Blood pressure measurement device

Abstract

A blood pressure measurement device (100), comprising an ultrasonic transducer array (101), a control module (102), and a signal processing module (103). The ultrasonic transducer array (101) comprises a plurality of ultrasonic transducer pixels arranged in an array, and is configured to emit a plurality of groups of plane waves at different angles to a blood vessel under test in response to an applied excitation signal and receive a plurality of groups of echo signals obtained after the plurality of groups of plane waves are reflected by the blood vessel; the control module (102) is in signal connection with the ultrasonic transducer array (101), and is configured to provide the excitation signal to the ultrasonic transducer array (101) to control the working state of the plurality of ultrasonic transducer pixels; the signal processing module (103) is in signal connection with the ultrasonic transducer array (101), and is configured to process the plurality of groups of echo signals to obtain a plurality of groups of echo data to obtain a blood pressure value of the blood vessel under test. The blood pressure measurement device (100) achieves integrated and portable non-invasive blood pressure measurement, and effectively improves the measurement accuracy and universality.

Description

Blood pressure monitoring device

[0001] This application claims priority to Chinese Patent Application No. 202311235349.9 filed on September 22, 2023, and the contents of the above-mentioned Chinese patent application disclosure are hereby incorporated by reference in their entirety as a part of this application. Technical Field

[0002] Embodiments of the present disclosure relate to a blood pressure detection device. Background Art

[0003] Traditional blood pressure testing can be divided into direct and indirect methods. Direct measurement involves puncturing a peripheral artery with a special cannula and inserting a catheter, with a transducer connected to the end of the catheter to measure blood pressure. Indirect measurement methods include cuff pressure, tonometry, and photoelectric methods. The cuff pressure method uses an air pump to inflate a cuff and squeeze the blood vessels to measure blood pressure. The tonometry method measures blood pressure by placing a pressure sensor directly in contact with an artery, such as the radial artery in the wrist. The photoelectric method uses light to generate a pulse waveform for blood pressure testing.

[0004] Direct measurement methods can accurately and intuitively measure blood pressure and enable continuous testing, but they require puncture, making measurement inconvenient, limiting application scenarios, and placing high demands on the equipment. Although indirect measurement methods are non-invasive, they also have certain limitations: the cuff pressurization method requires an air pump to inflate the cuff and can only measure a single blood pressure value at a time, making continuous testing impossible. While tensiometric and photoelectric methods have achieved miniaturization and increased portability, their measurement accuracy is extremely low, leading to large errors in blood pressure measurements for different individuals.

[0005] In summary, traditional blood pressure detection methods have certain limitations, including being invasive, non-continuous, inaccurate, and requiring large instruments.

[0006] Summary of the Invention

[0007] At least one embodiment of the present disclosure provides a blood pressure detection device, comprising: an ultrasonic transducer array, comprising a plurality of ultrasonic transducer pixels arranged in an array, and configured to transmit a plurality of plane waves of different angles to a measured blood vessel in response to an applied excitation signal and receive a plurality of echo signals obtained by reflection of the plurality of plane waves by the blood vessel; a control module, signal-connected to the ultrasonic transducer array, and configured to provide the excitation signal to the ultrasonic transducer array to control the working state of the plurality of ultrasonic transducer pixels; a signal processing module, signal-connected to the ultrasonic transducer array, and configured to process the plurality of echo signals to obtain a plurality of echo data for obtaining the blood pressure value of the measured blood vessel.

[0008] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, it also includes an image processing module, which is configured to receive the multiple sets of echo data, obtain the blood flow velocity based on the multiple sets of echo data, and obtain the blood pressure value based on the blood flow velocity and the vascular movement state.

[0009] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the image processing module is further configured to reconstruct a three-dimensional image of the blood vessel based on the multiple sets of echo data.

[0010] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the image processing module is further configured to: calculate the time delay of the multiple groups of echo signals; and superimpose the multiple groups of echo data according to the time delay to reconstruct the three-dimensional image of the blood vessel.

[0011] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the image processing module is further configured to: obtain the angle between the ultrasonic transducer array aperture and the blood vessel based on the three-dimensional image of the blood vessel; and calculate the blood flow velocity based on the frequencies of the multiple groups of plane waves of the ultrasonic transducer array, the frequencies of the multiple groups of echo signals and the angle.

