Blood pressure monitoring method and system based on wearable ultrasonic transducer

Abstract

The invention relates to a blood pressure monitoring method and system based on a wearable ultrasonic transducer, and the method comprises the following steps: obtaining an ultrasonic continuous image of a to-be-monitored artery through the ultrasonic transducer, and obtaining the continuous position change information of an artery wall; obtaining continuous change information of the artery diameter along with time according to the continuous position change information of the artery wall; according to the artery diameter-blood pressure relation, continuous blood pressure data are obtained in combination with continuous change information of the artery diameter along with time; wherein the establishment of the artery diameter-blood pressure relationship comprises the following steps: selecting a proper superficial limb artery as a measurement area, and determining a calibration blood vessel; the blood vessel calibration information is obtained through a sphygmomanometer and an ultrasonic transducer; the ultrasonic echo time difference between the anterior artery wall and the posterior artery wall is obtained through the ultrasonic transducer, and the diameter of the artery is obtained; and fitting the calibration information and the artery diameter to obtain an artery diameter-blood pressure relationship. Compared with the prior art, real-time continuous monitoring of the superficial arterial blood pressure of the human body is achieved.

Description

Technical Field

[0001] The present invention relates to the field of real-time measurement and monitoring of human blood pressure, and in particular to a blood pressure monitoring method and system based on a wearable ultrasonic transducer. Background Art

[0002] Traditional handheld ultrasound probes are mostly used in clinical medical imaging diagnosis. They are often large in size and poor in portability, which strictly limits the application scenarios of ultrasound technology. In recent years, as portable wearable ultrasound technology continues to mature, ultrasound transducers are developing in the direction of portable and wearable.

[0003] Cardiovascular disease, along with cancer, respiratory diseases, and diabetes, is known as one of the four major chronic diseases, which seriously endangers people's health. Arterial blood pressure is a key physiological parameter for evaluating the cardiovascular system. The arterial blood pressure waveform contains rich information about the dynamic cardiovascular state and can be used to diagnose or predict cardiovascular disease. Each protruding peak and concave trough in the arterial blood pressure waveform represents a specific heart activity. Continuous monitoring of these subtle waveform changes can provide a reliable basis for the diagnosis and prevention of cardiovascular disease.

[0004] At present, the main methods for measuring blood pressure include cuff pressure method, volume compensation method, tension method, etc. The cuff pressure method is the most widely used blood pressure measurement method in the world, but this method can only measure blood pressure intermittently, cannot monitor blood pressure changes in real time, and the comfort level during the measurement is low; the volume compensation method is easily affected by skin conditions and measurement environment; the tension method often causes discomfort to patients because the artery needs to be squeezed during the measurement process. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a blood pressure monitoring method and system based on a wearable ultrasonic transducer, which realizes real-time continuous monitoring of human superficial arterial blood pressure without squeezing the artery, improves comfort, and is not affected by skin condition and measurement environment.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A blood pressure monitoring method based on a wearable ultrasonic transducer comprises the following steps:

[0008] Obtaining continuous ultrasonic images of the artery to be monitored through an ultrasonic transducer, and obtaining continuous position change information of the artery wall according to the continuous ultrasonic images;

[0009] Obtaining information on continuous changes in the diameter of the artery over time according to the continuous position change information of the arterial wall;

[0010] According to the arterial diameter-blood pressure relationship, continuous blood pressure data is obtained through the continuous change information of the arterial diameter over time;

[0011] The steps for establishing the arterial diameter-blood pressure relationship are as follows:

[0012] Select appropriate superficial limb arteries as the measurement area and determine the calibration vessels;

[0013] Using a sphygmomanometer to obtain the systolic pressure and diastolic pressure of the calibration blood vessel, using an ultrasonic transducer to obtain the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure of the calibration blood vessel, and using the arterial systolic pressure, arterial diastolic pressure, arterial diameter corresponding to the systolic pressure and arterial diameter corresponding to the diastolic pressure as calibration information;

[0014] The ultrasonic echo time difference between the front wall and the back wall of the artery is obtained by ultrasonic transducer, and the diameter of the artery is calculated according to the speed of sound in human blood pressure;

[0015] The calibration information and the arterial diameter are fitted to obtain a corresponding arterial diameter-blood pressure relationship.

[0016] Furthermore, the superficial limb artery includes multiple ones of the brachial artery, radial artery, ulnar artery or carotid artery.

[0017] Furthermore, the superficial limb artery is located between 2 and 15 mm below the skin.

