A method and device for detecting blood flow velocity

Abstract

This invention relates to the field of fluid detection and discloses a method and apparatus for detecting blood flow velocity, comprising: S1, acquiring a first target signal of blood flow, wherein the first target signal is an analog signal; S2, converting the first target signal into a second target signal, wherein the second target signal is a digital signal; S3, performing noise reduction processing on the second target signal to obtain a third target signal; S4, acquiring the blood flow velocity based on the third target signal; and S5, converting the third target signal into a fourth target signal, wherein the fourth target signal is an analog signal. In this invention, blood flow velocity quantification calculation, high-fidelity audio playback, and signal strength visualization indication are simultaneously achieved after one noise reduction process. Compared with the qualitative detection mode in the prior art that relies on the operator's auditory experience and subjective judgment, this invention has the dual advantages of significantly improved detection accuracy and reduced usage threshold.

Description

Technical Field

[0001] This invention relates to the field of fluid detection, and more particularly to a method and apparatus for detecting blood flow velocity. Background Technology

[0002] Blood flow velocity is a key parameter reflecting the characteristics of blood flow and has significant applications in biomedical engineering research, medical device development, and extracorporeal fluid system monitoring. In biorheology research, accurate measurement of blood flow velocity can provide data support for the structural optimization of medical consumables such as artificial blood vessels and vascular stents, improving the performance of related implants. In extracorporeal circulation systems such as heart-lung machines, blood flow velocity monitoring is an important technical means to ensure stable system flow and safe operation. Furthermore, in vascular model experiments and blood preservation technology research, blood flow data can provide references for verifying fluid mechanics theories and optimizing related solutions; in the field of medical device calibration, it can also be used for the performance calibration of blood flow detection instruments to ensure measurement accuracy.

[0003] Currently, one existing technology for blood flow velocity detection is based on acoustic principles. Its core is to collect sound signals generated during blood flow and combine this with auditory recognition or simple sound signal feature extraction to determine flow velocity. However, this method has significant technical limitations: firstly, the intensity and frequency of blood flow sounds are easily affected by environmental noise and differences in the sampling location; secondly, the flow velocity determination relies entirely on the operator's auditory experience and subjective judgment, lacking a unified quantitative analysis standard and failing to convert flow velocity information into precise numerical parameters. This experience-based qualitative detection mode not only leads to poor repeatability and significant individual differences in measurement results, making it difficult to meet the technical requirements for quantitative analysis in biorheological research (National Natural Science Foundation of China), but also cannot adapt to the accuracy and objectivity requirements of scenarios such as extracorporeal circulation system monitoring and medical equipment calibration. Therefore, existing sound signal-based blood flow velocity detection methods, due to their lack of precise quantification capabilities and unified judgment standards, have limited the depth and breadth of their application in related fields. Therefore, the aforementioned problems in the existing technology still need to be solved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a blood flow velocity detection method and apparatus, which solves the above problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a blood flow velocity detection method, comprising: S1. Acquire a first target signal of blood flow, wherein the first target signal is an analog signal; S2. Convert the first target signal into a second target signal, wherein the second target signal is a digital signal; S3. Perform noise reduction processing on the second target signal to obtain the third target signal; S4. Obtain the blood flow velocity based on the third target signal; S5. Convert the third target signal into a fourth target signal, wherein the fourth target signal is an analog signal; Furthermore, after S5 converts the third target signal into a fourth target signal, the process further includes: S51. Obtain the signal strength of the fourth target signal; S52. Output intensity indication visual information based on the signal strength of the fourth target signal.

[0006] In this embodiment, the signal strength of the fourth target signal, specifically the peak amplitude of the signal, is directly and positively correlated with the volume of the blood flow sound and the strength of the blood flow signal. The intensity indication visual information is a visual display information corresponding to the signal strength level, used to intuitively show the current strength level of the blood flow signal. As a preferred embodiment, the intensity indication visual information is implemented by the number of LED indicator lights lit. Multiple progressively increasing signal strength thresholds are preset, with each threshold corresponding to one LED. The higher the signal strength of the fourth target signal, the higher the threshold level reached, and the more LED lights are lit, thus achieving a hierarchical visual display of signal strength.

