Method and apparatus for non-invasive measurement of central arterial pressure and other intraluminal aortic pressures

Abstract

The present invention provides a method and device for non-invasive measurement of central arterial pressure and other intraluminal aortic pressure. Blood flow and vascular elasticity are the main factors affecting the acquisition of pulse waveforms, and the position of the midstream airbag strap (2) can be placed at the same height as the intraluminal aorta of the human body, and the upstream signal channel (1) can be placed close to the trunk of the human body and very close to the intraluminal aorta, so that the influence of vascular elasticity can be minimized. Under the condition that the width of the midstream airbag strap (2) is sufficient, by using the relationship between the pressure in the blood vessel and the pressure of the airbag strap outside the blood vessel, under the condition that the blood flow velocity at the time of the upstroke of the pulse wave is zero, by using the relationship between the blood pressure in the upstream blood vessel and the blood pressure in the midstream blood vessel, under the condition that the blood flow acceleration is zero, by using the relationship between the blood pressure in the blood vessel under the complete block state and the blood pressure in the blood vessel under the semi-active state, the maximum value of the blood pressure in the blood vessel under the complete block state is obtained, and this value is approximately equal to the systolic blood pressure of the intraluminal aorta, and the measurement error caused by the blood flow is avoided to the maximum extent. The diastolic pressure of the intraluminal aorta is approximately equal to the diastolic pressure of the brachial or femoral arteries.

Description

[Technical field]

[0001] The present invention relates to blood pressure measurement, and in particular to a method and apparatus for the non-invasive measurement of central arterial pressure and other intraluminal aortic pressures. [Background technology]

[0002] The 2003 ESH / ESC Hypertension Management Guide states that there is a difference between central arterial pressure and brachial arterial pressure. Compared with the brachial arterial pressure measurement commonly used in daily clinical practice, central arterial pressure has a closer relationship with organs such as the heart, brain, and kidneys and their complications, and has a stronger independent predictive value for cardiovascular disease and related complications. Central arterial pressure is the lateral pressure received by the ascending aorta root vessel. In theory, central arterial pressure has a closer relationship with damage to target organs and cardiovascular disease, and its predictive value for cardiovascular events is better than that of peripheral brachial artery pressure, which has already been demonstrated in some clinical trials. Research has shown that central arterial pressure (brachial arterial pressure) has a better clinical predictive value than peripheral arterial pressure (brachial arterial pressure). Therefore, the measurement of central arterial pressure is of great significance.

[0003] The measurement method of central arterial blood pressure can be divided into non-invasive and minimally invasive measurement methods according to the presence or absence of wounds. The drug-inducing catheter method measures central arterial blood pressure, uses a left heart catheter to directly measure the ascending aortic root pressure, and at the same time converts the pressure into readable data with a pressure transducer, and continuously records the central arterial blood pressure waveform, which can accurately reflect the magnitude of central arterial blood pressure, and is the most accurate method of central arterial blood pressure measurement. Minimally invasive central arterial blood pressure measurement is considered the gold standard for central arterial blood pressure measurement, but its measurement method involves invasive testing, which is expensive and difficult to operate, and has certain limitations in its widespread deployment in clinical practice, limiting its widespread application.

[0004] Non-invasive measurement of central arterial blood pressure is a more feasible measurement method. Currently, the commonly used non-invasive measurement devices for central arterial blood pressure mainly obtain central arterial pressure by non-invasive methods such as plane pulse wave analysis of the carotid artery and radial artery and expansion wave analysis of the carotid artery. (1) Alternative method: The aortic pressure wave is approximated by the carotid pressure wave, but it cannot be directly measured by a sphygmomanometer. (2) Visual method: The ascending arterial pressure is changed and analyzed by visually observing the delayed systolic waveform of the radial artery pressure wave, which belongs to semi-quantitative. (3) Synthesis method: The ascending arterial pressure is synthesized from the radial artery pressure wave, that is, the radial artery pulse wave is non-invasively recorded by a contact pressure probe using an arterial pulse wave analyzer, and converted into a central arterial pulse wave by computer processing. However, all of the above three methods have the defect of large measurement errors. Summary of the Invention [Problem to be solved by the invention]

[0005] One object of the present invention is to provide a method for non-invasive measurement of central arterial and other intraluminal aortic pressures that can accurately measure central arterial and other intraluminal aortic pressures.

[0006] Another object of the present invention is to provide a non-invasive central arterial and other intraluminal aortic pressure measuring device that can accurately measure central arterial and other intraluminal aortic pressures.

[0007] Another object of the present invention is to provide a three-channel pulse wave signal sensor that can accurately measure central arterial pressure and other intraluminal aortic pressures. [Means for solving the problem]

[0008] In the present invention, the electronic signal sensor refers to an electrokinetic transducer for converting the pulse wave signal of the channel to be measured, excluding the airbag, into an electronic signal, including, but not limited to, a pressure sensor and a photoelectric sensor.

[0009] Central arterial pressure is the lateral pressure received by the blood vessels at the base of the ascending aorta. As can be seen from the structure of the human body, the left subclavian artery of the human body originates from the ascending aorta, continues to the axillary artery, and then continues to the brachial artery to form a continuous arterial tube. Several different arterial branches also originate from other positions of this continuous arterial tube, but most of them belong to relatively small arterial blood vessels. Here, one relatively large branch is the left basilar artery, which is connected to the upper wall of the first segment of the left subclavian artery. Therefore, when the left arm is blocked from the brachial artery blood vessel and the left arm blood pressure measurement position is in the same horizontal position as the ascending aorta, the pressure felt at the left arm blood pressure measurement position corresponds to the pressure at the connection point between the upper wall of the left subclavian artery starting segment and the left basilar artery. At the same time, the left subclavian artery first segment has a large inner diameter, is short in length, and the blood flow speed at this position is not fast. Therefore, when there is no serious blockage in the left subclavian artery first segment, the flow resistance of this segment is not large and the pressure difference formed is not significant. Thus, when the arterial blood vessels of the left arm are blocked and the left arm blood pressure measuring position is in the same horizontal position as the ascending aorta, the blood pressure at the left arm blood pressure measuring position corresponds to the pressure at the junction between one end of the left subclavian artery and the ascending aorta, which by definition is the central arterial pressure.

[0010] When the first segment of the left subclavian artery is seriously blocked, the right arm measurement can be adopted. When the right subclavian artery starts from the brachiocephalic artery, the right arm brachial artery vessel is blocked, and the blood pressure measurement position on the right arm is in the same horizontal position as the ascending aorta, the blood pressure at the blood pressure measurement position on the right arm corresponds to the pressure at the connection point between one end of the right subclavian artery and the brachiocephalic artery, which is close to the central arterial pressure, but has a certain measurement error. The central arterial pressure measured in the right arm has a relatively certain error, but in reality the blood pressure measured in the right arm is the innominate arterial pressure, which is only very close to the central arterial pressure.

[0011] In addition to the central arterial pressure, other intracavitary aortic pressures include the innominate arterial pressure and the abdominal aortic tip, etc. Here, intracavitary means intraperitoneally or intrathoracically. The blood measured in the right arm is actually the blood pressure of the innominate artery, and the blood pressure measured in the lower limb is the blood pressure at the end of the abdominal aorta. The technology of the present invention can measure not only the central arterial pressure, but also the aortic pressure in other cavities. Or, the technology of the present invention can measure the blood pressure in the lower limbs as well as the blood pressure in the upper limbs.

[0012] In order to accurately measure central arterial pressure and other intraluminal aortic pressure, first, the collected pulse wave and the central arterial or other intraluminal aortic waveform can be as close as possible. Because blood flow and blood vessel elasticity are factors that affect the collection of pulse waveforms, when collecting central arterial pressure or other intraluminal aortic pressure waveforms, the collection position should be as close as possible to the ascending aorta or other intraluminal aorta, while blocking arterial blood flow. Second, the position where the pulse wave waveform is collected and the position where the brachial artery blood pressure, femoral artery blood pressure, etc. are measured can be as close as possible.

[0013] The device of the present invention comprises a three-channel pulse wave signal sensor, a two-way air valve, a linear air valve, an air pump, a pressure sensor, a signal amplifier, a microprocessor, a display, a keyboard, etc. The microprocessor is connected to a pulse wave signal analog-to-digital converter (ADC), or the pulse wave signal analog-to-digital converter is directly integrated into the microprocessor.

[0014] The three-channel pulse wave signal sensor is divided into three signal channels, upstream, midstream, and downstream, according to the blood flow direction. The midstream signal channel is an air-filled airbag, which can block arterial blood flow when filled with air. The width of the airbag of the midstream signal channel is similar to that of the airbag of the conventional Korotkoff sound method, and the minimum width is determined according to the circumference of the subject's limb. The upstream signal channel and the downstream signal channel may be pressure or photoelectric sensors and designed as airbags. The separation distance between the upstream signal channel, the midstream signal channel, and the downstream signal channel is designed according to the length of the subject's limb. Depending on the use, the three signal channels may be closely connected to form one whole, or may be spaced apart. The separation distance between the upstream signal channel and the midstream signal channel may be preferably set between 0-15 cm, and the separation distance between the midstream signal channel and the downstream signal channel may be preferably set between 0-30 cm.

[0015] When the upstream signal channel and the downstream signal channel are airbags, the upstream airbag connects the first two-way air valve through a tube and connects the first pressure sensor through a tube. The midstream airbag connects the second two-way air valve through a tube and connects the micro-hole air valve through a tube, and the micro-hole air valve connects to the downstream airbag through a tube. The downstream airbag connects to the third two-way air valve through a tube and also connects to the second pressure sensor and the other end of the micro-hole air valve through a tube.

[0016] The other ends of the three two-way air valves are connected through tubes, and are connected through tubes to a third pressure sensor, an air pump, and a linear air valve. The three pressure sensors are respectively connected through wires to signal amplifiers, and the signal amplifier output ends are connected through wires to three analog-to-digital converter input ends of a microprocessor. The microprocessor is connected to a display and a keyboard, and the microprocessor is simultaneously connected through wires to the three two-way air valves, the three pressure sensors, the linear air valve, and the air pump.

[0017] In order to better explain the measurement process and calculation method of the present invention, the relevant times and variables are now defined as follows.

[0018] When the inflation pressure of the midstream airbag is much greater than the arterial systolic blood pressure, the arterial blood flow is completely blocked at this point, and the complete blockage time region t x It is called.

[0019] After the midstream airbag fills with air to block the arterial blood flow, it gradually releases the air, and the downstream signal sensor begins to generate multiple pulse wave signals, which is the half-block time region t y It is called.

[0020] Half block time domain t y At t, the downstream signal channel begins to generate a pulse wave signal. The upstroke time of the downstream pulse wave signal is t I It is called the time

[0021] After the midstream airbag is filled with air to block the arterial blood flow, the air pressure change of the midstream airbag can reflect the change in the volume of blood in the arterial blood vessel. I In the pulse wave signal cycle at time t, the pulse wave upstroke time is I Calculate the second derivative of the gas pressure curve in the mid-block airbag to obtain the brachial artery blood flow acceleration curve, and find the first positive-to-negative zero crossing point on the acceleration curve. II is called the time point.

[0022] Half block time domain t y In one pulse cycle, the pulse wave is II The delay time Δt from the upstroke of the upstream pulse wave to the time point t is measured, and in a pulse cycle with a complete block time region Tx, the time point is delayed by the same time Δt from the upstroke of the upstream pulse wave. III is called the time point.

[0023] The concept of measuring the central arterial pressure and the aortic pressure in other cavities according to the present invention is as follows.

[0024] 1. When the width of the midstream airbag strap is sufficient, the blood pressure in the brachial artery or femoral artery at the location of the midstream airbag strap will be equal to the pressure of the midstream airbag strap at the upstroke of the downstream pulse wave.

[0025] 2. In the half-block state, at the upstroke of the downstream pulse wave, the blood flow velocity is equal to zero, and the blood pressure in the brachial artery or femoral artery at the upstream position is equal to the blood pressure in the brachial artery at the midstream airbag strap position, and is also equal to the pressure of the midstream airbag strap. In other cases, none of them are equal to the pressure of the midstream airbag strap.

[0026] 3. In the half-block state, the time when the blood flow acceleration is zero is calculated by the midstream pressure curve. Based on the upstream pressure curve and the blood pressure in the brachial artery at the upstream position of the upstroke time of the downstream pulse wave, the blood pressure in the brachial artery or femoral artery at the upstream position of the time when the blood flow acceleration is zero is calculated. Here, the acceleration is found to be zero.

[0027] 4. According to the delay time when acceleration is zero under the half-block state, find the same delay time point under the full block state. The blood pressure in the brachial artery or femoral artery located upstream at this time point is equal to the blood pressure in the brachial artery located upstream at the time when acceleration is zero under the half-block state.

[0028] 5. Based on the upstream pressure curve under complete blockage and the blood pressure in the brachial artery at the upstream position at the time when the acceleration is zero under complete blockage, calculate the maximum pressure in the brachial artery or femoral artery at the upstream position under complete blockage, i.e., the systolic pressure of the aorta in the central artery or other cavity.

[0029] 6. Under diastolic blood pressure conditions, blood flow velocity approaches zero and the central arterial or other intraluminal aortic diastolic pressure is approximately equal to the brachial or femoral artery diastolic pressure.

