Non-invasive continuous blood pressure examination device and method

Abstract

The embodiment of the invention provides a non-invasive continuous blood pressure examination device and method, and the device comprises a finger cuff which is bound on a finger part and provides pressure for the finger; the emission control unit is used for emitting the emission signal generated by the emission control unit; the receiving control unit is used for receiving the transmitting signal and converting the transmitting signal into a digital signal; the feedback control unit is used for determining the volume change condition of blood in the finger through the digital signal, receiving a measured pressure value sent by the pressure gauge, judging a required target pressure value according to the measured pressure value and the digital signal, and controlling the over-inflation device and the deflation device to adjust the pressure value in the finger cuff to the target pressure value based on a control strategy; the pressure gauge is used for measuring a pressure value in the finger cuff and sending the measured pressure value to the feedback control unit; the inflating device is used for inflating the finger cuff under the control of the feedback control unit; and the deflation device is used for deflating the finger cuff under the control of the feedback control unit.

Description

Technical Field

[0001] This document relates to the field of computer technology, and particularly to a non-invasive continuous blood pressure detection device and method. Background Art

[0002] Non-invasive continuous blood pressure monitoring is a technology that can continuously and real-time obtain blood pressure data without invading the human blood vessels. Compared with traditional blood pressure measurement methods, it can provide more frequent and continuous blood pressure information, which helps to comprehensively understand the dynamic changes of blood pressure.

[0003] Common technical methods for non-invasive continuous blood pressure monitoring mainly include the oscillometric method, the pulse wave transit time method, and the volume clamp method, etc.

[0004] The volume clamp method is a technology for continuously and non-invasively measuring blood pressure. It is mainly based on the vascular unloading principle. Briefly speaking, when the external pressure reaches equilibrium with the pressure inside the blood vessel, the tension of the blood vessel wall will be "unloaded", and the blood pressure inside the blood vessel is indirectly measured by monitoring the external pressure in this equilibrium state.

[0005] The volume clamp method uses a special finger cuff, which contains an airbag that can quickly adjust the pressure and a sensor that can detect the change in finger volume, such as a photoplethysmogram (PPG) sensor.

[0006] When the cuff is inflated, the airbag applies pressure to the finger. The sensor will detect the change in finger volume in real time. Under normal circumstances, the pressure in the finger artery blood vessel will keep the blood vessel at a certain degree of fullness, thus maintaining the finger volume.

[0007] The system adjusts the pressure of the airbag continuously through a feedback control mechanism, so that the volume of the finger blood vessel remains at a set base level (usually the state where the blood vessel is not overly compressed or dilated). This process is like a dynamic equilibrium process. When the blood pressure in the finger blood vessel changes, in order to keep the finger volume unchanged, the pressure of the airbag also needs to change accordingly.

[0008] For example, when the arterial blood pressure rises, the pressure inside the blood vessel increases, which will cause the finger blood vessel to tend to dilate, resulting in an increase in finger volume. At this time, the volume detection sensor will sense this change, and then the feedback system will increase the airbag pressure to squeeze the blood vessel and prevent it from dilating, so as to "clamp" the finger volume at the set base level. And this airbag pressure used to balance the change in blood vessel pressure can be used as the measured value of blood pressure.

[0009] Such as Figure 1As shown, the working principle of a single electro-pneumatic control loop is as follows: A human limb containing an artery (e.g., finger, carpus, temple, etc.) is irradiated with infrared (IR) light. A portion of the light is absorbed by the pulsating blood volume, such that the reflected light is an inverse measure of the pulsating blood volume. The finger is the most suitable location for this method, but accuracy is limited due to the compressibility of the tissue and the viscoelastic properties of the artery. Figure 1 In the figure, F is the finger; L is the lamp; PC is the photocell; S is the segment of the transparent pressure cuff; C1 is the average value of the PC signal; DA is the differential amplifier; PG is the plethysmogram signal; PID is the correction network; C2 is the set point SP; SW is the switch between open-loop and closed-loop; PA is the power amplifier; EPT is the electro-pneumatic sensor.

