CN1778269A - A non-invasive electronic blood pressure detection method and device - Google Patents

Abstract

A non-wound electronic hematomanometer and its hemadynamometry are disclosed. It features that the data is processed by the firmed software determined nonlinearly fit pulse wave envelope algorithm to get actual average blood pressure. A three-way electromagnetic valve is arranged between armband and the first pressure sensor. Its common port, normally opened port and normally closed port are respectively communicated to the first pressure sensor, armband and atmosphere. An additional individual timer is used. When time-out or over-pressure occurs, its aerating pump can be immediately turned off and the pressure in armband is quickly released, so ensuring high safety.

Description

A non-invasive electronic blood pressure detection method and device

Technical Field The present invention relates to a method and device for detecting blood pressure and pulse rate for diagnostic purposes, and in particular to a method for accurately correcting zero-point pressure to detect blood pressure and adopting the algorithm of fitting and recovering the oscillation pulse wave trend envelope to electronic blood pressure detection Method and apparatus for processing data in a process.

Background Art The non-invasive blood pressure detection methods in the prior art all adopt the cuff pulse wave-based oscillation method. The non-invasive detection methods of human blood pressure mainly include the auscultation method using Korotkoff sounds (referred to as the Korotkoff sound method) and the proportional coefficient method using cuff oscillation waves (referred to as the oscillation method).

The Korotkoff sound method is that experienced medical personnel use medical stethoscopes, mercury manometers and cuffs to inflate/deflate the airbag. Inflate the cuff to increase the pressure until the blood flow in the arm is blocked, and then gradually reduce the pressure of the cuff to restore the blood flow in the arm through the inflation/deflation of the air bag. The Korotkoff sound changes from large to small, and the changes of the Korotkoff sound can be heard with the help of a stethoscope and a mercury manometer to determine systolic and diastolic blood pressure. While completing the above-mentioned inflation and deflation control, the software of the system also recognizes the cuff pressure detected on each step in the deflation process and the pulse wave in the cuff and the characteristic wave, and restores the cuff oscillation based on this characteristic pulse wave. Wave trend envelope curve. Different equipment manufacturers adopt different recovery methods. Because the recovery method has a direct impact on the formation of the envelope curve, it will determine the accuracy of human blood pressure detection to a large extent. At present, the main method used is to first use the linear interpolation method to restore the pulse wave amplitude value between the steps, and then use the multi-point moving average method to eliminate abnormal fluctuations, thereby linearly fitting the pulse wave amplitude envelope curve.

At present, the vast majority of electronic blood pressure detection devices use the blood pressure detection method based on the oscillation method. The basic process is very similar to the auscultation method, that is, the cuff is also inflated to increase the pressure to block the blood flow in the arm, and then the cuff is gradually released. In order to restore the blood flow in the arm, the static pressure in the cuff and the pressure pulse wave generated by the pulsation of arterial blood are monitored, but the calculation method is transmitted to the The pressure pulse waves generated in the cuff and the corresponding cuff pressure can detect a set of pressure pulse waves with amplitudes ranging from small to large, and then from large to small, and the corresponding cuff pressure from large to small, and the pressure pulse The cuff pressure corresponding to the maximum value of the wave is the average pressure, and then according to the amplitude proportional coefficient of the pressure pulse wave of the empirical value (the maximum value of the pressure pulse wave is multiplied by two coefficients less than 1 to obtain the cuff corresponding to the two amplitude values The systolic pressure and the diastolic pressure are used to calculate the systolic pressure in the direction of cuff pressure, and the diastolic pressure is calculated in the direction of cuff depression (referred to as the proportional coefficient method based on the cuff oscillation pulse amplitude).

The basic structure of electronic blood pressure detection equipment generally includes (1) pressure sensor and processing circuit for detecting cuff pressure, (2) pressure pulse wave processing circuit based on cuff pressure change, (3) overpressure detection sensor and amplification and protection processing Circuit, (4) cuff, control air release valve, gas path connected with air pump and pressure sensor and charge and deflate control, (5) analog/digital conversion, single-chip microcomputer system, (6) power supply part. The detection of pressure pulse wave and cuff pressure in the detection process can be placed in the deflation stage or inflation stage after inflation, and the deflation form of the deflation stage can be continuous and uniform deflation (that is, the uniform pressure of 3-5mmHg is gradually reduced, and at the same time Detect pressure pulse wave), or step deflation (that is, gradually reduce the cuff pressure in steps of 5-10mmHg, and detect pressure pulse wave on each pressure step), the size of each step pressure reduction will be based on the detected Determine the pulse wave amplitude. Continuous uniform deflation will increase the time of blood pressure detection process, and it is difficult to overcome the influence of arm movement and body position changes. Interference caused by changes, etc., has a good anti-interference ability, so many companies mostly use step deflation in blood pressure testing.

Disadvantages of existing technology:

The oscillation method of non-invasive blood pressure detection should rely on the integration of hardware and software to complete blood pressure detection. The hardware part mainly considers the amplification of cuff pressure and pressure pulse wave signal, and the other independent overvoltage protection of cuff pressure. The circuit, the third is the digital circuit part. The main defects of the hardware part we know so far are:

A. The detection with pressure requires regular zero calibration operation. At present, most of them are automatically zeroed directly when the cuff is not inflated. However, it is difficult to ensure the static pressure inside the cuff due to circuit drift and multiple blood pressure detection processes. It can be reduced to a pressure value close to "zero", which will lead to a possible zero calibration failure; second, a successful zero calibration may still produce a pressure value deviation caused by a zero point offset. In short, it will affect the cuff pressure detection. accuracy.

B. According to safety requirements, two independent timing systems are required in the blood pressure detection process to ensure the detection time limit. At present, the blood pressure detection module usually has a timing system of its own, and provides an interface with an external timing system. The trigger port is connected, and another set of independent timing system is realized through the timing function of the host computer, which can also meet the safety requirements of independent timing, but this blood pressure module does not realize a complete and safe independent timing system, which requires the cooperation of the host computer, which will give The safe application of the blood pressure module brings hidden dangers.