[0012] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the image processing module is further configured to: obtain the inner diameter and outer diameter of the blood vessel based on the three-dimensional image of the blood vessel; and obtain the blood pressure value based on the blood flow rate, the outer diameter of the blood vessel, and the inner diameter of the blood vessel.

[0013] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the ultrasonic transducer array is a row-column addressing array.

[0014] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the ultrasonic transducer array is a plurality of one-dimensional line arrays or a two-dimensional fully addressable array.

[0015] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the control module is further configured to: apply the excitation signals with different delays to the ultrasonic transducer array along the first direction of the ultrasonic transducer array, perform beamforming, transmit the plane waves of different angles, and receive the multiple echo signals from the multiple ultrasonic transducer pixels along the second direction of the ultrasonic transducer array; apply the excitation signals with different delays to the ultrasonic transducer array along the second direction of the ultrasonic transducer array, perform beamforming, transmit the plane waves of different angles, and receive the multiple echo signals from the multiple ultrasonic transducer pixels along the first direction of the ultrasonic transducer array, wherein one of the first direction and the second direction is a row direction, and the other is a column direction.

[0016] For example, in the blood pressure detection device provided by at least one embodiment of the present disclosure, each of the plurality of ultrasonic transducer pixels may include one or more ultrasonic transducer devices.

[0017] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, each of the one or more ultrasonic transducer devices may include a piezoelectric ceramic ultrasonic transducer, a capacitive micromachined ultrasonic transducer, or a piezoelectric micromachined ultrasonic transducer.

[0018] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the scanning range of the plane waves of different angles generated by the excitation signal is (-80°)-80°.

[0019] For example, in the blood pressure detection device provided in at least one embodiment of the present disclosure, the frequency of the excitation signal is 1 kHz-20 MHz.

[0020] At least one embodiment of the present disclosure also provides a blood pressure detection method based on the blood pressure detection device as described above, including: using a control module to provide an excitation signal to an ultrasonic transducer array to control the working status of multiple ultrasonic transducer pixels; using the ultrasonic transducer array to emit multiple groups of plane waves at different angles to the measured blood vessel in response to the applied excitation signal, and receiving multiple groups of echo signals obtained by the blood vessel reflecting the multiple groups of plane waves; using a signal processing module to process the multiple groups of echo signals to obtain multiple groups of echo data for obtaining the blood pressure value of the measured blood vessel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present disclosure, rather than limiting the present disclosure.

[0022] FIG1A is a schematic diagram of a blood pressure detection device provided by an embodiment of the present disclosure;

[0023] FIG1B is a schematic diagram of a blood pressure detection device provided by another embodiment of the present disclosure;

[0024] FIG2A is an exemplary three-dimensional image of a blood vessel in the YZ plane according to an embodiment of the present disclosure;

[0025] FIG2B is an exemplary three-dimensional image of a blood vessel in the XZ plane provided by an embodiment of the present disclosure;

[0026] FIG3 is a schematic diagram of blood flow velocity measurement according to an embodiment of the present disclosure;

[0027] FIG4A is a schematic diagram of a row-column addressed ultrasonic transducer array provided in one embodiment of the present disclosure;

[0028] FIG4B is a schematic diagram of a piezoelectric micromachined ultrasonic transducer structure provided by an embodiment of the present disclosure;

[0029] FIG5A is a schematic diagram of column transmission and row reception of an ultrasonic transducer array provided by an embodiment of the present disclosure;

[0030] FIG5B is a schematic diagram of row transmission and column reception of an ultrasonic transducer array provided by an embodiment of the present disclosure;

[0031] FIG6A is a schematic diagram of the transmission distance of an ultrasonic transducer array provided in one embodiment of the present disclosure;

[0032] FIG6B is a schematic diagram of the receiving distance of the ultrasonic transducer array provided by an embodiment of the present disclosure;

[0033] FIG7 is a flow chart of a blood pressure detection method provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0035] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0036] To achieve a non-invasive, more integrated, and portable blood pressure detection device, piezoelectric micro-electromechanical system (MEMS) technology and corresponding integrated circuit processes can be utilized. The inventors of this disclosure noted that continuous blood pressure detection devices based on MEMS technology calculate blood pressure by measuring changes in blood vessels in a direction perpendicular to the transducer aperture. However, if there is an angle between the blood vessels and the transducer, the detection accuracy is reduced, and simply using blood vessel expansion and contraction to perform blood pressure fitting has the problem of limited universality.