[0010] As can be seen from Figure 1 it, the more blood contained in the finger artery, the more IR light is absorbed, and the light reaching the photocell (PC) is correspondingly reduced. The instantaneous plethysmogram (PG) signal refers to the light signal PC compared to the constant C1, which in turn represents the average value of PC. Therefore, when the blood volume in the finger increases, PG decreases. C1 is subtracted from PC by the differential amplifier (DA). PG is fed to a control unit with proportional-integral-derivative characteristics (PID). The PID signal is added to the constant set point (SP or C2), amplified and fed to the electro-pneumatic sensor (EPT). EPT generates a pressure signal pC(t) in the cuff, which is applied to the finger irradiated with infrared light.

[0011] The control conditions are as follows: Due to the pulsating pressure pC(t) in the cuff, PG should become zero over a period of time, especially during the cardiac cycle. During systole, when the pulsating blood volume in the finger increases, the PID controller increases the control point, so pC(t) increases until the excess blood is removed by the external pressure of the cuff. On the other hand, during diastole, the blood volume in the finger decreases, resulting in an increase in PG, so the PID controller reduces the control point. Therefore, pC(t) decreases and the total blood volume remains constant. Since the blood volume and PG remain constant over time, the pressure difference between the cuff pressure pC(t) and the arterial pressure pA(t) (transmural pressure pT(t)) is zero.

[0012] Figure 2 Shows a schematic diagram of the internal control loop of TFM. Wherein, F is the finger; C is the cuff; PC is the photocell; SLF is the ambient light filter; PG is the plethysmogram signal; PG is the average PG signal; PID is the proportional-integral-derivative controller; P is the proportional tuning; I is the integral tuning; D is the differential tuning; SP is the set point; CP is the control point; IC is the intake valve controller; IV is the intake valve; OC is the outlet valve controller; OV is the outlet valve; BP is the blood pressure signal; IML is the innermost loop.

[0013] There is an urgent need for a method to provide high-performance pressure value control, so as to make the measurement results more accurate. Summary of the Invention

[0014] The purpose of the present invention is to provide a non-invasive continuous blood pressure detection device and method, aiming to solve the above problems in the prior art.

[0015] The present invention provides a non-invasive continuous blood pressure detection device, including:

[0016] A finger cuff for binding on the finger part to provide pressure to the finger;

[0017] A transmission control unit for transmitting the generated transmission signal to the finger in the finger cuff;

[0018] A reception control unit for receiving the transmission signal after being absorbed by the finger and converting the transmission signal into a digital signal and sending it to the feedback control unit;

[0019] A feedback control unit for determining the volume change of blood in the finger through the digital signal, receiving the measured pressure value sent by the pressure gauge, judging the required target pressure value according to the measured pressure value and the digital signal, controlling the over-inflation device and the deflation device based on the control strategy, adjusting the pressure value in the finger cuff to the target pressure value, and predicting the required pressure value curve;

[0020] A pressure gauge for measuring the pressure value in the finger cuff and sending the measured pressure value to the feedback control unit;

[0021] An inflation device for inflating the finger cuff under the control of the feedback control unit;

[0022] A deflation device for deflating the finger cuff under the control of the feedback control unit.

[0023] The present invention provides a non-invasive continuous blood pressure detection method for the non-invasive continuous blood pressure detection device, and the method specifically includes:

[0024] Binding the finger part with a finger cuff to provide pressure to the finger;

[0025] Transmitting the generated transmission signal to the finger in the finger cuff through the transmission control unit;

[0026] Receiving the transmission signal after being absorbed by the finger through the reception control unit and converting the transmission signal into a digital signal and sending it to the feedback control unit;

[0027] Measure the pressure value inside the finger cuff through a pressure gauge and send the measured pressure value to the feedback control unit;

[0028] Based on the digital signal, the feedback control unit determines the volume change of the blood inside the finger, receives the measured pressure value sent by the pressure gauge, judges the target pressure value required according to the measured pressure value and the digital signal, and based on the control strategy, controls the over-inflation device and the deflation device to adjust the pressure value inside the finger cuff to the target pressure value;

[0029] Inflate the finger cuff through the inflation device under the control of the feedback control unit; deflate the finger cuff through the deflation device under the control of the feedback control unit.

