Arteriovenous fistula monitoring method and wearable monitoring device

Abstract

The present invention relates to the field of medical equipment, in particular to medical monitoring equipment, and more specifically to an arteriovenous fistula visualization monitoring method and a wearable monitoring device, which forms a blood flow waveform in the arteriovenous fistula personalized for a specific user after a period of use by a dialysis patient, and continuously updates standard model data according to the blood flow changes of the patient during use, thereby realizing personalized monitoring and treatment. At the same time, due to the use of a wearable monitoring device, the cuff that can be used by dialysis patients on a daily basis is used as the wearable base of the monitoring device itself, which has the advantages of being beautiful and small in size.

Description

Technical Field

[0001] The present invention relates to the field of medical equipment, in particular to medical monitoring equipment, and more specifically to an arteriovenous fistula visualization monitoring method and a wearable monitoring device. Background Art

[0002] Vascular access is the "lifeline" of patients with chronic renal failure who are on maintenance hemodialysis. The guidelines of the Kidney Disease Improving Global Outcomes Organization (KDIGO) clearly identify autologous arteriovenous fistula as the "first choice" for patients with maintenance hemodialysis. Arteriovenous fistula formation is a vascular anastomosis surgery, which usually involves anastomosing the artery near the wrist of the forearm with the adjacent vein, so that the vein is filled with arterial blood and forms an "arterialized vein" after a period of time.

[0003] The blood flow in the arteriovenous fistula should be neither too high nor too low. Generally speaking, the minimum blood flow requirement of the arteriovenous fistula should not be lower than 400-500ml / min to ensure the flow rate requirement of hemodialysis; at the same time, the maximum blood flow of the arteriovenous fistula should not exceed 2000ml / min, otherwise it will increase the heart load and cause heart failure.

[0004] Therefore, establishing and maintaining a good and stable blood flow in the arteriovenous fistula is the key to ensuring the smooth progress of maintenance hemodialysis. Statistics show that up to 15-24% of maintenance hemodialysis patients have experienced vascular access stenosis and embolism. The resulting failure of the arteriovenous fistula is a major problem that plagues technicians in this field.

[0005] Therefore, timely monitoring of arteriovenous fistula blood flow and effective evaluation of arteriovenous fistula function, so as to provide timely warnings in the early stages of vascular access problems, is a research focus for those skilled in the art, and also a technical difficulty that they need to overcome.

[0006] At present, in the existing technology, the existing monitoring equipment and monitoring methods mainly rely on digital subtraction angiography. Digital subtraction angiography is recognized as the "gold standard" for vascular examination, but this technology requires arterial puncture and has limitations in clinical use.

[0007] The Kidney Disease Outcome Quality Guidelines (K / DOQI) recommends using ultrasound dilution, conductivity dilution, or vascular Doppler ultrasound to measure the blood flow of arteriovenous fistulas every month, but these examinations require the use of relatively large medical equipment and are not widely and regularly used in domestic medical institutions to maintain arteriovenous fistulas in dialysis patients. Some other indirect monitoring methods, such as laser vibrometers for measuring the amplitude of fistula fluctuation velocity and detectors for measuring fistula murmur intensity, also involve the problem of large measuring equipment. At the same time, because these devices are large and the monitoring methods are relatively complex, full-time monitoring is not possible. Patients are required to monitor regularly, such as once a month according to the requirements of the guidelines. This monitoring method cannot achieve timely monitoring and effective prevention of possible embolism or stenosis of the arteriovenous fistula.

[0008] Wearable medical devices are an important part of the wearable research field, such as traditional hearing aids, cardiac devices and insulin pumps, as well as new types of devices such as continuous glucose monitors (CGM) for diabetics, new electronic skin patches and emerging wearable medical devices. Summary of the invention

[0009] The technical problem to be solved by the present invention is how to monitor the arteriovenous fistula blood flow of maintenance hemodialysis recipients at all times with high accuracy, thereby providing reliable data to ensure stable and good blood flow of the arteriovenous fistula, timely detect vascular stenosis or embolism, and avoid arteriovenous fistula failure.