[0018] Furthermore, the central frequency of the ultrasonic transducer is 7-10 MHz, and the longitudinal limit resolution is 0.2-0.5 mm.

[0019] Furthermore, the arterial hardness coefficient is obtained according to the arterial systolic pressure, the arterial diastolic pressure, the arterial diameter corresponding to the systolic pressure, and the arterial diameter corresponding to the diastolic pressure.

[0020] Furthermore, the stiffness coefficient of the artery is as follows:

[0021]

[0022] Where β is the arterial stiffness coefficient, p d is the diastolic blood pressure, p s D is the systolic blood pressure, s D is the arterial diameter corresponding to systolic pressure. d is the arterial diameter corresponding to diastolic pressure.

[0023] Furthermore, the arterial diameter-blood pressure relationship is as follows:

[0024]

[0025] Where p(t) is the blood pressure value changing with time, pd is the arterial diastolic pressure, β is the arterial stiffness coefficient, D(t) is the arterial diameter that changes with time, and D d is the arterial diameter corresponding to diastolic pressure.

[0026] Furthermore, continuous position change information of the arterial wall is acquired according to the ultrasonic echo signal, and the continuous position change information of the arterial wall includes continuous position change information of the front wall of the artery and the back wall of the artery.

[0027] Furthermore, the continuous change information of the diameter of the artery over time is obtained according to the continuous position change information of the front wall of the artery and the back wall of the artery.

[0028] According to another aspect of the present invention, there is provided a blood pressure monitoring system based on a wearable ultrasonic transducer, comprising:

[0029] An arterial wall position information acquisition module, used to obtain an ultrasonic continuous image of the artery to be monitored through an ultrasonic transducer, and obtain continuous position change information of the arterial wall according to the ultrasonic continuous image;

[0030] An artery diameter acquisition module, used to obtain information on continuous changes in the artery diameter over time based on the continuous position change information of the artery wall;

[0031] A blood pressure data acquisition module, for obtaining continuous blood pressure data based on the diameter-blood pressure relationship and the continuous change information of the arterial diameter over time;

[0032] The steps for establishing the arterial diameter-blood pressure relationship are as follows:

[0033] Select appropriate superficial limb arteries as the measurement area and determine the calibration vessels;

[0034] Using a sphygmomanometer to obtain the systolic pressure and diastolic pressure of the calibration blood vessel, using an ultrasonic transducer to obtain the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure of the calibration blood vessel, and using the arterial systolic pressure, arterial diastolic pressure, arterial diameter corresponding to the systolic pressure and arterial diameter corresponding to the diastolic pressure as calibration information;

[0035] The ultrasonic echo time difference between the front wall and the back wall of the artery is obtained by ultrasonic transducer, and the diameter of the artery is calculated according to the speed of sound in human blood pressure;

[0036] The calibration information and the arterial diameter are fitted to obtain a corresponding arterial diameter-blood pressure relationship.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention relies on the advantages of wearable ultrasound technology such as real-time imaging, high resolution, low cost, and rapid monitoring. It uses an ultrasonic transducer to obtain the diameter information of the blood vessels, obtains the diastolic and systolic pressures of the arteries through a sphygmomanometer, determines the arterial hardness coefficient, and then fits the corresponding arterial diameter-blood pressure relationship formula. By measuring the continuous change information of the arterial diameter over time in real time, the real-time, continuous and accurate measurement of blood pressure is achieved, thereby ensuring the accuracy and stability of blood pressure measurement.

[0039] 2. The present invention measures blood pressure in real time by using a wearable ultrasonic transducer. The wearable ultrasonic transducer has high integration, light weight and compact size, breaking through the application scenario limitations of traditional ultrasonic probes. It can be worn on the human body and moved around. The ultrasonic transducer is used to measure blood pressure without squeezing the arteries, thereby improving the comfort of blood pressure measurement. The portability of the wearable ultrasonic transducer makes it possible to use ultrasonic blood pressure measurement technology at home. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a blood pressure monitoring method based on a wearable ultrasonic transducer proposed in the present invention;

[0041] Figure 2 A schematic diagram of the brachial artery in a human arm;

[0042] Figure 3 M-mode ultrasound echograms of porcine arteries were measured using a wearable ultrasound transducer;

[0043] Figure 4 This is the brightness distribution of a column of ultrasound signals in the M-mode ultrasound echogram of a pig artery;

[0044] Figure 5 It is an arterial diameter-blood pressure curve obtained according to the calibration information and a distribution diagram of data points within the normal blood pressure range obtained by the test.