[0030] Adopting the embodiment of the present invention can provide high-performance pressure value control during blood pressure measurement, making the measurement result more accurate. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in one or more embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is a schematic diagram of the principle of a single electro-pneumatic control loop in the prior art;

[0033] Figure 2 It is a schematic diagram of the internal control loop of TFM in the prior art;

[0034] Figure 3 It is a schematic diagram of a non-invasive continuous blood pressure detection device according to an embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of a typical PPG signal waveform according to an embodiment of the present invention;

[0036] Figure 5 It is a schematic diagram of the inflation and deflation control strategy according to an embodiment of the present invention;

[0037] Figure 6 It is a schematic diagram of the linear interval of the inflation and deflation valve according to an embodiment of the present invention;

[0038] Figure 7 It is a schematic diagram of the inflation and deflation control method according to an embodiment of the present invention;

[0039] Figure 8 It is a schematic diagram of the inflation and deflation control scheme according to an embodiment of the present invention;

[0040] Fig. 9 It is a flowchart of the non-invasive continuous blood pressure detection method according to an embodiment of the present invention. Detailed implementation manners

[0041] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the following will clearly and completely describe the technical solutions in one or more embodiments of this specification with reference to the accompanying drawings in one or more embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this document.

[0042] Device embodiments

[0043] According to an embodiment of the present invention, there is provided a non-invasive continuous blood pressure detection device. Figure 3 It is a schematic diagram of the non-invasive continuous blood pressure detection device according to an embodiment of the present invention, as Figure 3 shown. The non-invasive continuous blood pressure detection device according to an embodiment of the present invention specifically includes:

[0044] A finger cuff 10 for binding on the finger part to provide pressure to the finger;

[0045] A transmission control unit 11 for transmitting the generated transmission signal to the finger in the finger cuff;

[0046] A reception control unit 12 for receiving the transmission signal after being absorbed by the finger and converting the transmission signal into a digital signal and sending it to the feedback control unit;

[0047] A feedback control unit 13 for determining the volume change of blood in the finger through the digital signal, receiving the measured pressure value sent by the pressure gauge, judging the required target pressure value according to the measured pressure value and the digital signal, controlling the over-inflation device and the deflation device based on the control strategy to adjust the pressure value in the finger cuff to the target pressure value, and predicting the required pressure value curve; specifically, the feedback control unit 13 is used for:

[0048] Perform uniform sampling or non-uniform sampling according to the characteristics of the pulse wave. According to the inflation and deflation curve, control the inflation and deflation speed to be fast-slow-fast, adjust the pressure value in the finger cuff to the target pressure value, and use the PID control method or predict the required pressure value curve based on the standard PPG waveform collected at the mean pressure. Among them, the fast-slow-fast control specifically includes: at the initial stage of inflation and deflation, control the inflation and deflation to slowly increase from 0 with a first predetermined step; at the middle stage of inflation and deflation, when the inflation device or deflation device reaches the optimal position, control the inflation and deflation speed to reach the maximum value; at the end stage of inflation and deflation, control the inflation and deflation speed to slowly decrease with a second predetermined step. In practical applications, a low-pass filtering method or an interpolation method can be used to improve the smoothness of the uniform sampling or non-uniform sampling curve.

[0049] A pressure gauge 14 for measuring the pressure value in the finger cuff and sending the measured pressure value to the feedback control unit;

[0050] An inflation device 15 for inflating the finger cuff under the control of the feedback control unit; the inflation device 15 specifically includes: an inflation valve and an inflation pump, and the inflation valve is used to control inflation;

[0051] A deflation device 16 for deflating the finger cuff under the control of the feedback control unit. The deflation device 16 specifically includes: a deflation valve, and the deflation valve is used to notify deflation;

[0052] The initial positions of the inflation valve and the deflation valve are not at the closed point, but at a point within the linear range, so as to ensure that the inflation valve directly enters the linear range as soon as it starts. When in the holding stage, the opening sizes of the inflation valve and the deflation valve are the same, and the inflated gas is directly released to maintain the dynamic balance of the pressure in the finger cuff.

[0053] The inflation valve specifically includes: a plurality of switching valves and a plurality of fixed gas resistances respectively connected to the plurality of switching valves. Among them, the plurality of fixed gas resistances provide different inflation speeds for adapting to different finger cuffs.

