Flexible ultrasonic wearable device for blood flow velocity detection and thrombolysis treatment

Abstract

The invention discloses a flexible ultrasonic wearable device for blood flow velocity detection and thrombolysis treatment. Comprising an FPGA (Field Programmable Gate Array) system control device, a flexible ultrasonic blood flow velocity detection area based on an ultrasonic Doppler principle, a flexible ultrasonic thrombolysis treatment area for emitting low-frequency high-intensity ultrasonic-assisted microbubbles, a double-layer electrode network, a data acquisition card and a signal processing and analyzing module. The blood flow velocity of the human body is detected, the embolism condition of the blood vessel is determined by feeding back blood flow velocity information of multi-point detection, low-frequency high-intensity ultrasonic waves emitted by the flexible ultrasonic thrombolysis treatment area are combined with microbubbles for thrombolysis treatment, the blood flow velocity is monitored in real time in the treatment period, and the equipment safety is improved. The device has the advantages of being portable and wearable, simple to operate and high in signal acquisition precision, monitoring and treatment results of the device can be observed in real time on an upper computer, and the device is convenient to use.

Description

Technical Field

[0001] The present invention relates to the technical field of research and development of small flexible ultrasonic wearable devices, and in particular to a flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy. Background Art

[0002] The human body has blood vessels all over the body, and the detection of blood flow velocity in blood vessels is of great significance in medicine. By checking the blood flow velocity to understand the dynamic changes of the patient's blood flow, it is helpful to evaluate the health of their vascular system and determine whether there are problems such as vascular stenosis or blockage, so as to achieve the purpose of disease prevention and diagnosis. In addition, real-time monitoring of blood flow velocity during the treatment process can also play an important role in guiding surgery and interventional treatment.

[0003] However, the non-invasive blood flow velocity detection methods currently used in clinical practice mainly utilize large traditional rigid ultrasonic detection equipment and small handheld ultrasonic detection equipment. The diagnostic process of large traditional rigid ultrasonic equipment is quite cumbersome, and it is difficult to achieve rapid and real-time blood flow information detection of patients. Small handheld ultrasonic diagnostic equipment will inevitably cause disturbances (such as human breathing, etc.) during the detection process, which will have a great impact on the results. In addition, both large and small ultrasonic detection equipment must be operated by professional medical staff. The rigid probe needs to press the part to be tested during the inspection. The pressure will cause the blood vessels to deform at the part to be tested, resulting in inaccurate blood flow information. If the blood vessels at the part to be tested are fragile or traumatic, it may even cause secondary damage to the patient's blood vessels.

[0004] The development of intelligent medical care and new flexible materials has led to important breakthroughs and research in the field of small flexible ultrasonic transducer equipment. Flexible substrate materials with impedance close to that of human skin are selected to reduce sound attenuation, and the material has repeatable viscosity to ensure its wearability for independent detection. The flexible ultrasonic blood flow velocity detection area and the thrombolytic treatment area are parallel, realizing the functions of human blood flow velocity detection and auxiliary microbubble thrombolytic treatment. When vascular stenosis and blockage are found, timely treatment and feedback can be provided, and the treatment effect can be monitored in real time. This integrated diagnosis and treatment equipment will solve the clinical problems faced by existing detection and treatment methods. Summary of the invention

[0005] Purpose of the invention: The present invention provides a flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy, and monitors the blood flow velocity during treatment in real time to improve the safety of the device. The device has the advantages of being portable and wearable, and is easy to operate and has high signal acquisition accuracy. Its monitoring and treatment results can be observed in real time on a host computer, making it easy to use.