C. Since the amplitude change trend of the cuff pulse wave generated during the actual deflation process is from small to large, and then from large to small after reaching the extreme value of the amplitude, forming an asymmetric and nonlinear curve envelope trend, so the linear There are certain defects in trend fitting, which cannot accurately restore the envelope curve of pulse wave amplitude change, which is not conducive to accurate calculation of subsequent mean blood pressure, systolic blood pressure and diastolic blood pressure.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to propose a new non-invasive electronic blood pressure detection method and device in order to avoid the shortcomings of the prior art. In the method and device, a three-way solenoid valve is added between the cuff and the first pressure sensor. A normally vented port of the valve is connected to the cuff through an extended trachea, and its normally closed port communicates with the air. During the detection, the first pressure sensor communicates with the entire gas circuit to sense the pressure in the gas circuit in real time, which also makes it possible to periodically switch the three-way valve during each blood pressure detection process and between blood pressure detections. , so that the above-mentioned first pressure sensor can be directly communicated with the outside atmosphere, and the "zero pressure" calibration value can be accurately obtained, and the regular automatic calibration of the "zero pressure" without the participation of the internal air circuit in the cuff pressure detection can be realized, and the cuff can be completed Accurate detection of pressure.

At the same time, an independent timing circuit is added, which is composed of a microprocessor or two fixed 180 seconds ± 5 seconds time-limit timer circuits connected in series. The input terminal of this trigger is connected to the main microprocessor (MCU) of the blood pressure module. An I/O port connection of the main MCU, in which the time-limit timer is started when a start pulse from the main MCU is received, and the above-mentioned time-limit timer will be terminated when a stop pulse is received again, and there is a delay gate circuit at its input , to prevent the timing operation from being abnormally started when the trigger pulse is generated when the power is turned on.

Since the data of each sampling point includes the pressure pulse wave amplitude and its corresponding cuff pressure value, for the commonly used step deflation form, the system software controls the reduction value of each step pressure according to the detected pulse wave amplitude, which will make The cuff pressure difference of each adjacent sampling point is not equal. Therefore, in order to accurately restore the envelope and facilitate calculation, the present invention selects an appropriate step difference, and at each sampling point, uses the method of point-by-point movement, segmented multiple curve fitting and nonlinear interpolation to generate a series of adjacent equal pressures The pulse wave amplitude corresponding to the cuff pressure of the difference is stored, and then the curve is smoothed point by point to generate the recovered pulse wave oscillation envelope trend; find the maximum point of the trend curve, which is the average pressure location point.

The present invention solves described technical problem and realizes by adopting following technical scheme:

Implement a non-invasive electronic blood pressure detection method, based on a system consisting of a cuff, an air pump, a first pressure sensor, a second pressure sensor, a quick deflation solenoid valve, a main microprocessor, a display screen, a communication interface and a host computer, It is characterized in that the method comprises the steps of:

a. First, add a three-way solenoid valve between the cuff and the first pressure sensor;

b. Afterwards, when the system is energized and starts to work, first make the solenoid valve work in the state where the first pressure sensor is connected to the atmosphere, and the first pressure sensor performs zero point calibration detection;

c. After the zero point calibration is completed, make the solenoid valve work in the state where the first pressure sensor is connected to the cuff. When performing blood pressure detection, start the air pump to pressurize the cuff, and the host computer receives data through the communication interface and displays the cuff. The internal pressure or the internal pressure of the cuff is displayed on the display screen. When the internal pressure of the cuff reaches the set value, the inflation process stops;

d. The system opens/closes the deflation solenoid valve, deflates according to the set rate, and detects whether there is a pulse signal;

e. A pulse signal is detected; the main microprocessor performs data processing according to the nonlinear fitting algorithm determined by the firmware to restore the trend envelope of the oscillating pulse wave, and displays the measured blood pressure value on the display screen or on the host computer;

f. During the detection process, if overtime or overpressure occurs, the system immediately opens the deflation solenoid valve, closes the air pump, releases the cuff pressure, ensures safe use, and resets the main microprocessor;

g. After a test is completed normally, open the deflation solenoid valve, release the cuff pressure, and close the deflation solenoid valve;

h. When performing blood pressure detection again, start the cycle from step c, and periodically start the cycle from step b.

Step a of the above method, adding a three-way solenoid valve between the cuff and the first pressure sensor includes steps:

a. Connect the public air port of the three-way solenoid valve to the first pressure sensor, the normal air port to the cuff, and the normally closed air port to communicate with the atmosphere;

b. Set the three-way valve drive circuit, which is controlled by the main microprocessor;

c. The pins controlled by the main microprocessor to the three-way valve drive circuit output high level and low level, so that the solenoid valve works in the state of the public vent and the normal vent passage, the state of blocking the normally closed port and the public vent The state of the passage between the normally closed air port and the normally closed air port.

In the detection process described in step f of the non-invasive method, if an overtime or overpressure phenomenon is encountered, the system immediately closes the air pump and opens the quick deflation solenoid valve. An independent timing circuit is set in the system, and the independent timing circuit is controlled by the main microprocessor. When the timer is up, a control signal is output to the overvoltage overtime control circuit, which immediately opens the quick deflation solenoid valve, closes the air pump, and releases the pressure of the cuff.

The main microprocessor 100 in step e of the non-invasive method performs data processing according to the algorithm determined by the firmware to restore the trend envelope of the oscillatory pulse wave by nonlinear fitting. The software controls the pressure pulse wave amplitude Y and the cuff pressure value X at each point while controlling its deflation; the subsequent steps include:

a. Take the first sampling point X0, Y0 of the sampling as the initial value, select a pressure step Δ, which is convenient for subsequent trend item fitting with all sampling points Xn, Yn as the processing intermediate value, and generate Xm, Ym interpolation Point data, where n and m are natural numbers, Xm=X0-mΔ;

b. Based on the sampling points, move and select the data of at least 3 adjacent sampling points one by one, and perform the following processing respectively until the last sampling point is selected for processing:

Construct multiple curves with said at least 3 points and carry out segmental trend item fitting, between two adjacent sampling points of selected sequence positions (first and second, or second and third, or others), generate Trend interpolation points Xm and Ym are stored in sequence, wherein Xm is between the cuff pressure value interval of the two sampling points, and n and m are incremented one by one during this process;

c. Perform smoothing with the stored pulse wave amplitudes of each point as the intermediate value: move the amplitudes of each point one by one to make it weighted and average with the amplitudes of at least 2 adjacent points to obtain smoothing of this point After the amplitude, and store it.

d. Query the maximum pulse wave amplitude value in the stored smoothed curve data, select the data of 1 point or more on the left and right sides of the position based on this position, and construct multiple curves together with it, and calculate the maximum of the multiple curves Value, as the extreme value of the trend envelope curve of the oscillating pulse wave, the corresponding cuff pressure is the mean pressure.