[0054] The feedback control unit 13 is specifically used for:

[0055] When inflation operation is required, control the opening of the inflation valve to increase, control the opening of the deflation valve to decrease, and increase the inflation speed; when deflation operation is required, control the opening of the inflation valve to decrease, control the opening of the deflation valve to increase, and increase the deflation speed.

[0056] The device according to an embodiment of the present invention further includes:

[0057] An air chamber, communicated with the finger cuff, for reducing the influence of pulse wave fluctuations on pressure measurement.

[0058] The above technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0059] The continuous blood pressure detection device described in the embodiments of the present invention is as follows Figure 3 shown. The emission control unit generates an emission signal, which is converted into an optical signal by D1 in Figure 3 and emitted. After being absorbed by the finger, the optical signal is received by D2 and converted into a digital signal by the reception control unit and then transmitted to the feedback control unit. Since the absorption amount is directly related to the blood volume in the finger, the change in the blood volume in the finger can be represented by the waveform collected by D2. The feedback control unit adjusts the pressure value in the finger cuff by adjusting two proportional valves, one inflation valve, and one deflation valve. The pressure value is measured by a pressure gauge and input to the feedback control unit. The feedback control unit determines the required target pressure value based on the received optical signal and the pressure gauge signal, and at the same time controls the air valve and the deflation valve to act, so that the pressure value in the finger cuff reaches the target value.

[0060] Photoplethysmography (PPG for short) is a non-invasive detection method that uses optoelectronic technology to detect the change in blood volume in human microvessels. When light irradiates human tissue, phenomena such as absorption, reflection, and scattering will occur. The absorption characteristics of blood for light are different from those of surrounding tissues. Especially in pulsating arterial blood, due to the periodic change in blood volume, the degree of light absorption by it will also change periodically.

[0061] Generally, the light sources used are visible light (such as green light) and infrared light. Green light is more easily absorbed by hemoglobin in blood to a certain extent, while infrared light has relatively strong penetrability and can better penetrate deeper tissues. By detecting the change in the intensity of the reflected light or transmitted light, information on blood volume change can be obtained.

[0062] There are mainly two types of commonly used PPG sensors: reflective and transmissive. The reflective sensor places the light source and the light detector on the same side of the skin. The light emitted by the light source irradiates the skin surface and is received by the light detector after being reflected by the tissue. This method is suitable for measuring pulse wave signals of superficial blood vessels, such as fingers, wrists and other parts, because the skin of these parts is relatively thin, which is convenient for detecting light reflection. The transmissive sensor places the light source and the light detector on both sides of the tissue, such as the earlobe and other parts. The light irradiates from one side and is received by the detector on the other side after passing through the tissue. This case mainly uses the transmissive scheme.

[0063] When a constant pressure is applied, the typical change in the PPG signal is as Figure 4As shown, during the cardiac systolic phase, arterial blood fills, the blood volume increases, and the absorption of light increases; during the cardiac diastolic phase, arterial blood decreases, and the absorption of light also decreases accordingly. The average pressure in the cuff has a greater impact on the PPG amplitude. If the average pressure is too high, the blood vessels are always in a compressed state, with a small flow rate and weak pulsation, and the measured finger blood pressure is higher than the true value; if the average pressure is too low, the blood vessels are always in a diastolic state, with a large flow rate and weak pulsation, and the measured finger blood pressure is lower than the true value; only when the average pressure is close to the true average pressure of the finger can the pulsation amplitude reach the maximum and the true finger blood pressure value be obtained.

[0064] The core of the volume clamp method is to control the rapid change of the pressure in the cuff to keep the PPG signal amplitude unchanged. From the waveform in the figure, it can be seen that during the cardiac systolic phase, the pressure increases very rapidly, and the system needs to have a very high response speed to follow the change of the PPG signal. The general method of the volume clamp is based on the PPG signal at the average pressure. When the heart contracts and the finger blood pressure increases, the volume also increases accordingly, resulting in an increase in the PPG signal; the device increases the pressure in the cuff to offset the increase in the PPG signal, that is, to prevent the volume in the finger blood vessels from increasing and still maintain the volume at the average pressure. In this way, the increase in the blood vessel pressure is equal to the increase in the cuff pressure, and through this method, the true pressure value in the finger blood vessels is obtained.