[0037] At least one embodiment of the present disclosure provides a blood pressure detection device, which includes: an ultrasonic transducer array, a control module, and a signal processing module. The ultrasonic transducer array includes a plurality of ultrasonic transducer pixels arranged in an array, and is configured to transmit multiple groups of plane waves at different angles to a measured blood vessel in response to an applied excitation signal and receive multiple groups of echo signals obtained by the blood vessel reflecting the multiple groups of plane waves; the control module is connected to the ultrasonic transducer array signal and is configured to provide an excitation signal to the ultrasonic transducer array to control the working state of the multiple ultrasonic transducer pixels; the signal processing module is connected to the ultrasonic transducer array signal and is configured to process the multiple groups of echo signals to obtain multiple groups of echo data for obtaining the blood pressure value of the measured blood vessel.

[0038] The blood pressure detection device of the above-mentioned embodiment of the present disclosure utilizes the characteristics of ultrasound to realize the non-invasive continuous blood pressure detection function, and utilizes the ultrasonic plane waves of different angles generated by the ultrasonic transducer array to effectively improve the accuracy and universality of blood pressure detection.

[0039] FIG1A is a schematic diagram of a blood pressure detection device provided in one embodiment of the present disclosure.

[0040] As shown in FIG1A , the blood pressure detection device 100 includes an ultrasonic transducer array 101 , a control module 102 , and a signal processing module 103 .

[0041] In the blood pressure detection device 100, the ultrasonic transducer array 101 includes a plurality of ultrasonic transducer pixels arranged in an array and configured to transmit multiple sets of plane waves at different angles toward the measured blood vessel in response to an applied excitation signal and receive multiple sets of echo signals resulting from the reflection of the multiple sets of plane waves from the blood vessel. For example, the array 101 includes multiple rows and columns of ultrasonic transducer pixels, e.g., each row / column has the same number of ultrasonic transducer pixels, or different rows / columns can have different numbers of ultrasonic transducer pixels. These pixels respectively capture image data at corresponding locations, thereby forming a desired image as a whole.

[0042] In the blood pressure detection device 100, the control module 102 is signal-connected to the ultrasonic transducer array 101 and is configured to provide an excitation signal to the ultrasonic transducer array 101 to control the operating state of multiple ultrasonic transducer pixels. For example, the control module 102 may include analog / digital circuits, etc., and may be implemented in the form of a central processing unit (CPU), etc. For example, it may be formed on the same semiconductor substrate as the ultrasonic transducer array 101, or it may be prepared independently of the ultrasonic transducer array 101 and then combined with the ultrasonic transducer 101. For example, the two are directly electrically connected or connected by other means so that signals (control signals or data signals) can be transmitted between them.

[0043] In the blood pressure detection device 100, the signal processing module 103 is signal-connected to the ultrasonic transducer array 101 and is configured to process multiple sets of echo signals to obtain multiple sets of echo data for use in obtaining the blood pressure value of the measured blood vessel. For example, the signal processing module 103 may include analog / digital circuits, etc., and may be implemented in the form of a digital signal processor (DSP). For example, it may be formed on the same semiconductor substrate as the ultrasonic transducer array 101 or the control module 102, or it may be prepared independently of the ultrasonic transducer array 101 or the control module 102 and then combined with the ultrasonic transducer 101 or the control module 102, for example, directly electrically connected to the ultrasonic transducer array 101 or connected by other means so that signals (control signals or data signals) can be transmitted between the two.

[0044] FIG1B is a schematic diagram of a blood pressure detection device provided by another embodiment of the present disclosure.

[0045] Compared with the embodiment shown in FIG. 1A , as shown in FIG. 1B , the blood pressure detection device 100 may further include an image processing module 104 .

