A method and device for dynamic monitoring of microbubbles for blood purification

Abstract

The present invention provides a method and device for dynamic monitoring of microbubbles for blood purification. The method comprises: measuring the amplitude and frequency of an ultrasonic signal after it passes through a pipeline; calculating the flow rate of the liquid in the pipeline using a frequency difference method based on the measured frequency; determining whether bubbles exist in the pipeline based on the measured amplitude, and returning to the first step if no bubbles exist; if bubbles exist, classifying them according to their volume; when the bubble volume exceeds a limit, determining them as large bubbles and proceeding to the next step; when the bubble volume is below a limit, determining them as small bubbles and returning to the first step; and issuing an alarm when the flow rate of the liquid in the pipeline is greater than zero and large bubbles exist in the pipeline. The device comprises an ultrasonic detection module, a liquid flow rate test module, a waveform shaping module, a comparison module, a control module, and an alarm output module; only microbubbles in the flowing liquid are accumulated, thereby accurately measuring the microbubbles, achieving microbubble monitoring and alarming, and reducing false alarms.

Description

Technical Field

[0001] The present invention relates to the technical field of blood purification equipment, and in particular to a method and device for dynamically monitoring tiny bubbles for blood purification. Background Art

[0002] Blood purification equipment removes a patient's blood from the body and removes certain pathogenic substances, purifying the blood and achieving the purpose of treating the disease. Currently, in blood purification equipment, the patient's blood flows out of the body through an extracorporeal circuit formed by tubing and returns to the body. During this extracorporeal circulation process, air can enter the blood circulation loop and flow into the body through the veins, endangering the patient's life and causing serious medical accidents. Therefore, monitoring the presence of air and bubbles in the tubing is particularly important. Currently, ultrasonic air monitors are commonly used to monitor the venous return section of the extracorporeal blood circulation in real time, continuously, and reliably for the presence of bubbles.

[0003] In the prior art, ultrasonic waves are typically transmitted into a pipeline, followed by detection of the amplitude of the ultrasonic signal after it passes through the pipeline to determine bubble size and integrate the bubble duration, thereby achieving a micro-bubble alarm. For example, patent application number CN200520010559.9 discloses an ultrasonic air monitor for blood purification equipment. The monitor comprises an ultrasonic transmitter circuit, an ultrasonic transducer, an ultrasonic receiver circuit, and a dynamic level discrimination circuit. A single-chip microcomputer is used as the transmitter source for the ultrasonic transmitter circuit, ensuring the stability of the ultrasonic transmission frequency. The dynamic level discrimination circuit is insensitive to the position of the debubbler clamped on the acoustic sensor and only triggers an alarm when a bubble is detected, eliminating false alarms and ensuring the stability and reliability of the detection process. However, existing detection methods and devices cannot distinguish whether the liquid in the pipeline is flowing or stationary, and cannot discriminate micro-bubbles generated when the liquid is stationary. This results in false alarms even when bubbles are generated when the liquid is stationary, thus affecting the normal use of the equipment. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems in the prior art, that is, it is impossible to identify whether the liquid in the pipeline is flowing or stationary, and it is impossible to distinguish the tiny bubbles generated when the liquid is stationary, resulting in false alarms even if bubbles are generated when the liquid is stationary.

[0005] To this end, the first aspect of the present invention provides a method for dynamic monitoring of microbubbles for blood purification.

[0006] A second aspect of the present invention provides a device for dynamic monitoring of microbubbles for blood purification.

[0007] The present invention provides a method for dynamic monitoring of microbubbles for blood purification. During the blood purification process, the patient's blood flows out of the body and returns to the body through an extracorporeal circulation formed by a pipeline, comprising the following steps:

[0008] S1. Measure the amplitude and frequency of the ultrasonic signal after it passes through the pipeline;

[0009] S2. Calculate the liquid flow rate in the pipeline using the frequency difference method based on the frequency measured in S1;

[0010] S3. Determine whether there are bubbles in the pipeline based on the amplitude measured in S1. If no bubbles exist, return to S1. If bubbles exist, classify them according to their volume. When the bubble volume exceeds the limit, it is determined to be a large bubble and proceed to the next step. When the bubble volume is lower than the limit, it is determined to be a small bubble and return to S1.