[0065] There are many methods to feedback blood pressure through PPG. For example, the traditional PID method. The advantage of PID is that it has a certain self - adaptability and can meet more specific situations. Another method is to predict using the PPG waveform morphology, and this method requires precise control of blood pressure. The reference PPG waveform can be obtained through the PPG signal under static pressure, and this waveform is in a stable state for a certain period. A pressure change curve can be generated through this PPG waveform to suppress the PPG waveform, thereby achieving the goal of keeping the PPG signal basically constant. When the PPG waveform changes, since it no longer matches the previous pressure change curve, its PPG feedback waveform will also change. The pressure change waveform can be used for revision to make the PPG feedback waveform return to a near - straight line to ensure normal operation for a long time.

[0066] The core of the control in the embodiment of the present invention is to precisely control the pressure in the cuff. The challenges here are, on the one hand, the high - speed change of blood pressure during the cardiac systolic phase, which requires the system to have a high response speed; on the other hand, during the high - speed charging and discharging process, there is a certain oscillation, which causes deviation of the target value.

[0067] Therefore, an inflation strategy is designed in the embodiments of the present invention. In the initial stage of inflation and deflation, since the valve just starts to act, the inflation and deflation need to gradually increase from 0. In the middle stage of inflation, the valve reaches the optimal position and the inflation and deflation speed reaches the maximum value. In the final stage of inflation and deflation, the speed slows down. On the one hand, it is necessary to wait for the gas path to reach stability. On the other hand, the slower speed is due to the accurate control target value. Its inflation control curve is shown by Figure 5 as shown by A in

[0068] If the air flow fluctuates too much in the final stage of inflation and deflation, faster inflation can be carried out in the early stage, and then a longer gas path stability time can be reserved in the later stage, as shown by Figure 5 C in

[0069] After adopting this inflation and deflation scheme, the inflation and deflation curve is no longer smooth, and the typical waveforms are shown by Figure 5 B and D in Figure 5 For each point that needs to be accurately controlled, the inflation and deflation values can reach a very high accuracy. Its main disadvantage is that for non-control points, there is a certain difference between the target value and the actual value, and at the same time, the curve appears not smooth enough. For this, some algorithm means can be used for processing, such as common low-pass filtering, which can reduce this high-frequency interference. Assuming that the sampling rate of the control point is fs, then setting the cut-off frequency at fs can effectively filter out signals higher than fs and make the curve smooth. Another commonly used method is the interpolation algorithm, such as cubic spline interpolation, which can well restore the shape of the curve, as shown by the dotted lines in Figure 5 B and D in

[0070] When the sampling rate of the control point is sufficient, the control point can be directly displayed. If the required sampling rate is higher than the sampling rate of the control point, the above display algorithm can be used to increase the sampling rate and then display it.

[0071] In addition, since the human pulse wave has relatively typical characteristics, it can be considered to set sampling points according to the waveform characteristics and control at the key points of the waveform, so that high-quality signal restoration can be achieved with a lower sampling rate, as shown by Figure 4 B in

[0072] When controlling inflation and deflation, the inflation valve and deflation valve need to be frequently opened and closed. However, the valve is a mechanical component and can only maintain a linear range within a certain range. The typical linear range is shown by Figure 6 As shown, at the opening and closing position, it is often in the non-linear range and takes a relatively long time to truly close. Additionally, after exceeding the linear range, there will be a rapid increase in the ventilation speed.