[0010] In order to solve the above technical problems, the present invention discloses an arteriovenous fistula monitoring method, comprising the following steps:

[0011] Part 1: Establish standard data for comparison, including the following steps:

[0012] S1: The measuring light source emits measuring light in the area where the arteriovenous fistula is located;

[0013] S2: The measurement light emitted in step S1 passes through the skin and, after being absorbed and attenuated, is reflected to the photosensor, and the photosensor captures the light signal;

[0014] S3: converting the optical signal in step S2 into an electrical signal;

[0015] S4: Processing the electrical signal to obtain waveform graphic data and characteristic numerical signal data respectively;

[0016] S5: storing the waveform data and characteristic numerical signal data within a certain period of time after the arteriovenous fistula is successfully constructed in a memory as standard data for subsequent comparison;

[0017] Part II: Real-time monitoring of arteriovenous fistula blood flow, including the following steps:

[0018] K1: The measuring light source emits measuring light in the area where the arteriovenous fistula is located;

[0019] K2: The measurement light emitted in step K1 passes through the skin and, after being absorbed and attenuated, is reflected to the photosensor, and the photosensor captures the light signal;

[0020] K3: converting the optical signal in step K2 into an electrical signal;

[0021] K4: Process the electrical signal to obtain waveform graphic data and characteristic numerical signal data;

[0022] K5: comparing the waveform graphic data and characteristic numerical signal data obtained by real-time monitoring with the waveform graphic data and characteristic numerical signal data stored in the memory as standard data;

[0023] K6: If the comparison result satisfies both of the following conditions, it is considered abnormal; otherwise, it is considered normal.

[0024] a. The waveform image data is significantly different by more than the preset amount;

[0025] b. The characteristic numerical signal data value fluctuates greater than the threshold.

[0026] Preferably, the measuring light is light emitted by a light emitting diode, and more preferably, the measuring light emitted by the measuring light source is green light.

[0027] As a preferred technical solution, the photosensor is a photodiode.

[0028] Further preferably, processing the electrical signal to obtain waveform graphic data specifically refers to: converting the intensity of the electrical signal into an amplitude signal, presenting the strength of the amplitude signal at different corresponding time points, and plotting the change of the amplitude signal over time.

[0029] At the same time, as a preference, processing the electrical signal to obtain characteristic numerical signal data refers to: the intensity variation law of the amplitude in the waveform graphic data, and the variation law of the area under the curve of the waveform per unit time.

[0030] Furthermore, in step K6, the waveform image data referred to as being significantly different refers to: the waveform graphic data measured in real time is compared with the waveform graphic data in the memory as standard data, if the intensity change pattern of the waveform amplitude and / or the change pattern of the area under the curve of the waveform per unit time shows a numerical change of 25%.

[0031] More preferably, the preset amount mentioned here is 10 minutes. When the waveform image data is significantly different for 10 minutes, it is considered that the judgment condition a in step K6 is satisfied.

[0032] Preferably, the present invention also discloses that the comparison threshold of the characteristic numerical signal data value is 25%, that is, if the monitored characteristic numerical signal data value is higher than the characteristic numerical signal standard data value by 25%, or lower than the characteristic numerical signal standard data value by 25%, it is considered that the judgment condition b in step K6 is met.

[0033] Further preferably, data remote transmission is also included, and the waveform image data, characteristic numerical signal data and comparison results are transmitted to a specific receiver through data transmission technology.

[0034] Further preferably, data display is also included, and the waveform image data, characteristic numerical signal data and comparison results are displayed on a display.

[0035] In a preferred technical solution, an alarm is also included, and when it is determined that an abnormality occurs in step K6, an alarm is issued. Further preferably, the alarm is in the form of a light alarm and / or an acoustic alarm.

[0036] In a preferred technical solution, the measuring light sources are two or more. Thus, a series of data at different positions are formed at a time point. More preferably, the measuring light sources are arranged in pairs. Further preferably, the measuring light sources are arranged along the wrist where the arteriovenous fistula is located, and they can be arranged in pairs or not.

[0037] When the measuring light sources are set in pairs at the wrist where the arteriovenous fistula is located, the data from the two measuring light sources set in pairs are integrated into one data. That is, when the two measuring light sources located at opposite positions of the cuff axis are used as paired light sources and the measured light signals are converted into electrical signals and then form graphic signals, the amplitude signals at the same time point are superimposed on each other and integrated into a group of graphic signals.

