is used to receive the power supply voltage from the measuring device to the physiological index sensor, and the other end is grounded through the seventeenth resistor (R17); The connection node between the sixteenth resistor (R16) and the seventeenth resistor (R17) is connected to the non-inverting input terminal of the fifth operational amplifier (U5); the inverting input terminal of the fifth operational amplifier (U5) is connected to the output terminal of the fifth operational amplifier (U5). One end of the eighteenth resistor (R18) is connected to the output of the fifth operational amplifier (U5), and the other end is used to output the baseline signal.

9. The physiological indicator simulator according to claim 1, characterized in that, The signal generation module (10) includes an input module (101), an output module (102), a controller (103), and a digital-to-analog converter (104); The input module (101) is connected to the controller (103) and is used to transmit the waveform parameters of the input physiological indicators to the controller (103); The controller (103) is used to generate a normalized signal in the form of an analog signal based on the waveform parameters of the physiological indicators; The digital-to-analog converter (104) is connected to the controller (103) and is used to convert the normalized signal in digital signal form into analog signal form and transmit it to the proportional attenuation circuit (20). The output module (102) is connected to the controller (103) and is used to output the waveform parameters of the physiological indicators and / or the simulation results of the physiological indicator simulator.

10. The physiological indicator simulator according to claim 1, characterized in that, The physiological indicator simulator is an invasive blood pressure simulator.

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