[0006] Technical solution: A flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy described in the present invention comprises: an FPGA system control device, a flexible ultrasonic blood flow velocity detection area based on the ultrasonic Doppler principle, a flexible ultrasonic thrombolytic therapy area that emits low-frequency and high-intensity ultrasonic assisted microbubbles, a double-layer electrode network, a data acquisition card, and a signal processing and analysis module; the FPGA system control device applies a continuous sinusoidal wave ultrasonic excitation signal with adjustable frequency and intensity to the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolytic therapy area, the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolytic therapy area are distributed in parallel, the ultrasonic excitation signal will cause the piezoelectric array elements of the two areas to generate ultrasonic signals, the flexible ultrasonic blood flow velocity detection area generates ultrasonic Doppler signals in the blood vessels, the flexible ultrasonic thrombolytic therapy area emits low-frequency and high-intensity ultrasonic assisted microbubbles for thrombolytic therapy, the double-layer electrode network connects the positive and negative poles of the piezoelectric array elements in each area, the data acquisition card is used to collect ultrasonic Doppler echo signals, and send the collected signals to the signal processing and analysis module for processing, calculation and analysis.

[0007] Furthermore, the piezoelectric array elements of the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolytic therapy area are processed and fixed on the flexible PDMS membrane material.

[0008] Furthermore, the piezoelectric array element material of the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolytic treatment area is PZT.

[0009] Furthermore, the flexible ultrasonic blood flow velocity detection area is a 2×3 array structure, where the inclination angle of the 1×3 array element is θ 1 , the inclination angle of another 1×3 array element is θ 2 , dual-angle ultrasonic Doppler detection is used to measure the absolute flow velocity.

[0010] Furthermore, the inclination angle is θ 1 The 1×3 array has two end elements for ultrasonic transmission and the middle element for ultrasonic reception. The inclination angle is θ 2 The 1×3 array has two elements at both ends for ultrasonic transmission and the middle element for ultrasonic reception, that is:

[0011]

[0012]

[0013] Δf=f ′ -f 0 (3)

[0014] Among them, v is the blood flow velocity of the part to be measured, c is the propagation speed of ultrasound in the human body, and f 0 is the center frequency of the transmitted ultrasound, f ′is the frequency of the received signal, Δf is the calculated frequency shift, α is the inclination angle between the blood vessel and the skin plane at the measured site. In the above three formulas, v and α are two unknowns, and the accurate blood flow velocity value is solved.

[0015] Furthermore, the area of ​​the ultrasonic emission surface of the array element in the flexible ultrasonic thrombolytic treatment area is larger than that of the array element in the flexible ultrasonic blood flow velocity detection area, and the emitted ultrasound is low-frequency and high-intensity ultrasound.

[0016] Furthermore, the double-layer electrode network includes a grounding network connected to the bottom surfaces of all array elements and another input and output network connected to the top surfaces of all array elements. The pins are distributed on one side of the flexible ultrasound device for connecting to the data acquisition card and the FPGA system control device.

[0017] Furthermore, the data acquisition card uses the AD9238 dual-channel acquisition chip, and the inclination angles of the flexible ultrasonic blood flow velocity detection area are θ 1 and θ 2 The signal is collected by the array element in the middle position to obtain blood flow velocity information.

[0018] Furthermore, in the FPGA system control device, the system buttons control the emission of the ultrasonic excitation signal and the reception of the echo signal, and realize the control of the frequency and intensity of the ultrasonic excitation signal. The ultrasonic excitation signal emission part is composed of three sub-modules including a sine wave generator module, a frequency control module and an amplitude control module. The echo signal receiving part includes a part that communicates with the hardware ADC for signal acquisition and a part for sending the collected data to the signal processing and analysis module.

[0019] Furthermore, the processing and analysis part of the signal processing and analysis module is implemented through MATLAB on the host computer side, and the signals sent by the FPGA system control device and the signals received by the data acquisition card are processed by various algorithms including filtering, amplification, modulation, as well as amplitude-frequency characteristic analysis, power spectrum density estimation analysis, etc., and finally the ultrasonic Doppler frequency shift is identified and the blood flow velocity is calculated, and the results are displayed in real time on the host computer.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the present invention detects the blood flow rate of the human body, determines the embolism of the blood vessels through the feedback information of multi-point detection, assists the microbubbles in emitting low-frequency and high-intensity ultrasonic waves in the ultrasonic emission area for thrombolytic therapy, and monitors the treatment effect in real time to ensure the safety of equipment detection and treatment. The device is flexible, portable and wearable, easy to operate, and has high signal acquisition accuracy. The results can be observed in real time on the host computer, which is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a system block diagram of the flexible ultrasonic wearable device of the present invention.