In the step b of the algorithm for recovering the trend envelope of the oscillatory pulse wave by nonlinear fitting, the data of three adjacent sampling points is used to construct a quadratic fitting curve point by point, and the cuff pressure at each point From the value up to the cuff pressure value at the second point, the interpolation of the pressure pulse wave amplitude at the predetermined cuff pressure value X0-mΔ within the range is generated.

In the step c of the algorithm of the nonlinear fitting restoration of the oscillation pulse wave trend envelope, for the pulse wave amplitude of each storage point, the pulse wave amplitude data of 2 points on the left and right are taken, and the arithmetic mean is calculated together with it. smooth.

In the step d of the algorithm for restoring the trend envelope of the oscillatory pulse wave by nonlinear fitting, the position of the maximum pulse wave amplitude is used as the reference, and the data of one point adjacent to the pressure increasing direction is selected, and two points adjacent to the pressure decreasing direction are selected. Point data, together with the least squares method to construct a quadratic curve, and find its extremum.

In the step d of the algorithm for restoring the trend envelope of the oscillatory pulse wave by nonlinear fitting, the position of the maximum pulse wave amplitude is used as a benchmark, and the data of one adjacent point on the left and right are selected, and a quadratic curve is constructed jointly with it, and find its extreme value.

The present invention can also be further implemented through the following technical solutions:

Design and manufacture a non-invasive electronic blood pressure detection device according to the above method, including a cuff, an air pump, a first pressure sensor, a second pressure sensor, a quick deflation solenoid valve, a slow deflation solenoid valve, a main microprocessor, a display screen and The communication interface especially also includes a three-way solenoid valve connected between the cuff and the first pressure sensor.

The fast deflation solenoid valve is connected to a fast valve drive circuit, the input terminal of the fast valve drive circuit is connected to the main microprocessor and the overvoltage timeout control circuit, and the other input terminal of the overvoltage timeout control circuit is connected to an independent timing circuit Output.

The independent timing circuit includes a second microprocessor, and two I/O pins of the second microprocessor are connected with two I/O pins of the main microprocessor, and realize timing and triggering by software function, accepting delay start, delay termination commands and adult/neonatal setting commands from the main microprocessor, and the second microprocessor also has a pin to output a timeout signal to the overvoltage timeout control circuit.

The communication interface is an RS232 interface, and may also be a USB interface.

The output of the first pressure sensor is connected to the instrumentation amplifier circuit, and one output of the instrumentation amplifier circuit is input to the A/D conversion circuit as a pressure signal, and the other is amplified by the pre-amplifier and the post-amplifier and is also input to the A/D conversion circuit as a pulse signal circuit.

The gain control and reference voltage circuit can be mainly composed of a three-to-one bidirectional analog switch digital circuit 4053 .

The pre-amplifier has an input resistor, and another resistor is connected in parallel or not associated with the input resistor through the gain control and reference voltage circuit to adjust the magnification. The parallel connection or not associated is controlled by the SETP and AN_MODE signals output by the main microprocessor. And the A, B, C pins of the reference voltage circuit are determined.

Described rear amplifier also has an input resistance, also another resistance is connected in parallel with this input resistance through gain control and reference voltage circuit or not associated, the amplification factor of the adjusted rear amplifier, parallel connection or not associated is also SETP, The AN_MODE signal controls the gain control and is determined by the A, B, and C pins of the reference voltage circuit.

The control pins A, B, and C of the digital circuit 4053 are connected to the main microprocessor, and an output pin X of the digital circuit 4053 is connected to the reverse input terminal of the output amplifier through a resistor, and its corresponding input pin X1 is connected to the reference voltage V1. 25. Pin X0 is connected to the reference voltage V2.0. Different reference voltages make the thresholds of the output amplifiers different.

The output of the second pressure sensor is connected to a combined instrument amplifying circuit composed of an upper amplifier, a lower amplifier, and an output amplifier. The output of the circuit is driven by a field effect transistor to output an overvoltage signal OP, and the overvoltage signal OP is connected to an overvoltage timeout control circuit. .

The overvoltage timeout control circuit includes two inverters and two NOR gate digital circuits, the overvoltage signal OT output by the independent timing circuit and the overvoltage signal OP output by the output amplifier are connected to the overvoltage timeout control circuit At the input end, the output of the circuit is connected to the fast valve drive circuit and the slow valve drive circuit. Once the cuff pressure exceeds the limit, the valve is immediately opened to release the pressure to ensure safety.

Compared with the circuit design of the prior art, the present invention has the first advantage: it optimizes the connection structure of the gas circuit, realizes the automatic and accurate automatic calibration of the "zero pressure point" of the cuff pressure without the influence of the residual pressure of the gas circuit, and increases Accuracy of cuff pressure detection.

The second advantage is: a set of timing circuit is used to realize the independent time-limited time function in the process of blood pressure detection, truly realize the independent timing of the module level, and enhance the safety guarantee in the process of blood pressure detection.

The third advantage: by using the method of the present invention, the pulse wave amplitude variation trend envelope can be accurately recovered, so that the obtained average pressure can be more in line with the actual clinical situation.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of the composition principle of the method and device of the present invention;

Fig. 2, Fig. 3, Fig. 4 are the flow charts of method of the present invention;

Fig. 5 is the electric schematic diagram of independent timing circuit in the device of the present invention;

Fig. 6 is the electric schematic diagram of sensor and amplifier circuit thereof in the device of the present invention;

Fig. 7 is a schematic diagram of the pulse wave amplitude variation trend envelope of the present invention;

Fig. 8 is a flow chart of the algorithm data processing of the non-linear fitting recovery oscillation pulse wave trend envelope of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described in detail in conjunction with the accompanying drawings and preferred embodiments.