[0038] Preferably, when the data is a series of multi-point data, weight sorting is first performed, and the data is weighted in a manner that the weaker the light signal, the greater the weight. The weaker the light signal reflected by the measurement light source, the stronger the blood flow signal at the measured site, the more thoroughly the light signal is absorbed, and accordingly, the closer the position relationship between the measurement point and the arteriovenous fistula is, and the greater the weight in the signal measurement.

[0039] At the same time, the present invention also discloses a wearable monitoring device suitable for the above-mentioned arteriovenous fistula monitoring method, including a monitoring component, a controller, and a memory, wherein the monitoring component is composed of a light-emitting diode and a photosensitive photodiode, the photosensitive photodiode is connected to the memory and the controller respectively, the memory is connected to the controller, the monitoring component, the controller, and the memory are all fixed on a wearable base, and the monitoring component is fixed on the side of the wearable base close to the skin.

[0040] More preferably, a communication device is also included, and the communication device is connected to the controller. Preferably, the communication device is Bluetooth.

[0041] More preferably, an alarm device is further included, and the alarm device is connected to the controller. Further preferably, the alarm device includes a sounding device and / or a light-emitting device. Further preferably, the sounding device is a buzzer, and the light-emitting device is an alarm light.

[0042] The controller mentioned here is preferably a CPU controller.

[0043] Further, it is particularly preferred that the wearable substrate is a sleeve, and the monitoring component is fixed on the inner side of the sleeve. In a preferred technical solution, the sleeve is a hypoallergenic breathable elastic sleeve. More preferably, the monitoring component is embedded in the arteriovenous sleeve. Preferably, the thickness of the sleeve is 5 mm or more. Particularly preferably, it is 5 mm.

[0044] It is further preferred that there are two or more monitoring components, which are fixedly arranged in a ring shape on the inner side of the arteriovenous cuff.

[0045] More preferably, the monitoring components are arranged in pairs in a ring shape and fixed inside the cuff, and the two paired monitoring components are respectively arranged at two end points of the diameter.

[0046] The technical solution disclosed in the present invention has the following beneficial effects:

[0047] First, the monitoring device disclosed in the present invention is a wearable monitoring device, which uses the sleeve that dialysis patients can use daily as the wearable base of the monitoring device itself, and has the advantages of being beautiful and small in size. At the same time, because it is wearable, it can achieve real-time monitoring. At the same time, the gradual change law of the pattern waveform collected by the smartphone can also provide useful information for the medical physiological observation of arteriovenous fistula.

[0048] Secondly, the present invention takes into account the personalized changes in arteriovenous fistula blood flow of different users. After the dialysis patient has used it for a period of time, a personalized blood flow waveform in the arteriovenous fistula is formed for a specific user. At the same time, the standard model data is continuously updated according to the blood flow changes of the patient during use, thereby realizing personalized monitoring and treatment and avoiding invalid alarms as much as possible.

[0049] Thirdly, since the components of the monitoring device are arranged in a ring-shaped distributed manner, the user does not need to consider the direction and angle of the cuff when wearing it. At the same time, since the data of multiple monitoring components arranged in a ring are comprehensively considered and weighted calculations are performed to obtain the final comprehensive signal, the monitoring signal is stable and will not cause data abnormalities due to wearing or movement.

[0050] Finally, the patented sound and light alarm module of the present invention is placed on the outer surface of the cuff, and once there is a significant difference between the collected blood flow information and the pattern waveform memorized by the device or smartphone, an alarm can be automatically issued. The combined sound and light stimulation can immediately remind the user of possible problems with the arteriovenous fistula, improving the alarm efficiency of the monitoring device.

[0051] In summary, the wearable monitoring device and the corresponding arteriovenous fistula visualization monitoring method disclosed in the present invention can measure the blood flow of the arteriovenous fistula in real time, and realize real-time monitoring of the fistula blood flow. At the same time, the monitoring results are transmitted to an external device, such as a smart phone, via Bluetooth or other wireless communication means, so as to realize visualization of data monitoring and recording. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic diagram of a wearable monitoring device;

[0053] Figure 2 Schematic diagram of the arrangement of monitoring components in a wearable monitoring device. DETAILED DESCRIPTION

[0054] In order to better understand the present invention, the present invention is further described below in conjunction with specific embodiments.