[0007] S6. Input the fourth target signal into the sound processing circuit so that the sound processing circuit plays the blood flow rate sound according to the fourth target signal.

[0008] Preferably, acquiring the first target signal of blood flow further includes: S11. A probe wave of a preset frequency is emitted to the blood flow bearing structure, wherein the blood flow bearing structure is a carrier for the blood flow velocity to be detected; S12. Obtain the received wave as the first target signal, wherein the received wave is the sound wave that returns after the probe wave reaches the blood being tested in the blood flow bearing structure; S13. The step of obtaining the blood flow velocity based on the third target signal includes: S14. Obtain the blood flow velocity based on the frequency difference between the received wave and the probe wave, and the angle between the probe wave emission direction and the measured blood flow direction.

[0009] Preferably, obtaining the blood flow velocity based on the frequency difference between the received wave and the detected wave, and based on the angle between the emission direction of the detected wave and the direction of the blood flow being measured, includes obtaining the blood flow velocity using the following algorithm: in, It's the blood flow velocity. It is the transmission frequency of the probe wave. It is the frequency difference between the received wave and the detected wave. It is the propagation speed of the probe wave in the blood flow-bearing structure. It is the angle between the direction of the probe wave emission and the direction of the blood flow being measured. This is the angle correction factor.

[0010] Preferably, the step of inputting the fourth target signal into the sound processing circuit so that the sound processing circuit plays a blood flow rate sound according to the fourth target signal includes: The fourth target signal is subjected to multi-stage audio amplification processing; The fourth target signal, after audio amplification, is played. This fourth target signal is an analog audio signal converted from digital to analog. Since the original blood flow echo signal collected by the probe is a weak signal at the microvolt level, even after front-end amplification and digital processing, the amplitude of the fourth target signal after digital-to-analog conversion is still insufficient to directly drive the speaker. Therefore, multi-stage amplification is required through a sound processing circuit. This multi-stage amplification specifically involves at least two stages of sequential amplification, including two core stages: pre-amplification and power amplification. The pre-amplification stage amplifies the voltage of the fourth target signal to increase its amplitude and simultaneously performs impedance matching to ensure signal fidelity. The power amplification stage amplifies the pre-amplified signal to output sufficient drive current to match the speaker's rated power parameters, ultimately driving the speaker to play a clearly audible blood flow sound.

[0011] Preferably, after converting the third target signal into a fourth target signal, the method further includes: Obtain the signal strength of the fourth target signal; Based on the signal strength of the fourth target signal, output intensity indication visual information.

[0012] Preferably, after obtaining the blood flow velocity based on the third target signal, the method further includes: The blood flow rate is displayed on a segmented screen; The step of outputting intensity indication visual information based on the signal strength of the fourth target signal includes: indicating the signal strength of the fourth target signal by the number of LED indicators lit.

[0013] A blood flow velocity detection device includes: a sound processing circuit and a flow velocity detection circuit, wherein the sound processing circuit includes a digital potentiometer chip, a volume control unit, an audio driver amplifier chip, and an audio amplifier; the digital potentiometer chip is used to perform primary amplification of the detected blood flow velocity sound signal; the volume control unit is used to adjust the signal strength of the blood flow velocity sound signal; the audio driver amplifier chip is used to perform secondary amplification of the blood flow velocity sound signal; and the audio amplifier is used to convert the blood flow velocity sound signal into an auditory signal. The flow rate detection circuit is used to obtain the value of blood flow rate based on the detected blood flow rate sound signal.

[0014] Preferably, it also includes an intensity indication visual information processing sub-circuit, which is connected to the volume level adjustment unit to obtain the signal intensity of the blood flow velocity sound signal; The intensity indication visual information processing subcircuit includes at least two amplifiers. When one amplifier detects that the signal strength of the blood flow velocity sound signal is greater than or equal to a preset value, it sends the blood flow velocity sound signal to the next amplifier. Otherwise, the amplifier sends the blood flow velocity sound signal to the LED signal processing unit, so that the LED signal processing unit lights up a preset number of LED beads according to the blood flow velocity sound signal. The analog drive signal output by amplifier 151 in the intensity indication visual information processing subcircuit first passes through the AD conversion channel of the digital-to-analog converter circuit, converting the continuously changing analog signal amplitude into discrete digital high and low level signals. After the digital signal passes through the isolation shaping circuit composed of inverters and AND gates, electrical isolation and waveform shaping are completed, and a stable and jitter-free digital control signal is output. This digital control signal is transmitted to the MOS transistor drive circuit to control the conduction and cutoff of the MOS transistor, ultimately realizing the lighting and extinguishing of the corresponding LED beads.