As shown in Figures 1 to 4: implement a non-invasive electronic blood pressure detection method, based on the cuff 10, the air pump 50, the first pressure sensor 30, the second pressure sensor 40, the quick deflation solenoid valve 60, the slow deflation A system composed of solenoid valve 70, main microprocessor 100, display screen 110, communication interface 120 and host computer 200, the method includes steps:

a. First, add a three-way solenoid valve 20 between the cuff 10 and the first pressure sensor 30;

b. Afterwards, when the system is energized and starts to work, the electromagnetic valve 20 is first operated in the state where the first pressure sensor 30 is connected to the atmosphere, and the first pressure sensor 30 performs zero calibration detection;

c. After the zero point calibration is completed, make the electromagnetic valve 20 work in the state where the first pressure sensor 30 is connected to the cuff 10. When performing blood pressure detection, start the air pump 50 and start to pressurize the cuff 10. The host computer 200 communicates through the communication interface 120 Receive data and display the pressure inside the cuff 10, or display the pressure inside the cuff by the display screen 110, when the pressure inside the cuff 10 reaches the set value, the inflation process stops;

d. The system opens/closes the fast deflation solenoid valve 60 and the slow deflation solenoid valve 70, deflates according to the set rate, and detects whether there is a pulse signal;

e. Detect that a pulse signal occurs; the main microprocessor 100 performs data processing according to the non-linear fitting algorithm determined by the firmware to restore the oscillation pulse wave trend envelope, and displays the measured signal on the display screen 110 or the upper computer 200 blood pressure value;

f. During the detection process, if overtime or overpressure occurs, the system immediately closes the air pump 50, opens the quick deflation solenoid valve 60, and releases the pressure in the cuff 10 to ensure safe use; and makes the main microprocessor 100 Reset again;

g. Once the detection is over, open the quick deflation solenoid valve 60, release the pressure of the cuff 10, and close the quick deflation solenoid valve 60;

h. When performing blood pressure testing again, start the cycle from step c, and periodically start the cycle from b. Adding a three-way solenoid valve 20 between the cuff 10 and the first pressure sensor 30 in step a includes steps:

a. Connect the common air port of the three-way solenoid valve 20 to the first pressure sensor 30, the normal air port to the cuff 10, and the normally closed air port to communicate with the atmosphere;

b. a three-way valve driving circuit 21 is set, and the circuit 21 is controlled by the main microprocessor 100;

c. The pins controlled by the main microprocessor 100 to the three-way valve drive circuit 21 output high level and low level, so that the solenoid valve 20 works in the state of the public air port and the normal air port passage, and the normally closed air port blockage and The common vent and the normally closed vent are blocked, and the normal vent is blocked.

Referring to Fig. 1 and Fig. 5, in the detection process described in step f of the non-invasive method, if overtime or overpressure occurs, the system immediately closes the air pump 50 and opens the quick deflation solenoid valve 60, which is to set an independent timing circuit 45 in the system , the independent timing circuit 45 is started under the control of the main microprocessor 100, and when the timing time arrives, an overtime signal OT is output to the overvoltage overtime control circuit 46, and the circuit 46 immediately opens the quick deflation solenoid valve 60 and closes the air pump 50 , to relieve the cuff pressure.

Referring to Fig. 7 and Fig. 8, the main microprocessor 100 described in step e of the non-invasive method performs data processing according to the algorithm of non-linear fitting and restoration of the trend envelope of the oscillation pulse wave determined by the firmware, and first pressurizes the cuff to make the cuff The pressure reaches a predetermined value; then the pressure pulse wave amplitude Y and the cuff pressure value X of each point are sampled while controlling its deflation by software; the subsequent steps include:

a . With the first sampling point X0, Y0 of the sampling as the initial value, select a pressure step Δ, which is convenient for subsequent trend item fitting with all sampling points Xn, Yn as the intermediate value of processing, and generate Xm, Ym interpolation Point data, where n and m are natural numbers, Xm=X-mΔ;

b. Based on the sampling points, move and select the data of at least 3 adjacent sampling points one by one, and perform the following processing respectively until the last sampling point is selected for processing:

Construct multiple curves with said at least 3 points and carry out segmental trend item fitting, between two adjacent sampling points of selected sequence positions (first and second, or second and third, or others), generate Trend interpolation points Xm and Ym are stored in sequence, wherein Xm is between the cuff pressure value interval of the two sampling points, and n and m are incremented one by one during this process;

c. Perform smoothing with the stored pulse wave amplitudes of each point as the intermediate value: move the amplitudes of each point one by one to make it weighted and average with the amplitudes of at least 2 adjacent points to obtain smoothing of this point After the amplitude, and store it.

d. Query the maximum pulse wave amplitude value in the stored smoothed curve data, select the data of 1 point or more on the left and right sides of the position based on this position, and construct multiple curves together with it, and calculate the maximum of the multiple curves Value, as the extreme value of the trend envelope curve of the oscillating pulse wave, the corresponding cuff pressure is the mean pressure.

In the step b of the algorithm for recovering the trend envelope of the oscillatory pulse wave by nonlinear fitting, the data of three adjacent sampling points is used to construct a quadratic fitting curve point by point, and the cuff pressure at each point From the value up to the cuff pressure value at the second point, the interpolation of the pressure pulse wave amplitude at the predetermined cuff pressure value X0-mΔ within the range is generated.

In the step c of the algorithm of the nonlinear fitting restoration of the oscillation pulse wave trend envelope, for the pulse wave amplitude of each storage point, the pulse wave amplitude data of 2 points on the left and right are taken, and the arithmetic mean is calculated together with it. smooth.

In the step d of the algorithm for restoring the trend envelope of the oscillatory pulse wave by nonlinear fitting, the position of the maximum pulse wave amplitude is used as the reference, and the data of one point adjacent to the pressure increasing direction is selected, and two points adjacent to the pressure decreasing direction are selected. Point data, together with the least squares method to construct a quadratic curve, and find its extremum.

In the step d of the algorithm for restoring the trend envelope of the oscillatory pulse wave by nonlinear fitting, the position of the maximum pulse wave amplitude is used as a benchmark, and the data of one adjacent point on the left and right are selected, and a quadratic curve is constructed jointly with it, and find its extreme value.

As shown in Figure 1, the best embodiment of a non-invasive electronic blood pressure detection device is designed and manufactured according to the above method, including a cuff 10, an air pump 50, a first pressure sensor 30, a second pressure sensor 40, and a quick deflation solenoid valve 60. Slow deflation electromagnetic valve 70, main microprocessor 100, display screen 110 and communication interface 120, especially: also include three-way electromagnetic valve 20, described three-way electromagnetic valve 20 is connected to cuff 10 and first pressure Between the sensors 30.

The common air port of the three-way solenoid valve 20 is connected to the first pressure sensor 30 , the normally air port is connected to the cuff 10 , and the normally closed air port is connected to the atmosphere.

Also as shown in Figure 1, in the preferred embodiment, the fast deflation solenoid valve 60 is connected to the fast valve drive circuit 61, and the input terminal of the fast valve drive circuit 61 is connected to the main microprocessor 100 and the overvoltage overtime control The output terminal of the circuit 46 , an input terminal of the overvoltage timeout control circuit 46 is connected to the output of the independent timing circuit 45 .