[0030] In the following, the blood pressure measurement process is described by taking the airbags as the upstream channel and downstream channel as an example and using a three-channel pulse wave signal sensor as follows.

[0031] First step: (Generally, the first step is an unnecessary step) Open the two-way air valve connected to the midstream airbag, close the linear air valve, start the air pump, fill the midstream airbag with air through the two-way air valve, and fill the downstream airbag with air through the micro-hole air valve, and detect and collect the air pressure fluctuation signal of the downstream airbag until the arterial blood flow stops, that is, until the pulse wave signal of the downstream airbag becomes zero. Open the two-way air valve connected to the midstream airbag, gradually open the linear air valve, the midstream airbag gradually degasses, the brachial artery blood flow gradually begins to flow, the downstream signal channel begins to appear a pulse wave signal, record the first several pulse wave signal amplitudes that appear in the downstream signal channel, and synchronously record the air pressure of the midstream airbag for each pulse, and both perform linear fitting to calculate the air pressure of the midstream airbag corresponding to the time when the pulse wave signal amplitude of the downstream signal channel is at the zero crossing point, that is, the brachial artery systolic blood pressure. The midstream airbag continues to vent, and the time delay between the air pressure fluctuation signal of the midstream airbag and the pulse wave signal of the downstream signal channel is measured, and the time when the time delay gradually decreases to a certain value is calculated by fitting, and the air pressure of the midstream airbag at this time is the brachial artery diastolic blood pressure. For the calculation method of using the pulse wave amplitude and time delay to determine the brachial artery blood pressure, please refer to the Chinese invention patent ZL 201010247968.6 entitled "Non-invasive blood pressure measurement device", its registration number is CN101912259B, and its inventor is the first inventor of this application, Wu Xiaoguang. Herein, the entire content of this patent document CN101912259B is incorporated herein by reference.

[0032] Second step: Start the air pump and fill the upstream airbag with air to several tens of milliamers through the two-way air valve. (When the first step is performed, the upstream airbag is pressurized to about the brachial artery diastolic pressure according to the arterial diastolic pressure measured in the first step.) At that time, start synchronously collecting the pulse wave signal of the upstream signal channel, the pulse wave signal of the downstream signal channel, and the gas pressure signal of the midstream airbag until the measurement is completed.

[0033] Third step: start the air pump, fill the midstream airbag with air through the two-way air valve, and fill the downstream airbag with air through the micro-hole air valve, collect the pulse wave signal of the downstream airbag, and synchronously detect and collect until the flow of the brachial artery blood flow stops, that is, until the pulse wave signal of the downstream airbag becomes zero. At that time, the air pressure of the midstream airbag is almost equal to the brachial artery systolic blood pressure. By continuously filling the midstream airbag with air, the air pressure of the midstream airbag is greater than the brachial artery systolic blood pressure, which is generally 10-100 mmHg.

[0034] Fourth step: Close all air valves, stop filling the midstream airbag with air, and wait for several cardiac cycles, now in a completely blocked state. The waiting period is the complete block time domain t x It is called

[0035] Fifth step: open the two-way air valve connected to the midstream airbag, gradually open the linear air valve, the midstream airbag gradually releases gas, the brachial artery blood flow gradually starts to flow, and the downstream signal channel starts to show a pulse wave signal, which is in a half-block state. At this time, the half-block time domain t yIt is called. Record the amplitude values ​​of the pulse wave signal that first begin to appear in the downstream signal channel, synchronously record the air pressure of the midstream airbag for each pulse, and linearly fit the two to calculate the air pressure of the midstream airbag corresponding to the zero crossing point of the amplitude of the pulse wave signal of the downstream signal channel, that is, the brachial artery systolic blood pressure. The midstream airbag continues to release gas, and measures the time delay between the air pressure fluctuation signal of the midstream airbag and the pulse wave signal of the downstream signal channel, and fittingly calculates the time when the time delay gradually decreases to a certain value, and the air pressure of the midstream airbag at this time is the brachial artery diastolic blood pressure. This brachial artery diastolic blood pressure is used to calculate the central artery systolic blood pressure.

[0036] Sixth step: Based on the pulse wave signal of the upstream signal channel, the pulse wave signal of the downstream signal channel, the air pressure signal of the midstream airbag, and the brachial artery diastolic blood pressure value collected synchronously in the above steps, the central arterial systolic pressure and diastolic blood pressure values ​​are calculated, and the measurement is completed.

[0037] Based on the upstream, midstream and downstream three-channel pulse wave signal data collected by the above method and the gas pressure in the upstream and midstream airbags, the central arterial pressure was calculated, and five steps were adopted.

[0038] The meaning of the steps and parameters of the method of the present invention can be understood with reference to FIGS.

[0039] For ease of explanation, the relevant variables are defined as follows:

[0040] P C is the central arterial blood pressure, and P CS is the central arterial systolic pressure, and P CII , P CIII are t II , t III is the central arterial blood pressure at the time point, P Cd is the central arterial diastolic pressure.

[0041] P1 is the blood pressure in the brachial artery at the upstream signal channel location, and P 1I , P 1II, P 1III are t I , t II , t III is the blood pressure in the brachial artery at the upstream signal channel position at time 1s is the complete block time domain t x In the middle, t I is the maximum value of the blood pressure in the brachial artery at the upstream signal channel position within one pulse cycle where P d is the diastolic blood pressure in the brachial artery at the upstream signal channel position. H1 is the signal strength at the upstream signal channel position or the air pressure in the upstream airbag, and H 1I , H 1II , H 1III are t I , t II , t III is the signal strength of the upstream signal channel at the time or the air pressure in the upstream airbag, 1s is the complete block time domain t x In the middle, t I The maximum value of the upstream signal channel signal strength or the air pressure in the upstream airbag within one pulse cycle where is located.

[0042] H d is the signal amplitude at diastolic pressure in the upstream signal channel; P2 is the blood pressure in the brachial artery at the midstream airbag location; P 2I , P 2II are t I , t II is the blood pressure in the brachial artery at the position of the midstream airbag at time t1, H2 is the air pressure in the midstream airbag, and H 2I , H 2II are t I , t II is the air pressure in the midstream airbag at the time.

[0043] P 2d is the diastolic pressure of the blood in the brachial artery at the midstream signal channel position. When the blood in the brachial artery is in the diastolic phase, the blood in the artery does not flow, so the diastolic pressure of the blood in the brachial artery is equal to that at the upstream signal channel position and the midstream airbag position, i.e., P d =P2d It is.

[0044] At the time of diastolic blood pressure, the blood in the brachial artery does not flow, and during the measurement process, the measurement airbag and the ascending aorta are in the same horizontal position, so the diastolic blood pressure P measured at the position of the brachial artery d , i.e., the diastolic pressure of the central artery, i.e., P Cd =P d =P 2d It is.

[0045] The specific calculation steps are as follows:

[0046] First step: Half-block time domain t y Within the time period, the downstream signal sensor starts to generate a pulse wave signal, and at the upstroke time of the pulse wave signal, i.e., t I The gas pressure in the midstream block airbag at time t I This is the blood pressure in the brachial artery at time t.

[0047] t I At this point, if the width of the midstream block airbag is sufficient, the blood pressure in the brachial artery at the location of the midstream signal channel will be approximately equal to the gas pressure in the midstream block airbag, and the following equation 1 will hold:

[0048] P 2I =H 2I (1)

[0049] Step 2: I The blood pressure P in the brachial artery at the midstream airbag position at the time 2I By t I The lateral pressure P due to blood in the brachial artery at the upstream signal channel position at 1I Calculate.

[0050] At the regular time, the midstream airbag is filled with air and pressurized, and then the arterial blood flow is blocked. The brachial artery blood pressure P 2I has the following formula 2:

[0051] P2I =P C -ρa I L2(2)

[0052] In formula 2, P C is the central arterial pressure, and a I is I is the acceleration of the blood flow at the time point, L2 is the length of the blood vessel from the connection point between one end of the left subclavian artery and the ascending aorta to the midstream airbag, and ρ is the density of blood.

[0053] The sensor or air bag in the upstream signal channel appropriately pressurizes the limb to be measured, senses the pulse wave fluctuations of the brachial artery located in the upstream signal channel, and does not block blood flow. I The upstream signal channel position at the time, the lateral pressure P of the blood in the brachial artery to the arterial blood vessel 1I has the following formula 3:

[0054]

number

[0055] In equation 3, V I is I where L1 is the velocity of blood flow in the brachial artery at the time point, and L2 is the length of the blood vessel from the connection between one end of the left subclavian artery and the ascending aorta to the upstream channel.

[0056] t I At this time, the arterial blood flow velocity is approximately zero, i.e.

number

number

[0057]

number

[0058] Furthermore, the following equation is obtained from equations 1 and 4. P 1I =H 2I (5)

[0059] That is, t I The blood pressure in the brachial artery at the upstream channel position at time t I The pressure in the midstream airbag at that point is equal to the pressure of the gas in the midstream airbag.

[0060] Third step: Time domain t x In I The upstream channel pressure curve within one pulse cycle at a time, and t I The blood pressure in the brachial artery at the upstream channel position at the time P 1I By this, t II The blood pressure in the brachial artery at the upstream channel position at the time P 1II Calculate.

[0061] Half block time domain t y In order to keep the air pressure in the upstream airbag constant, the sensor in the upstream signal channel measures the degree of pressurization to the brachial artery. I Within a given cardiac cycle, the proportional relationship between the air pressure signal strength in the upstream airbag and the blood pressure in the brachial artery remains constant.

[0062] Therefore, we have the following equation 6.

[0063]

number

[0064] Furthermore, the following formula 7 was obtained.

number

[0065] Fourth step: Half-block time domain t y , tII The blood pressure in the brachial artery at the upstream signal channel position at time P 1II Based on the complete block time domain t x , t III The blood pressure in the brachial artery at the upstream signal channel position at time P 1III Calculate.

[0066] t II As can be seen from the definition of time, the acceleration of the blood in the brachial artery at this time is a = 0, and t II The blood pressure in the brachial artery at the upstream signal channel position at time P 1II is given by the following equation 8.

[0067]

number

[0068] In the formula, V II t II The maximum brachial artery blood flow velocity V is 60-100 cm / s when the blood density is assumed to be 60-100 cm / s. max = 100 cm / s, the maximum effect of blood flow velocity on pressure is:

[0069]

number

[0070] t II At time t, the brachial artery is partially blocked and the blood flow velocity of the brachial artery is much smaller than the maximum blood flow velocity when the artery is fully open. II At this point, the effect of blood flow velocity on pressure is less than 3.75 mmHg and can be neglected.

[0071] Therefore, we have the following equation 9.

[0072]

number

[0073] t III At time t x Since the brachial artery blood flow velocity and acceleration are both close to zero,

number

[0074] Here, V III t III is the velocity of blood flow in the brachial artery at time a III t III is the acceleration of blood flow at a given point in time.

[0075]

number

[0076] In short-term measurements, the subject's central arterial pressure and the onset of its waveform are considered to be constant. II Time and t III For the cardiac cycle in which the time is located, the upstroke time of the pulse wave is t xC and t yC If so, the following may be possible:

[0077]

number

[0078] Here, t is any time interval less than one cardiac cycle.

[0079] Therefore, t II Time and t III Since the delay time Δt at the upstroke of the pulse wave at each point is the same, we obtain Equation 11.

[0080] P CII =P CIII (11)

[0081] Equation 12 is obtained from equations 9, 10, and 11.

[0082] P 1III =P 1II (12)

[0083] Fifth step: III Within the cardiac cycle in which the time point is located, the pressure curve of the upstream signal channel and t III The blood pressure in the brachial artery at the upstream signal channel position at time P 1III The maximum value of the blood pressure in the brachial artery at the position of the upstream signal channel, P 1s Calculate the central arterial systolic pressure P cs can be obtained approximately.

[0084] Complete block time domain t x , the brachial artery blood flow velocity and acceleration are both close to zero, and during the measurement process, the measurement airbag and the ascending aorta are kept in the same horizontal position, so the central arterial pressure systolic pressure is the maximum value P 1s That is, P CS ≒P 1s It is.

[0085] Complete block time domain t x In order to maintain a constant pressure level in the brachial artery or air pressure in the upstream airbag, the sensor in the upstream signal channel III Within a given cardiac cycle, the proportional relationship between the air pressure signal strength in the upstream airbag and the blood pressure in the brachial artery remains constant.

[0086]

number

[0087] From equations 5, 7, 12, and 13, the following equations 14 and 15 can be obtained.

[0088]

number

[0089] P cs =P 1s (15)

[0090] Therefore, the non-invasive measurement method for central arterial pressure and other intracavity aortic pressure of the present invention uses a three-channel pulse wave signal sensor to obtain a pulse wave signal, and further obtains accurate central arterial pressure and other intracavity aortic pressure, and is characterized in that: Feature 1 is as follows: a midstream block airbag is used, and the air pressure of the airbag is much higher than that of the arterial blood systole. At this time, the arterial blood vessel is completely blocked, and almost no blood flows in the blood vessel, eliminating the influence of blood flow on the central arterial pressure measurement. Therefore, the blood pressure that the midstream blocker can feel is close to the central arterial pressure.