[0022] FIG. 2( a ) is a diagram showing the interlayer structure of the flexible ultrasonic blood flow velocity detection area of ​​the present invention.

[0023] FIG. 2( b ) is a diagram showing the interlayer structure of the flexible ultrasonic thrombolytic treatment area of ​​the present invention.

[0024] FIG3( a ) is a diagram showing the ultrasonic emission signal detection results of the flexible ultrasonic wearable device of the present invention for blood flow velocity detection and thrombolytic therapy. The ultrasonic excitation signal is a sinusoidal wave signal with a frequency and intensity of 1 MHz / 1 V.

[0025] FIG3( b ) is a diagram showing the ultrasonic emission signal detection results of the flexible ultrasonic wearable device of the present invention for blood flow velocity detection and thrombolytic therapy. The ultrasonic excitation signal is a sinusoidal wave signal with a frequency and intensity of 3 MHz / 300 mV.

[0026] FIG3( c ) is a diagram showing the ultrasonic emission signal detection results of the flexible ultrasonic wearable device of the present invention for blood flow velocity detection and thrombolytic therapy. The ultrasonic excitation signal is a sinusoidal wave signal with a frequency and intensity of 5 MHz / 200 mV.

[0027] FIG3( d ) is a diagram showing the ultrasonic emission signal detection results of the flexible ultrasonic wearable device of the present invention for blood flow velocity detection and thrombolytic therapy. The ultrasonic excitation signal is a sinusoidal wave signal with a frequency and intensity of 10 MHz / 250 mV.

[0028] FIG. 4( a ) is a diagram showing a segment of the original collected signal under an ultrasonic transmission signal with a frequency of 1 MHz and a result diagram after filtering displayed in MATLAB according to the present invention.

[0029] FIG4( b ) is a graph showing the result of the amplitude-frequency characteristic analysis of the signal in FIG4( a ) after filtering. DETAILED DESCRIPTION

[0030] like Figure 1As shown, a flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy includes: an FPGA system control device 1, a flexible ultrasonic blood flow velocity detection area 2 based on the ultrasonic Doppler principle, a flexible ultrasonic thrombolytic therapy area 3 that emits low-frequency and high-intensity ultrasonic assisted microbubbles, a double-layer electrode network 4, a data acquisition card 5, and a signal processing and analysis module 6; the FPGA system control device 1 applies an ultrasonic excitation signal to the flexible ultrasonic blood flow velocity detection area 2 and the flexible ultrasonic thrombolytic therapy area 3, the flexible ultrasonic blood flow velocity detection area 2 and the flexible ultrasonic thrombolytic therapy area 3 are arranged in parallel, the ultrasonic excitation signal will cause the flexible ultrasonic blood flow velocity detection area 2 to generate an ultrasonic Doppler signal in the blood vessel, the flexible ultrasonic thrombolytic therapy area 3 emits low-frequency and high-intensity ultrasonic assisted microbubbles for thrombolytic therapy, the double-layer electrode network 4 connects the positive and negative electrodes of the piezoelectric array elements in the two parts, and the AN9238 acquisition card 5 is used to collect ultrasonic Doppler echo signals and send the collected signals to the signal processing and analysis module 6.

[0031] As shown in Figure 2(a), it is a diagram of the interlayer structure of the flexible ultrasonic blood flow velocity detection area. The bottom is the PDMS flexible substrate, the top is a PDMS support layer constructed with different curing temperatures, the top layer is the lower electrode layer of the double-layer electrode network, the top layer is the PZT piezoelectric array element, the top layer is the upper electrode layer of the double-layer electrode network, and the top is the packaging layer of the entire flexible ultrasonic wearable device.

[0032] As shown in Figure 2(b), it is a diagram of the interlayer structure of the flexible ultrasonic thrombolysis treatment area. The bottom is the PDMS flexible substrate, the top is the lower electrode layer of the double-layer electrode network, the next layer is the PZT piezoelectric array element, the next layer is the upper electrode layer of the double-layer electrode network, and the top is the packaging layer of the entire flexible ultrasonic wearable device.