As shown in Figure 5, in the preferred embodiment, described independent timing circuit 45 comprises the second microprocessor U2, and U2 selects MSP430 microprocessor for use, and U2 realizes timing, triggering function by software mode, and described second microprocessor The two I/O pins of the device U2 are connected with the two I/O pins of the main microprocessor 100, and accept the delay start, delay termination instructions and adult/neonatal setting instructions of the main microprocessor 100. The second microprocessor U2 also has a pin that outputs the timeout signal OT to the overvoltage timeout control circuit 46 .

The communication interface 120 is an RS232 interface in a preferred embodiment, and of course a USB interface can also be selected.

As shown in Figure 6 and Figure 1, the output of the first pressure sensor 30 is connected to the instrumentation amplifier circuit 31, the output of the instrumentation amplifier circuit 31 is input to the A/D conversion circuit 35 as a pressure signal (CUFFPRESS) one way, and the other way is passed through The pulse signal (PULSEWAVE) amplified by the pre-amplifier 32 and the post-amplifier 33 is also input to the A/D conversion circuit 35 .

The output of the first pressure sensor 30 is connected to port 2 and port 3 of the instrument amplifier 31, the input lead 4 of the first pressure sensor 30 is connected to the port 7 of the operational amplifier U3A, and the lead 2 and lead 5 of the first pressure sensor 30 are connected in parallel Input the port 3 of the operational amplifier U3A, the pin 2 of the operational amplifier U3A is grounded, the pin 6 is connected to the power supply Vcc and grounded to AGND through the capacitor C1, the pin 6 of the first pressure sensor 30 is grounded, and the pin 1 of the instrumentation amplifier 31 is connected to the resistor R1 Then connect the pin 8 of the instrumentation amplifier 31, the pin 7 of the instrumentation amplifier 31 is connected to the power supply Vcc, and ground through the capacitor C2, the pin 4 of the instrumentation amplifier 31 is grounded, and the pin 5 of the instrumentation amplifier 31 is connected to the resistors R2 and R3 Among them, the other end of R2 is connected to Vcc, and the other end of R3 is grounded. The output pin 6 of the instrumentation amplifier 31 is divided into two circuits. ground, and output the pressure signal CuffPress at the same time, the other is connected to the resistor R5 through the DC blocking capacitor E1, and input to the pre-amplifier 32 through R5. At the same time, a programmable gain selection is also implemented on the preamplifier 32 to ensure that different gains are set in different application modes (adult/neonatal). In a preferred embodiment this is done:

The pre-amplifier 32 has an input resistor R5, and another resistor R6 is connected in parallel with the resistor R5 through the gain control and reference voltage circuit 44 or not, and the parallel connection or not is controlled by the SETP and AN_MODE signals of the main microprocessor 100. Gain control and reference voltage determined by the A, B, and C pins of the circuit 44.

The rear amplifier 33 also has an input resistor R8, and another resistor R9 is connected in parallel with the resistor R8 through the gain control and reference voltage circuit 44 or not, and the parallel connection or not is also controlled by the SETP and AN_MODE signals of the main microprocessor 100. Gain control and reference voltage determined by the A, B, and C pins of the circuit 44. The resistance value of the input resistor determines the development multiple of the amplifier, and the main microprocessor 100 controls whether the resistors R6 and R9 are connected in parallel to the input resistor as required during operation.

The gain control and reference voltage circuit 44 is mainly composed of three 2-to-1 bidirectional analog switch digital circuits 4053, its control pins A, B, C are connected to the main microprocessor 100, and its output pin X is connected through a resistor R28 The inverting input terminal of the output amplifier 43 has its input pin X1 connected to the reference voltage V1.25, and its pin X0 connected to the reference voltage V2.0. Different input voltages lead to different thresholds of the output amplifier 43 . The pins 7, 8 and 6 of the analog switch digital circuit 4053 are grounded to AGND, and the pin 9 is connected to STEP, which is a port from the CPU to complete the connection and disconnection of pin 4 and pin 3 or 5, and pin 10 and 11 connected in parallel to AN_MODE is a port from the CPU to complete the synchronous switching of pin 15 connected to pin 1 or 2, and pin 14 connected to pin 13 or 12.

As shown in Fig. 1, Fig. 6 and Fig. 5, the output of the second pressure sensor 40 is connected to a voltage follower made up of an upper amplifier 41 and a preamplifier made up of a lower amplifier 42, the output of the lower amplifier 42 and the gain control and an output "X" of the reference voltage circuit 44 are respectively connected to the two input ends of the output amplifier 43, the output of the output amplifier 43 is driven by the field effect transistor Q7 to output the overvoltage signal OP, and the overvoltage signal OP is connected to the overvoltage timeout control circuit 46 . To achieve the purpose of detecting whether the cuff pressure exceeds the predetermined protection pressure point and ensuring the safety of the subject.

The process of overvoltage protection is that the pin 1 of the second pressure sensor 40 is connected to the power input VI through R18, the regulator tube D1 and the capacitor C5 are connected in parallel to the ground AGND, and the pin 3 of the second pressure sensor 40 is also connected to the ground AGND, the pin 4 of the second pressure sensor 40 is connected to the pin 3 of the upper amplifier 41, and the pin 4 is connected to the pin 5 through the resistor R26, and this pin 4 is also connected in series with the potentiometer TR2 through the resistor R24 To the pin 8 of the lower amplifier 42, the pin 2 of the second pressure sensor 40 is connected to the pin 1 of the lower amplifier 42, and its pin 8 is connected to the pin 7 through the resistor R25, and the pin 7 is connected through the resistor R27 To the pin 4 of the output amplifier 43, the pin 4 is connected to the pin 14 of the three 2 selection 1 bidirectional analog switch digital circuit 4053 through the resistor R28, and further passes through the pin 4053 of the three 2 selection 1 bidirectional analog switch digital circuit 4053 13 or 12 are respectively connected to the reference voltage V1.25 and V2.5, the pin 5 of the lower amplifier 42 is connected with the pin 3 of the output amplifier 43 through R29, and the pin 3 of the output amplifier 43 is passed through the resistor R30 and the resistor R31 Connect to ground GND and pin 5 respectively, connect between pins 3 and 4 of the output amplifier 43 through capacitor C49, pin 5 of the output amplifier 43 is connected to pin 1 of the field effect transistor Q7, and the pin 1 of the field effect transistor Q7 Pin 1 is connected to pin 2 through resistor R35 and connected to ground AGND. Pin 3 of field effect transistor Q7 is connected to power supply Vcc through resistor R54. This pin 3 is also the output of overvoltage signal OP.