[0045] Legend: 1. Wearable ultrasonic transducer; 2. Coupling layer; 3. Signal conductor; 4. Brachial artery; 5. Muscle tissue; 6. Bone tissue; 7. Human arm; 8. Anterior wall of artery; 9. Posterior wall of artery. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0047] Example 1

[0048] This embodiment provides a blood pressure monitoring method based on a wearable ultrasonic transducer, such as Figure 1 As shown, the following steps are included:

[0049] S1. Obtaining continuous ultrasonic images of the artery to be monitored through an ultrasonic transducer, and obtaining continuous position change information of the arterial wall based on the continuous ultrasonic images.

[0050] In this embodiment, a human arm 7 is selected as a research object. Figure 2 shown.

[0051] In this embodiment, a wearable ultrasonic transducer 1 is composed of an array, including 32 independent array elements, and has structures such as an acoustic matching layer and a backing layer, and can transmit and receive ultrasonic signals through a signal conductor 3. The center frequency of the ultrasonic transducer is 7 to 10 MHz, and the longitudinal limit resolution is 0.2 to 0.5 mm.

[0052] The calibration sphygmomanometer uses an electronic sphygmomanometer for measurement. The coupling layer 2 uses a silicone rubber or hydrogel product with fluidity, and the thickness should be less than 1 mm.

[0053] The brachial artery 4 of the human arm 7 is selected as the artery to be monitored, and the muscle tissue 5 and bone tissue 6 should be avoided. A coupling layer 2 is filled between the wearable ultrasonic transducer and the skin to reduce the reflection and loss of the ultrasonic signal, and it is fixed above the brachial artery 4 of the human arm 7 with medical tape.

[0054] The wearable ultrasonic transducer 1 is used to obtain M-mode ultrasonic continuous images of the target artery, and the continuous position change information of the arterial wall is obtained according to the information in the image.

[0055] S2. Obtaining information on continuous changes in the diameter of the artery over time based on the continuous position change information of the artery wall.

[0056] The arterial diameter is calculated based on the ultrasonic echo time difference between the anterior wall and the posterior wall of the artery and the speed of sound in the human artery of 1570m / s, and the continuous change information of the arterial diameter over time is obtained.

[0057] S3. According to the relationship between arterial diameter and blood pressure, continuous blood pressure data is obtained through the continuous change information of arterial diameter over time.

[0058] The steps to establish the arterial diameter-blood pressure relationship are as follows:

[0059] Select appropriate superficial limb arteries as the measurement area and determine the calibration blood vessels. The superficial limb arteries are the brachial artery, radial artery, ulnar artery or carotid artery. The artery diameter is 3 to 10 mm and is located between 2 and 15 mm below the skin.

[0060] The systolic and diastolic pressures are measured by a sphygmomanometer, and the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure are obtained by an ultrasonic transducer. The systolic pressure, diastolic pressure, arterial diameter corresponding to the systolic pressure and arterial diameter corresponding to the diastolic pressure are used as calibration information.

[0061] The diameter-blood pressure relationship of the corresponding artery is fitted according to the calibration information.

[0062] In this embodiment, a fixed wearable ultrasonic transducer is used to obtain an ultrasonic signal of a cardiac cycle of the target artery, and the systolic diameter D of the measured artery is calculated based on the obtained ultrasonic signal. s1 and diastolic diameter D d1 , use a sphygmomanometer to measure the systolic blood pressure of the ipsilateral arm 7 s1 With diastolic blood pressure d1 , as calibration information.

[0063] According to the calibrated arterial systolic pressure p s1 and its diameter D s1 and diastolic blood pressure d1 and its diameter D d1 , according to the arterial hardness calculation formula, the hardness coefficient β1 of the target artery is calculated and obtained.

[0064] The calculation formula of arterial stiffness coefficient is as follows:

[0065]

[0066] Where β is the arterial stiffness coefficient, p d is the diastolic blood pressure, p s D is the systolic blood pressure, s D is the arterial diameter corresponding to systolic pressure. d is the arterial diameter corresponding to diastolic pressure.

[0067] According to the calculated hardness coefficient β1 and diastolic pressure p d1 and its diameter D d1 Calculate the arterial diameter-blood pressure relationship formula y1=p(t).

[0068] The relationship between arterial diameter and blood pressure is as follows:

[0069]

[0070] Where p(t) is the blood pressure value changing with time, p d is the diastolic pressure of the artery, β is the stiffness coefficient of the artery, D(t) is the diameter of the artery changing with time, D d is the arterial diameter corresponding to diastolic pressure.

