An ultrasonic compound electronic sphygmomanometer and blood pressure detection method thereof

Abstract

The present invention belongs to the field of medical detection technology, and specifically relates to an ultrasonic compound electronic sphygmomanometer and a blood pressure detection method thereof. The ultrasonic compound electronic sphygmomanometer is characterized in that a pickup is provided on the coating, and the pickup is connected to the CPU signal through an audio conditioning circuit. The audio conditioning circuit includes a pickup plug, a transient suppression diode, a high-frequency filter resistor, a high-frequency filter capacitor and an operational amplifier. The high-frequency filter resistor, the transient suppression diode and the high-frequency filter capacitor are connected in series and the high-frequency filter resistor is connected in parallel between the pickup plug and the operational amplifier. The blood pressure detection method is characterized in that when the coating enters the deflation process, after the Korotkoff sound is first detected by the pickup, the difference between the frequency of the ultrasonic reflection signal and the frequency of the ultrasonic emission signal is detected, and the blood pressure value is calculated using the difference. The present invention has the advantages of good stability of measurement results and strong practicality.

Description

Technical Field

[0001] The invention belongs to the technical field of medical detection, and in particular relates to an ultrasonic compound electronic sphygmomanometer and a blood pressure detection method thereof. Background Art

[0002] Blood pressure is a very important physiological parameter of the human body, which can reflect the working function of the human circulatory system. By measuring blood pressure and understanding one's own blood pressure value, one can better understand one's own health status and effectively regulate oneself. Blood pressure refers to the pressure exerted by blood in blood vessels on the blood vessel walls. It is because of the effect of blood pressure that blood can be transported to every part of the human body. Blood pressure is a variable that changes periodically with the beating of the heart. When the heart contracts, blood is injected into the arteries, and blood pressure rises; when the heart relaxes, blood flows back to the heart, and blood pressure decreases. Usually, the blood pressure refers to the range of blood pressure changes, not the blood pressure throughout the entire heart cycle. Blood pressure measurement obtains systolic pressure and diastolic pressure. Systolic pressure is the maximum value of blood pressure during the heart contraction process, and diastolic pressure is the minimum value during the heart relaxation process. The unit of blood pressure value is generally mm Hg (millimeters of mercury).

[0003] With the development of society and the improvement of people's living standards, people are paying more and more attention to the health of themselves and their families. The increase in the incidence of hypertension has made electronic blood pressure monitors enter people's lives and become one of the indispensable household appliances for many people. Electronic blood pressure monitors bring convenience to early detection of hypertension and monitoring of treatment effects.

[0004] The auscultation method (Korotkoff's sound method) was proposed by Russian doctor Korotkoff in 1905. It is currently one of the most commonly used blood pressure measurement methods in clinical practice and is the standard for measuring blood pressure. The principle of the auscultation method is that the cuff is an expandable sealed bag with a liquid bag connected to the mercury column, and another air bag connected to the inflatable ball. The cuff is tied to the upper arm of the right hand, and the stethoscope is placed on the artery at the same time. It is inflated and pressurized until the brachial artery is compressed. At this time, the blood vessel is completely blocked, and the pressure of the blood on the blood vessel pushes the mercury column upward through the liquid bag, so that the mercury column has a certain height. When the stethoscope can't hear the pulse sound at all, the blood vessel is completely blocked, and then the air in the squeezed air bag is slowly released. The pressure of the cuff will gradually decrease with the reduction of the pressure of the pressurized air. When the pressure is reduced to the point where the blood can flow, the sound of blood flowing in the blood vessels can be heard from the stethoscope. When the sound can be heard for the first time, the mercury pressure indication is the systolic pressure, and the sound heard is the Korotkoff sound. Continuing to deflate the cuff reduces the pressure, and the sound heard by the stethoscope will gradually increase to reach the maximum. Later, because the pressure between the stethoscope and the skin gradually decreases, when the sound reaches the minimum until the measurer can't hear it at all, the blood vessel is fully open, and the indication of the mercury column is the diastolic pressure. From the measurement process and details, we can see that the advantage of the auscultation method is accurate measurement, but it also has many disadvantages:

[0005] 1) The reaction and proficiency of the measurer have an impact on the measurement results. The measurer needs to constantly observe the mercury pressure gauge, listen to the sound, and release the air. Each person's reaction time and proficiency are different, which causes human errors.

[0006] 2) Different people have different hearing, vision and estimation abilities, and their readings are also different when identifying characteristic sounds and selecting the right time to read them.

[0007] 3) The deflation speed during the measurement process also affects the accuracy of the measurement data.

[0008] Therefore, the industry has developed electronic blood pressure monitors one after another. However, the commonly used electronic blood pressure monitors currently have the defect of unstable measurement data. Summary of the invention

[0009] The purpose of the present invention is to provide an ultrasonic compound electronic sphygmomanometer and a blood pressure detection method thereof, which adds a sound pickup function on the basis of a traditional electronic sphygmomanometer, simplifies the program design, improves the stability of the measurement results, and enhances practicability.