The output of the second pressure sensor 40 is connected to the voltage follower formed by the upper amplifier 41, the output of the voltage follower is connected to the inverting input of the lower amplifier 42, and the non-inverting input of the lower amplifier 42 is connected to the other of the second pressure sensor 40. One output is used to complete the preamplification of the static cuff pressure. The output end of this amplifying circuit is connected to the non-inverting input end of the output amplifier 43, and an adjustable reference voltage is connected to the inverting input end of the output amplifier 43 at the same time, so that Accurate state reversal of overvoltage point protection can be realized to meet the needs of setting different overvoltage protection points in different application modes.

As shown in Fig. 5 and Fig. 1, described overvoltage overtime control circuit 46 comprises inverter U4-1, U4-2 and NOR gate digital circuit U3-1, U3-2, the overtime output by independent timing circuit 45 The signal OT and the overvoltage signal OP output by the output amplifier 43 are connected to the input terminal of the overvoltage timeout control circuit 46 , and the output of the circuit 46 is connected to the fast valve driving circuit 61 and the slow valve driving circuit 71 .

The communication interface 120 adopts RS232 interface in the best embodiment, and can also choose USB interface in other embodiments.

The preferred embodiment shown in FIG. 5 : the starting timing input terminal of the independent timing circuit 45 is connected to the P02 interface of the main microprocessor 100 . The second microprocessor U2 in the figure is composed of MSP430 MCU of TI, and the system software of MSP430 completes the timing. When U2 detects the start timer signal, it starts the software timer; when U2 detects the end timer signal , that is to terminate the software timer; the limit of this software timer will depend on the application mode setting: that is, the adult/neonatal mode setting, the adult mode is 180±1 seconds, and the neonatal mode is 90±1 seconds.

Of course, the above-mentioned timer can also use an analog device or a digital circuit to realize the same function.

In the preferred embodiment of the present invention, an I/O port P1.0 of the microprocessor U2 is connected to the input end of the overtime control circuit 46, and when the system is in other standby states except the detection state, this port remains low level, and when the system is in the normal detection working state, this port will output a high level and keep it until the end of this detection process, and this port will return to the low level again to continue to maintain the standby state. When an input terminal of the overtime control circuit 46 was at a low level, the timer was in the stop counting state, only when the timing of the timer exceeded the limit (as 180 ± 1 second (adult) or 90 ± 1 second (newborn baby)) At this time, this port just has output, starts deflation solenoid valve 70, terminates air pump 50, and notifies main microprocessor 100.

The system software solidified in the main microprocessor 100 is responsible for monitoring during the detection process, data processing, result calculation, and communication with the upper control system. During detection, the system pressurizes the air circuit to make the cuff pressure reach a predetermined value, and then controls its deflation through software, and samples the pressure pulse wave amplitude and corresponding cuff pressure value at each point at the same time. The deflation form is step discharge. Inflation or continuous deflation, as shown in Figure 7, the sampled data takes the cuff pressure as the horizontal axis, and the oscillation pulse wave amplitude as the vertical axis, so that there are discrete point data A(X, Y), B(X, Y) , C(X, Y)..., X _A , X _B , X _C ... shown in the figure are non-equal differential cuff pressure sampling values. When fitting the recovery curve envelope, in order to facilitate calculation and fine fitting, this method uses nonlinear interpolation to obtain a series of data points (X0, Y0), (X1, Y1) representing the curve envelope at equal pressure intervals , (X2, Y2), (X3, Y3)... where X1-X0=X2-X1=X3-X2=...=Δ, and then carry out the calculation process.

As shown in Figure 8, the specific processing flow includes the following steps

a. With the cuff pressure X0, Y0 of the first sampling point as the initial value, select a pressure step Δ, which is convenient for subsequent trend fitting with all sampling points Xn, Yn as the intermediate value of processing, and generate Xm, Ym interpolation Point data, where n and m are natural numbers, Xm=X0-mΔ;

b. Based on the sampling points, move one by one to select the data of 3 adjacent sampling points one by one, and use them to construct a quadratic curve for segmental trend fitting. With the pressure value, the pressure pulse wave amplitude interpolation value Ym at each predetermined cuff pressure interpolation value X0-mΔ within the range is generated, and stored in sequence; m is incremented one by one during this process;

c. Perform smoothing with the stored pulse wave amplitude at each point as the intermediate value: move the amplitude Y _n of each point one by one to make it smooth with the weighted average of the amplitudes of the two adjacent left and right points , get the smoothed amplitude of the point, and store it;

d. Query the maximum pulse wave amplitude in the stored smoothed data, select the data of more than 1 point respectively on the left and right with this position as the benchmark, construct a multiple curve together with it, and calculate the maximum value of the multiple curve, As the extremum of the trend envelope curve of the oscillating pulse wave, the corresponding cuff pressure is the mean pressure.

Wherein, the step difference Δ in step a can be selected in the range of 3-5 mmHg pressure difference according to the difference of the test human body.

The quadratic curve in step b is fitted with 3 points, which can be expressed as Y=a _n X ² +b _n X+c _n and satisfies

Y _n ＝Y(X _n ), Y _n+1 ＝Y(X _n+1 ), Y _n-1 ＝Y(X _n-1 )

From this, a _n , _bn , c _n are determined, and the Y _m data at the pressure of X0-mΔ≤X _n is further calculated. If the system has sufficient resources and computing speed, more than 3 points of data can be used to construct multiple fitting curves for nonlinear interpolation.

In addition to the interpolation between the first two sampling points of each segment used in the example, interpolation between the last two sampling points can also be used; when all sampling points Xn, Yn are used as the intermediate values of the processing, the segmentation trend item is simulated Generally, because there are enough sampling points, it is allowed to give up interpolation between the last two sampling points or between the first two sampling points.

In the smoothing and filtering process in step c, the rolling weighted average method of adjacent points is adopted. Taking 5 points as an example, the weighted average of 3 points or 4 points is not ruled out in practice. The weighted average can also be simplified as an arithmetic average.