[0091] Feature 2 is as follows: a midstream block airbag is used, and a downstream pulse wave detector is installed downstream of the midstream block airbag in the arterial blood flow direction. The airbag is blocked from filling with air, and after blocking the arterial blood flow, the gas is gradually released. Just after the block airbag enters a semi-blocked state, the air pressure value of the block airbag corresponding to the upstroke time when the downstream pulse wave detector outputs a signal is collected. If the width of the block airbag is sufficient, the air pressure value of the block airbag corresponding to this upstroke time is close to the blood pressure in the arterial blood vessel at this time.

[0092] Feature 3 is as follows: an upstream pulse wave detector is installed upstream of the block airbag in the direction of arterial blood flow. At the time of the upstroke when the downstream pulse wave detector outputs a signal, the blood flow velocity in the arterial blood vessel is close to zero, and the blood pressure in the arterial blood vessel at the position of the upstream pulse wave detector is equal to the blood pressure in the arterial blood vessel at the position of the block airbag.

[0093] Feature 4 is as follows: the second derivative of the air pressure fluctuation curve immediately after the midstream block airbag enters the half-block state is calculated, the first zero-cross point where the airbag changes from positive to negative, i.e., the zero-cross point of the blood flow acceleration, is found, and the delay time from the upstroke of the pulse wave to the zero-cross point of the acceleration is measured. In the two states, the half-block state and the complete block state, for each pulse wave signal of a certain cardiac cycle, the delay time starting from the upstroke of the pulse wave and the blood pressure in the arterial blood vessel at the upstream pulse wave detection position corresponding to these two times are approximately equal.

[0094] Feature 5 is as follows: the tightness with which the upstream pulse wave detector is attached to the limb is kept constant during measurement, or if the upstream pulse wave detector is an air-filled airbag, the pressure of the filled air does not change during measurement, so that the strength of the output signal from the upstream pulse wave detector is directly proportional to the blood pressure in the blood vessel located upstream.

[0095] Feature 6 is as follows: the signal curve when the upstream pulse wave detector is completely blocked and the pressure in the arterial blood vessel at the acceleration zero crossing point at the upstream pulse wave detection position are collected, and the maximum pressure in the arterial blood vessel at the upstream pulse wave detection position is calculated, which is approximately equal to the central arterial systolic pressure.

[0096] The widths and positions of the three signal channels of the three-channel pulse wave signal sensor will be described below.

[0097] 1. Determine the width and location of the upstream, midstream and downstream airbag straps

[0098] 1. The width of the midstream airbag strap is determined by the circumference of the upper limb of the subject. The correspondence between the width and the circumference of the upper limb of the subject is similar to the cuff requirements of the Korotkoff blood pressure monitor. If the circumference of the upper limb of the subject is large, the width of the midstream airbag strap will be increased accordingly, and if the circumference of the upper limb of the subject is small, the width of the midstream airbag strap will be decreased accordingly.

[0099] 2. The width of the upstream and downstream airbag straps should not be too narrow or too wide. If the width of the upstream and downstream airbag straps is too narrow, the output pressure signal will be too small, which will affect the measurement accuracy. If the width of the upstream and downstream airbag straps is too wide, the time resolution will be poor, and the subject's upper limb length is limited, so the width of the upstream and downstream airbag straps should not be too wide.

[0100] Generally, the width of the upstream and downstream airbag straps is in the range of 1 to 5 cm, preferably 2 to 3 cm, and both the measurement accuracy and time resolution accuracy are favorable within this range.

[0101] 3. In order to ensure measurement accuracy, it is preferable that the upstream airbag strap is as close as possible to the parts close to the limbs and trunk, and the upper edge of the midstream airbag strap is as close as possible to the lower edge of the upstream airbag strap and is not completely connected; otherwise, it is easy to cause mutual interference between the upstream airbag strap and the midstream airbag strap.

[0102] In actual measurements, if the upper limb length allows, the upstream, midstream, and downstream airbag straps may be positioned simultaneously on the upper limb above the elbow joint, or the upstream and midstream airbag straps may be positioned on the upper limb above the elbow joint, and the downstream airbag strap may be positioned below the elbow joint.

[0103] When measuring the lower leg, the downstream airbag strap may be bound below the knee joint.

[0104] Second, when the upstream and / or downstream signal channel adopts an electronic signal sensor, such as a pressure sensor or a photoelectric sensor, a strap bracket can be used to fix the upstream and downstream pressure sensors or photoelectric sensors and the midstream airbag strap. The distance and position between the upstream, midstream and downstream are determined by the strap bracket, and the clearance between the center position of the upstream electronic signal sensor and the upper edge of the midstream airbag can be between 0-15cm, generally 1cm. The clearance between the center position of the downstream electronic signal sensor and the lower edge of the midstream airbag can be between 0-30cm, generally 1cm.

[0105] There is a fixing strap on the upper surface of the strap bracket to fix the upstream and downstream sensors. In actual application, the fixing straps of the upstream and downstream electronic signal sensors should be appropriately fastened so that the upstream and downstream electronic signal sensors are fixed to the body surface of the artery of the measured body so that they cannot move and do not affect the blood flow.

[0106] As with the sensor strap using three airbags, in a sensor strap using an electronic signal sensor in an upstream signal channel, it is preferable that the upstream electronic signal sensor is as close as possible to the limbs or trunk, and the upper edge of the midstream airbag strap is as close as possible to the lower edge of the upstream electronic signal sensor without being completely connected, otherwise it is easy to cause mutual interference between the upstream and midstream signal channels.

[0107] In actual measurements, if the length of the upper limb allows, the upstream, midstream, and downstream signal channels may be placed simultaneously in the upper limb above the elbow joint, or the upstream and midstream signal channels may be placed in the upper limb above the elbow joint and the downstream signal channel may be placed below the elbow joint and further in the arm artery.

[0108] When measuring the lower limbs, the downstream electronic signal sensor may be positioned below the knee joint.

[0109] In the three-channel pulse wave signal sensor of the present invention, at least the midstream signal channel uses an airbag and the airbag is fixed by a strap, while the upstream and midstream signal channels do not necessarily need to be fixed by a strap, and the upstream and downstream electronic signal sensors need to be fixed to the body surface of the artery of the subject to be measured, so as to be immobile and not affect the blood flow. In other words, the upstream, midstream and downstream signal channels may be integrated or separated, and may be integrated or connected to the body part at a certain distance only by a connecting structure, such as a bracket, a connecting strip, etc.

[0110] In order to achieve the object of the present invention, the present invention provides a method for non-invasively measuring central arterial pressure and other intracavitary aortic pressure, comprising: acquiring pulse wave signals using a three-channel pulse wave signal sensor corresponding to a limb to be measured; the three-channel pulse wave signal sensor is divided into an upstream signal channel, a midstream signal channel and a downstream signal channel according to the blood flow direction; the upstream signal channel is a strap body incorporating an airbag or an upstream electronic signal sensor; the midstream signal channel is a midstream strap of a strap body incorporating an airbag; and the downstream signal channel is a The central arterial pressure and other intracavitary aortic pressure non-invasively measuring method includes the following steps: filling the airbag of the midstream strap with air, and detecting and collecting the pulse wave output signal of the upstream signal channel and the pulse wave output signal of the downstream signal channel until the brachial artery blood flow or the femoral artery blood flow stops, that is, until the pulse wave output signal of the downstream signal channel becomes zero; Step C: recording the air pressure value, continuing to inflate the air bag of the midstream strap with air, and monitoring the air pressure of the midstream strap, stopping air inflation until the air pressure of the midstream strap is 10-100 mmHg greater than the recorded air pressure value, at which time the blood flow of the brachial artery or the blood flow of the femoral artery is in a completely blocked state, and collecting pulse wave output signals of the upstream signal channel for several cardiac cycles; and step C: gradually deflating the air bag of the midstream strap, and collecting the output signal of the upstream signal channel through a signal amplifier and the Start to synchronously collect the output signal of the midstream signal channel and the output signal of the downstream signal channel, and a pulse wave signal gradually appears in the downstream signal channel, indicating that the blood flow of the brachial artery or the blood flow of the femoral artery gradually begins to flow, and at this time, the blood flow of the brachial artery or the blood flow of the femoral artery is in a semi-blocked state; during this process, collect the output signal of the upstream signal channel, the output signal of the midstream signal channel, and the output signal of the downstream signal channel, and collect some pulse wave signals that first appear in the downstream signal channel, therebyStep D: determining a time of an upstroke point of the pulse wave signal of the downstream signal channel, measuring the air pressure in the airbag of the midstream signal channel at that time, obtaining the blood pressure in the brachial artery or the femoral artery at the position of the midstream signal channel at that time, and obtaining that the blood flow velocity at the time of the upstroke point of the pulse wave signal of the downstream signal channel is approximately zero, the blood pressure in the brachial artery or the femoral artery at the position of the upstream signal channel is equal to the blood pressure in the brachial artery or the femoral artery at the position of the midstream signal channel, and the blood pressure in the brachial artery or the femoral artery at the position of the upstream signal channel is equal to the air pressure in the airbag of the midstream strap at that time; and Step D: recording the amplitude of several pulse wave signals that first appear in the downstream signal channel under a half-blocked state, synchronously recording the air pressure in the airbag of the midstream signal channel for each pulse, and performing linear fitting between the two, and obtaining the blood pressure in the brachial artery or the femoral artery at the time of the upstroke point of the pulse wave signal of the downstream signal channel. Calculate the air pressure of the airbag of the midstream signal channel, i.e., the systolic blood pressure of the brachial artery or the systolic blood pressure of the femoral artery; continue deflating the airbag of the midstream strap; measure the time delay between the air pressure fluctuation signal of the airbag of the midstream strap and the pulse wave signal of the downstream signal channel; perform fitting; and calculate the time when the time delay gradually decreases to a certain value; the air pressure of the midstream airbag at that time is the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery; Step E, the diastolic blood pressure of the artery is used to calculate the systolic blood pressure of the central artery or the systolic blood pressure of the other intraluminal aorta; and based on the pulse wave signal of the upstream signal channel, the pulse wave signal of the downstream signal channel, the air pressure signal of the midstream airbag, and the diastolic blood pressure value of the brachial artery or the diastolic blood pressure value of the femoral artery, which are synchronously collected in the process, the systolic blood pressure value and the diastolic blood pressure value of the central artery or the systolic blood pressure value and the diastolic blood pressure value of the other intraluminal aorta are calculated, and the measurement is terminated, where at the delay time under a complete block state:and F. obtaining a maximum value of the blood pressure in the brachial artery or the blood pressure in the femoral artery under a complete block state based on the blood pressure in the brachial artery or the blood pressure in the femoral artery at the position of the upstream signal channel and the curve of the pulse wave signal of the upstream signal channel of several cardiac cycles under a complete block state collected in the step C, the maximum value being approximately equal to the systolic blood pressure of the central artery or the systolic blood pressure of the aorta in the other cavity, and in the vicinity of the diastolic blood pressure point, the velocity of the blood flow in the brachial artery or the blood flow in the femoral artery is approximately zero, so that the diastolic blood pressure value measured at the position of the brachial artery or the femoral artery is approximately equal to the diastolic blood pressure of the central artery or the diastolic blood pressure of the aorta in the other cavity.

[0111] In a preferred embodiment, in step D, the second derivative of the airbag air pressure variation curve of the midstream signal channel under the half-blocked state is calculated to find the first zero-crossing point where the airbag air pressure changes from positive to negative, i.e., the zero-crossing point of the blood flow acceleration, and based on the signal curve of the upstream signal channel at that time and the blood pressure in the brachial artery at the position of the upstream signal channel at the upstroke time of the pulse wave signal of the downstream signal channel under the half-blocked state, calculate the blood pressure in the brachial artery or the blood pressure in the femoral artery at the position of the upstream signal channel at the time of the zero-crossing point of the blood flow acceleration under the half-blocked state; and for one cardiac cycle of the airbag air pressure curve of the midstream signal channel, measure the delay time between the upstroke time of the pulse wave and the zero-crossing point of the blood flow acceleration under the half-blocked state; Under the complete block state, for one cardiac cycle of the signal curve of the upstream signal channel, the corresponding delay time, i.e., the delay time from the upstroke time of the pulse to that point, is determined to be the same as the delay time, and under the complete block state, the blood pressure in the brachial artery or the femoral artery at the position of the upstream signal channel at this delay time is approximately equal to the blood pressure in the brachial artery or the femoral artery at the position of the upstream signal channel at the same delay time under a half block state.

[0112] In a preferred embodiment, during the measurement process, the airbag of the midstream strap and the intraluminal aorta to be measured are held in the same horizontal position, and when measuring the left arm, the intraluminal aorta is the ascending aorta, when measuring the right arm, the intraluminal aorta is the innominate artery, and when measuring the lower limb, the intraluminal aorta is the terminal abdominal aorta.

[0113] In a preferred embodiment, the air-filled airbag of the midstream strap is connected to one end of a two-way air valve via a tube, and the other end of the two-way air valve is connected to a pressure sensor, an air pump, and a linear air valve via a tube, wherein in step C, air is filled into the midstream strap by opening the two-way air valve, closing the linear air valve, and starting the air pump, and in step D, the midstream strap is gradually deflated by opening the two-way air valve connected to the air-filled airbag of the midstream strap and gradually opening the linear air valve.