[0046] In the blood pressure detection device 100, the image processing module 104 is configured to receive multiple sets of echo data, obtain blood flow velocity based on the multiple sets of echo data, and obtain a blood pressure value based on the blood flow velocity and vascular motion state. The image processing module 104 may include analog / digital circuits, such as a central processing unit (CPU), a digital signal processor (DSP), etc. For example, it may be formed on the same semiconductor substrate as the ultrasonic transducer array 101, the control module 102, or the signal processing module 103, or it may be prepared or provided independently of the ultrasonic transducer array 101, the control module 102, or the signal processing module 103 and then combined with the ultrasonic transducer 101, the control module 102, or the signal processing module 103. For example, it may be directly electrically connected to the signal processing module 103 or connected by other means so that signals (control signals or data signals) can be transmitted between the two. The image processing module 104 can obtain the multiple sets of echo data generated by the signal processing module 103. For another example, the image processing module 104 can be integrated with the signal processing module 103, providing a functional module that has both signal processing and image processing functions. This functional module can be implemented using analog / digital circuits, such as an FPGA. Alternatively, the components shown in FIG1A can be integrated together, while the image processing module 104 is provided separately and connected to the components shown in FIG1A via a communication device (not shown). For example, the communication device can be a wired or wireless communication device, and the wireless communication device can be based on a communication standard such as Bluetooth or WIFI.

[0047] For example, the image processing module 104 can be further configured to reconstruct a three-dimensional image of a blood vessel based on multiple sets of echo data. Examples of projections of the three-dimensional image of a blood vessel reconstructed by the image processing module 104 according to at least one embodiment of the present disclosure on the YZ plane and the XZ plane are shown in Figures 2A and 2B, respectively. The motion state and position information of the blood vessel can be obtained from the three-dimensional image of the blood vessel.

[0048] For example, the image processing module 104 can be further configured to obtain the angle between the ultrasonic transducer array aperture and the blood vessel based on the three-dimensional image of the blood vessel, and calculate the blood flow velocity based on the frequencies of multiple groups of plane waves emitted by the ultrasonic transducer array and the frequencies and angles of multiple groups of echo signals.

[0049] FIG3 is a schematic diagram of blood flow velocity measurement provided by an embodiment of the present disclosure.

[0050] For example, the blood flow velocity can be calculated using the ultrasonic Doppler effect. As shown in Figure 3, the ultrasonic transducer array 101 transmits a plane wave (ultrasound) to the blood vessel 201 and receives the echo reflected by the blood vessel 201. Due to the Doppler effect, the frequency of the plane wave emitted by the ultrasonic transducer array 101 changes after being reflected by the flowing blood. By analyzing the frequency of the echo signal received by the ultrasonic transducer array 101, the blood flow velocity can be calculated. The specific formula is as follows: Δf = f R -f T (1)

[0051] Among them, f T represents the plane wave frequency emitted by the ultrasonic transducer array, f R represents the frequency of the echo signal received by the ultrasonic transducer array, Δf represents the frequency change, α represents the angle between the ultrasonic transducer array aperture and the blood vessel, v represents the blood flow velocity, and c represents the speed of light.

[0052] The difficulty of Doppler ultrasound velocimetry lies in obtaining the angle between the aperture of the ultrasonic transducer array and the direction of fluid flow. The embodiments of the present disclosure utilize the characteristics of ultrasound to non-invasively obtain the movement state and position information of the blood vessels based on the three-dimensional image of the blood vessels, and then use the Doppler velocimetry method to obtain the blood flow velocity.

[0053] It should be noted that in the embodiments of the present disclosure, the blood flow velocity can be obtained not only by the ultrasonic Doppler effect, but also by using ultrasonic signals to perform vector Doppler velocity measurement, particle monitoring velocity measurement, and oscillation velocity measurement methods to obtain the blood flow velocity, and the embodiments of the present disclosure are not limited to this.

[0054] For example, the image processing module 104 may be further configured to obtain the inner diameter and outer diameter of the blood vessel according to the three-dimensional image of the blood vessel, and obtain the blood pressure value according to the blood flow velocity, the outer diameter of the blood vessel, and the inner diameter of the blood vessel.

[0055] For example, based on the motion state of blood vessels and changes in blood flow rate, the blood pressure value can be approximately calculated using the following formula:

[0056] Where v represents the blood flow velocity, k represents the fitted constant, p represents the pressure on the blood vessel, x represents the distance along the blood vessel, R represents the outer diameter of the blood vessel, and r represents the inner diameter of the blood vessel.