[0011] S4. When the liquid flow rate in the pipeline is greater than zero and there are large bubbles in the pipeline, an alarm is issued; and / or, the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero is accumulated, and when the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero reaches a set upper limit, an alarm is issued.

[0012] The method for dynamic monitoring of microbubbles for blood purification according to the above technical solution of the present invention may also have the following additional technical features:

[0013] In the above technical solution, the method for measuring the frequency of the ultrasonic signal after passing through the pipeline in step S1 is as follows:

[0014] A first ultrasonic detection unit is provided on one side of the blood pipeline, and a second ultrasonic detection unit is provided on the other side;

[0015] The first ultrasonic detection unit or the second ultrasonic detection unit is driven to emit an ultrasonic pulse signal. The ultrasonic signal is received by the second ultrasonic detection unit or the first ultrasonic detection unit after passing through the blood pipeline. The ultrasonic signal at the receiving end is amplified, shaped, and identified, and then the transmitting end is triggered to continue to send the next pulse signal. After several cycles, a pulse sequence is obtained, and the frequency of the pulse sequence is measured as the frequency of the ultrasonic signal after passing through the pipeline.

[0016] In the above technical solution, the method for calculating the flow rate of the liquid in the pipeline using the frequency difference method in step S2 is as follows:

[0017] V 液 =(F up -F down )*L / (2*Cosθ);

[0018] Among them, V 液 is the liquid flow rate in the pipeline; F upF is the uplink measurement frequency, that is, the frequency of the pulse sequence formed when the first ultrasonic detection unit sends an ultrasonic pulse signal and the second ultrasonic detection unit receives the ultrasonic pulse signal; down is the downlink measurement frequency, that is, the frequency of the pulse sequence formed when the second ultrasonic detection unit sends an ultrasonic pulse signal and the first ultrasonic detection unit receives the ultrasonic pulse signal; L is the distance the ultrasonic pulse signal propagates from the transmitting end to the receiving end in the liquid medium; θ is the angle between the connecting line between the first ultrasonic detection unit and the second ultrasonic detection unit and the flow direction of the pipeline liquid.

[0019] In the above technical solution, in S3, the first ultrasonic detection unit emits an ultrasonic pulse signal, which is received by the second ultrasonic detection unit after passing through the pipeline and becomes a signal to be tested. The amplitude offset of the signal to be tested is used to determine whether there are bubbles in the blood. When bubbles exist, the level of the signal to be tested is compared with the set fixed level to determine whether the generated bubbles are large bubbles or small bubbles.

[0020] In the above technical solution, in S4, the number of small bubbles in the pipeline whose volume exceeds the minimum limit is accumulated.

[0021] The present invention also provides a blood purification micro-bubble dynamic monitoring device, comprising:

[0022] An ultrasonic detection module, for measuring the amplitude and frequency of an ultrasonic signal after it passes through the pipeline, comprising a first ultrasonic detection unit and a second ultrasonic detection unit, wherein the first ultrasonic detection unit and the second ultrasonic detection unit are respectively located on either side of the pipeline, and the ultrasonic signal is transmitted between the first ultrasonic detection unit and the second ultrasonic detection unit;

[0023] The liquid flow rate testing module is connected to the ultrasonic detection module and is used to calculate the liquid flow rate in the pipeline by using the frequency difference method;

[0024] The waveform shaping module is connected to the ultrasonic detection module and is used to amplify and shape the ultrasonic signal generated during the testing process of the ultrasonic detection module;

[0025] The comparison module is connected to the waveform shaping module. It determines whether there are bubbles in the pipeline according to the output signal of the waveform shaping module and compares the volume of the bubbles with the limit value. When the bubble volume is higher than the limit value, it is a large bubble. When the bubble volume is lower than the limit value, it is a small bubble.