[0073] In view of this characteristic of the linear valve, a method for controlling inflation and deflation is designed in this case, as Figure 7 shown. The inflation operation is controlled by an inflation valve, and the deflation operation is controlled by a deflation valve. To accelerate the response speed of the valve, the initial position of the valve is not at the closed point but at a certain point within the linear range, so as to ensure that the valve can directly enter the linear range as soon as it starts. Since the valve is not at the closed point, during the holding stage, the openings of the inflation valve and the deflation valve are the same size, and the inflated gas is directly released, and the pressure inside the cuff can be dynamically balanced. Since this case controls the gas in the finger cuff and its volume is usually a few milliliters, these gas losses can be tolerated and will not have too much impact on the system. Due to the large difference in the thickness of human fingers, several sizes of cuffs usually need to be designed, which may result in a large difference in the cuff volume. When the volume inside the cuff is different, different inflation and deflation speeds are required to give appropriate pressure value changes. Therefore, this initial position is determined by the cuff volume and is a variable parameter, as Figure 7 shown as A in

[0074] Figure 7 B in

[0075] shows another control idea. In the balanced state, since both valves are in the open state, reducing one valve and increasing the other valve have the same effect. When inflation operation is required, the opening of the inflation valve increases and the opening of the deflation valve decreases, which can further increase the inflation speed; when deflation operation is required, the opening of the inflation valve decreases and the opening of the deflation valve increases, which can further increase the deflation speed. In this way, the two valves are equivalent to doubling the inflation and deflation speeds, making the system response speed faster.

[0075] In addition, the fluctuation caused by inflation and deflation can also be reduced by increasing the gas volume. The advantage of this is that the impact of the fluctuation on the system is smaller, but the disadvantage is that it has higher requirements for the inflation and deflation ability of the system.

[0076] The inflation and deflation valves that can vary linearly are relatively expensive. If the cost is reduced and the product life is increased, the method of using a fixed air resistance plus a switching valve can be considered. For example Figure 8For the shown solution, three switching valves and three fixed air resistances are used to replace the inflation valve. The three air resistances can provide different inflation speeds for adapting to different cuffs. For example, the inflation speeds of the three fixed air resistances can be 1:2:4, so that eight inflation speeds, namely 0, 1, 2, 3, 4, 5, 6, and 7, can be achieved, which has high practicability. The switching valve has a simple structure and has the advantages of low cost and high service life, and its solution also has good practicability. If the inflation valve and the deflation valve are swapped, a similar effect can also be achieved.

[0077] In summary, the non-invasive continuous blood pressure detection device according to the embodiment of the present invention includes at least one photoelectric emission and reception unit; a blood pressure cuff; a feedback control system; a gas path pressure control system: including an inflation control valve and a deflation control valve; the pressure control system controls the opening and closing of the two valves to make the cuff reach the target pressure value; slow-fast-slow inflation and deflation are adopted to ensure the accuracy of pressure setting; data during inflation and deflation is obtained by interpolation method to ensure smooth and continuous curves. A gas chamber can be added and connected to the cuff to reduce the influence of pulse wave fluctuation on pressure measurement. One of the two control valves can be implemented by a fixed air resistance. The feedback system can be based on the PPG principle, and the pressure feedback value is controlled by the PID method. The feedback system can be based on the PPG principle, and the pressure feedback value is predicted through the PPG waveform. Both valves work in the linear range, and when the inflation and deflation are balanced, the pressure inside the cuff remains unchanged. Through non-uniform sampling, control is only performed at the key points of the pulse waveform, reducing the requirements for system performance.

[0078] Method Embodiment

[0079] According to the embodiment of the present invention, a non-invasive continuous blood pressure detection method is provided for the above non-invasive continuous blood pressure detection device. Fig. 9 It is a flowchart of the non-invasive continuous blood pressure detection method according to the embodiment of the present invention. As Fig. 9 shown, the non-invasive continuous blood pressure detection method according to the embodiment of the present invention specifically includes:

[0080] Step S901, bundling the finger cuff on the finger part to provide pressure for the finger;

[0081] Step S903, emitting the emitted signal generated by the emission control unit to the finger inside the finger cuff;

[0082] Step S903, receiving the emitted signal after being absorbed by the finger through the receiving control unit, and converting the emitted signal into a digital signal and sending it to the feedback control unit;

[0083] Step S904, measuring the pressure value inside the finger cuff through the pressure gauge, and sending the measured pressure value to the feedback control unit;

[0084] Step S905: Based on the digital signal, the feedback control unit determines the volume change of the blood in the finger, receives the measured pressure value sent by the pressure gauge, determines the target pressure value required according to the measured pressure value and the digital signal, controls the over-inflation device and the deflation device based on the control strategy, adjusts the pressure value in the finger cuff to the target pressure value, and predicts the required pressure value curve;