[0057] It should be noted that in the embodiments of the present disclosure, the relationship between blood flow rate and blood pressure can not only be described by the above formula, but also because there are differences between different individuals, the relationship between blood flow rate and blood pressure can also be found by methods such as machine learning. The embodiments of the present disclosure are not limited to this.

[0058] FIG4A is a schematic structural diagram of a row-column addressed ultrasonic transducer array provided in an embodiment of the present disclosure.

[0059] In the blood pressure detection device of at least one embodiment of the present disclosure, the ultrasonic transducer array can be a row-column addressable array (RCA). In the row-column addressable array, the two-dimensional array can be regarded as two interchangeable, overlapping, large-sized one-dimensional line arrays, and the same row or the same column is controlled by the signal of the same channel. For example, for the case where each row and each column has N ultrasonic transducer pixels (of course, each row and each column can also have a different number of ultrasonic transducer pixels), compared with the two-dimensional fully addressable array, the row-column addressable array can make the number of array channels of N×N increase from N to N. 2 It is reduced to 2N, greatly simplifying the array manufacturing process and circuit design.

[0060] It should be noted that although FIG4A illustrates an ultrasonic transducer array as a row-column addressable array, other embodiments of the present disclosure are not limited thereto. In some examples, the ultrasonic transducer array may be a plurality of one-dimensional linear arrays or a two-dimensional fully addressable array. For example, two one-dimensional linear arrays may overlap and be orthogonally arranged.

[0061] In at least one embodiment of the present disclosure, the size of the ultrasound transducer array is determined by the volume and distance of the imaged object. Because the minimum required ultrasound transducer aperture in ultrasound imaging is closely related to the volume and distance of the imaged object, larger objects and greater distances require a larger aperture. Therefore, in various embodiments of the present disclosure, the transducer array size can range from 4×4 to 1024×1024, or even larger.

[0062] In at least one embodiment of the present disclosure, each ultrasonic transducer pixel may include one or more ultrasonic transducer devices. To increase sound pressure, the number of ultrasonic transducer devices in each pixel may be increased. For example, the number of ultrasonic transducer devices in each array element may be 1-64. The ultrasonic transducer device may be made of a piezoelectric ceramic ultrasonic transducer, a capacitive micromachined ultrasonic transducer, or a piezoelectric micromachined ultrasonic transducer, although this is not limited in the embodiments of the present disclosure.

[0063] The use of piezoelectric micromechanical ultrasonic transducers processed by MEMS technology can improve design freedom, facilitate mass production of products, and better integrate with back-end circuits to achieve miniaturization and portability of blood pressure detection devices, providing simpler and more diverse methods for product packaging, testing and application.

[0064] FIG4B is a schematic diagram of an exemplary structure of a piezoelectric micromachined ultrasonic transducer provided in an embodiment of the present disclosure.

[0065] 4B , the piezoelectric micromachined ultrasonic transducer 300 includes a bottom electrode 302, a piezoelectric layer 303, a top electrode 304, and an acoustic impedance matching layer 305 sequentially disposed on a substrate 301. It should be noted that the present disclosure does not limit the structure of the piezoelectric micromachined ultrasonic transducer.

[0066] In at least one embodiment of the present disclosure, the acoustic impedance matching layer is a transition layer disposed between the piezoelectric layer and the human body, enabling impedance transition from the piezoelectric layer to the human body, thereby improving the acoustic transmittance and sensitivity of the ultrasonic transducer. In some examples, the material of the acoustic impedance matching layer may include polyethylene, polyurethane, epoxy resin, aluminum oxide, silicon nitride, aluminum, copper, or titanium, although the embodiments of the present disclosure are not limited thereto.

[0067] It should be noted that although FIG4B shows the bottom electrode 302 and the top electrode 304 as circular, the present disclosure does not limit the shape of the top and bottom electrodes. For example, in some embodiments, the top and bottom electrodes may be square or oval. Similarly, the present disclosure does not limit the size of the top and bottom electrodes, which can be determined according to different requirements.

[0068] In some examples, the vibration mode of the piezoelectric micromachined ultrasonic transducer is a flexural mode, whose resonant frequency is strongly correlated with the planar dimensions of the ultrasonic transducer array element and weakly correlated with the thickness of the ultrasonic transducer array element. In the flexural mode, the piezoelectric micromachined ultrasonic transducer is more easily formed into an array with higher sensitivity, larger bandwidth, and more functions. It should be noted that the embodiments of the present disclosure do not limit the vibration mode of the piezoelectric micromachined ultrasonic transducer.