[0026] a control module, connected to the liquid flow rate testing module and the comparison module, respectively, for receiving signals transmitted by the liquid flow rate testing module and the comparison module to calculate the liquid flow rate and determine the bubble size, and to determine whether there are bubbles in the pipeline that may affect patient safety based on the liquid flow rate and the bubble size;

[0027] The alarm output module is connected to the control module and issues a warning when there are bubbles in the pipeline that affect patient safety.

[0028] The method for dynamic monitoring of microbubbles for blood purification according to the above technical solution of the present invention may also have the following additional technical features:

[0029] In the above technical solution, the comparison module includes:

[0030] The large bubble comparison unit is connected to the waveform shaping module and is used to compare the output signal of the waveform shaping module with a set fixed level and output a level signal indicating whether it is a large bubble according to the comparison result;

[0031] The small bubble comparison unit is connected to the waveform shaping module and is used to compare the output signal of the waveform shaping module with a set fixed level, and output a level signal indicating whether it is a small bubble according to the comparison result.

[0032] In the above technical solution, the control module is also used to accumulate the number of small bubbles, and when the number of small bubbles reaches a set upper limit, the alarm output module is controlled to issue an alarm.

[0033] In the above technical solution, the control module is connected to the liquid flow rate testing module via an SPI interface.

[0034] In the above technical solution, the angle between the connecting line between the first ultrasonic detection unit and the second ultrasonic detection unit and the flow direction of the liquid in the pipeline is 30° to 60°.

[0035] In summary, due to the adoption of the above technical features, the beneficial effects of the present invention are:

[0036] By combining ultrasonic flow velocity measurement with amplitude measurement, only tiny bubbles in the flowing liquid are accumulated, thereby accurately measuring tiny bubbles, realizing tiny bubble monitoring alarm, reducing false alarms, and improving equipment adaptability.

[0037] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0039] Figure 1 This is a schematic structural diagram of a device for dynamic monitoring of micro-bubbles for blood purification according to one embodiment of the present invention;

[0040] Figure 2This is a schematic diagram of a method for dynamically monitoring microbubbles for blood purification according to an embodiment of the present invention, which uses a frequency difference method to calculate the flow rate of liquid in a pipeline;

[0041] Figure 3 The present invention is a flowchart of a method for dynamic monitoring of microbubbles for blood purification according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0044] Refer to the following Figures 1 to 3 A method and apparatus for dynamic monitoring of microbubbles for blood purification according to some embodiments of the present invention will be described.

[0045] Some embodiments of the present application provide a method for dynamic monitoring of microbubbles for blood purification.

[0046] like Figures 1 to 3 As shown, the first embodiment of the present invention provides a method for dynamic monitoring of microbubbles for blood purification. During the blood purification process, the patient's blood flows out of the body and returns to the body through an extracorporeal circulation formed by a pipeline, including the following steps:

[0047] S1. Measure the amplitude and frequency of the ultrasonic signal after it passes through the pipeline;

[0048] The method for measuring the frequency of the ultrasonic signal after passing through the pipeline in step S1 is as follows:

[0049] A first ultrasonic detection unit is provided on one side of the blood pipeline, and a second ultrasonic detection unit is provided on the other side;

[0050] The first ultrasonic detection unit or the second ultrasonic detection unit is driven to emit an ultrasonic pulse signal. The ultrasonic signal is received by the second ultrasonic detection unit or the first ultrasonic detection unit after passing through the blood pipeline. The ultrasonic signal at the receiving end is amplified, shaped, and identified, and then the transmitting end is triggered to continue to send the next pulse signal. After several cycles, a pulse sequence is obtained, and the frequency of the pulse sequence is measured as the frequency of the ultrasonic signal after passing through the pipeline.