[0015] Preferably, a digital-to-analog converter circuit is provided between the LED signal processing unit and the LED beads.

[0016] Preferably, the flow rate detection circuit includes a segment code screen interface, which is connected to a segment code screen. The segment code screen is used to display the blood flow rate value detected by the flow rate detection circuit. The segment code screen is a segment liquid crystal display (also known as a segmented display), which is a display screen that displays numbers and fixed symbols by controlling the independent segment code electrodes to light up / off. It is commonly found in car dashboards, elevator floor displays, home appliance control panels, and other scenarios. The segment code screen is connected to the MCU main chip through a dedicated driver chip and a communication interface. After the MCU main chip calculates the blood flow rate value, it sends the value data to the segment code screen driver chip through the communication interface. After the driver chip parses the data, it controls the corresponding digital segment code and unit symbol segment code on the segment code screen to light up, and finally clearly displays the complete value of the blood flow rate on the segment code screen. The corresponding display unit is m / s or cm / s.

[0017] This invention provides a method and apparatus for detecting blood flow velocity. Compared with the prior art, it has the following advantages: 1. In this invention, blood flow velocity quantification calculation, high-fidelity audio playback, and signal strength visualization are simultaneously achieved through a single noise reduction process. Compared to the qualitative detection mode in existing technologies that relies on the operator's auditory experience and subjective judgment, this invention has the dual advantages of significantly improved detection accuracy and lower usage threshold. On the one hand, the flow velocity calculation and audio playback share the same set of noise-reduced pure digital signals, avoiding the problem of simultaneous noise amplification during traditional analog signal amplification. The noise-free third target signal can accurately extract Doppler frequency shift information, especially for weak blood flow signals in 0.2mm-level microvessels. To ensure detection accuracy, the blood flow audio output after digital-to-analog conversion is clear and free of noise, allowing operators to accurately distinguish the differences in blood flow sound between arteries and veins. On the other hand, the quantitative flow velocity values ​​displayed on the segment screen and the signal strength indications of the LED indicator provide objective and repeatable detection results, unaffected by subjective auditory differences of operators or noise interference from the operating room environment. This significantly reduces the equipment's reliance on operator experience, enabling non-professionals to quickly master the detection techniques. At the same time, the mutual verification of multi-dimensional information enhances the comprehensiveness of vascular type identification and blood flow status judgment, effectively avoiding the risk of intraoperative vascular damage. 2. In this invention, the sound processing circuit and the flow rate detection circuit share the front-end signal acquisition and primary amplification link. The digital potentiometer chip achieves adaptive gain adjustment of up to 100 levels, which avoids the hardware redundancy caused by setting up separate acquisition circuits for sound playback and flow rate detection. It also adapts to blood flow signals of different intensities through multi-level amplification design, preventing saturation distortion of strong signals and acquisition failure of weak signals. The intensity indication visual information processing sub-circuit adopts a pure hardware cascaded comparator amplifier graded detection scheme, which can achieve stable LED bead driving display without occupying the computing resources of the MCU main chip. With the electrical isolation design of the digital-to-analog conversion circuit, it effectively blocks the switching noise crosstalk of the subsequent driving circuit, ensuring the signal-to-noise ratio of the weak front-end signal acquisition. In addition, the segment code screen is connected to the MCU through the IIC serial communication interface, and data transmission can be completed with only two communication lines. The dedicated driver chip undertakes the refresh work, allowing the MCU computing power to focus on filtering and flow rate algorithm calculation. The overall circuit structure is simplified, the components are highly versatile, and the static power consumption is extremely low, which significantly improves the stability and reliability of the equipment in the complex electromagnetic environment of the operating room and fully adapts to the long-term operation requirements of portable, battery-powered medical equipment. Attached Figure Description

[0018] Figure 1 This is a flowchart of a blood flow velocity detection method and device proposed in this invention; Figure 2 This is a circuit diagram of the sound processing circuit in a blood flow velocity detection method and device proposed in this invention; Figure 3 This is a circuit diagram of the intensity indication visual information processing sub-circuit in the blood flow velocity detection method and device proposed in this invention; Figure 4 This is a circuit diagram of the flow velocity detection circuit in a blood flow velocity detection method and device proposed in this invention.