[0069] In some examples, the material of the piezoelectric layer may include lead zirconate titanate (PZT), aluminum nitride (AlN), zinc oxide (ZnO), lead magnesium niobate-lead titanate (PMN-PT), lithium niobate (LiNbO3), lithium tantalate (LiTaO3) or quartz (Quartz), but the embodiments of the present disclosure are not limited to this.

[0070] It should be noted that in ultrasound imaging, the higher the ultrasound frequency, the shorter the propagation distance and the higher the resolution, and vice versa. Therefore, the device resonant frequency can be varied based on different needs. The frequency of the first-order resonant mode of the ultrasonic transducer device in at least one embodiment of the present disclosure can be, for example, 1 kHz to 20 MHz. For example, the frequency of the first-order resonant mode of the ultrasonic transducer device is 14 MHz to 16 MHz.

[0071] It should be noted that after adding the acoustic impedance matching layer, the bandwidth of the piezoelectric micromechanical ultrasonic transducer is very high. Therefore, the transmission frequency of the ultrasonic transducer device in at least one embodiment of the present disclosure can be, for example, 1kHz-20MHz, and is not limited to being equal to the resonant frequency of the ultrasonic transducer device.

[0072] It should be noted that since the period of the signal varies with the transmission frequency, the excitation signal can be a sine wave or square wave with a period of 0.5-10, or a pulse signal, which is not limited in this disclosure. For example, the excitation signal is a sine wave with a period of 1-2.

[0073] It should be noted that the more plane waves generated by the excitation signal, the smaller the imaging artifacts, but the slower the imaging rate. Therefore, the scanning range and number of plane waves can be changed according to different needs. In at least one embodiment of the present disclosure, the plane wave scanning range is (-80°)-80°, and the number can be 1-1000. For example, the plane wave scanning range is (-20°)-20°.

[0074] Since the speed of ultrasound in human tissue is approximately 1540 m / s and the distance between human blood vessels and the skin surface is generally less than 2 cm, the interval between each plane wave emission is less than 25.97 μs, that is, 38,500 measurements per second, which is much greater than the heart rate. Therefore, the blood pressure detection device disclosed in the present invention can be approximately regarded as a continuous detection device.

[0075] It should be noted that the sampling rate of the received echo signal can range from the Nyquist frequency corresponding to the transmission frequency to 1 GHz. The higher the sampling rate, the higher the imaging quality.

[0076] At least one embodiment of the present disclosure provides a blood pressure detection device that uses an orthogonal plane wave imaging method to reconstruct a three-dimensional image of a blood vessel.

[0077] 5A and 5B are respectively a schematic diagram of column transmission and row reception and a schematic diagram of row transmission and column reception of an ultrasonic transducer array provided by an embodiment of the present disclosure.

[0078] For example, the control module is further configured to apply excitation signals of different delays to the ultrasonic transducer array along the column direction of the ultrasonic transducer array, perform beamforming, emit plane waves of different angles, and receive multiple echo signals from multiple ultrasonic transducer pixels along the row direction of the ultrasonic transducer array, as shown in Figure 5A. For another example, excitation signals of different delays are applied to the ultrasonic transducer array along the row direction of the ultrasonic transducer array, perform beamforming, emit plane waves of different angles, and receive multiple echo signals from multiple ultrasonic transducer pixels along the column direction of the ultrasonic transducer array, as shown in Figure 5B. The excitation signal is typically a sine wave with 1-2 cycles, and the frequency is the resonant frequency of the ultrasonic transducer. Compared with the B-mode and synthetic aperture scanning methods, the above scanning method can reduce the time of one imaging, increase the speed of the imaging system, and achieve the purpose of continuous imaging.

[0079] It should be noted that although in the above embodiment, column transmission and row reception are performed first, and then row transmission and column reception are performed, the embodiments of the present disclosure do not impose any restrictions on this order. For example, row transmission and column reception can be performed first, and then column transmission and row reception can be performed.

[0080] For example, the image processing module may be further configured to calculate the time delays of multiple groups of echo signals, and to superimpose the multiple groups of echo data according to the time delays to reconstruct a three-dimensional image of the blood vessel.