[0051] S2. Calculate the liquid flow rate in the pipeline using the frequency difference method based on the frequency measured in S1;

[0052] The method for calculating the liquid flow rate in the pipeline using the frequency difference method in step S2 is as follows:

[0053] V 液 =(F up -F down )*L / (2*Cosθ);

[0054] Among them, V 液 is the liquid flow rate in the pipeline; F up F is the uplink measurement frequency, that is, the frequency of the pulse sequence formed when the first ultrasonic detection unit sends an ultrasonic pulse signal and the second ultrasonic detection unit receives the ultrasonic pulse signal; down is the downlink measurement frequency, that is, the frequency of the pulse sequence formed when the second ultrasonic detection unit sends an ultrasonic pulse signal and the first ultrasonic detection unit receives the ultrasonic pulse signal; L is the distance the ultrasonic pulse signal propagates from the transmitting end to the receiving end in the liquid medium; θ is the angle between the connecting line between the first ultrasonic detection unit and the second ultrasonic detection unit and the flow direction of the pipeline liquid.

[0055] Specifically, if Figure 2 As shown, the first ultrasonic detection unit sends an ultrasonic pulse signal. After the sound wave propagates a distance L in the liquid medium, it is received by the second ultrasonic detection unit and converted into a small electrical signal. The small electrical signal is amplified, shaped and identified in the signal unit, and then triggers the first ultrasonic detection unit to send the next pulse signal again. This cycle repeats to obtain a sound pulse sequence. The frequency of the sound pulse sequence is measured by the measurement unit, that is, the uplink measurement frequency F up ;

[0056] F up =1 / t1=1 / (L / V)=1 / (L / (V0+V 液 *Cosθ)=(V0+V*Cosθ) / L;

[0057] Where: t1 is the propagation time of the ultrasonic wave on L; V is the comprehensive propagation velocity of the ultrasonic wave on L; V0 is the standard propagation velocity of the ultrasonic wave on L.

[0058] Then, the second ultrasonic detection unit is controlled to send an ultrasonic pulse signal. After the sound wave propagates a distance L in the liquid medium, it is received by the first ultrasonic detection unit and converted into a small electrical signal. The small electrical signal is amplified, shaped and identified in the signal unit, and then triggers the second ultrasonic detection unit to send the next pulse signal again. This cycle repeats to obtain a sound pulse sequence. The frequency of the sound pulse sequence is measured by the measurement unit, that is, the downlink measurement frequency F down ;

[0059] F down =1 / t1=1 / (L / V)=1 / (L / (V0-V 液 *Cosθ)=(V0-V 液 *Cosθ) / L;

[0060] According to the frequency difference method, we have:

[0061] F up -Fdown=2V 液 *Cosθ / L;

[0062] but:

[0063] V 液 =(F up -F down )*L / (2*Cosθ).

[0064] S3. Determine whether there are bubbles in the pipeline based on the amplitude measured in S1. If no bubbles exist, return to S1. If bubbles exist, classify them according to their volume. When the bubble volume exceeds the limit, it is determined to be a large bubble and proceed to the next step. When the bubble volume is lower than the limit, it is determined to be a small bubble and return to S1.

[0065] In S3, the first ultrasonic detection unit emits an ultrasonic pulse signal, which is received by the second ultrasonic detection unit after passing through the pipeline and becomes a test signal. The test signal is detected once and the amplitude offset of the test signal is used to determine whether there are bubbles in the blood. When bubbles are present, the amplitude offset is large, causing the level of the test signal to be lower than when no bubbles are present. The presence of bubbles can be determined by comparison. After determining the presence of bubbles, the level of the test signal is compared with a set fixed level to determine whether the generated bubbles are large or small. The set fixed level is the level value of the test signal corresponding to the bubble volume A1. Specifically, A1 can be set to 20ul, and can also be set to 15ul, 18ul, 22ul, 25ul, etc. as needed. When the level of the test signal is not higher than the set fixed level, it is confirmed that the volume of the bubble is not less than A1, and it is determined to be a large bubble. When the level of the test signal is higher than the set fixed level, it is confirmed that the volume of the bubble is less than A1, and it is determined to be no bubble or small bubble.