[0114] In a preferred embodiment, the upstream signal channel and the downstream signal channel are both strap bodies incorporating air-filled airbags, the air-filled airbag of the upstream signal channel is connected to one end of a first two-way air valve via a tube and also connected to a first pressure sensor via a tube, the air-filled airbag of the midstream signal channel is connected to one end of a second two-way air valve via a tube and also connected to a micro-hole air valve via a tube, and the micro-hole air valve is connected to the air-filled airbag of the downstream signal channel via a tube. The downstream signal channel is connected to an air-filled air bag, and the downstream signal channel is connected to one end of a third two-way air valve through a tube, and is also connected to the second pressure sensor and the micro-hole air valve through a tube. The other ends of the three two-way air valves are connected to the third pressure sensor, the air pump, and the linear air valve through tubes. The first pressure sensor, the second pressure sensor, and the third pressure sensor are respectively connected to a first signal amplifier, a second signal amplifier, and a third signal amplifier through electric wires; and further including step B before step C, i.e., starting the air pump and filling the air-filled air bag of the upstream signal channel to several tens of milliamalgam through the two-way air valve of the upstream signal channel, and simultaneously starting to synchronously collect the pulse wave signal of the upstream signal channel, the pulse wave signal of the downstream signal channel, and the air pressure signal of the air-filled air bag of the midstream signal channel until the measurement is completed, and step C includes opening the two-way air valve connected to the air-filled air bag of the midstream signal channel. By gradually opening the linear air valve, the air-filled airbag of the midstream signal channel is gradually released, the blood flow of the brachial artery or the blood flow of the femoral artery gradually starts to flow, and the pulse wave signal begins to appear in the downstream signal channel, which is in a half-blocked state at this time. The amplitude values ​​of the first several pulse wave signals that appear in the downstream signal channel are recorded, and at the same time, the air pressure of the air-filled airbag of the midstream signal channel for each pulse is recorded, and a linear fitting is performed between the two. When the amplitude value of the pulse wave signal of the downstream signal channel passes through the zero crossing point,Calculate the air pressure of the air-filled airbag of the midstream signal channel at that time, i.e., the systolic blood pressure of the brachial artery or the systolic blood pressure of the femoral artery; while the air-filled airbag of the midstream signal channel continues to deflate, measure the time delay between the air pressure fluctuation signal of the air-filled airbag of the midstream signal channel and the pulse wave signal of the downstream signal channel, perform fitting, and calculate the time when the time delay gradually decreases to a certain value; the air pressure of the air-filled airbag of the midstream signal channel at that time is the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery;

[0115] In a preferred embodiment, the method further includes the following step A before step B: opening the two-way air valve connected to the air-filled airbag of the midstream signal channel, closing the linear air valve, starting the air pump, filling the air-filled airbag of the midstream signal channel with air through the two-way air valve and filling the air-filled airbag of the downstream signal channel with air through the micro-hole air valve, and detecting and collecting the air pressure fluctuation signal of the air-filled airbag of the downstream signal channel until the blood flow of the brachial artery or the blood flow of the femoral artery stops, i.e., the pulse wave signal of the air-filled airbag of the downstream signal channel becomes zero, and opening the two-way air valve connected to the air-filled airbag of the midstream signal channel; gradually opening the linear air valve to gradually deflate the air-filled airbag of the midstream signal channel, so that the blood flow of the brachial artery or the femoral artery starts to gradually flow, and the pulse wave signal begins to appear in the downstream signal channel, and the downstream signal record the first several pulse wave signal amplitude values ​​appearing in the channels, and at the same time record the air pressure of the air-filled airbag of the midstream signal channel for each pulse, perform linear fitting between the two, calculate the air pressure of the air-filled airbag of the midstream signal channel corresponding to the time when the amplitude of the pulse wave signal of the downstream signal channel passes through a zero crossing point, i.e., the systolic blood pressure of the brachial artery or the systolic blood pressure of the femoral artery; continue degassing the air-filled airbag of the midstream signal channel, measure the time delay between the air pressure fluctuation signal of the air-filled airbag of the midstream signal channel and the pulse wave signal of the downstream signal channel, perform fitting, and calculate the time when the time delay gradually decreases to a certain value, at which time the air pressure of the air-filled airbag of the midstream signal channel is the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery; and the step B of "filling the air-filled airbag of the upstream signal channel with air to tens of milliamalgams by the two-way air valve of the upstream signal channel" means:"The two-way air valve of the upstream signal channel fills the air-filled airbag of the upstream signal channel with air up to the diastolic pressure of the brachial artery or the diastolic pressure of the femoral artery obtained from step A."

[0116] Meanwhile, the present invention further provides a three-channel pulse wave signal sensor, which is divided into an upstream signal channel, a midstream signal channel, and a downstream signal channel according to the direction of blood flow in a limb to be measured, and during blood pressure measurement, the upstream signal channel, the midstream signal channel, and the downstream signal channel are fixed to upstream, midstream, and downstream, respectively, according to the direction of blood flow. The upstream signal channel is a strap body containing an air-filled airbag or an upstream electronic signal sensor, and the midstream signal channel is a midstream strap in the strap body containing an air-filled airbag. the downstream signal channel is a strap body with a built-in air-filled airbag or a downstream electronic signal sensor, the built-in air-filled airbag of the upstream signal channel, the built-in air-filled airbag of the midstream signal channel and the built-in air-filled airbag of the downstream signal channel are respectively connected to three corresponding connection jacks of a main device of a non-invasive blood pressure measuring device through air guide tubes, and the upstream electronic signal sensor and the downstream electronic signal sensor respectively transmit an upstream pulse wave signal of blood flow and a downstream pulse wave signal of blood flow to the main device of the non-invasive blood pressure measuring device.

[0117] In a preferred embodiment, the distances between the upstream signal channel, the midstream signal channel and the downstream signal channel are designed according to the length of the subject's limb, and the three signal channels may be closely connected as a whole by a connecting structure, or may be spaced apart from each other.

[0118] In a preferred embodiment, the separation distance between the edge of the upstream signal channel and the edge of the midstream signal channel ranges from 0 cm to 15 cm, typically 1 cm, and the separation distance between the edge of the midstream signal channel and the edge of the downstream signal channel ranges from 0 cm to 30 cm, typically 1 cm.

[0119] In a preferred embodiment, the width of the air-filled airbag of the midstream strap is determined based on the circumference of the upper limb of the subject, and this width corresponds to the circumference of the upper limb of the subject based on the requirements of the cuff of the Korotkoff sound blood pressure monitor, and a minimum width is determined according to the circumference of the limb of the subject, and the width range of the air-filled airbag of the upstream signal channel and the width range of the air-filled airbag of the downstream signal channel are both within the range of 2 to 3 cm.

[0120] In a preferred embodiment, when measuring the upper limbs, the air-filled airbag of the downstream signal channel may be bound to a position below the elbow joint, and when measuring the lower limbs, the air-filled airbag of the downstream signal channel may be bound to a position below the knee joint.

[0121] In a preferred embodiment, the upstream signal channel, the midstream signal channel, and the downstream signal channel should be bound to the same measured limb, and the relative positions of the upstream signal channel, the midstream signal channel, and the downstream signal channel are fixed and do not change during use.

[0122] In a preferred embodiment, when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, the electronic signal sensor is a pressure sensor or a photoelectric sensor.

[0123] In a preferred embodiment, when the upstream signal channel, the midstream signal channel, and the downstream signal channel are all strap bodies incorporating the air-filled airbag, the strap body of the upstream signal channel and the strap body of the midstream signal channel are fixedly connected, the strap body of the midstream signal channel and the strap body of the downstream signal channel are fixedly connected, and the strap body of the upstream signal channel, the strap body of the midstream signal channel, and the strap body of the downstream signal channel are fixedly attached as the same strap body.

[0124] When at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, a strap bracket is used to fix the electronic signal sensor of the upstream signal channel and / or the electronic signal sensor of the downstream signal channel and the midstream strap, and the strap bracket is provided with a fixing strap to fix the electronic signal sensor of the upstream signal channel and / or the electronic signal sensor of the downstream signal channel, and the distance and position between the upstream signal channel, the midstream signal channel and the downstream signal channel are determined by the strap bracket.

[0125] In a preferred embodiment, when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, the electronic signal sensor is also attached to the measured limb via a strap body, and the strap body of the electronic signal sensor is connected to the strap body of the midstream strap.

[0126] In a preferred embodiment, when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, the electronic signal sensor and the midstream strap are separate.

[0127] Meanwhile, the present invention further provides a non-invasive measuring device for central arterial pressure and other intracavitary aortic pressure, which comprises said three-channel pulse wave signal sensor.

[0128] In a preferred embodiment, the non-invasive central arterial pressure and other intraluminal aortic pressure measuring device further comprises a master unit, the master unit comprising a microprocessor, The upstream signal channel, the midstream signal channel, and the downstream signal channel of the three-channel pulse wave signal sensor all include the strap body incorporating an air-filled airbag, and the airbag of the upstream signal channel is connected to one end of a first two-way air valve via a tube and also connected to a first pressure sensor via a tube, the airbag of the midstream signal channel is connected to one end of a second two-way air valve via a tube and also connected to one end of a micro-hole air valve via a tube, the other end of the micro-hole air valve is connected to the airbag of the downstream signal channel via a tube, the airbag of the downstream signal channel is connected to a third two-way air valve via a tube and also connected to a third pressure sensor and the other end of the micro-hole air valve via a tube, and the other end of the first two-way air valve and the second two-way air valve are connected to each other. The other end of the valve and the other end of the third bidirectional air valve are connected via a tube, and are also connected via a tube to the second pressure sensor, the air pump, and the linear air valve. The first pressure sensor, the second pressure sensor, and the third pressure sensor are connected via electric wires to a first signal amplifier, a second signal amplifier, and a third signal amplifier, respectively. The output end of the first signal amplifier, the output end of the second signal amplifier, and the output end of the third signal amplifier are connected via electric wires to input ends of three analog-to-digital converters (ADCs) of the microprocessor. The microprocessor is connected via electric wires to the first bidirectional air valve, the second bidirectional air valve, the third bidirectional air valve, the first signal pressure sensor, the second signal pressure sensor, the third signal pressure sensor, the linear air valve, and the air pump.

[0129] In a preferred embodiment, the non-invasive central arterial pressure and other intraluminal aortic pressure measuring device further comprises a main unit, the main unit comprises a microprocessor, the upstream signal channel of the three-channel pulse wave signal sensor is an upstream electronic signal sensor, the downstream signal channel is a downstream electronic signal sensor, the upstream electronic signal sensor is connected to a first signal amplifier via an electric wire, the air bag of the midstream signal channel is connected to one end of a two-way air valve via a tube, the other end of the two-way air valve is connected to the signal pressure sensor, the air pump, and the linear air valve via a tube, the pressure sensor is connected to a second signal amplifier via an electric wire, the downstream electronic signal sensor is connected to a third signal amplifier via an electric wire, and the output end of the first signal amplifier; The output terminal of the second signal amplifier and the output terminal of the third signal amplifier are connected to the input terminals of three analog-to-digital converters (ADCs) of the microprocessor via electric wires, and the microprocessor is connected to the two-way air valve, the signal pressure sensor, the linear air valve, and the air pump via electric wires. Effect of the Invention

[0130] Blood flow and vascular elasticity are the main factors that affect pulse waveform collection, and the present invention can make the horizontal position of the midstream airbag of the three-channel signal sensor at the same height as the ascending aorta of the human body when measuring the intracavity aortic pressure waveform, for example, fix the three-channel signal sensor to the upper limb part of the left arm. At this time, the upstream signal channel is close to the trunk of the human body and very close to the aorta in the human body cavity, for example, the influence of vascular elasticity on the ascending aorta is reduced to a minimum. By utilizing the relationship between the intravascular pressure and the pressure of the extravascular airbag strap under the condition that the width of the midstream airbag strap is sufficient, by utilizing the relationship between the blood pressure in the downstream, upstream, and midstream blood vessels under the condition that the blood flow velocity at the time of the upstroke of the pulse wave is equal to zero, by utilizing the relationship between the blood pressure in the blood vessel under the complete block state and the semi-active state under the condition that the blood flow acceleration is zero, the maximum value of the blood pressure in the blood vessel under the complete block state is obtained, and this maximum value is approximately equal to the intracavity aortic systolic pressure. At this time, because it is under the complete block state, measurement errors caused by blood flow are avoided to the maximum extent. In the diastolic pressure state, blood flow velocity approaches zero and the intraluminal aortic diastolic pressure is approximately equal to the brachial or femoral artery diastolic pressure.