[0019] Figure 5 This is a system framework diagram of a blood flow velocity detection method and device proposed in this invention.

[0020] Legend: 100. Sound processing circuit; 110. Digital potentiometer chip; 120. Volume level adjustment unit; 130. Audio driver amplifier chip; 140. Audio amplifier; 150. Intensity indication visual information processing sub-circuit; 151. Amplifier; 200. Flow rate detection circuit. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-5 The present invention provides the following technical solutions, specifically including the following embodiments: Example 1: Clinical Ultrasound Diagnosis (Cardiac Blood Flow Detection) This embodiment provides a method and device for detecting blood flow velocity, and its application in mitral valve orifice blood flow detection.

[0023] S1. Obtain the first target signal of blood flow; A probe wave of a preset frequency is emitted toward the blood flow support structure (human heart tissue) at the mitral valve orifice. The probe wave is ultrasound, and the emission frequency is... =5 MHz (5×10 6 (Hz); the received wave is the first target signal, and the received wave is the sound wave that returns after the probe wave reaches the blood at the mitral valve orifice.

[0024] S2. Convert the first target signal into the second target signal; The first target signal is converted into a second target signal by the built-in AD acquisition module of the MCU main chip. The second target signal is a digital signal.

[0025] S3. Perform noise reduction processing on the second target signal to obtain the third target signal; The second target signal is denoised by using the built-in digital filtering algorithm of the MCU to filter out underlying noise and environmental interference signals, resulting in a third target signal with a significantly improved signal-to-noise ratio.

[0026] S4. Obtain the blood flow velocity based on the third target signal; Extract Doppler frequency shift information from the third target signal; the frequency difference between the received wave and the probe wave. =1200Hz, the angle between the direction of the probe wave emission and the direction of the blood flow being measured. =30° (cos30°≈0.866), the speed of sound in human soft tissue is c=1540 m / s.

[0027] The blood flow velocity is obtained using the following algorithm: Substitute the parameters into the formula: v≈0.214 m / s That is, the diastolic blood flow velocity at the mitral valve orifice is 21.4 cm / s.

[0028] S5. Convert the third target signal into the fourth target signal; The third target signal is converted into a fourth target signal through a DA conversion module. The fourth target signal is an analog signal.

[0029] S6. Input the fourth target signal into the sound processing circuit (100) so that the sound processing circuit (100) plays the blood flow rate sound according to the fourth target signal.

[0030] The fourth target signal undergoes multi-stage audio amplification processing, including two stages: pre-amplification and power amplification, ultimately driving the speaker to play clear mitral valve orifice blood flow sounds.

[0031] Intensity indication and flow rate display: The signal strength of the fourth target signal is acquired, and the signal strength level is indicated by the number of LED indicators lit; at the same time, the blood flow velocity value of 0.214 m / s is displayed on the segment code screen.

[0032] Clinical significance: The diastolic blood flow velocity at the mitral valve orifice in normal adults is approximately 0.8–1.5 m / s. The test results in this example indicate that the patient's mitral valve orifice blood flow velocity is within the normal range, and the heart valve function is normal.

[0033] Example 2: Diagnosis of Vascular Diseases (Carotid Artery Blood Flow Detection) This embodiment provides a blood flow velocity detection method and device for blood flow detection in patients with carotid artery stenosis.

[0034] S1. Obtain the first target signal of blood flow; A probe wave of a preset frequency is emitted toward the carotid artery blood flow support structure (human neck tissue). The probe wave is ultrasound, and the emission frequency is... =7.5 MHz (7.5 × 10 6 (Hz); the received wave is the first target signal, and the received wave is the sound wave that returns after the probe wave reaches the blood in the carotid artery.

[0035] S2. Convert the first target signal into the second target signal; The first target signal is converted into a second target signal by the built-in AD acquisition module of the MCU main chip. The second target signal is a digital signal.