[0033] The array elements of the flexible ultrasonic blood flow velocity detection area 2 are supported by two wedge-shaped support layers at different angles to achieve the emission and reception of ultrasonic waves with a fixed angle.

[0034] The PZT piezoelectric array elements of the flexible ultrasonic blood flow velocity detection area 2 and the flexible ultrasonic thrombolytic treatment area 3 are connected from top to bottom by a double-layer electrode network 4. The electrode network layers are layered by spin-coating insulating silicone to prevent short circuits. The two areas are fixed in parallel on the PDMS flexible substrate. The leads extending from the electrode network are connected to the system's key control device 1 and data acquisition card 5 to realize the input and output of electrical signals.

[0035] In the FPGA system control device 1, the system buttons control the emission of the ultrasonic excitation signal and the reception of the echo signal, and realize the control of the frequency and intensity of the ultrasonic excitation signal. The ultrasonic excitation signal emission part is composed of three sub-modules including a sine wave generator module, a frequency control module and an amplitude control module. The echo signal receiving part includes a part that communicates with the hardware ADC of the signal acquisition and a part for sending the collected data to the signal processing and analysis module 6.

[0036] The processing and analysis part of the signal processing and analysis module 6 is realized through MATLAB on the host computer side. The signal sent by the FPGA system control device 1 and the signal received by the data acquisition card 5 are processed by various algorithms including filtering, amplification, modulation, as well as amplitude-frequency characteristic analysis, power spectrum density estimation analysis, etc., and finally the ultrasonic Doppler frequency shift is identified and the blood flow velocity is calculated, and the results are displayed in real time on the host computer.

[0037] The signal transmission process is as follows: the FPGA system control device 1 controls the waveform emission, frequency adjustment, and amplitude adjustment, and the transmitted ultrasonic excitation signal is applied to the piezoelectric array element used for transmitting ultrasound in the flexible ultrasonic blood flow velocity detection area 2. The piezoelectric array element used for receiving is responsible for receiving the ultrasonic Doppler echo signal, which is collected by the ADC data acquisition card 5 and transmitted to the host computer. The echo signal is processed and analyzed based on the MATLAB software, and the blood flow velocity is calculated and displayed. Then, a low-frequency and high-intensity ultrasonic excitation signal is applied to the piezoelectric array element in the flexible ultrasonic thrombolytic treatment area 3, and ultrasonic microbubbles are injected at the same time to assist it in thrombolytic treatment. After a period of time, the blood flow velocity is continued to be monitored to evaluate the ultrasonic thrombolytic effect.

[0038] Ultrasonic excitation signals are transmitted by the FPGA-based system control device and applied to the flexible ultrasonic blood flow velocity detection area and the thrombolytic therapy area respectively, so that the corresponding PZT array elements in the two areas transmit ultrasonic signals. The ultrasonic signals transmitted from the two areas are detected by the hydrophone. The signal detection results are shown in Figure 3. (a)-(d) represent the signals received by the hydrophone when the frequency and intensity of the ultrasonic excitation signal are 1MHz / 1V, 3MHz / 300mV, 5MHz / 200mV, and 10MHz / 250mV, respectively.

[0039] The simulated blood flow is detected by using the ultrasonic signal emitted from the flexible ultrasonic blood flow velocity detection area. The AN9238 data acquisition card collects and receives the ultrasonic Doppler echo signal and transmits it to the host computer. After amplification, filtering, calculation and analysis, the detection results are displayed. Figure 4 (a) shows one section of the original acquisition signal Original Signal under the ultrasonic transmission signal with a frequency of 1MHz and the result FilteredSignal displayed after filtering in MATLAB. It can be seen from the results that the filtering process effectively suppresses the noise in the original signal. Figure 4 (b) is the result of the amplitude-frequency characteristic analysis of this section of the signal after filtering. Since the filter bandpass cutoff frequency interval is set to 0.8-1.4MHz, it can be seen from the results that the central frequency of the transmitted ultrasound is 1MHz, and the signals outside the cutoff frequency interval are filtered out, which proves that the present invention can achieve ultrasonic signal transmission, reception and processing performance.