[0131] Compared with the prior art, the present invention can accurately measure central arterial pressure and other intraluminal aortic pressures. [Brief description of the drawings]

[0132] [Figure 1] FIG. 1 is a system block diagram of a central arterial pressure measuring device using a three-channel pulse wave signal sensor. [Diagram 2] FIG. 1 is a schematic diagram of the structure of a three-channel pulse wave signal sensor using airbag straps for the first type of upstream and downstream signal channels. [Diagram 3] FIG. 1 is a schematic diagram showing the structure of a three-channel pulse wave signal sensor using airbag straps for the second type of upstream and downstream signal channels. [Figure 4] FIG. 13 is a schematic diagram showing the structure of a three-channel pulse wave signal sensor using airbag straps for the third type of upstream and downstream signal channels. [Diagram 5]FIG. 2 is a schematic diagram of a central arterial pressure measuring device. [Figure 6] FIG. 1 is a schematic diagram showing three airbag straps blocking brachial artery blood flow. [Figure 7] FIG. 1 is a schematic diagram of pressure analysis at each point during the measurement process. [Figure 8] Air pressure curves of the upstream, midstream and downstream airbag straps during the entire measurement process. [Figure 9] These are the air pressure curves of the upstream, midstream, and downstream airbag straps at time TI within the half-block time domain ty. [Figure 10] The air pressure curves of the midstream airbag strap at time TII within the half-block time domain ty and its second derivative curves are shown. [Figure 11] 1 is a pressure curve of the upstream airbag strap at time TIII within the complete block time domain tx. [Figure 12] 1 is a system block diagram of a central arterial pressure measuring device in which the upstream and downstream signal channels use pressure sensors or photoelectric sensors, and the midstream signal channel uses an airbag strap. [Figure 13] FIG. 1 is a schematic diagram of the structure of a three-channel pulse wave signal sensor that uses pressure sensors or photoelectric sensors in the first type upstream and downstream signal channels. [Figure 14] FIG. 13 is a schematic diagram of the structure of a three-channel pulse wave signal sensor using pressure sensors or photoelectric sensors in the second type upstream and downstream signal channels. [Figure 15] FIG. 11 is a schematic diagram showing the structure of a three-channel pulse wave signal sensor using pressure sensors or photoelectric sensors in the third type of upstream and downstream signal channels. [Figure 16] FIG. 13 is a schematic diagram showing blocking arterial blood flow using upstream and downstream signal channel sensors and using a midstream airbag strap. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0133] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with reference to the drawings, embodiments of the method and apparatus for non-invasively measuring central arterial pressure and other intraluminal aortic pressures and the three-channel pulse wave signal sensor of the present invention will be described.

[0134] The examples described herein are specific specific embodiments of the present invention, and are intended to explain the concept of the present invention, and are all interpretive and exemplary, and should not be construed as limiting the embodiments and the scope of the present invention. Except for the examples described herein, a person skilled in the art may adopt other obvious technical solutions based on the claims and the contents disclosed in the specification of this application, and these technical solutions include technical solutions that make any obvious substitutions and modifications to the examples described herein.

[0135] The drawings in this specification are schematic diagrams, which auxiliary explain the concept of the present invention and show the shape of each part and their interrelationships. In order to clarify the configuration of each component in the embodiment of the present invention, each drawing does not necessarily have to be drawn to the same scale. The same reference numerals are used to indicate the same parts. In addition, when describing with reference to the drawings, directional terms such as "upper", "lower", "front", and "rear" are adopted for ease of expression, and they do not specifically limit the structure of the features.

[0136] [Embodiment 1] As shown in Fig. 1, the non-invasive central arterial pressure measuring device of the present invention includes an upstream airbag strap 1, a midstream airbag strap 2 and a downstream airbag strap 3 in a three-channel pulse wave signal sensor, two-way air valves 4, 5 and 6, a micro-hole air valve 7, a linear air valve 8, an air pump 9, pressure sensors 10, 11 and 12, signal amplifiers 13, 14 and 15, a display 16, a keyboard 17, a microprocessor 18, etc. In the present invention, the microprocessor 18 is connected to a pulse wave signal analog-digital converter, or the pulse wave signal analog-digital converter is directly integrated in the microprocessor 18. Here, the main device of the non-invasive central arterial pressure measuring device of the present invention includes the two-way air valves 4, 5 and 6, the micro-hole air valve 7, the linear air valve 8, the air pump 9, the pressure sensors 10, 11 and 12, the signal amplifiers 13, 14 and 15, and the microprocessor 18.

[0137] In this embodiment, as shown in Figures 1, 5, 6 and 7, the central arterial pressure is measured by measuring the upper limb as an example. In Figure 5, the three-channel pulse wave signal sensor is fixed to the upper limb 31, and measures the lateral pressure of the ascending aorta 33, i.e., the central arterial pressure, by measuring the pulse wave signal of the brachial artery 32. In Figure 6, the airbag of the midstream airbag strap 2 of the three-channel pulse wave signal sensor compresses the brachial artery 32 to stop the blood flow, and the brachial artery 32 is in a blocked state. In Figure 7, P c is the central arterial blood pressure, P1 is the brachial arterial blood pressure at the upstream signal channel location, and P2 is the brachial arterial blood pressure at the midstream airbag location.

[0138] 2-4, the three-channel pulse wave signal sensor is divided into three signal channels, an upstream airbag strap 1, a midstream airbag strap 2, and a downstream airbag strap 3, according to the blood flow direction. In the measurement process, the midstream airbag strap 2 can block the arterial blood flow when air is filled. The airbag width of the midstream airbag strap 2 is determined by the circumference of the upper limb, which is the circumference of the upper limb of the subject, as in the conventional Korotkoff sound airbag, and the minimum width is determined according to the circumference of the limb of the subject. The correspondence relationship between the width and the circumference of the upper limb of the subject is the same as the strap requirements of the Korotkoff sound blood pressure monitor. If the circumference of the upper limb of the subject is large, the width of the midstream airbag strap 2 will be increased accordingly, and if the circumference of the upper limb of the subject is small, the width of the midstream airbag strap 2 will be decreased accordingly. The width of the midstream airbag strap 2 is generally divided into a large number, a medium number, and a small number, and at least two model numbers are required.

[0139] The distance between the airbag straps of the three signal channels, the upstream airbag strap 1, the midstream airbag strap 2, and the downstream airbag strap 3, is designed according to the length of the subject's limb, and can be divided into three types, for example, large number, medium number, and small number. According to the need of use, the three signal channels can be integrally formed by tightly connecting one whole, or can be spaced apart. As shown in Figures 2, 3, and 4, the distance between the upstream airbag strap 1 and the midstream airbag strap 2 can be 0-15 cm, and the distance between the midstream airbag strap 2 and the downstream airbag strap 3 can be 0-30 cm.

[0140] The upstream airbag strap 1 is connected to a two-way air valve 4 via a tube, and is also connected to a pressure sensor 10 via a tube.

[0141] The midstream airbag strap 2 is connected to a two-way air valve 5 via a tube and is also connected to a micro-hole air valve 7 via a tube, the other end of which is connected to the downstream airbag strap 3 via a tube.

[0142] The downstream airbag strap 3 is connected to a two-way air valve 6 via a tube, and is also connected to a pressure sensor 11 and the other end of a micro-hole air valve 7 via a tube.

[0143] The other ends of the three two-way air valves 4, 5, and 6 are connected via tubes, and are also connected to a pressure sensor 12, an air pump 9, and a linear air valve 8 via tubes.

[0144] The three pressure sensors 10, 11 and 12 are connected to signal amplifiers 14, 15 and 13 via wires, respectively, and the output terminals of the signal amplifiers 14, 15 and 13 are connected to the input terminals of three analog-to-digital converters (ADC) of a microprocessor 18 via wires. Through calibration of the standard pressure gauge and calculation processing of the microprocessor, the signals are output from the three pressure sensors 10, 11 and 12, and the actual pressure values ​​of the three airbag straps 1, 2 and 3, upstream, midstream and downstream, can be obtained.

[0145] The microprocessor 18 is connected to the display 16 and the keyboard 17, and the microprocessor 18 is simultaneously connected via electrical wires to the three bidirectional air valves 4, 5 and 6, the three signal pressure sensors 10, 11 and 12, the linear air valve 8 and the air pump 9.

[0146] The built-in air-filled airbag of the upstream signal channel, the built-in air-filled airbag of the midstream signal channel, and the built-in air-filled airbag of the downstream signal channel are all connected to three corresponding connection jacks of the main device of the non-invasive central arterial pressure measuring device respectively through the air conducting tube 34.

[0147] The measurement procedure is as follows.

[0148] First step: open the two-way air valve 5, close the two-way air valves 4 and 6, close the linear air valve 8, start the air pump 9, fill the midstream airbag strap 2 with air, and collect and detect the output signal of the pressure sensor 11 connected to the downstream airbag strap 3 until the blood flow of the brachial artery 32 stops flowing, that is, the pulse wave signal output by the pressure sensor 11 is zero, close the air pump 9, gradually open the linear air valve 8, the midstream airbag strap 2 gradually releases gas, and collect and detect the output signal of the pressure sensor 11 connected to the downstream airbag strap 3, and the pulse wave signal gradually begins to appear, indicating that the brachial artery blood flow starts to gradually flow from the blocked state. During this process, the output signals of the pressure sensors 12 and 11 can be collected to obtain the gas pressure value of the midstream airbag strap 2 and the pulse wave signal amplitude value of the downstream airbag strap 3. Linearly fitting some pulse wave signal amplitudes that first begin to appear in the downstream airbag strap 3 and the gas pressure of the midstream airbag strap 2 of the corresponding pulse, calculate the gas pressure of the midstream airbag strap 2 when the pulse wave signal amplitude value of the downstream signal channel is zero, that is, the brachial artery systolic blood pressure. Then, gradually open the linear air valve 8, and the midstream airbag strap 2 continues to vent, during this process, collect the output signals of the pressure sensors 12 and 11, obtain the gas pressure change curve of the midstream airbag strap 2 and the pulse wave signal curve of the downstream airbag strap 3, measure the time delay of the upstroke time point of the above two curves, and find the time point when the time delay gradually decreases to a certain value, here it is the brachial artery diastolic blood pressure.

[0149] Second step: Open the two-way air valves 4, 5 and 6, open the linear air valve 8, and allow the three-channel airbag straps 1, 2 and 3 to vent to atmospheric pressure. Close the two-way air valves 5 and 6, open the two-way air valve 4, start the air pump 9, fill the upstream airbag strap 1 with air, and collect the output signal of the pressure sensor 10 to measure the air pressure of the upstream airbag strap 1. Based on the brachial artery diastolic blood pressure value measured in the third step, pressurize the upstream airbag strap 1 to about the brachial artery diastolic blood pressure, then close the two-way air valve 4 and stop the air pump 9. At that time, start synchronously collecting the output signals of the pressure sensors 10, 12 and 11, and continue to synchronously collect the output signals of the pressure sensors 10, 12 and 11 until the measurement is completed.

[0150] Third step: Close the two-way air valves 4 and 6, open the two-way air valve 5, start the air pump 9, fill the midstream airbag strap 2 with air through the two-way air valve 5, and fill the downstream airbag strap 3 with air through the micro-hole air valve 7. During this process, the output signal of the pressure sensor 12 is simultaneously collected and used to monitor the air pressure of the midstream airbag strap 2 until the air pressure of the midstream airbag strap 2 is several tens of millimeters of mercury higher than the brachial artery systolic blood pressure measured in the second step, which is generally 10 to 100 mmHg. Stop the air pump 9 and stop filling the midstream airbag strap 2 with air.

[0151] Fourth step: Stop the air pump 9 and wait for several cardiac cycles.

[0152] Fifth step: gradually open the linear air valve 8, the midstream airbag strap 2 gradually releases gas, collect and detect the output signal of the pressure sensor 11 connected to the downstream airbag strap 3, and gradually the pulse wave signal begins to appear, indicating that the brachial artery blood flow gradually starts to flow from the blocked state. In this process, the output signals of the pressure sensors 12 and 11 can be collected, and the gas pressure value of the midstream airbag strap 2 and the pulse wave signal amplitude value of the downstream airbag strap 3 can be obtained. Linearly fit several pulse wave signal amplitudes that first begin to appear in the downstream airbag strap 3 and the gas pressure of the midstream airbag strap 2 of the corresponding pulse, and calculate the gas pressure of the midstream airbag strap 2 corresponding to when the pulse wave signal amplitude value of the downstream signal channel is zero, that is, the brachial artery systolic blood pressure. Then, the linear air valve 8 is gradually opened, and the midstream airbag strap 2 continues to vent, during this process, the output signals of the pressure sensors 12 and 11 are collected, the gas pressure change curve of the midstream airbag strap 2 and the pulse wave signal curve of the downstream airbag strap 3 are obtained, and the time delay at the upstroke point of the above two curves is measured, and the time delay gradually decreases to a certain value, which is the brachial artery diastolic pressure. This brachial artery diastolic pressure is used to calculate the central arterial systolic pressure.

[0153] Sixth step: The output signals of the pressure sensors 10, 12 and 11 at each time collected based on the above method respectively represent the pressure data of the airbag straps 1, 2 and 3 of the three upstream, midstream and downstream channels at each time.

[0154] Hereinafter, a method for calculating central arterial pressure will be described with reference to the drawings.