[0010] The present invention is achieved through the following technical solutions:

[0011] That is, an ultrasonic compound electronic sphygmomanometer, including a coating, an inflation and deflation control device, an ultrasonic transmitting device, an ultrasonic receiving device and a CPU, characterized in that a microphone is provided on the coating, and the microphone is connected to the CPU signal through an audio conditioning circuit, and the audio conditioning circuit includes a microphone plug, a transient suppression diode, a high-frequency filter resistor, a high-frequency filter capacitor and an operational amplifier, and the high-frequency filter resistor, the transient suppression diode and the high-frequency filter capacitor are connected in series and connected in parallel with the high-frequency filter resistor between the microphone plug and the operational amplifier.

[0012] The microphone on the package of the present invention is connected to the audio conditioning circuit through the microphone plug, the transient suppression diode prevents the interference peak, the high-frequency filter resistor and the high-frequency filter capacitor filter out the high-frequency components in the microphone, and then send them to the A / D input end of the CPU, and the CPU can digitally process and analyze the signal.

[0013] The present invention adds a microphone and an audio conditioning circuit on the basis of the sphygmomanometer disclosed in CN201610916421.8.

[0014] The components in the pickup and the audio conditioning circuit of the present invention are all mature products on the market in the prior art. The model of the pickup is COTT-S30.

[0015] The coating of the present invention is a prior art product, which is internally provided with a gas pressure sensor, an air pump, a constant speed exhaust valve and a solenoid valve. The signal of the gas pressure sensor is transmitted to the CPU after signal conditioning and data collection. The CPU model is STM32F103RCT6.

[0016] When the envelope is inflated, the air pump is used to inflate the envelope first, and the pressure of the envelope increases. When the pressure of the envelope is greater than the systolic pressure, the blood cannot flow and the inflation stops. Then, the air is released through the constant speed exhaust valve and the solenoid valve, and the pressure of the envelope gradually decreases. In the process of the envelope pressure first increasing and then decreasing, the gas pressure sensor is used to detect the pressure of the envelope. The gas pressure sensor commonly used for blood pressure measurement is MPS20N0040D.

[0017] A blood pressure monitoring method using an ultrasonic compound electronic sphygmomanometer, characterized by the following steps:

[0018] 1) Tie the covering body to the upper arm of the right hand, inflate the covering body through the inflation and deflation control device, the CPU detects the output signal of the audio conditioning circuit, starts the ultrasonic transmitting device to emit ultrasonic waves for detection, and receives the return signal of the ultrasonic receiving device at the same time;

[0019] 2) The sheath is inflated and pressurized until the brachial artery is compressed. At this time, the blood vessel is completely blocked, the output signal of the audio conditioning circuit is less than the set value (typical value 20mv), and the ultrasound cannot detect blood flow, indicating that the blood vessel is completely blocked. The sheath is deflated through the inflation and deflation control device;

[0020] 3) When the package enters the deflation process, the blood flow signal obtained by the pickup is integrated according to the set time window (2s); when the integral value is greater than the set threshold (typical value 1000), it can be considered that Korotkoff sound is detected;

[0021] 4) After the Korotkoff sound is detected during the first monitoring, the difference between the frequency of the ultrasonic reflected signal and the frequency of the ultrasonic emitted signal is detected, and the blood pressure value is calculated using the difference;

[0022] 5) Calculate the blood pressure value at regular intervals and store it sequentially in the CPU memory;

[0023] 6) When the Korotkoff sounds disappear and the ultrasonic blood flow rate reaches its maximum value, it means that deflation is completed. In the CPU memory, the first measured value is the systolic pressure and the last measured value is the diastolic pressure.

[0024] As a preferred solution: In step 3), before integration within the time window, filtering should be performed using FFT or STFT or wavelet algorithm.

[0025] As a preferred solution: in step 5), blood pressure values ​​are calculated sequentially every 1 second.

[0026] The principle of ultrasonic blood pressure detection of the present invention is the same as CN201610916421.8.

[0027] The principle used by the pickup of the present invention is as follows:

[0028] 1) When the pressure of the sheath is greater than the systolic pressure, the arterial blood flow is blocked and the microphone in the sheath can hardly detect the pulse wave;

[0029] 2) As the pressure of the sheath gradually decreases, blood flow gradually recovers, and the amplitude of the pulse wave detected by the microphone in the sheath increases;

[0030] 3) When the pressure of the sheath is equal to the average pressure, the blood vessel is completely open and the pulse wave amplitude detected by the microphone in the sheath reaches the maximum value;

[0031] 4) When the pressure of the covering body gradually decreases from the average pressure, the contact between the covering body and the arm becomes looser, and the amplitude of the pulse wave detected by the pickup in the covering body gradually decreases.

[0032] The CPU can use digital algorithms to calculate the amplitude of each pulse wave, pulse width and other parameters, which can be used as parameters or criteria for blood pressure calculation.