[0036] S3. Perform noise reduction processing on the second target signal to obtain the third target signal; The second target signal is denoised by using the built-in digital filtering algorithm of the MCU to filter out underlying noise and environmental interference signals, resulting in a third target signal with a significantly improved signal-to-noise ratio.

[0037] S4. Obtain the blood flow velocity based on the third target signal; Extract Doppler frequency shift information from the third target signal; the frequency difference between the received wave and the probe wave. =2500Hz, the angle between the direction of the probe wave emission and the direction of the blood flow being measured. =0° (cos0°=1, meaning the direction of blood flow is completely consistent with the direction of sound waves), the speed of sound in human soft tissue is c=1540 m / s.

[0038] The blood flow velocity is obtained using the following algorithm: Substitute the parameters into the formula: v≈0.257 m / s That is, the blood flow velocity in the carotid artery is 25.7 cm / s.

[0039] S5. Convert the third target signal into the fourth target signal; The third target signal is converted into a fourth target signal through a DA conversion module. The fourth target signal is an analog signal.

[0040] S6. Input the fourth target signal into the sound processing circuit (100) so that the sound processing circuit (100) plays the blood flow rate sound according to the fourth target signal.

[0041] The fourth target signal undergoes multi-stage audio amplification processing, including two stages: pre-amplification and power amplification, ultimately driving the speaker to play clear carotid artery blood flow sounds.

[0042] Intensity indication and flow rate display: The signal strength of the fourth target signal is acquired, and the signal strength level is indicated by the number of LED indicators lit; at the same time, the blood flow velocity value of 0.257 m / s is displayed on the segment code screen.

[0043] Clinical significance: If a patient's carotid artery stenosis exceeds 50%, the blood flow velocity will usually increase significantly (e.g., exceeding 1.5 m / s). The test results in this example suggest that the patient's carotid artery stenosis is relatively mild and the hemodynamics are not significantly affected.

[0044] Example 3: Industrial Doppler Flow Meter (Liquid Flow Velocity Detection) This embodiment provides an application of a blood flow velocity detection method and device in industrial pipeline water flow detection.

[0045] S1. Obtain the first target signal of blood flow; A probe wave of a preset frequency is emitted into the liquid flow-bearing structure (water pipe) of an industrial pipeline. The probe wave is ultrasonic, and the emission frequency is... =2 MHz (2×10 6 (Hz); the received wave is the first target signal, and the received wave is the sound wave that returns after the probe wave reaches the water flow in the pipe.

[0046] S2. Convert the first target signal into the second target signal; The first target signal is converted into a second target signal by the built-in AD acquisition module of the MCU main chip. The second target signal is a digital signal.

[0047] S3. Perform noise reduction processing on the second target signal to obtain the third target signal; The second target signal is denoised by using the built-in digital filtering algorithm of the MCU to filter out underlying noise and environmental interference signals, resulting in a third target signal with a significantly improved signal-to-noise ratio.

[0048] S4. Obtain the blood flow velocity based on the third target signal; Extract Doppler frequency shift information from the third target signal; the frequency difference between the received wave and the probe wave. =800Hz, the angle between the direction of the probe wave emission and the direction of the measured water flow. =60° (cos60°=0.5), the speed of sound in water is c=1480 m / s.

[0049] The flow velocity of the water is obtained using the following algorithm: Substitute the parameters into the formula: v=0.592 m / s That is, the water flow velocity inside the pipe is 59.2 cm / s.

[0050] S5. Convert the third target signal into the fourth target signal; The third target signal is converted into a fourth target signal through a DA conversion module. The fourth target signal is an analog signal.

[0051] S6. Input the fourth target signal into the sound processing circuit (100) so that the sound processing circuit (100) plays the sound of water flow according to the fourth target signal; The fourth target signal undergoes multi-stage audio amplification processing, including two stages: pre-amplification and power amplification, ultimately driving the speaker to play a clear sound of flowing water.

[0052] Intensity indication and flow rate display: The signal strength of the fourth target signal is obtained, and the signal strength level is indicated by the number of LED indicators lit; at the same time, the flow velocity of the water is displayed on the segment code screen as 0.592 m / s.

[0053] Industrial significance: This flow velocity can be used to calculate the flow rate in a pipe (flow rate = flow velocity × pipe cross-sectional area), thereby enabling real-time monitoring and control of liquid flow.