[0055] like Figure 1 and Figure 2 The wearable monitoring device shown in the figure includes a monitoring component 1, a controller 2, and a memory 3, wherein the monitoring component is composed of a light-emitting diode and a photosensitive photodiode, the photosensitive photodiode is connected to the memory 3 and the controller 2 respectively, the memory 3 is connected to the controller 2, and the monitoring component 1, the controller 2, and the memory 3 are all fixed on a wearable substrate. In this embodiment, we see that the wearable substrate here is a sleeve 4, as shown in FIG. Figure 2 As shown in , the sleeve preferably has a certain thickness, which is preferably 5 mm in this embodiment, and the monitoring component 1 is fixed to the side of the wearable base close to the skin.

[0056] Further preferably, in this embodiment, a communication device 5 is also included, and the communication device 5 is connected to the controller 2. Preferably, the communication device is Bluetooth.

[0057] More preferably, an alarm device 6 is also included, and the alarm device 6 is connected to the controller 2. Further preferably, the alarm device includes a sound device and / or a light device. In this embodiment, the alarm device preferably includes both a sound device and a light device. The sound device is a buzzer 601, and the light device is an alarm light 602.

[0058] In this embodiment, the controller is a CPU controller.

[0059] Combination Figure 1 and Figure 2 We can see that in this embodiment, we further prefer that there are two or more monitoring components, and they are arranged in a ring shape and fixed inside the arteriovenous cuff. In this embodiment, we design six monitoring components, each of which includes a light-emitting diode and a photosensitive diode. The six monitoring components are marked as A, B, C, D, E, and F respectively.

[0060] More preferably, the monitoring components are arranged in pairs in a ring shape and fixed inside the cuff, and the two paired monitoring components are respectively arranged at two end points of the diameter.

[0061] like Figure 2 As shown in , in this embodiment, the six monitoring components can be divided into three pairs, monitoring components A and D are a pair, monitoring components B and E are a pair, and monitoring components C and F are a pair.

[0062] refer to Figure 1 and Figure 2 ,The working principle of the wearable monitoring device and the ,implementation of visual monitoring are further explained below.

[0063] In this embodiment, the arteriovenous fistula monitoring method includes two parts. The first part is to establish standard data for comparison, and the second part is to monitor the blood flow of the arteriovenous fistula in real time and send out an alarm signal for abnormal blood flow signals.

[0064] After the patient completes the arteriovenous fistula surgery, the patient will be given a cuff for fixation. The aforementioned monitoring device uses the cuff as a wearable base to contact the patient's arteriovenous fistula arm. Figure 2 The monitoring component fixed on the inner surface of the sleeve shown in the figure is attached to the skin surface of the user's forearm in a ring shape. Since the light signal emitted by the light emitting diode in the monitoring device is absorbed to different degrees at different locations due to different blood flow, the light signal reflected back by the photosensitive diode with different strengths can reflect the blood flow at that location.

[0065] When the user puts on the cuff,

[0066] S1: The measuring light source emits measuring light in the area where the arteriovenous fistula is located; for example, in this embodiment, the preferred measuring light source is a light emitting diode that emits a green light signal;

[0067] S2: The measurement light emitted in step S1 passes through the skin, and after being absorbed and attenuated, is reflected to the photosensor, and the photosensor captures the light signal; for example, in this embodiment, the green light signal is emitted by the light-emitting diodes in the six monitoring components of AF, and is respectively absorbed by the forearm where the skin is located, forming an emitted red light signal, which is collected by the photosensitive diode and transmitted to the controller;

[0068] S3: converting the optical signal in step S2 into an electrical signal;

[0069] S4: Processing the electrical signal to obtain waveform graphic data and characteristic numerical signal data respectively;

[0070] For example, in this embodiment, the controller can complete the conversion of optical signals and electrical signals; and further transmit the signal to the memory;

[0071] S5: storing the waveform data and characteristic numerical signal data within a certain period of time after the arteriovenous fistula is successfully constructed in a memory as standard data for subsequent comparison;

[0072] Through the above process, standard data for comparison can be constructed. Generally, we use 72 hours of waveform data and characteristic numerical signal data as the basis for comparison.

[0073] It should be noted that at the beginning of use, a database based on the user's 72-hour waveform data and characteristic numerical signal data is first established. As monitoring continues, new data constantly replaces the original data in the database, and the data used for comparison is always the data within 72 hours of the nearest comparison time point.