[0066] S4. When the liquid flow rate in the pipeline is greater than zero and there are large bubbles in the pipeline, an alarm is issued; and / or, the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero is accumulated, and when the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero reaches a set upper limit, an alarm is issued.

[0067] In S4, the number of small bubbles whose volume in the pipeline exceeds the minimum limit is accumulated.

[0068] To further reduce false alarms, it is necessary to set a minimum limit A2 for the volume of small bubbles, that is, the number of small bubbles will be accumulated only when the bubble volume is less than A1 and not less than A2. A2 can be set to 0.3ul, or it can be set to 0.1ul, 0.2ul, 0.4ul, etc. as needed; the signal to be tested can be judged first as to whether it is a large bubble, and then as to whether it is a small bubble; or both can be judged at the same time.

[0069] The second embodiment of the present invention proposes a method for dynamic monitoring of microbubbles for blood purification, and based on the first embodiment, Figures 1 to 3 As shown, Figure 3 As shown, first the MCU initializes each functional component, internal circuit, external chip and port, and the MCU automatically measures the frequency through the SPI interface circuit to obtain F up ; MCU controls TDC-GP22 through SPI interface to switch to downlink measurement, and the circuit automatically measures the frequency to obtain F down ; MCU calculates the liquid flow rate V 液 ; Repeatedly and uninterruptedly measure the liquid velocity.

[0070] In the bubble alarm process, first check whether there are bubbles, if not, repeat the detection process;

[0071] When bubbles are detected, if they are "large bubbles" and the liquid speed is greater than 0, an alarm will be issued;

[0072] If it is not a big bubble, but a "small bubble" and the liquid speed is greater than 0, the count will be accumulated. When the count reaches a certain number, an alarm will be issued as a dangerous bubble.

[0073] The third embodiment of the present invention provides a blood purification micro-bubble dynamic monitoring device, and based on any of the above embodiments, as Figures 1 to 3 Shown, including:

[0074] An ultrasonic detection module, for measuring the amplitude and frequency of an ultrasonic signal after it passes through the pipeline, comprising a first ultrasonic detection unit and a second ultrasonic detection unit, each located on either side of the pipeline, with the ultrasonic signal transmitted between them; the first and second ultrasonic detection units may be made of piezoelectric ceramics;

[0075] The angle between the connecting line between the first ultrasonic detection unit and the second ultrasonic detection unit and the flow direction of the liquid in the pipeline is 30° to 60°, and specifically, can be set to 45°.

[0076] Liquid flow rate test module, which can use GP22 and is connected to the ultrasonic detection module, is used to calculate the liquid flow rate in the pipeline by frequency difference method;

[0077] The waveform shaping module is connected to the ultrasonic detection module and is used to amplify and shape the ultrasonic signal generated during the testing process of the ultrasonic detection module;

[0078] The comparison module is connected to the waveform shaping module. It determines whether there are bubbles in the pipeline according to the output signal of the waveform shaping module and compares the volume of the bubbles with the limit value. When the bubble volume is higher than the limit value, it is a large bubble. When the bubble volume is lower than the limit value, it is a small bubble.

[0079] The comparison module includes:

[0080] The large bubble comparison unit is connected to the waveform shaping module and is used to compare the output signal of the waveform shaping module with a set fixed level and output a level signal indicating whether it is a large bubble according to the comparison result;

[0081] The small bubble comparison unit is connected to the waveform shaping module and is used to compare the output signal of the waveform shaping module with a set fixed level, and output a level signal indicating whether it is a small bubble according to the comparison result.

[0082] The control module uses a microcontroller unit (MCU) and is connected to the liquid flow rate test module and the comparison module respectively. It is used to receive signals transmitted by the liquid flow rate test module and the comparison module to complete the calculation of the liquid flow rate and the determination of the bubble size. It also determines whether there are bubbles in the pipeline that affect patient safety based on the liquid flow rate and the bubble size.