[0071] According to the arterial diameter-blood pressure relationship formula y1=p(t), the continuous systolic and diastolic pressure changes of the artery are calculated. Through the continuous systolic and diastolic pressure data of the artery, physiological information such as heart rate can be calculated.

[0072] The arterial diameter-blood pressure curve obtained based on the calibration information and the data point distribution diagram within the normal blood pressure range obtained by the test are shown in the figure below: Figure 5 As shown, the error of all points is less than 3mmHg. Figure 5 It can be seen that the blood pressure monitoring method based on a wearable ultrasonic transducer proposed in this embodiment has a good blood pressure monitoring effect.

[0073] Example 2

[0074] Since the structure and properties of porcine arteries are similar to those of human arteries, this embodiment selects an ex vivo porcine artery as the artery to be monitored. A rubber catheter is tightly connected to the porcine artery, and the two ends are respectively connected to a pressurizing device and a pressure gauge. The wearable ultrasonic transducer is fixed 3 mm away from the upper wall of the artery. Both the ultrasonic transducer and the porcine artery are in a 0.9% NaCl saline solution.

[0075] The fixed wearable ultrasonic transducer is used to obtain the ultrasonic signals of the front wall 8 and the back wall 9 of the target artery. The diastolic pressure is 75 mmHg and the systolic pressure is 127.5 mmHg. After pressurization, the systolic diameter D of the artery is calculated based on the obtained ultrasonic signals. s2 and diastolic diameter D d2 , systolic blood pressure s2 and diastolic blood pressure d2 , as calibration information.

[0076] The calibrated arterial systolic pressure p s2 and its diameter D s2 and diastolic blood pressure d2 and its diameter D d2 According to the arterial hardness calculation formula, the hardness coefficient β2 of the target artery is calculated and obtained; according to the calculated hardness coefficient β2 and diastolic pressure p d2 and its diameter D d2 Calculate the arterial diameter-blood pressure relationship formula y2=p'(t).

[0077] A wearable ultrasonic transducer is used to obtain a continuous M-mode ultrasonic image of the target artery, and the continuous position change information of the anterior wall 8 and the posterior wall 9 of the artery is obtained based on the information in the image, and the continuous change information of the arterial diameter over time is obtained based on the position difference of the arterial wall. Figure 3 The figure shows an M-mode ultrasound echogram of an isolated porcine artery measured by a wearable ultrasound transducer. The figure shows the position changes of the front wall 8 and the back wall 9 of the artery over time in the horizontal axis, and the vertical axis shows the distance of the artery wall from the ultrasound transducer.

[0078] The brightness distribution of a series of ultrasound signals in the M-mode ultrasound echogram of an isolated porcine artery is shown in the figure below. Figure 4 As shown, the artery diameter information can be obtained through the position difference between the front wall 8 and the back wall 9 of the artery.

[0079] According to the obtained arterial diameter-blood pressure relationship formula y2=p'(t), the continuous systolic and diastolic pressure changes of the artery are calculated.

[0080] The rest is the same as in Example 1.

[0081] Example 3

[0082] This embodiment provides a blood pressure monitoring system based on a wearable ultrasonic transducer, comprising:

[0083] An arterial wall position information acquisition module is used to obtain an ultrasonic continuous image of the artery to be monitored through an ultrasonic transducer, and obtain continuous position change information of the arterial wall according to the ultrasonic continuous image;

[0084] An artery diameter acquisition module, used to obtain information on continuous changes in the artery diameter over time based on the continuous position change information of the artery wall;

[0085] A blood pressure data acquisition module is used to obtain continuous blood pressure data based on the diameter-blood pressure relationship and the continuous change information of the arterial diameter over time;

[0086] The steps for establishing the arterial diameter-blood pressure relationship are as follows:

[0087] Select appropriate superficial limb arteries as the measurement area and determine the calibration vessels;

[0088] The systolic pressure and diastolic pressure of the calibration blood vessel are obtained by using a sphygmomanometer, and the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure of the calibration blood vessel are obtained by using an ultrasonic transducer, and the arterial systolic pressure, the arterial diastolic pressure, the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure are used as calibration information;

[0089] The ultrasonic echo time difference between the front wall and the back wall of the artery is obtained by ultrasonic transducer, and the diameter of the artery is calculated according to the speed of sound in human blood pressure;

[0090] The calibration information and arterial diameter are fitted to obtain the corresponding arterial diameter-blood pressure relationship.