[0155] FIG. 8 shows the air pressure curves of downstream airbag straps 1, 2 and 3 during the entire measurement process. x is called the complete block time region, in which the pressure of the air filling of the midstream airbag strap 2 is much greater than the brachial artery systolic pressure, and the brachial artery blood flow is completely blocked. yis called the half-block time region, in which the midstream airbag strap 2 is filled with air and gradually degassed after blocking the brachial artery blood flow until the downstream signal sensor 11 starts to generate multiple blood flow signals. y In I The air pressure curves of the upstream, midstream, and downstream airbag straps at time t y Within II The air pressure of the midstream airbag at time t and its second derivative curve are shown in Fig. 11. x In III 4 is an air pressure curve of the upstream airbag strap at time t1.

[0156] In FIG. 8 to FIG. 11, A is the air pressure curve of the downstream airbag strap 3, B is the air pressure curve of the midstream airbag strap 2, and C is the half block time region t y A is the air pressure curve of the midstream airbag strap 2, B is the air pressure curve of the midstream airbag strap 2, C is the blood flow acceleration curve obtained by calculating the second derivative of the air pressure curve of the midstream airbag strap 2, E is the complete block time domain t x This is the air pressure curve at

[0157] The specific calculation steps are as follows:

[0158] First step: As shown in FIG. 9, measure the half-block time domain t y The air pressure curve A of the downstream airbag strap 3 is located at the upstroke time t in the cardiac cycle. I Find t I The gas pressure in the mid-block airbag at time H 2I Based on t I Blood pressure in the brachial artery at time P 2I Get the.

[0159] P 2I =H 2I (1)

[0160] Second step:I Brachial artery blood pressure P at the midstream airbag position at time 2I By t I The lateral pressure P of the brachial artery due to blood at the upstream signal channel position at 1I Calculate.

[0161] P 1I =H 2I (5)

[0162] Third step: As shown in FIG. 10, based on the air pressure curve B of the midstream airbag strap 2, calculate the second derivative to obtain the blood flow acceleration curve D, and find the first positive-to-negative zero crossing point on the acceleration curve; II Determine the time t I The pressure curve at the upstream channel position at time t I Brachial artery blood pressure P at the upstream channel position at 1I By t II Blood pressure P in the brachial artery at the upstream channel location at time 1II Calculate.

[0163]

number

[0164] Fourth step: As shown in FIG. 11, the half-block time domain t y In one pulse cycle, from the upstroke of the pulse wave to t II Measure the time length Δt up to the point in time, and calculate the complete block time domain t x In one pulse cycle, the pulse wave is delayed by a time length Δt from the upstroke point of the pulse wave, and t III Determine the time point in the half-block time domain t y , t II Blood pressure P in the brachial artery at the upstream signal channel location at time 1II By the complete block time domain t x , t III Blood pressure P in the brachial artery at the upstream signal channel location at time 1III is calculated.

[0165] P 1III =P 1II (12)

[0166] Fifth step: III Pressure curves E and t at the upstream signal channel position III Blood pressure P in the brachial artery at the upstream signal channel location at time 1III The maximum value of the blood pressure in the brachial artery at the upstream signal channel position P 1S is calculated, and the central arterial systolic pressure is approximately obtained.

[0167]

number

[0168] P CS =P 1S (15)

[0169] [Embodiment 2] Compared with embodiment 1, in embodiment 2, one or two of the upstream and downstream airbag straps in embodiment 1 are replaced with electronic signal sensors. As an example, in this embodiment, the upstream and downstream airbag straps are simultaneously replaced with pressure or photoelectric sensors. As shown in FIG. 12, the non-invasive central arterial pressure measuring device of the present invention includes an upstream electronic signal sensor 21, a midstream airbag strap 2, a downstream electronic signal sensor 23, a two-way air valve 5, a linear air valve 8, an air pump 9, a pressure sensor 12, signal amplifiers 13, 14 and 15, a display 16, a keyboard 17, a microprocessor 18, etc. In the present invention, the microprocessor 18 is connected to a pulse wave signal analog-digital converter, or the pulse wave signal analog-digital converter is directly integrated in the microprocessor 18. Of these, the main device of the non-invasive central arterial pressure measuring device of the present invention comprises the two-way air valves 4, 5 and 6, the linear air valve 8, the air pump 9, the pressure sensors 10, 11 and 12, the signal amplifiers 13, 14 and 15, and the microprocessor 18.

[0170] The structure diagrams of the airbag strap of the upstream pressure sensor and the airbag strap of the downstream pressure sensor are shown in Figure 13, Figure 14 and Figure 15. The three signal channels are divided into the upstream electronic signal sensor 21, the midstream airbag strap 2 and the downstream electronic signal sensor 23 according to the blood flow direction. In the measurement process, the midstream airbag strap 2 can block the arterial blood flow when filled with air. The airbag width of the midstream airbag strap 2 is similar to that of the conventional Korotkoff sound airbag, and the minimum width is determined according to the circumference of the subject's limb, and can be divided into three types, for example, large number, medium number and small number. The separation distance between the three signal channels of the upstream electronic signal sensor 21, the midstream airbag strap 2 and the downstream electronic signal sensor 23 is designed according to the length of the subject's limb. Depending on the use, the three channels can be closely connected to form one whole, or can be spaced apart by one distance. As shown in Figures 13, 14 and 15, the distance between the upstream electronic signal sensor 21 and the midstream airbag strap 2 may be between 0 and 15 cm, and the distance between the midstream airbag strap 2 and the downstream electronic signal sensor 23 may be between 0 and 30 cm.

[0171] 16 is a schematic diagram showing that the midstream airbag strap according to the second embodiment blocks the brachial artery blood flow. The airbag of the midstream airbag strap 2 compresses the brachial artery 32 of the upper limb 31 to stop the blood flow, and the brachial artery 32 is in a blocked state. The upstream electronic signal sensor 21 and the downstream electronic signal sensor 23 are attached to the skin of the upper limb 31, and the figure shows that the upstream electronic signal sensor 21 and the downstream electronic signal sensor 23 are fixed to the upper limb 31 by a fixing structure, for example, a strap body. The upstream electronic signal sensor 21 and the downstream electronic signal sensor 23 are connected to the midstream airbag strap 2 by a strap bracket to be integrated.

[0172] The upstream electronic signal sensor 21 is connected to the signal amplifier 14 via an electric wire, the downstream electronic signal sensor 23 is connected to the signal amplifier 15 via an electric wire, the midstream airbag strap 2 is connected to the two-way air valve 5 via a tube, and the other end of the two-way air valve 5 is connected to the pressure sensor 12, the air pump 9 and the linear air valve 8 via a tube.

[0173] The output terminals of the signal amplifiers 13, 14 and 15 are connected via electric wires to three analog-to-digital converter (ADC) input terminals of a microprocessor 18. Through calibration of a standard pressure gauge and calculation processing by a microprocessor, the signals from the three pressure sensors 10, 11 and 12 can be output to obtain the actual pressure values ​​of the three airbag straps 1, 2 and 3, upstream, midstream and downstream.

[0174] The microprocessor 18 is connected to the display 16 and keyboard 17, and is simultaneously connected to the bidirectional air valve 5, the pressure sensor 12, the linear air valve 8 and the air pump 9 via electrical wires.

[0175] The built-in air-filled airbag of the upstream signal channel is connected to one corresponding connection jack of the main device of the non-invasive central arterial pressure and other intraluminal aortic pressure measuring device via an air conducting tube 34, and the pressure sensor of the upstream signal channel and the pressure sensor of the downstream signal channel are both connected to two corresponding connection jacks of the main device of the non-invasive central arterial pressure measuring device via signal connecting lines 36, respectively.

[0176] The measurement procedure is as follows.

[0177] First step: open the two-way air valve 5, close the linear air valve 8, start the air pump 9 to fill the midstream airbag strap 2 with air, and detect and collect the output signal of the signal amplifier 15 connected to the downstream electronic signal sensor 23 until the brachial artery blood flow stops, that is, until the output signal of the signal amplifier 15 becomes zero, and record the air pressure value of the midstream airbag strap 2 at this time. Keep the two-way air valve 5 open and open the linear air valve 8. During this process, collect the output signal of the pressure sensor 12 at the same time, and use it to monitor the air pressure of the midstream airbag strap 2 until the air pressure of the midstream airbag strap 2 is several tens of millimeters of mercury higher than the recorded air pressure value, which is generally 10 to 100 mmHg, and this time region is the complete block region t x The air pump 9 is closed to stop filling the midstream airbag strap 2 with air.

[0178] Step 2: gradually open the linear air valve 8, and the midstream airbag strap 2 gradually releases the gas, and then start synchronously collecting the output signals of the signal amplifiers 13, 14 and 15. The midstream airbag strap 2 gradually releases the gas. Collect the output signal of the detection signal amplifier 15, and gradually a pulse wave signal appears, which indicates that the brachial artery blood flow is gradually starting to flow from the blocked state. This time region is the half-blocked region t y In this process, the output signals of the detection signal amplifiers 13, 15 can be collected, and the gas pressure value of the midstream airbag strap 2 and the pulse wave signal amplitude of the downstream electronic signal sensor 23 can be obtained. Linear fitting is performed between some pulse wave signal amplitudes that first begin to appear in the downstream electronic signal sensor 23 and the gas pressure of the midstream airbag strap 2 of the corresponding pulse, and the gas pressure of the midstream airbag strap 2 corresponding to when the pulse wave signal amplitude value is zero is calculated, that is, the brachial artery systolic blood pressure.

[0179] Step 3: Continue to gradually open the linear air valve 8, and the midstream airbag strap 2 continues to vent. During this process, collect and detect the output signals of the detection signal amplifiers 13, 15, obtain the pulse wave signal curves of the midstream airbag strap 2 and the downstream electronic signal sensor 23, measure the time delay at the upstroke point of the above two curves, and find the point at which the time delay gradually decreases to a certain value, here it is the brachial artery diastolic blood pressure.

[0180] Fourth step: gradually open the linear air valve 8 and the two-way air valve 5 to gradually vent the midstream airbag strap 2 to atmospheric pressure, and then the measurement is completed.

[0181] In the present embodiment, the air pressure curves of the upstream and downstream signal channels and the midstream airbag strap 2 corresponding to the upstream and downstream channel signal sensors 21 and 23 in the entire measurement process in Fig. 8 can be obtained in the same manner. The method of calculating the central arterial pressure is the same as that in the first embodiment.

[0182] [Embodiment 3] As can be seen from the explanation of the first and second embodiments, the non-invasive central arterial pressure measuring device of the present invention includes a three-channel pulse wave signal sensor of the present invention.

[0183] 1 to 7 and 12 to 16, the three-channel pulse wave signal sensor of the present invention is divided into an upstream signal channel, a midstream signal channel and a downstream signal channel according to the direction of blood flow, the upstream signal channel is a strap body 35 incorporating an air-filled airbag or a strap body 35 having an electronic signal sensor attached thereto, the midstream signal channel is a strap body 35 incorporating an air-filled airbag, and the downstream signal channel is a strap body 35 incorporating an air-filled airbag or a strap body 35 having an electronic signal sensor attached thereto, the air-filled airbag incorporated in the upstream signal channel, the air-filled airbag incorporated in the midstream signal channel and the air-filled airbag incorporated in the downstream signal channel are all respectively connected to three corresponding connection jacks of a main device of a non-invasive central arterial pressure measuring device via air conducting tubes, and the electronic signal sensor of the upstream signal channel and the electronic signal sensor of the downstream signal channel are each respectively connected to two corresponding connection jacks of a main device of a non-invasive central arterial pressure measuring device via signal connecting lines.

[0184] Here, the upstream signal channel, the middle signal channel and the downstream signal channel are divided according to the limb blood flow direction, the middle signal channel is installed at the position where the upper limb brachial artery signal or the lower limb femoral artery signal is measured, the upstream signal channel and the downstream signal channel are upstream and downstream of the blood flow of the middle signal channel, respectively, and are used to detect the pulse wave signal, and their positions can be set by those skilled in the art as necessary so as to achieve the object of the present invention. The present invention can provide preferred positions for the upstream signal channel and the downstream signal channel from the above description, but the positions are not limited to these preferred positions. For example, the downstream signal channel may be provided on the wrist artery.

[0185] 1 to 7, the upstream, midstream and downstream signal channels of the three-channel pulse wave signal sensor of the present invention all use airbag straps, and include an upstream airbag strap 1, a midstream airbag strap 2, a downstream airbag strap 3, an air guide tube 34 and a strap body 35. The air-filled airbags of the upstream airbag strap 1, the midstream airbag strap 2 and the downstream airbag strap 3 are each connected to one air guide tube 4, and these three air guide tubes 4 are respectively connected to three corresponding connection jacks of the main device of the non-invasive central arterial pressure measuring device.

[0186] The distance between the three signal channels of the upstream airbag strap 1, the midstream airbag strap 2 and the downstream airbag strap 3 is designed according to the length of the subject's limb, and can be divided into three types, for example, large number, medium number and small number. According to the need of use, the three signal channels can be closely connected to form one whole, or can be fixedly connected at a distance. The distance between the upstream airbag strap 1 and the midstream airbag strap 2 can be between 0 cm and 15 cm, and the distance between the midstream airbag strap 2 and the downstream airbag strap 3 can be between 0 cm and 30 cm.

[0187] When measuring the upper limbs, the downstream airbag strap 3 may be bound to a position below the elbow joint, and when measuring the lower limbs, the downstream airbag strap 3 may be bound to a position below the knee joint.