[0085] Among them, controlling the over-inflation device and the deflation device to adjust the pressure value in the finger cuff to the target pressure value specifically includes:

[0086] Perform uniform sampling or non-uniform sampling according to the pulse wave characteristics. According to the inflation and deflation curve, control the inflation and deflation speed to increase slowly-fast-slow, adjust the pressure value in the finger cuff to the target pressure value, and use the PID control method or predict the required pressure value curve by using the standard PPG waveform collected at the mean pressure. Among them, the slow-fast-slow control specifically includes: at the initial stage of inflation and deflation, control the inflation and deflation to slowly increase from 0 with a first predetermined step; in the middle stage of inflation and deflation, when the inflation device or the deflation device reaches the optimal position, control the inflation and deflation speed to reach the maximum value; at the end stage of inflation and deflation, control the inflation and deflation speed to slowly decrease with a second predetermined step. Among them, performing uniform sampling or non-uniform sampling according to the pulse wave characteristics specifically includes: using the low-pass filtering method or the interpolation method to improve the smoothness of the uniform sampling or non-uniform sampling curve;

[0087] Step S906: Under the control of the feedback control unit, the finger cuff is inflated by the inflation device; the finger cuff is deflated by the deflation device under the control of the feedback control unit. Specifically includes:

[0088] Set the initial positions of the inflation valve and the deflation valve at a point within the linear range to ensure that the inflation valve directly enters the linear range as soon as it starts. When in the holding stage, the opening sizes of the inflation valve and the deflation valve are the same, and the inflated gas is directly released to maintain the dynamic balance of the pressure in the finger cuff;

[0089] When inflation operation is required, the opening of the inflation valve increases and the opening of the deflation valve decreases to increase the inflation speed; when deflation operation is required, the opening of the inflation valve decreases and the opening of the deflation valve increases to increase the deflation speed.

[0090] The method further includes:

[0091] Reducing the influence of pulse wave fluctuations on pressure measurement through the air chamber connected to the finger cuff.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A non-invasive continuous blood pressure monitoring device, characterized in that: include: Finger cuffs are used to tie around the finger to provide pressure to the finger; A transmitting control unit, used for transmitting the transmitting signal generated by it to the finger in the finger cuff; A receiving control unit, used for receiving the transmission signal after being absorbed by the finger, and converting the transmission signal into a digital signal and sending it to the feedback control unit; A feedback control unit, used to determine the volume change of the blood in the finger through the digital signal, receive the measured pressure value sent by the pressure gauge, determine the required target pressure value according to the measured pressure value and the digital signal, control the over-inflation device and the deflation device based on the control strategy, adjust the pressure value in the finger cuff to the target pressure value, and predict the required pressure value curve; A pressure gauge, used to measure the pressure value in the finger cuff and send the measured pressure value to a feedback control unit; an inflation device, used to inflate the finger cuff under the control of the feedback control unit; A deflation device is used to deflate the finger cuff under the control of the feedback control unit.

2. The device according to claim 1, characterized in that The feedback control unit is specifically used for: Perform uniform sampling or non-uniform sampling according to the pulse wave characteristics, control the inflation and deflation speed according to the inflation and deflation curve, adjust the pressure value in the finger cuff to the target pressure value, and use the PID control method or the standard PPG waveform collected at the average pressure to predict the required pressure value curve, wherein the fast, slow and fast control specifically includes: in the initial stage of inflation and deflation, control the inflation and deflation to increase slowly from 0 with a first predetermined step length; in the middle stage of inflation and deflation, the inflation device or the deflation device reaches the optimal position, and the inflation and deflation speed is controlled to reach the maximum value; at the end of inflation and deflation, control the inflation and deflation speed to decrease slowly with a second predetermined step length.

3. The device according to claim 2, characterized in that The feedback control unit is specifically used for: A low-pass filtering method or an interpolation method is used to improve the smoothness of the uniform sampling or non-uniform sampling curve.