In order to make the data more accurate, the above step d can be further processed, as shown in Figure 7: according to the position of the maximum value found in the query, select one adjacent data point in the direction of increasing pressure, and select two adjacent data points in the direction of decreasing pressure , so that there are more data points at the steeper end of the trend, so as to ensure the trend weight of the rising edge; then according to the above four data points, use the least square method to construct a quadratic curve, and the apex of the curve is confirmed as the pulse wave amplitude trend envelope The extreme value of the corresponding mean pressure; according to the extreme value of the range, the range corresponding to the systolic blood pressure and the diastolic blood pressure can be further calculated, so that the systolic blood pressure and the diastolic blood pressure can be calculated according to this envelope.

When using the method of the present invention, the data acquisition and preprocessing program modules of the system software are also combined with the recognition of the pulse wave and the calculation and judgment of the amplitude. Only when a normal trend pulse occurs, can the follow-up pulse Fitting and interpolation calculations, and further blood pressure calculations, when failing to find a normal trending pulse, will continue to search for pulse waves or report abnormalities, and generate corresponding error messages. This processing process is not within the purpose of the present invention. Not elaborated.

Practice has proved that the present invention optimizes the gas circuit connection structure, realizes automatic and accurate "zero pressure point" automatic calibration of cuff pressure without residual pressure influence, and increases the accuracy of cuff pressure detection.

At the same time, the present invention adopts a set of timing circuits to realize the independent time-limiting function in the blood pressure detection process, truly realizes the independent timing of the module level, and enhances the safety guarantee in the blood pressure detection process.

In the present invention, non-linear fitting is used to restore the trend envelope of the oscillatory wave, which can accurately realize the acquisition of extreme pulse waves and the positioning of the average pressure; clinical verification, the obtained average pressure is more in line with the actual situation of the test, especially It can effectively process the data obtained by step deflation, thereby shortening the test process and being beneficial to safety.

Claims (20)