[0054] Example 4: Ultrasonic Doppler fetal heart rate monitoring (fetal blood flow detection) This embodiment provides a blood flow velocity detection method and device for the application of fetal umbilical artery blood flow detection.

[0055] S1. Obtain the first target signal of blood flow; A probe wave of a preset frequency is emitted towards the fetal umbilical artery blood flow support structure (maternal uterine tissue). The probe wave is ultrasound, and the emission frequency is... =4 MHz (4×10 6 (Hz); the received wave is the first target signal, and the received wave is the sound wave that returns after the probe wave reaches the fetal umbilical artery blood.

[0056] S2. Convert the first target signal into the second target signal; The first target signal is converted into a second target signal by the built-in AD acquisition module of the MCU main chip. The second target signal is a digital signal.

[0057] S3. Perform noise reduction processing on the second target signal to obtain the third target signal; The second target signal is denoised by using the built-in digital filtering algorithm of the MCU to filter out underlying noise and environmental interference signals, resulting in a third target signal with a significantly improved signal-to-noise ratio.

[0058] S4. Obtain the blood flow velocity based on the third target signal; Extract Doppler frequency shift information from the third target signal; the frequency difference between the received wave and the probe wave. =1800Hz, the angle between the direction of the probe wave emission and the direction of the blood flow being measured. =45° (cos45°≈0.707), the speed of sound in human soft tissue is c=1540 m / s.

[0059] The blood flow velocity is obtained using the following algorithm: Substitute the parameters into the formula: v≈0.491 m / s That is, the blood flow velocity in the fetal umbilical artery is 49.1 cm / s.

[0060] S5. Convert the third target signal into the fourth target signal; The third target signal is converted into a fourth target signal through a DA conversion module. The fourth target signal is an analog signal.

[0061] S6. Input the fourth target signal into the sound processing circuit (100) so that the sound processing circuit (100) plays the blood flow rate sound according to the fourth target signal.

[0062] The fourth target signal undergoes multi-stage audio amplification processing, including two stages: pre-amplification and power amplification, ultimately driving the speaker to play a clear sound of fetal umbilical artery blood flow.

[0063] Intensity indication and flow rate display: The signal strength of the fourth target signal is acquired, and the signal strength level is indicated by the number of LED indicators lit; at the same time, the blood flow velocity value of 0.491 m / s is displayed on the segment code screen.

[0064] Clinical significance: The normal fetal umbilical artery diastolic blood flow velocity is approximately 0.3–0.8 m / s. The test results in this example indicate that the fetus has good blood perfusion and normal blood oxygen supply.

[0065] The following is a comparison table of parameters for four embodiments.

[0066] Based on the detection results of the four embodiments above, the blood flow velocity detection method and device of the present invention exhibit excellent detection accuracy, wide clinical applicability, stable method reliability, and outstanding technical universality. The four embodiments respectively cover different transmission frequencies of 2–7.5 MHz, two propagation media (human soft tissue and water), and a detection angle range of 0°–60°. Embodiment 1 (mitral valve orifice) measured a flow velocity of 0.214 m / s, and Embodiment 2 (carotid artery)... The measured speed was 0.257 m / s at the optimal angle of 0°, 0.592 m / s in Example 3 (industrial water flow), and 0.491 m / s in Example 4 (fetal umbilical artery). All results are consistent with the normal reference range or engineering expectations for their respective scenarios, fully validating the angle correction factor. The effective compensation for probe placement deviation ensures the accuracy of quantitative calculations under different conditions; In summary, this invention effectively solves the technical defects of existing technologies, such as lack of accurate quantification capabilities, reliance on subjective auditory judgment, and poor detection repeatability, through the deep integration of ultrasonic Doppler effect and digital signal processing. It has significant application value and industrialization prospects in the fields of biomedical engineering, clinical diagnosis, and industrial testing.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for detecting blood flow velocity, characterized in that: include: S1. Acquire a first target signal of blood flow, wherein the first target signal is an analog signal; S2. Convert the first target signal into a second target signal, wherein the second target signal is a digital signal; S3. Perform noise reduction processing on the second target signal to obtain the third target signal; S4. Obtain the blood flow velocity based on the third target signal; S5. Convert the third target signal into a fourth target signal, wherein the fourth target signal is an analog signal; S6. Input the fourth target signal into the sound processing circuit (100) so that the sound processing circuit (100) plays the blood flow rate sound according to the fourth target signal.