Claims

1. A flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy, characterized in that: include: FPGA system control device, flexible ultrasonic blood flow velocity detection area based on ultrasonic Doppler principle, flexible ultrasonic thrombolysis treatment area emitting low-frequency and high-intensity ultrasonic assisted microbubbles, double-layer electrode network, data acquisition card and signal processing and analysis module; the FPGA system control device applies continuous sinusoidal wave ultrasonic excitation signals with adjustable frequency and intensity to the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolysis treatment area, the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolysis treatment area are distributed in parallel, the ultrasonic excitation signal will make the piezoelectric array elements of the two areas generate ultrasonic signals, the flexible ultrasonic blood flow velocity detection area generates ultrasonic Doppler signals in the blood vessels, the flexible ultrasonic thrombolysis treatment area emits low-frequency and high-intensity ultrasonic assisted microbubbles for thrombolysis treatment, the double-layer electrode network connects the positive and negative poles of the piezoelectric array elements in each area, the data acquisition card is used to collect ultrasonic Doppler echo signals, and send the collected signals to the signal processing and analysis module for processing, calculation and analysis.

2. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The piezoelectric array elements of the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolysis treatment area are processed and fixed on the flexible PDMS membrane material.

3. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The piezoelectric array element material of the flexible ultrasonic blood flow velocity detection area and the flexible ultrasonic thrombolysis treatment area is PZT.

4. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The flexible ultrasonic blood flow velocity detection area is a 2×3 array structure, in which the inclination angle of 1×3 array elements is θ1, and the inclination angle of another group of 1×3 array elements is θ2. Dual-angle ultrasonic Doppler detection is used to measure the absolute flow velocity.

5. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy as claimed in claim 4, characterized in that: The array elements at both ends of the 1×3 array with an inclination angle of θ1 perform ultrasonic transmission, and the array elements in the middle perform ultrasonic reception. The array elements at both ends of the 1×3 array with an inclination angle of θ2 perform ultrasonic transmission, and the array elements in the middle perform ultrasonic reception, that is: Δf=f ′ -f0 (3) Among them, v is the blood flow velocity of the measured part, c is the propagation speed of ultrasound in the human body, f0 is the center frequency of the transmitted ultrasound, and f ′ is the frequency of the received signal, Δf is the calculated frequency shift, and α is the inclination angle between the blood vessel and the skin plane at the measured site, and the accurate blood flow velocity value is solved.

6. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The area of ​​the ultrasonic emission surface of the array element in the flexible ultrasonic thrombolytic treatment area is larger than that of the array element in the flexible ultrasonic blood flow velocity detection area, and the emitted ultrasound is low-frequency and high-intensity ultrasound.

7. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The double-layer electrode network includes a grounding network connected to the bottom surfaces of all array elements and another input and output network connected to the top surfaces of all array elements. The pins are distributed on one side of the flexible ultrasound device for connecting to the data acquisition card and the FPGA system control device.

8. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The data acquisition card uses the AD9238 dual-channel acquisition chip to collect signals from the middle position array elements in the flexible ultrasonic blood flow velocity detection area with inclination angles of θ1 and θ2 respectively, in order to obtain blood flow velocity information.

9. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: In the FPGA system control device, the system buttons control the emission of the ultrasonic excitation signal and the reception of the echo signal, and realize the control of the frequency and intensity of the ultrasonic excitation signal. The ultrasonic excitation signal emission part is composed of three sub-modules including a sine wave generator module, a frequency control module and an amplitude control module. The echo signal receiving part includes a part that communicates with the hardware ADC of the signal acquisition and a part for sending the collected data to the signal processing and analysis module.

10. The flexible ultrasonic wearable device for blood flow velocity detection and thrombolytic therapy according to claim 1, characterized in that: The processing and analysis part of the signal processing and analysis module is implemented through MATLAB on the host computer side. The signals sent by the FPGA system control device and the signals received by the data acquisition card are processed by multiple algorithms including filtering, amplification, modulation, amplitude-frequency characteristic analysis, power spectrum density estimation analysis, and finally the ultrasonic Doppler frequency shift is identified and the blood flow velocity is calculated, and the results are displayed in real time on the host computer.

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