[0188] The width of the upstream and downstream airbag straps should not be too narrow, and it is not preferable that they are too wide. If the width of the upstream and downstream airbag straps is too narrow, the output pressure signal will be too small, which will affect the measurement accuracy, and if the width of the upstream and downstream airbag straps is too wide, it will cause deterioration of the time resolution and the subject's body length is limited, so the width of the upstream and downstream airbag straps should not be too wide. In general, the width of the upstream and downstream airbag straps is preferably 2 to 3 cm.

[0189] In order to ensure measurement accuracy, it is preferable that the upstream airbag strap 1 is as close as possible to the part that brings the upper limbs as close to the torso as possible, and it is preferable that the upper edge of the midstream airbag strap 2 is as close as possible to the lower edge of the upstream airbag strap 1, and it is preferable that they are not completely connected, otherwise it is easy to cause mutual interference between the upstream airbag strap and the midstream airbag strap.

[0190] In actual measurements, if the length of the upper limbs allows, the upstream, midstream and downstream airbag straps may be placed simultaneously on the upper limbs above the elbow joint, or the upstream and midstream airbag straps may be placed on the upper limbs above the elbow joint, and the downstream airbag strap 3 may be placed at a position below the elbow joint.

[0191] The midstream airbag strap 2 can block arterial blood flow when filled with air. The airbag width of the midstream airbag strap 2 is similar to that of a conventional Korotkoff sound airbag strap, and the minimum width is determined according to the circumference of the subject's limb.

[0192] The upstream airbag strap 1 is connected by binding to the midstream airbag strap 2, and the midstream airbag strap 2 is fixedly connected to the downstream airbag strap 3, so that the upstream, midstream and downstream airbags are fixedly attached to the same strap body 35. When in use, they are bound to the same limb to be measured, and the relative positions of the upstream, midstream and downstream airbags are constant during use.

[0193] 12 to 16 show an example of a three-channel pulse wave signal sensor according to the present invention. Compared with the example shown in Fig. 1 to 7, the three-channel pulse wave signal sensor of this example employs electronic signal sensors in the upstream signal channel and downstream signal channel, which may be, for example, a pressure sensor or a photoelectric sensor, and an airbag strap in the midstream signal channel. The three-channel pulse wave signal sensor of this example includes an upstream electronic signal sensor strap 21, a midstream airbag strap 2, a downstream electronic signal sensor strap 23, an air guide tube 34, a strap body 35, etc.

[0194] The upstream electronic signal sensor strap 21 includes an upstream electronic signal sensor, and the downstream electronic signal sensor strap 23 includes a downstream electronic signal sensor, the electronic signal sensor being, for example, a pressure sensor or a photoelectric sensor, and in this description, in Fig. 12, for the sake of brevity, the upstream electronic signal sensor strap 21 and the downstream electronic signal sensor strap 23 in Fig. 12 only show the electronic signal sensor in a schematic manner, and do not show the strap body required for the electronic signal sensor. The skin of the body surface muscle is slightly undulated due to the change in intravascular pressure, so a strap body as a restraining means is required when measuring blood pressure, and the electronic signal sensor needs to be restrained on the skin surface with a certain pressure, thereby achieving the purpose of accurately measuring blood pressure.

[0195] An air guide tube 34 is connected to the air-filled airbag of the midstream airbag strap 2, and the air guide tube 34 is connected to one corresponding connection jack of the main device of the non-invasive central arterial pressure measuring device, and the electronic signal sensors of the upstream electronic signal sensor strap 21 and the downstream electronic signal sensor strap 23 are respectively connected to two corresponding connection jacks of the main device of the non-invasive central arterial pressure measuring device via signal connection lines 36.

[0196] The distance between the three signal channels of the upstream electronic signal sensor strap 21, the midstream airbag strap 2, and the downstream electronic signal sensor strap 23 is designed according to the length of the subject's limb, and can be divided into three types, for example, large number, medium number, and small number. According to the need of use, the three signal channels can be closely connected to form one whole, or can be fixedly connected at a distance. The distance between the edge of the upstream electronic signal sensor strap 21 and the midstream airbag strap 2 can be between 0 and 25 cm, preferably between 0 and 15 cm, for example, 1, 2, 5, 10 cm, etc., and the distance between the edge of the midstream airbag strap 2 and the downstream electronic signal sensor strap 23 can be between 0 and 30 cm.

[0197] The midstream airbag strap 2 can block arterial blood flow when filled with air. The airbag width of the midstream airbag strap 2 is similar to that of a conventional Korotkoff sound airbag, and the minimum width is determined according to the circumference of the subject's limb.

[0198] The upstream electronic signal sensor strap 21 is bound and connected to the midstream airbag strap 2, and the midstream airbag strap 2 is fixedly connected to the downstream electronic signal sensor strap 23, so that the upstream, midstream and downstream signal channels are fixedly attached to the same strap body. In use, they are bound to the same measured limb, and the relative positions of the upstream, midstream and downstream signal channels are constant during use.

[0199] When using upstream and downstream electronic signal sensors, such as pressure sensors or photoelectric sensors, strap brackets can be adopted to fix the upstream and downstream pressure sensors or photoelectric sensors and the midstream airbag straps. The distances and positions between the upstream, midstream and downstream signal channels are determined by the strap brackets, and the clearance between the edge of the upstream electronic signal sensor and the upper edge of the midstream airbag can be between 0 and 15 cm, generally 1 cm. The clearance between the edge of the downstream electronic signal sensor and the lower edge of the midstream airbag can be between 0 and 30 cm, generally 1 cm.

[0200] The strap bracket has fixing straps for fixing the upstream and downstream sensors. In actual measurement applications, it is preferable that the fixing straps of the upstream and downstream sensors are appropriately fastened, and the upstream and downstream sensors are fixed to the body surface of the brachial artery on the limb to be measured so that they cannot move and do not affect the blood flow.

[0201] It should be noted here that in the specific embodiments of the present application, only two configurations as shown in Figures 1 and 12 have been described for the non-invasive central arterial pressure measuring device and three-channel pulse wave signal sensor of the present invention, but in reality, the non-invasive central arterial pressure measuring device and three-channel pulse wave signal sensor of the present invention may both be configured so that one of the upstream signal channel and the downstream signal channel uses an electronic signal sensor, in which case the signal channel using the electronic signal sensor may be directly connected to the signal amplifier via an electric wire, in which case a person skilled in the art can design the structure between the three signal channels and the microprocessor, as is clear from the preceding description of the present application.

[0202] The present invention may be applied to the measurement of the upper limbs or the lower limbs. When measuring blood pressure through the upper limbs, the obtained blood pressure value is the ascending arterial pressure or the innominate arterial pressure. When measuring blood pressure through the lower limbs, the obtained blood pressure value is the abdominal aortic pressure, more specifically, the blood pressure at the tip of the abdominal aorta, and the measurement operation is preferably performed while lying down, so that the position of the midstream airbag is approximately the same height as the abdominal aorta.

[0203] The above description is a detailed description of the present invention in combination with specific preferred embodiments, and the specific implementation of the present invention is not limited to these descriptions. For those skilled in the art to which the present invention pertains, some equivalent substitutions or obvious modifications can be made without departing from the concept of the present invention, and the performance or application is the same, and all of them should be considered as belonging to the patent protection scope determined by the scope of the claims submitted by the present invention.

Claims

1. 1. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures, comprising: A pulse wave signal is acquired using a three-channel pulse wave signal sensor, corresponding to the limb being measured; The three-channel pulse wave signal sensor is divided into an upstream signal channel, a midstream signal channel, and a downstream signal channel according to the blood flow direction; The upstream signal channel is a strap body containing an airbag or an upstream electronic signal sensor; The midstream signal channel is a midstream strap of a strap body incorporating an airbag; The downstream signal channel is a strap body containing an airbag or a downstream electronic signal sensor; The limb to be measured is an upper limb or a lower limb, The method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures comprises the following steps: C. filling the airbag of the midstream strap with air, and detecting and collecting the pulse wave output signal of the upstream signal channel and the pulse wave output signal of the downstream signal channel until the brachial artery blood flow or the femoral artery blood flow stops, i.e., until the pulse wave output signal of the downstream signal channel becomes zero, and recording the air pressure value of the midstream strap at that time; continuing to fill the airbag of the midstream strap with air and monitoring the air pressure of the midstream strap; stopping the air filling until the air pressure of the midstream strap is 10 to 100 mmHg higher than the recorded air pressure value, at which time the brachial artery blood flow or the femoral artery blood flow is in a completely blocked state, and collecting the pulse wave output signal of the upstream signal channel for several cardiac cycles; The airbag of the midstream strap gradually releases gas, and starts to synchronously collect the output signal of the upstream signal channel, the output signal of the midstream signal channel, and the output signal of the downstream signal channel through the signal amplifier. A pulse wave signal gradually appears in the downstream signal channel, indicating that the blood flow of the brachial artery or the blood flow of the femoral artery gradually begins to flow. At this time, the blood flow of the brachial artery or the blood flow of the femoral artery is in a half-blocked state. In this process, the output signal of the upstream signal channel, the output signal of the midstream signal channel, and the output signal of the downstream signal channel are collected, and some of the pulse wave signals that first appear in the downstream signal channel are collected, thereby upstreaming the pulse wave signal of the downstream signal channel. Step D: determining a time of a lock point, measuring the air pressure in the airbag of the midstream signal channel at that time, obtaining the blood pressure in the brachial artery or the femoral artery at the position of the midstream signal channel at that time, and obtaining that at the time of the upstroke point of the pulse wave signal of the downstream signal channel, the blood flow velocity at that time is approximately zero, the blood pressure in the brachial artery or the femoral artery at the position of the upstream signal channel is equal to the blood pressure in the brachial artery or the femoral artery at the position of the midstream signal channel, and further the blood pressure in the brachial artery or the femoral artery at the position of the upstream signal channel is equal to the air pressure in the airbag of the midstream strap at that time; E. under half-blocked state, record the amplitude of the first several pulse wave signals appearing in the downstream signal channel, synchronously record the air pressure in the airbag of the midstream signal channel for each pulse, perform linear fitting between the two, calculate the air pressure of the airbag of the midstream signal channel when the amplitude of the pulse wave signal of the downstream signal channel passes through a zero crossing point, i.e., the systolic blood pressure of the brachial artery or the systolic blood pressure of the femoral artery; continue deflating the airbag of the midstream strap, measure the time delay between the air pressure fluctuation signal of the airbag of the midstream strap and the pulse wave signal of the downstream signal channel, perform fitting, calculate the time when the time delay gradually decreases to a constant value, the air pressure of the airbag of the midstream strap at this time is the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery, and the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery is used to calculate the systolic blood pressure of the central artery or the systolic blood pressure of the aorta in another cavity; Based on the pulse wave signal of the upstream signal channel, the pulse wave signal of the downstream signal channel, the air pressure signal of the midstream airbag, and the diastolic blood pressure value of the brachial artery or the diastolic blood pressure value of the femoral artery, which are synchronously collected in the above process, the systolic blood pressure value and the diastolic blood pressure value of the central artery or the systolic blood pressure value and the diastolic blood pressure value of the other intracavitary aorta are calculated, and the measurement is completed, where the blood pressure in the brachial artery or the blood pressure in the femoral artery at the position of the upstream signal channel at the time delay time under the complete block state, and the blood pressure in the several cardiac arteries under the complete block state collected in the above step C are calculated. Step F: obtaining a maximum value of blood pressure in the brachial artery or a maximum value of blood pressure in the femoral artery under a complete block state according to a curve of the pulse wave signal of the upstream signal channel in a pulse cycle, the maximum value being approximately equal to the systolic blood pressure of the central artery or the systolic blood pressure of the other intraluminal aorta, and in the vicinity of a diastolic pressure point, the velocity of blood flow in the brachial artery or the velocity of blood flow in the femoral artery is approximately zero, so that the diastolic blood pressure value measured at the position of the brachial artery or the femoral artery is approximately equal to the diastolic blood pressure of the central artery or the diastolic blood pressure of the other intraluminal aorta; 13. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures comprising:

2. In step D, the second derivative of the air pressure variation curve of the airbag of the midstream signal channel under the half-blocked state is calculated, and the first positive-to-negative zero crossing point, i.e., the zero crossing point of the blood flow acceleration, is found; Calculating the blood pressure in the brachial artery or the blood pressure in the femoral artery at the position of the upstream signal channel at the time of the zero crossing point of the blood flow acceleration under the half-block state based on the signal curve of the upstream signal channel at that time and the blood pressure in the brachial artery at the position of the upstream signal channel at the time of the upstroke of the pulse wave signal of the downstream signal channel under the half-block state; Measure the delay time between the upstroke point of the pulse wave and the zero crossing point of the blood flow acceleration under the half-block state for one cardiac cycle of the air pressure curve of the airbag of the midstream signal channel; Under the complete blockage state, for one cardiac cycle of the signal curve of the upstream signal channel, determine a corresponding delay time point, i.e., the delay time from the upstroke point of the pulse wave to this point is equal to the delay time; Under the full block condition, the blood pressure in the brachial artery or the femoral artery at the location of the upstream signal channel at this delay time is approximately equal to the blood pressure in the brachial artery or the femoral artery at the location of the upstream signal channel at the same delay time under the half block condition.

2. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures according to claim 1.

3. During the measurement process, the airbag of the midstream strap and the intraluminal aorta to be measured are held in the same horizontal position. When measuring the left arm, the intraluminal aorta is the ascending aorta, when measuring the right arm, the intraluminal aorta is the innominate aorta, and when measuring the lower limb, the intraluminal aorta is the terminal abdominal aorta.

2. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures according to claim 1.

4. The air-filled airbag of the midstream strap is connected to one end of a two-way air valve via a tube, and the other end of the two-way air valve is connected to a pressure sensor, an air pump, and a linear air valve via a tube, whereby in step C, air is filled into the midstream strap by opening the two-way air valve, closing the linear air valve, and starting the air pump, and in step D, the midstream strap is gradually degassed by opening the two-way air valve connected to the air-filled airbag of the midstream strap and gradually opening the linear air valve. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures according to any one of claims 1 to 3.

5. The upstream signal channel and the downstream signal channel are both strap bodies incorporating air-filled airbags, and the air-filled airbag of the upstream signal channel is connected to one end of a first two-way air valve via a tube, and is also connected to a first pressure sensor via a tube; The air-filled air bag of the midstream signal channel is connected to one end of a second two-way air valve through a tube, and is also connected to a micro-hole air valve through a tube, and the micro-hole air valve is connected to the air-filled air bag of the downstream signal channel through a tube; The air-filled air bag of the downstream signal channel is connected to one end of a third two-way air valve through a tube, and is also connected to the second pressure sensor and the micro-hole air valve through a tube; The other ends of the three two-way air valves are connected via tubes to the third pressure sensor, the air pump, and the linear air valve, and the first pressure sensor, the second pressure sensor, and the third pressure sensor are connected via electric wires to a first signal amplifier, a second signal amplifier, and a third signal amplifier, respectively; The method further includes the following step B before the step C, namely: Start the air pump, fill the air-filled airbag of the upstream signal channel with several tens of milliamperes through the two-way air valve of the upstream signal channel, and simultaneously start synchronously collecting the pulse wave signal of the upstream signal channel, the pulse wave signal of the downstream signal channel, and the air pressure signal of the air-filled airbag of the midstream signal channel until the measurement is completed; and Step C is to open the two-way air valve connected to the air-filled air bag of the middle signal channel, and gradually open the linear air valve, so that the air-filled air bag of the middle signal channel gradually releases gas, and the blood flow of the brachial artery or the blood flow of the femoral artery gradually starts to flow, and a pulse wave signal begins to appear in the downstream signal channel, which is in a half-blocked state; Record the amplitude values ​​of the pulse wave signal that first appears in the downstream signal channel, and at the same time, record the air pressure of the air-filled airbag of the midstream signal channel for each pulse. Perform linear fitting between the two. When the amplitude value of the pulse wave signal of the downstream signal channel passes through a zero crossing point, calculate the air pressure of the air-filled airbag of the midstream signal channel at that time, i.e., the systolic blood pressure of the brachial artery or the systolic blood pressure of the femoral artery; The air-filled airbag of the midstream signal channel continues to deflate, and a time delay between the air pressure fluctuation signal of the air-filled airbag of the midstream signal channel and the pulse wave signal of the downstream signal channel is measured and fitted to calculate a time point at which the time delay gradually decreases to a certain value, and the air pressure of the air-filled airbag of the midstream signal channel at this time is the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures according to any one of claims 1 to 3.

6. The method further includes the following step A before the step B, i.e. open the two-way air valve connected to the air-filled airbag of the midstream signal channel, close the linear air valve, start the air pump, fill the air-filled airbag of the midstream signal channel with air through the two-way air valve, fill the air-filled airbag of the downstream signal channel with air through the micro-hole air valve, and detect and collect the air pressure fluctuation signal of the air-filled airbag of the downstream signal channel until the blood flow of the brachial artery or the blood flow of the femoral artery stops, i.e., the pulse wave signal of the air-filled airbag of the downstream signal channel becomes zero; opening the two-way air valve connected to the air-filled airbag of the midstream signal channel, and gradually opening the linear air valve to gradually release the gas in the air-filled airbag of the midstream signal channel, so that the blood flow in the brachial artery or the blood flow in the femoral artery gradually starts to flow, and a pulse wave signal starts to appear in the downstream signal channel, recording how many amplitude values ​​of the pulse wave signal that first appear in the downstream signal channel are recorded, and at the same time, recording the air pressure of the air-filled airbag of the midstream signal channel for each pulse, and performing linear fitting between the two to calculate the air pressure of the air-filled airbag of the midstream signal channel when the amplitude of the pulse wave signal of the downstream signal channel passes through a zero crossing point, i.e., the systolic blood pressure of the brachial artery or the systolic blood pressure of the femoral artery; Continue deflating the air-filled airbag of the midstream signal channel, measure the time delay between the air pressure fluctuation signal of the air-filled airbag of the midstream signal channel and the pulse wave signal of the downstream signal channel, perform fitting, and calculate the time when the time delay gradually decreases to a certain value, at which time the air pressure of the air-filled airbag of the midstream signal channel is the diastolic blood pressure of the brachial artery or the diastolic blood pressure of the femoral artery; and In the step B, "filling the air-filled airbag of the upstream signal channel with air to several tens of milliamalgams by the bidirectional air valve of the upstream signal channel" means "filling the air-filled airbag of the upstream signal channel with air to the diastolic pressure of the brachial artery or the diastolic pressure of the femoral artery described in the step A by the bidirectional air valve of the upstream signal channel." 6. A method for non-invasively measuring central arterial pressure and other intraluminal aortic pressures according to claim 5.

7. 1. A three-channel pulse wave signal sensor, comprising: The upstream signal channel is divided into an upstream signal channel, a midstream signal channel, and a downstream signal channel according to the blood flow direction corresponding to the limb to be measured, and the upstream signal channel, the midstream signal channel, and the downstream signal channel are fixed according to the blood flow direction during blood pressure measurement, respectively. The upstream signal channel is a strap body containing an air-filled airbag or an upstream electronic signal sensor, the midstream signal channel is a midstream strap in a strap body containing the air-filled airbag, and the downstream signal channel is The air-filled airbag of the upstream signal channel, the air-filled airbag of the midstream signal channel, and the air-filled airbag of the downstream signal channel are connected to a main device of the non-invasive blood pressure measuring device through air pipes, respectively, to transmit a blood vessel pressure signal, and the upstream electronic signal sensor and the downstream electronic signal sensor transmit an upstream pulse wave signal of blood flow and a downstream pulse wave signal of blood flow, respectively, to the main device of the non-invasive blood pressure measuring device.

1. A three-channel pulse wave signal sensor comprising:

8. The three-channel pulse wave signal sensor of claim 7, characterized in that the separation distances between the upstream signal channel, the midstream signal channel and the downstream signal channel are designed according to the length of the subject's limb, and the three signal channels may be closely connected to form a whole by a connection structure, or may be spaced apart from each other.

9. 8. The three-channel pulse wave signal sensor of claim 7, wherein the range of the separation distance between the edge of the upstream signal channel and the edge of the midstream signal channel is in the range of 0 cm to 15 cm, typically 1 cm, and the range of the separation distance between the edge of the midstream signal channel and the edge of the downstream signal channel is in the range of 0 cm to 30 cm, typically 1 cm.

10. The three-channel pulse wave signal sensor of claim 7, characterized in that the width of the air-filled airbag of the midstream strap is determined based on the circumference of the upper limb of the subject, and this width corresponds to the circumference of the upper limb of the subject based on the requirements of the cuff of a Korotkoff sound blood pressure monitor, and a minimum width is determined according to the circumference of the limb of the subject, and the width range of the air-filled airbag of the upstream signal channel and the width range of the air-filled airbag of the downstream signal channel are both within the range of 2 to 3 cm.

11. 8. The three-channel pulse wave signal sensor of claim 7, wherein when measuring the upper limbs, the air-filled airbag of the downstream signal channel may be bound to a position below the elbow joint, and when measuring the lower limbs, the air-filled airbag of the downstream signal channel may be bound to a position below the knee joint.

12. The three-channel pulse wave signal sensor of claim 7, characterized in that the upstream signal channel, the midstream signal channel and the downstream signal channel should be bound to the same measured limb, and the relative positions of the upstream signal channel, the midstream signal channel and the downstream signal channel are fixed and do not change during use.

13. 8. The three-channel pulse wave signal sensor of claim 7, wherein when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, the electronic signal sensor is a pressure sensor or a photoelectric sensor.

14. 13. The three-channel pulse wave signal sensor of claim 7, wherein when the upstream signal channel, the midstream signal channel, and the downstream signal channel are all strap bodies incorporating the air-filled airbag, the strap body of the upstream signal channel and the strap body of the midstream signal channel are fixedly connected, the strap body of the midstream signal channel and the strap body of the downstream signal channel are fixedly connected, and the strap body of the upstream signal channel, the strap body of the midstream signal channel, and the strap body of the downstream signal channel are fixedly attached as a single strap body.

15. 14. The three-channel pulse wave signal sensor according to any one of claims 7 to 9, 12 and 13, characterized in that, when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, a strap bracket is used to fix the electronic signal sensor of the upstream signal channel and / or the electronic signal sensor of the downstream signal channel and the midstream strap, the strap bracket is provided with a fixing strap for fixing the electronic signal sensor of the upstream signal channel and / or the electronic signal sensor of the downstream signal channel, and the distances and positions between the upstream signal channel, the midstream signal channel and the downstream signal channel are determined by the strap bracket.

16. A three-channel pulse wave signal sensor as described in any one of claims 7 to 9, 12 and 13, characterized in that when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, the electronic signal sensor is also attached to the measured limb via a strap body, and the strap body of the electronic signal sensor is connected to the strap body of the midstream strap.

17. A three-channel pulse wave signal sensor as described in any one of claims 7 to 9, 12 and 13, characterized in that when at least one of the upstream signal channel and the downstream signal channel is an electronic signal sensor, the electronic signal sensor and the midstream strap are separated.

18. 1. An apparatus for non-invasively measuring central arterial pressure and other intraluminal aortic pressures, comprising: A device for non-invasively measuring central arterial pressure and other intraluminal aortic pressures, comprising a three-channel pulse wave signal sensor according to any one of claims 7 to 17.

19. The non-invasive central arterial pressure and other intraluminal aortic pressure measuring device further comprises a master unit, the master unit comprising a microprocessor; the upstream signal channel, the midstream signal channel, and the downstream signal channel of the three-channel pulse wave signal sensor all include the strap body having an air-filled airbag built therein; The air bag of the upstream signal channel is connected to one end of a first two-way air valve through a tube, and is also connected to a first pressure sensor through a tube; The airbag of the midstream signal channel is connected to one end of a second two-way air valve through a tube, and is also connected to one end of a micro-hole air valve through a tube, and the other end of the micro-hole air valve is connected to the airbag of the downstream signal channel through a tube; The air bag of the downstream signal channel is connected to a third two-way air valve through a tube, and is also connected to a third pressure sensor and the other end of the micro-hole air valve through a tube; the other end of the first two-way air valve, the other end of the second two-way air valve, and the other end of the third two-way air valve are connected via a tube, and are also connected via a tube to a second pressure sensor, an air pump, and a linear air valve; the first pressure sensor, the second pressure sensor, and the third pressure sensor are connected to a first signal amplifier, a second signal amplifier, and a third signal amplifier, respectively, via electric wires; and the output terminal of the first signal amplifier, the output terminal of the second signal amplifier, and the output terminal of the third signal amplifier are connected to input terminals of three analog-to-digital converters (ADCs) of the microprocessor via electric wires; 20. The device for non-invasively measuring central arterial and other intraluminal aortic pressures as recited in claim 18, wherein the microprocessor is connected via electrical wires to the first bi-way air valve, the second bi-way air valve, the third bi-way air valve, the first signal pressure sensor, the second signal pressure sensor, the third signal pressure sensor, the linear air valve, and the air pump.

20. The non-invasive central arterial pressure and other intraluminal aortic pressure measuring device further comprises a master unit, the master unit comprising a microprocessor; The upstream signal channel of the three-channel pulse wave signal sensor is an upstream electronic signal sensor, and the downstream signal channel is a downstream electronic signal sensor; the upstream electronic signal sensor is connected via an electrical wire to a first signal amplifier; The air bag of the midstream signal channel is connected to one end of a two-way air valve through a tube, and the other end of the two-way air valve is connected to a signal pressure sensor, an air pump, and a linear air valve through a tube, and the pressure sensor is connected to a second signal amplifier through an electric wire; the downstream electronic signal sensor is connected via an electrical wire to a third signal amplifier; an output terminal of the first signal amplifier, an output terminal of the second signal amplifier, and an output terminal of the third signal amplifier are connected to input terminals of three analog-to-digital converters (ADCs) of the microprocessor via electric wires; 20. The device for non-invasively measuring central arterial and other intraluminal aortic pressures as described in claim 18, wherein the microprocessor is connected to the two-way pneumatic valve, the signal pressure sensor, the linear pneumatic valve, and the air pump via electrical wires.

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