[0091] The rest is the same as in Example 1.

[0092] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A blood pressure monitoring method based on a wearable ultrasonic transducer, characterized in that: The following steps are involved: Obtaining continuous ultrasonic images of the artery to be monitored through an ultrasonic transducer, and obtaining continuous position change information of the artery wall according to the continuous ultrasonic images; Obtaining information on continuous changes in the diameter of the artery over time according to the continuous position change information of the arterial wall; According to the arterial diameter-blood pressure relationship, continuous blood pressure data is obtained through the continuous change information of the arterial diameter over time; The steps for establishing the arterial diameter-blood pressure relationship are as follows: Select appropriate superficial limb arteries as the measurement area and determine the calibration vessels; Using a sphygmomanometer to obtain the systolic pressure and diastolic pressure of the calibration blood vessel, using an ultrasonic transducer to obtain the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure of the calibration blood vessel, and using the arterial systolic pressure, arterial diastolic pressure, arterial diameter corresponding to the systolic pressure and arterial diameter corresponding to the diastolic pressure as calibration information; The ultrasonic echo time difference between the front wall and the back wall of the artery is obtained by ultrasonic transducer, and the diameter of the artery is calculated according to the speed of sound in human blood pressure; The calibration information and the arterial diameter are fitted to obtain a corresponding arterial diameter-blood pressure relationship.

2. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 1, characterized in that: The superficial limb arteries include multiple ones of the brachial artery, radial artery, ulnar artery or carotid artery.

3. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 2, characterized in that: The superficial limb artery is located between 2 and 15 mm below the skin.

4. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 1, characterized in that: The central frequency of the ultrasonic transducer is 7-10 MHz, and the longitudinal limit resolution is 0.2-0.5 mm.

5. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 1, characterized in that: The hardness coefficient of the artery is obtained according to the arterial systolic pressure, the arterial diastolic pressure, the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure.

6. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 5, characterized in that: The stiffness coefficient of the artery is as follows: Where β is the arterial stiffness coefficient, p d is the diastolic blood pressure, p s is the systolic blood pressure, D s D is the arterial diameter corresponding to systolic pressure. d is the arterial diameter corresponding to diastolic pressure.

7. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 1, characterized in that: The arterial diameter-blood pressure relationship is as follows: Where p(t) is the blood pressure value changing with time, p d is the arterial diastolic pressure, β is the arterial stiffness coefficient, D(t) is the arterial diameter that changes with time, and D d is the arterial diameter corresponding to diastolic pressure.

8. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 1, characterized in that: The continuous position change information of the arterial wall is acquired according to the ultrasonic echo signal, and the continuous position change information of the arterial wall includes the continuous position change information of the front wall of the artery and the back wall of the artery.

9. The blood pressure monitoring method based on a wearable ultrasonic transducer according to claim 8, characterized in that: The continuous change information of the artery diameter over time is obtained according to the continuous position change information of the front wall of the artery and the back wall of the artery.

10. A blood pressure monitoring system based on a wearable ultrasonic transducer, comprising: An arterial wall position information acquisition module, used to obtain an ultrasonic continuous image of the artery to be monitored through an ultrasonic transducer, and obtain continuous position change information of the arterial wall according to the ultrasonic continuous image; An artery diameter acquisition module, used to obtain information on continuous changes in the artery diameter over time based on the continuous position change information of the artery wall; A blood pressure data acquisition module, for obtaining continuous blood pressure data based on the diameter-blood pressure relationship and the continuous change information of the arterial diameter over time; The steps for establishing the arterial diameter-blood pressure relationship are as follows: Select appropriate superficial limb arteries as the measurement area and determine the calibration vessels; Using a sphygmomanometer to obtain the systolic pressure and diastolic pressure of the calibration blood vessel, using an ultrasonic transducer to obtain the arterial diameter corresponding to the systolic pressure and the arterial diameter corresponding to the diastolic pressure of the calibration blood vessel, and using the arterial systolic pressure, arterial diastolic pressure, arterial diameter corresponding to the systolic pressure and arterial diameter corresponding to the diastolic pressure as calibration information; The ultrasonic echo time difference between the front wall and the back wall of the artery is obtained by ultrasonic transducer, and the diameter of the artery is calculated according to the speed of sound in human blood pressure; The calibration information and the arterial diameter are fitted to obtain a corresponding arterial diameter-blood pressure relationship.

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