[0083] When large bubbles are detected, it is determined that there are dangerous bubbles that affect patient safety; when small bubbles are detected, the number of small bubbles is accumulated. When the number of small bubbles reaches the set upper limit, the alarm output module is controlled to issue an alarm.

[0084] The alarm output module is connected to the control module and issues a warning when there are bubbles in the pipeline that affect patient safety.

[0085] A fourth embodiment of the present invention provides a method for dynamic monitoring of microbubbles for blood purification. Based on any of the above embodiments, a waveform shaping module is used to amplify the small ultrasonic signal into an electrical signal at the 1000 mV level and output it to a comparison module for evaluation.

[0086] In the large bubble comparator, a reference signal is given by setting a fixed level, and the reference signal is compared with the output signal of the waveform shaping module. If the signal voltage of the waveform shaping module output signal is lower than the reference signal, a low level ('0') is output, indicating "large bubbles exist"; if the signal voltage of the waveform shaping module output signal is higher than the reference signal, a high level ('1') is output, indicating "no large bubbles exist";

[0087] In the small bubble comparator, a fixed level is set and another reference signal is given. The reference signal is compared with the output signal of the waveform shaping module. If the signal voltage of the output signal of the waveform shaping module is lower than the reference signal, a low level ('0') is output, indicating "small bubbles exist"; if the signal voltage of the output signal of the waveform shaping module is higher than the reference signal, a high level ('1') is output, indicating "no small bubbles exist".

[0088] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples.

[0089] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for dynamic monitoring of microbubbles for blood purification, wherein during the blood purification process, the patient's blood flows out of the body and returns to the body through an extracorporeal circulation system formed by a pipeline, characterized in that: The following steps are involved: S1. Measure the amplitude and frequency of the ultrasonic signal after it passes through the pipeline; S2. Calculate the liquid flow rate in the pipeline using the frequency difference method based on the frequency measured in S1; S3. Determine whether there are bubbles in the pipeline based on the amplitude measured in S1. If no bubbles exist, return to S1. If bubbles exist, classify them according to their volume. When the bubble volume exceeds the limit, it is determined to be a large bubble and proceed to the next step. When the bubble volume is lower than the limit, it is determined to be a small bubble and return to S1. S4. When the liquid flow rate in the pipeline is greater than zero and there are large bubbles in the pipeline, an alarm is issued; and / or, the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero is accumulated, and when the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero reaches a set upper limit, an alarm is issued.

2. A method for dynamic monitoring of microbubbles for blood purification according to claim 1, characterized in that: The method for measuring the frequency of the ultrasonic signal after passing through the pipeline in step S1 is as follows: A first ultrasonic detection unit is provided on one side of the blood pipeline, and a second ultrasonic detection unit is provided on the other side; The first ultrasonic detection unit or the second ultrasonic detection unit is driven to emit an ultrasonic pulse signal. The ultrasonic pulse signal is received by the second ultrasonic detection unit or the first ultrasonic detection unit after passing through the blood pipeline. The ultrasonic signal at the receiving end is amplified, shaped, and identified, and then the transmitting end is triggered to continue sending the next pulse signal. After several cycles, a pulse sequence is obtained, and the frequency of the pulse sequence is measured as the frequency of the ultrasonic signal after passing through the pipeline.

3. A method for dynamic monitoring of microbubbles for blood purification according to claim 2, characterized in that: The method for calculating the liquid flow rate in the pipeline using the frequency difference method in step S2 is as follows: V 液 = (F up - F down )*L / (2* Cosθ); Among them, V 液 is the liquid flow rate in the pipeline; F up F is the uplink measurement frequency, that is, the frequency of the pulse sequence formed when the first ultrasonic detection unit sends an ultrasonic pulse signal and the second ultrasonic detection unit receives the ultrasonic pulse signal; down is the downlink measurement frequency, that is, the frequency of the pulse sequence formed when the second ultrasonic detection unit sends an ultrasonic pulse signal and the first ultrasonic detection unit receives the ultrasonic pulse signal; L is the distance the ultrasonic pulse signal propagates from the transmitting end to the receiving end in the liquid medium; θ is the angle between the connecting line between the first ultrasonic detection unit and the second ultrasonic detection unit and the flow direction of the pipeline liquid.