[0081] 6A and 6B are schematic diagrams of the transmitting distance and receiving distance of the ultrasonic transducer array provided in an embodiment of the present disclosure, respectively.

[0082] For example, taking single imaging as an example (column transmission and row reception), as shown in Figure 6A, the transmission distance of the ultrasonic transducer array is the distance between the scattering point P and the emission plane of the plane wave, corresponding to the projection of the scattering point P on the plane wave, and is independent of the position of the array. The specific calculation formula is as follows: T (x,z,θ)=z·cosθ+x·sinθ (4)

[0083] Among them, d T represents the emission distance, (x, y, z) represents the coordinates of the scattering point P in space, and θ represents the angle between the plane wave and the aperture of the ultrasonic transducer.

[0084] As shown in FIG6B , the ultrasonic transducer pixels on each row form a receiving array element. The receiving distance of the ultrasonic transducer array is the distance from the scattering point P to the i-th receiving array element. The specific calculation formula is as follows:

[0085] Among them, d R Indicates the receiving distance, r iIndicates the center coordinate of each receiving array element along the y-axis in the case of row reception.

[0086] In the case of row transmission and column reception, the calculation formulas for the transmission distance and the reception distance are similar to the above calculation formulas and are not repeated here.

[0087] According to the transmission distance and the receiving distance, the delay of the echo signal can be calculated:

[0088] Where τ represents the angle between the plane wave and the aperture of the ultrasonic transducer. When the angle between the plane wave and the aperture is θ, the time delay for the i-th receiving element to receive the echo signal from the scattering point P in space.

[0089] In at least one embodiment of the present disclosure, multiple sets of echo data are superimposed according to the calculated time delay to reconstruct a three-dimensional image of the blood vessel, thereby effectively reducing artifacts during imaging.

[0090] An embodiment of the present disclosure further provides a blood pressure detection method, which can be implemented based on the blood pressure detection device described in any of the above embodiments. For the specific implementation and technical effects of the blood pressure detection method based on the blood pressure detection device, please refer to the blood pressure detection device provided in the above embodiments of the present disclosure.

[0091] FIG7 is a flow chart of a blood pressure detection method provided in an embodiment of the present disclosure.

[0092] For example, as shown in FIG7 , a blood pressure detection method provided by an embodiment of the present disclosure includes steps S1 to S3 .

[0093] Step S1: using a control module to provide an excitation signal to the ultrasonic transducer array to control the working state of multiple ultrasonic transducer pixels;

[0094] Step S2: using an ultrasonic transducer array, emitting multiple sets of plane waves at different angles toward the measured blood vessel in response to an applied excitation signal, and receiving multiple sets of echo signals obtained by reflecting the multiple sets of plane waves from the blood vessel;

[0095] Step S3: using a signal processing module to process the multiple groups of echo signals to obtain multiple groups of echo data for obtaining the blood pressure value of the measured blood vessel.

[0096] Embodiments of the present disclosure provide a blood pressure detection device and a blood pressure detection method implemented based on the blood pressure detection device. In at least one embodiment, the blood pressure detection device and the blood pressure detection method implemented based on the blood pressure detection device have one or more of the following beneficial effects:

[0097] (1) The ultrasonic transducer device in the blood pressure detection device provided in at least one embodiment of the present disclosure can be processed by MEMS technology, for example, which can improve the design freedom, be more conducive to the mass production of products, and can also be better integrated with the back-end circuit to achieve the miniaturization and portability of the blood pressure detection device, providing a simpler and more diverse method for the packaging, testing and application of the product.

[0098] (2) The ultrasonic transducer array in the blood pressure detection device provided in at least one embodiment of the present disclosure may be a row-column addressing array, which reduces the number of array channels required for three-dimensional imaging from N to 2 It is reduced to 2N, greatly simplifying the array manufacturing process and circuit design.

[0099] (3) The blood pressure detection device provided by at least one embodiment of the present disclosure utilizes the characteristics of ultrasound to obtain the movement state and position information of the blood vessels based on the three-dimensional image of the blood vessels in a non-invasive manner, thereby overcoming the problem of difficulty in obtaining the angle between the aperture of the ultrasonic transducer array and the direction of fluid flow during Doppler ultrasound velocity measurement, and greatly improving the accuracy of blood pressure detection.