[0033] The present invention has the advantages of good measurement result stability and strong practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural principle block diagram of the present invention;

[0035] Figure 2 This is a block diagram of the structural principle of the inflation and deflation of the present invention;

[0036] Figure 3 is a corresponding curve diagram of the pressure of the coating and the pickup signal of the present invention;

[0037] Figure 4 The circuit diagram of the audio conditioning circuit of the present invention is shown in FIG. DETAILED DESCRIPTION

[0038] The embodiments of the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and the protection scope of the present invention cannot be limited thereto. It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should be the common meanings understood by those skilled in the art to which the present invention belongs.

[0039] like Figure 1 As shown: a microphone, an ultrasonic transmitting probe and an ultrasonic receiving probe are arranged in the coating body, the coating body is connected to the CPU signal through the inflation and deflation control device, the microphone is short-circuited through the audio conditioning, the ultrasonic transmitting probe is connected through the ultrasonic transmitting device, and the ultrasonic receiving probe is connected through the ultrasonic receiving device. The CPU is also connected to the power supply, LCD display and keyboard.

[0040] like Figure 2 As shown: the structure of the coating is the existing technology, and a gas pressure sensor, an air pump, a constant speed exhaust valve and a solenoid valve are arranged inside it. The signal of the gas pressure sensor is transmitted to the CPU after signal conditioning and data collection.

[0041] like Figure 4 As shown: the transient suppression diode TVS1 and the high-frequency filter capacitor C7 of the audio conditioning circuit are connected in series and connected in parallel with the high-frequency filter resistor R13 and are arranged between the pickup plug H2 and the operational amplifier LM324.

[0042] The steps of the present invention during detection are as follows:

[0043] 1) Tie the covering body to the upper arm of the right hand, inflate the covering body through the inflation and deflation control device, the CPU detects the output signal of the audio conditioning circuit, starts the ultrasonic transmitting device to emit ultrasonic waves for detection, and receives the return signal of the ultrasonic receiving device at the same time;

[0044] 2) The sheath is inflated and pressurized until the brachial artery is compressed. At this time, the blood vessel is completely blocked, the output signal of the audio conditioning circuit is less than 20mv, and the ultrasound cannot detect blood flow, indicating that the blood vessel is completely blocked. The sheath is deflated through the inflation and deflation control device;

[0045] 3) When the sheath enters the deflation process, the blood flow signal obtained by the microphone is integrated according to the time window (2s); when the integral value is greater than the set threshold (1000), it can be considered that Korotkoff sound is detected. Before integration within the time window, FFT, STFT or wavelet algorithm must be used for filtering.

[0046] 4) After the Korotkoff sound is detected during the first monitoring, the difference between the frequency of the ultrasonic reflected signal and the frequency of the ultrasonic emitted signal is detected, and the blood pressure value is calculated using the difference;

[0047] 5) Calculate the blood pressure value every 1 second and store it sequentially in the CPU memory;

[0048] 6) When the Korotkoff sounds disappear and the ultrasonic blood flow rate reaches its maximum value, it means that deflation is completed. In the CPU memory, the first measured value is the systolic pressure and the last measured value is the diastolic pressure.

[0049] Obviously, the above-described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. For example, radar waves are used instead of ultrasonic waves.

Claims

1. A blood pressure monitoring method using an ultrasonic compound electronic sphygmomanometer, characterized in that: The ultrasonic compound electronic sphygmomanometer comprises a coating, a gas charging and discharging control device, an ultrasonic transmitting device, an ultrasonic receiving device and a CPU. A pickup is arranged on the coating, and the pickup is connected to the CPU signal through an audio conditioning circuit. The audio conditioning circuit comprises a pickup plug, a transient suppression diode, a high-frequency filter resistor, a high-frequency filter capacitor and an operational amplifier. The high-frequency filter resistor, the transient suppression diode and the high-frequency filter capacitor are connected in series and connected in parallel with the high-frequency filter resistor between the pickup plug and the operational amplifier. The blood pressure monitoring method steps are as follows: 1) Tie the covering body to the upper arm of the right hand, inflate the covering body through the inflation and deflation control device, the CPU detects the output signal of the audio conditioning circuit, starts the ultrasonic transmitter to emit ultrasonic waves for detection, and receives the return signal of the ultrasonic receiver at the same time; 2) The sheath is inflated and pressurized until the brachial artery is compressed. At this time, the blood vessel is completely blocked, the output signal of the audio conditioning circuit is less than the set value, and the ultrasound cannot detect blood flow, indicating that the blood vessel is completely blocked. The sheath is deflated through the inflation and deflation control device; 3) When the envelope enters the deflation process, the blood flow signal obtained by the pickup is integrated according to the set time window; when the integral value is greater than the set threshold, it can be considered that Korotkoff sound is detected. Before integration within the time window, FFT, STFT or wavelet algorithm must be used for filtering; 4) After the Korotkoff sound is detected during the first monitoring, the difference between the frequency of the ultrasonic reflected signal and the frequency of the ultrasonic emitted signal is detected, and the blood pressure value is calculated using the difference; 5) Calculate the blood pressure value every 1 second and store it sequentially in the CPU memory; 6) When the Korotkoff sounds disappear and the ultrasonic blood flow rate reaches its maximum value, it means that deflation is completed. In the CPU memory, the first measured value is the systolic pressure and the last measured value is the diastolic pressure.

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