4. A method for dynamic monitoring of microbubbles for blood purification according to claim 3, characterized in that: In S3, the first ultrasonic detection unit sends out an ultrasonic pulse signal, which is received by the second ultrasonic detection unit after passing through the pipeline and becomes a test signal. The amplitude offset of the test signal is used to determine whether there are bubbles in the blood. When bubbles exist, the level of the test signal is compared with the set fixed level to determine whether the generated bubbles are large bubbles or small bubbles.

5. A method for dynamic monitoring of microbubbles for blood purification according to any one of claims 1 to 4, characterized in that: In S4, the number of small bubbles whose volume in the pipeline exceeds the minimum limit is accumulated.

6. A micro-bubble dynamic monitoring device for blood purification, characterized in that: include: An ultrasonic detection module, for measuring the amplitude and frequency of an ultrasonic signal after it passes through the pipeline, comprising a first ultrasonic detection unit and a second ultrasonic detection unit, wherein the first ultrasonic detection unit and the second ultrasonic detection unit are respectively located on either side of the pipeline, and the ultrasonic signal is transmitted between the first ultrasonic detection unit and the second ultrasonic detection unit; The liquid flow rate testing module is connected to the ultrasonic detection module and is used to calculate the liquid flow rate in the pipeline by using the frequency difference method; The waveform shaping module is connected to the ultrasonic detection module and is used to amplify and shape the ultrasonic signal generated during the testing process of the ultrasonic detection module; The comparison module is connected to the waveform shaping module. It determines whether there are bubbles in the pipeline according to the output signal of the waveform shaping module and compares the volume of the bubbles with the limit value. When the bubble volume is higher than the limit value, it is a large bubble. When the bubble volume is lower than the limit value, it is a small bubble. a control module, connected to the liquid flow rate testing module and the comparison module, respectively, for receiving signals transmitted by the liquid flow rate testing module and the comparison module to calculate the liquid flow rate and determine the bubble size, and to determine whether there are bubbles in the pipeline that may affect patient safety based on the liquid flow rate and the bubble size; The alarm output module is connected to the control module and issues a warning when there are bubbles in the pipeline that affect the patient's safety; Among them, when the liquid flow rate in the pipeline is greater than zero and there are large bubbles in the pipeline, the control module controls the alarm output module to issue an alarm; and / or, the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero is accumulated, and when the number of small bubbles generated when the liquid flow rate in the pipeline is greater than zero reaches a set upper limit, the control module controls the alarm output module to issue an alarm.

7. The blood purification micro-bubble dynamic monitoring device according to claim 6, characterized in that: The comparison module includes: The large bubble comparison unit is connected to the waveform shaping module and is used to compare the output signal of the waveform shaping module with a set fixed level and output a level signal indicating whether it is a large bubble according to the comparison result; The small bubble comparison unit is connected to the waveform shaping module and is used to compare the output signal of the waveform shaping module with a set fixed level, and output a level signal indicating whether it is a small bubble according to the comparison result.

8. The blood purification micro-bubble dynamic monitoring device according to claim 6, characterized in that: The control module is also used to accumulate the number of small bubbles, and when the number of small bubbles reaches a set upper limit, the alarm output module is controlled to issue an alarm.

9. The blood purification micro-bubble dynamic monitoring device according to claim 6, characterized in that: The control module is connected to the liquid flow rate test module via an SPI interface.

10. The blood purification micro-bubble dynamic monitoring device according to claim 6, characterized in that: The angle between the connecting line between the first ultrasonic detection unit and the second ultrasonic detection unit and the flow direction of the liquid in the pipeline is 30°~60°.

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