2. The blood flow velocity detection method according to claim 1, characterized in that: The acquisition of the first target signal of blood flow further includes: S11. A probe wave of a preset frequency is emitted to the blood flow bearing structure, wherein the blood flow bearing structure is a carrier for the blood flow velocity to be detected; S12. Obtain the received wave as the first target signal, wherein the received wave is the sound wave that returns after the probe wave reaches the blood being tested in the blood flow bearing structure; S13. The step of obtaining the blood flow velocity based on the third target signal includes: S14. Obtain the blood flow velocity based on the frequency difference between the received wave and the probe wave, and the angle between the probe wave emission direction and the measured blood flow direction.

3. The blood flow velocity detection method according to claim 1, characterized in that: The step of obtaining the blood flow velocity based on the frequency difference between the received wave and the detected wave, and based on the angle between the direction of the detected wave emission and the direction of the measured blood flow, includes obtaining the blood flow velocity according to the following algorithm: in, It's the blood flow velocity. It is the transmission frequency of the probe wave. It is the frequency difference between the received wave and the detected wave. It is the propagation speed of the probe wave in the blood flow-bearing structure. It is the angle between the direction of the probe wave emission and the direction of the blood flow being measured. This is the angle correction factor.

4. The blood flow velocity detection method according to claim 1, characterized in that: The step of inputting the fourth target signal into the sound processing circuit (100) so that the sound processing circuit (100) plays a blood flow rate sound according to the fourth target signal includes: The fourth target signal is subjected to multi-stage audio amplification processing; Play the fourth target signal after audio amplification.

5. The blood flow velocity detection method according to claim 1, characterized in that: After converting the third target signal into a fourth target signal, the method further includes: Obtain the signal strength of the fourth target signal; Based on the signal strength of the fourth target signal, output intensity indication visual information.

6. The blood flow velocity detection method according to claim 1, characterized in that: After obtaining the blood flow velocity based on the third target signal, the method further includes: The blood flow rate is displayed on a segmented screen; The step of outputting intensity indication visual information based on the signal strength of the fourth target signal includes: indicating the signal strength of the fourth target signal by the number of LED indicators lit.

7. A blood flow velocity detection device, based on any one of the blood flow velocity detection methods according to claims 1-6, characterized in that: include: The sound processing circuit (100) and the flow rate detection circuit (200) are provided. The sound processing circuit (100) includes a digital potentiometer chip (110), a volume level adjustment unit (120), an audio driver amplifier chip (130), and an audio amplifier (140). The digital potentiometer chip (110) is used to perform primary amplification of the detected blood flow rate sound signal. The volume level adjustment unit (120) is used to adjust the signal strength of the blood flow rate sound signal. The audio driver amplifier chip (130) is used to perform secondary amplification of the blood flow rate sound signal. The audio amplifier (140) is used to convert the blood flow rate sound signal into an auditory signal. The flow rate detection circuit (200) is used to obtain the value of the blood flow rate based on the detected blood flow rate sound signal.

8. A blood flow rate detection device according to claim 7, characterized in that: It also includes an intensity indication visual information processing sub-circuit (150), which is connected to the volume level adjustment unit (120) to obtain the signal intensity of the blood flow velocity sound signal; the intensity indication visual information processing sub-circuit (150) includes at least two amplifiers (151). When one amplifier (151) detects that the signal intensity of the blood flow velocity sound signal is greater than or equal to a preset value, it sends the blood flow velocity sound signal to the next amplifier (151); otherwise, the amplifier (151) sends the blood flow velocity sound signal to the LED signal processing unit so that the LED signal processing unit lights up a preset number of LED beads according to the blood flow velocity sound signal.

9. A blood flow rate detection device according to claim 7, characterized in that: A digital-to-analog converter circuit is provided between the LED signal processing unit and the LED beads.

10. A blood flow rate detection device according to claim 7, characterized in that: The flow rate detection circuit (200) includes a segment code screen interface, which is connected to a segment code screen. The segment code screen is used to display the blood flow rate value detected by the flow rate detection circuit.

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