4. The device according to claim 1, characterized in that The inflation device specifically includes: an inflation valve and an inflation pump, wherein the inflation valve is used to control inflation; the deflation device specifically includes: a deflation valve, wherein the deflation valve is used to notify deflation; The initial positions of the inflation valve and the deflation valve are not at the closed point, but at a point within the linear interval, to ensure that the inflation valve directly enters the linear interval upon startup; when in the holding stage, the inflation valve and the deflation valve have the same opening size, and the injected gas is directly released to maintain the dynamic balance of the pressure in the finger cuff.

5. The device according to claim 4, characterized in that The feedback control unit is specifically used for: When inflation operation is required, the inflation valve opening is controlled to increase, and the deflation valve opening is controlled to decrease, thereby increasing the inflation speed; when deflation operation is required, the inflation valve opening is controlled to decrease, and the deflation valve opening is controlled to increase, thereby increasing the deflation speed.

6. The device according to claim 4, characterized in that The device further comprises: The air chamber is connected to the finger cuff and is used to reduce the influence of pulse wave fluctuation on pressure measurement.

7. The device according to claim 4, characterized in that The inflation valve specifically includes: a plurality of switch valves and a plurality of fixed air resistors respectively connected to the plurality of switch valves, wherein the plurality of fixed air resistors provide different inflation speeds for adapting to different finger cuffs.

8. A non-invasive continuous blood pressure monitoring method, characterized in that: The non-invasive continuous blood pressure monitoring device according to any one of claims 1 to 6, wherein the method specifically comprises: The finger cuff is tied around the finger to provide pressure to the finger; The transmitting control unit transmits the generated transmitting signal to the finger in the finger cuff; The receiving control unit receives the transmission signal absorbed by the finger, and converts the transmission signal into a digital signal and sends it to the feedback control unit; Measuring the pressure value in the finger cuff by a pressure gauge and sending the measured pressure value to a feedback control unit; Determine the volume change of the blood in the finger based on the digital signal through a feedback control unit, receive the measured pressure value sent by the pressure gauge, judge the required target pressure value according to the measured pressure value and the digital signal, control the over-inflation device and the deflation device based on the control strategy, adjust the pressure value in the finger cuff to the target pressure value, and predict the required pressure value curve; The finger cuff is inflated by an inflation device under the control of the feedback control unit; and the finger cuff is deflated by an deflation device under the control of the feedback control unit.

9. The method according to claim 8, characterized in that Based on the control strategy, controlling the over-inflation device and the deflation device to adjust the pressure value in the finger cuff to the target pressure value specifically includes: Perform uniform sampling or non-uniform sampling according to the pulse wave characteristics, control the inflation and deflation speed according to the inflation and deflation curve, adjust the pressure value in the finger cuff to the target pressure value, and use the PID control method or the standard PPG waveform collected at the average pressure to predict the required pressure value curve, wherein the fast, slow and fast control specifically includes: in the initial stage of inflation and deflation, control the inflation and deflation to increase slowly from 0 with a first predetermined step length; in the middle stage of inflation and deflation, the inflation device or the deflation device reaches the optimal position, and the inflation and deflation speed is controlled to reach the maximum value; at the end of inflation and deflation, control the inflation and deflation speed to decrease slowly with a second predetermined step length.

10. The method according to claim 9, characterized in that The uniform sampling or non-uniform sampling according to the pulse wave characteristics specifically includes: Adopting a low-pass filtering method or an interpolation method to improve the smoothness of the uniform sampling or non-uniform sampling curve; Inflating the finger cuff by an inflation device under the control of the feedback control unit; and deflating the finger cuff by an deflation device under the control of the feedback control unit specifically include: The initial positions of the inflation valve and the deflation valve are set at a point within the linear interval to ensure that the inflation valve directly enters the linear interval upon startup. When in the holding stage, the inflation valve and the deflation valve have the same opening size, and the gas filled is directly released to maintain a dynamic balance of pressure in the finger cuff. When inflation is required, the inflation valve opening increases and the deflation valve opening decreases, thereby increasing the inflation speed; when deflation is required, the inflation valve opening decreases and the deflation valve opening increases, thereby increasing the deflation speed; The method further comprises: The influence of pulse wave fluctuation on pressure measurement is reduced by the air chamber connected to the finger cuff.

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