1. A non-invasive electronic blood pressure detection method, based on comprising a cuff (10), an air pump (50), a first pressure sensor (30), a second pressure sensor (40), a fast deflation solenoid valve (60), a slow The system composed of deflation solenoid valve (70) main microprocessor (100), display screen (110), communication interface (120) and host computer (200), is characterized in that, described method comprises steps: a. First, add a three-way solenoid valve (20) between the cuff (10) and the first pressure sensor (30); b. Afterwards, when the system is energized and starts to work, the electromagnetic valve (20) is first operated in the state where the first pressure sensor (30) is connected to the atmosphere, and the first pressure sensor (30) carries out zero calibration detection; c. After the zero-point calibration is finished, make the electromagnetic valve (20) work in the state where the first pressure sensor (30) is connected to the cuff (10), and when performing blood pressure detection, start the air pump (50) to start charging the cuff (10) Pressurization, the upper computer (200) receives data through the communication interface (120) and displays the pressure in the cuff (10), or displays the pressure in the cuff (110) on the display screen (110), when the pressure in the cuff (10) reaches the set After the value, the inflation process stops; d. The system opens/closes the fast deflation solenoid valve (60) and the slow deflation solenoid valve (70), deflates according to the set rate, and detects whether there is a pulse signal; E. detect that there is a pulse signal to occur; the main microprocessor (100) performs data processing according to the non-linear fitting determined by the firmware to restore the oscillation pulse wave trend envelope, and displays it on the display screen (110) or the upper computer ( 200) to display the measured blood pressure value; f. During the detection process, if overtime or overpressure occurs, the system immediately shuts down the air pump (50), opens the quick deflation solenoid valve (60), and releases the pressure in the cuff (10) to ensure safe use; and Make the main microprocessor (100) reset again; g. Once the detection is over, open the quick deflation solenoid valve (60), release the pressure of the cuff (10), and close the quick deflation solenoid valve (60); h. When performing blood pressure testing again, start the cycle from step c, and periodically start the cycle from b. 2. The non-invasive electronic blood pressure detection method according to claim 1, characterized in that: adding a three-way solenoid valve (20) between the cuff (10) and the first pressure sensor (30) in step a includes the step : a. Connect the public air port of the three-way solenoid valve (20) to the first pressure sensor (30), the normal air port to the cuff (10), and the normally closed air port to communicate with the atmosphere; b. a three-way valve drive circuit (21) is set, and the circuit (21) is controlled by the main microprocessor (100); c. The pins controlled by the main microprocessor (100) to the three-way valve drive circuit (21) output high level and low level, so that the solenoid valve (20) works in the common ventilation port and the normal ventilation port passage, and the normal ventilation port. The blocked state of the closed air port and the blocked state of the passage between the common vent and the normally closed air port, and the blocked state of the normal vent. 3. The non-invasive electronic blood pressure detection method according to claim 1, characterized in that: in the detection process described in step f, when encountering overtime or overpressure, the system immediately closes the air pump (50) and opens the quick deflation solenoid valve (60), is to arrange an independent timing circuit (45) in the system, described independent timing circuit (45) is controlled and started by the main microprocessor (100), when timing time arrives, just output a control signal to overvoltage overtime control Circuit (46), this circuit (46) opens quick deflation solenoid valve (60), closes air pump (50) immediately, cuff pressure is discharged. 4. The non-invasive electronic blood pressure detection method according to claim 1, characterized in that: the main microprocessor (100) in step e performs the algorithm according to the non-linear fitting determined by the firmware to restore the oscillation pulse wave trend envelope For data processing, the pressure of the cuff reaches a predetermined value by pressurizing the air circuit; then the pressure pulse wave amplitude Y and the cuff pressure value X of each point are sampled while deflated by the software; the subsequent steps include: a. Take the first sampling point X0, Y0 of the sampling as the initial value, select a pressure step Δ, which is convenient for subsequent trend item fitting with all sampling points Xn, Yn as the processing intermediate value, and generate Xm, Ym interpolation Point data, where n and m are natural numbers, Xm=X0-mΔ; b. Based on the sampling points, move and select the data of at least 3 adjacent sampling points one by one, and perform the following processing respectively until the last sampling point is selected for processing: Construct multiple curves with said at least 3 points and carry out segmental trend item fitting, between two adjacent sampling points of selected sequence positions (first and second, or second and third, or others), generate Trend interpolation points Xm and Ym are stored in sequence, wherein Xm is between the cuff pressure value interval of the two sampling points, and n and m are incremented one by one during this process; c. Perform smoothing with the stored pulse wave amplitudes of each point as the intermediate value: move the amplitudes of each point one by one to make it weighted and average with the amplitudes of at least 2 adjacent points to obtain smoothing of this point After the amplitude, and store it. d. Query the maximum pulse wave amplitude value in the stored smoothed curve data, select the data of 1 point or more on the left and right sides of the position based on this position, and construct multiple curves together with it, and calculate the maximum of the multiple curves Value, as the extreme value of the trend envelope curve of the oscillating pulse wave, the corresponding cuff pressure is the mean pressure. 5. according to the non-invasive electronic blood pressure detection method in the described non-invasive electronic blood pressure detection method of claim 4, the algorithm that the non-linear fitting restores the oscillation pulse wave trend envelope is characterized in that: In the step b, the data of 3 adjacent sampling points is used to construct a quadratic fitting curve point by point, and the cuff pressure value at the first point to the cuff pressure value at the second point is used to generate the Interpolation of the pressure pulse wave amplitude at a predetermined cuff pressure value X0-mΔ within the above range. 6. according to the non-invasive electronic blood pressure detection method in the described non-invasive electronic blood pressure detection method of claim 4, the algorithm that the non-linear fitting restores the oscillation pulse wave trend envelope is characterized in that: In the step c, for the pulse wave amplitude of each storage point, the pulse wave amplitude data of two points on the left and right are taken, and the arithmetic mean is used together for smoothing. 7. according to the non-invasive electronic blood pressure detection method described in claim 4, the non-linear fitting restores the algorithm of oscillation pulse wave trend envelope, it is characterized in that: In the step d, based on the position of the maximum pulse wave amplitude, select data of one point adjacent to the direction of increasing pressure, and data of two points adjacent to the direction of pressure decreasing, and jointly construct a quadratic curve with the least square method , and find its extreme value. 8. According to claim 4, the non-invasive electronic blood pressure detection method in the non-linear fitting restores the algorithm of oscillation pulse wave trend envelope, characterized in that: in the step d, the position of the maximum pulse wave amplitude is used as a reference , select one point data adjacent to the left and right, construct a quadratic curve together with it, and find its extremum. 9. A non-invasive electronic blood pressure detection device, comprising a cuff (10), an air pump (50), a first pressure sensor (30), a second pressure sensor (40), a quick deflation solenoid valve (60), a slow release Air electromagnetic valve (70), main microprocessor (100), display screen (110) and communication interface (120), it is characterized in that: also comprise three-way electromagnetic valve (20), described three-way electromagnetic valve (20) Connected between the cuff (10) and the first pressure sensor (30). 10. The non-invasive electronic blood pressure detection device according to claim 9, characterized in that: the fast deflation solenoid valve (60) is connected to the fast valve drive circuit (61), and the input terminal of the fast valve drive circuit (61) is connected to A main microprocessor (100) and an overvoltage timeout control circuit (46), an input terminal of the overvoltage timeout control circuit (46) is connected to an output of an independent timing circuit (45). 11. The non-invasive electronic blood pressure detection device according to claim 10, characterized in that: the independent timing circuit (45) includes a second microprocessor U2, U2 implements timing and triggering functions through software, and the second microprocessor Two I/O pins of the device U2 are connected with two I/O pins of the main microprocessor (100), and accept the delay start of the main microprocessor (100), the delay termination instruction and the adult/neonatal In order to set the instruction, the second microprocessor U2 also has a pin to output the overtime signal OT to the overvoltage overtime control circuit (46). 12. The non-invasive electronic blood pressure detection device according to claim 9, characterized in that: the common vent of the three-way solenoid valve (20) is connected to the first pressure sensor (30), the normal vent is connected to the cuff (10), The normally closed air port communicates with the atmosphere. 13. The noninvasive electronic blood pressure detection device according to claim 9, characterized in that: the communication interface (120) is an RS232 interface. 14. The noninvasive electronic blood pressure detection device according to claim 9, characterized in that: the communication interface (120) is a USB interface. 15. The non-invasive electronic blood pressure detection device according to claim 9, characterized in that: the output of the first pressure sensor (30) is connected to the instrument amplifier circuit (31), and one output of the instrument amplifier circuit (31) is used as a pressure signal It is input to the A/D conversion circuit (35), and the other path is amplified by the pre-amplifier (32) and the rear amplifier (33) as a pulse signal and also input to the A/D conversion circuit (35). 16. The non-invasive electronic blood pressure detection device according to claim 15, characterized in that: the preamplifier (32) has an input resistor R5, and another resistor R6 is connected in parallel with the resistor R5 through the gain control and reference voltage circuit (44) or not Correlation, parallel connection or non-correlation is determined by SETP, AN_MODE signal control gain control of main microprocessor (100) and A, B, C pins of reference voltage circuit (44). 17. The non-invasive electronic blood pressure detection device according to claim 15, characterized in that: the post-amplifier (33) has an input resistor R8, and another resistor R9 is connected in parallel with the resistor R8 through the gain control and reference voltage circuit (44) or not Parallel connection, parallel connection or non-parallel connection is determined by the SETP and AN_MODE signal control gain control of the main microprocessor (100) and the A, B, C pins of the reference voltage circuit (44). 18. The non-invasive electronic blood pressure detection device according to claims 16 and 17, characterized in that: the gain control and reference voltage circuit (44) is mainly composed of a three-to-one bidirectional analog switch digital circuit 4053, and its control pin A, B, and C are connected to the main microprocessor (100), and its output pin X is connected to the reverse input terminal of the output amplifier (43) through a resistor R28, and its input access pin X1 is connected to the reference voltage V1.25, leading to Pin X0 is connected to reference voltage V2.0. 19. The non-invasive electronic blood pressure detection device according to claim 9, characterized in that: the output connection of the second pressure sensor (40) is composed of an upper amplifier (41), a lower amplifier (42), and an output amplifier (43). Combination instrument amplifying circuit, the output of the circuit is driven by the field effect transistor Q7 to output the overvoltage signal OP, and the overvoltage signal OP is connected to the overvoltage timeout control circuit (46). 20. The non-invasive electronic blood pressure detection device according to claim 9, characterized in that: the overvoltage timeout control circuit (46) includes inverters U4-1, U4-2 and NOR gate digital circuits U3-1, U3 -2, the overvoltage signal OT output by the independent timing circuit (45) and the overvoltage signal OP output by the output amplifier (43) are connected to the input end of the overvoltage overtime control circuit (46), and the output of the circuit (46) Connect the fast valve drive circuit (61) and the slow valve drive circuit (71).

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