[0100] In addition to the above non-limiting description, the following points should be noted:

[0101] (1) The drawings of the embodiments of the present disclosure only relate to the structures involved in the embodiments of the present disclosure. Other structures may refer to conventional designs.

[0102] (2) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to form new embodiments.

[0103] The above description is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. The protection scope of the present disclosure shall be based on the protection scope of the claims.

Claims

1. A blood pressure detection device, comprising: An ultrasonic transducer array, comprising a plurality of ultrasonic transducer pixels arranged in an array, and configured to transmit a plurality of plane waves at different angles to a measured blood vessel in response to an applied excitation signal and to receive a plurality of echo signals obtained by reflecting the plurality of plane waves from the blood vessel; a control module, connected to the ultrasonic transducer array signal and configured to provide the excitation signal to the ultrasonic transducer array to control the working state of the plurality of ultrasonic transducer pixels; The signal processing module is connected to the ultrasonic transducer array signal and is configured to process the multiple groups of echo signals to obtain multiple groups of echo data for obtaining the blood pressure value of the measured blood vessel.

2. The blood pressure detection device according to claim 1, further comprising: The image processing module is configured to receive the multiple sets of echo data, obtain the blood flow velocity according to the multiple sets of echo data, and obtain the blood pressure value according to the blood flow velocity and the vascular movement state.

3. The blood pressure detection device according to claim 2, wherein: The image processing module is further configured to reconstruct a three-dimensional image of a blood vessel according to the multiple sets of echo data.

4. The blood pressure detection device according to claim 3, wherein: The image processing module is further configured to: Calculating the time delays of the multiple groups of echo signals; The multiple groups of echo data are superimposed according to the time delay to reconstruct the three-dimensional image of the blood vessel.

5. The blood pressure detection device according to claim 3 or 4, wherein: The image processing module is further configured to: Obtaining an angle between the ultrasonic transducer array aperture and the blood vessel according to the three-dimensional image of the blood vessel; The blood flow velocity is calculated according to the frequencies of the multiple groups of plane waves of the ultrasonic transducer array, the frequencies of the multiple groups of echo signals and the angle.

6. The blood pressure detection device according to any one of claims 3 to 5, wherein: The image processing module is further configured to: Obtaining the inner diameter and outer diameter of the blood vessel according to the three-dimensional image of the blood vessel; The blood pressure value is obtained according to the blood flow rate, the blood vessel outer diameter and the blood vessel inner diameter.

7. The blood pressure detection device according to any one of claims 1 to 6, wherein: The ultrasonic transducer array is a row-column addressing array.

8. The blood pressure detection device according to any one of claims 1 to 7, wherein: The ultrasonic transducer array is a plurality of one-dimensional line arrays or a two-dimensional fully addressable array.

9. The blood pressure detection device according to any one of claims 1 to 8, wherein: The control module is further configured to: Applying the excitation signals with different delays to the ultrasonic transducer array along a first direction of the ultrasonic transducer array, performing beamforming, transmitting the plane waves with different angles, and receiving the multiple echo signals from the multiple ultrasonic transducer pixels along a second direction of the ultrasonic transducer array; applying the excitation signals with different delays to the ultrasonic transducer array along the second direction of the ultrasonic transducer array, performing beamforming, transmitting the plane waves at different angles, and receiving the multiple echo signals from the multiple ultrasonic transducer pixels along the first direction of the ultrasonic transducer array, One of the first direction and the second direction is a row direction, and the other is a column direction.

10. The blood pressure detection device according to any one of claims 1 to 9, wherein: Each of the plurality of ultrasound transducer pixels may include one or more ultrasound transducer devices.

11. The blood pressure detection device according to claim 10, wherein: Each of the one or more ultrasonic transducer devices may include a piezoelectric ceramic ultrasonic transducer, a capacitive micromachined ultrasonic transducer, or a piezoelectric micromachined ultrasonic transducer.

12. The blood pressure detection device according to any one of claims 1 to 11, wherein: The scanning range of the plane waves of different angles generated by the excitation signal is (-80°)-80°.

13. The blood pressure detection device according to any one of claims 1 to 12, wherein: The frequency of the excitation signal is 1kHz-20MHz.

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