[0074] This can form a user-specific fistula blood flow model, which can be continuously updated as the user's personalized changes occur, achieving personalized monitoring and effectively avoiding invalid alarms caused by standard stereotypes.

[0075] Next, we will explain the real-time monitoring of arteriovenous fistula blood flow, which includes the following steps:

[0076] K1: The measuring light source emits measuring light in the area where the arteriovenous fistula is located;

[0077] K2: The measurement light emitted in step K1 passes through the skin and, after being absorbed and attenuated, is reflected to the photosensor, and the photosensor captures the light signal;

[0078] K3: converting the optical signal in step K2 into an electrical signal;

[0079] K4: Process the electrical signal to obtain waveform graphic data and characteristic numerical signal data;

[0080] The acquisition of real-time data is similar to the acquisition of the aforementioned standard data. In this embodiment, the measuring light source is a green light signal emitted by a light-emitting diode; the green light signal is emitted by the light-emitting diodes in the six monitoring components of AF, and is absorbed by the forearms where the skin is located, forming an emitted red light signal, which is collected by the photosensitive diode and transmitted to the controller.

[0081] After the controller obtains the waveform data and characteristic numerical signal data monitored in real time, it further retrieves the stored standard data for comparison from the memory; and

[0082] K5: comparing the waveform graphic data and characteristic numerical signal data obtained by real-time monitoring with the waveform graphic data and characteristic numerical signal data stored in the memory as standard data;

[0083] K6: If the comparison result satisfies both of the following conditions, it is considered abnormal; otherwise, it is considered normal.

[0084] a. The waveform image data is significantly different in an amount exceeding a preset amount; for example, in this embodiment, the waveform image data is significantly different means: the waveform graph data measured in real time is compared with the waveform graph in the memory as the standard data, if the intensity change rule of the waveform amplitude or / and the change rule of the area under the curve of the waveform per unit time show a 25% value change; in particular, the preset amount here is preferably 10 minutes, and when the aforementioned waveform image data is significantly different for 10 minutes, it is considered that the waveform image data is significantly different;

[0085] b. The characteristic numerical signal data value fluctuates greater than a threshold value; for example, in the present embodiment, the preferred comparison threshold value of the characteristic numerical signal data value is 25%, that is, if the monitored characteristic numerical signal data value is 25% higher than the characteristic numerical signal standard data value, or 25% lower than the characteristic numerical signal standard data value, it is considered that the characteristic numerical signal data value fluctuates greater than the threshold value.

[0086] It should be further explained that, in the present embodiment, processing the electrical signal to obtain waveform graphic data specifically refers to: converting the intensity of the electrical signal into an amplitude signal, presenting the strength of the amplitude signal at different time points, and plotting the change of the amplitude signal over time; processing the electrical signal to obtain characteristic numerical signal data refers to: the intensity change law of the amplitude in the waveform graphic data, and the change law of the area under the curve of the waveform per unit time.

[0087] In the present embodiment, it is further preferred to include remote data transmission, in which the waveform image data, characteristic numerical signal data and comparison results are transmitted to a specific receiver through data transmission technology. For example, the data can be remotely transmitted to a smart phone via Bluetooth, and then the data can be further transmitted to the port of the user's doctor or a specific system with the help of the communication function of the smart phone, thereby realizing the collection and storage of personalized data.

[0088] Further preferably, the waveform image data, characteristic numerical signal data and comparison results are displayed on a display. For example, the patient can directly see the real-time monitoring data and comparison results in a visual way on his or her smart phone, or the doctor can see them on a specific display interface.

[0089] Preferably, in this embodiment, an alarm is also included, and when it is determined that an abnormality occurs in step K6, an alarm is issued. Further preferably, the buzzer 601 emits an alarm sound, and the alarm light 602 flashes to emit a light alarm.

[0090] Next we combine Figure 2 The method of fitting multiple sets of data is specifically explained as shown in FIG.

[0091] like Figure 2 As shown in this embodiment, the six monitoring components can be divided into three pairs, monitoring components A and D are a pair, monitoring components B and E are a pair, and monitoring components C and F are a pair.

[0092] When the user puts on the sleeve, the monitoring components A, B, C, D, E, and F form a series of data at different positions at the same time point. The data at the two measuring light sources set in pairs are integrated into one data. That is, when the two measuring light sources located at the relative positions of the sleeve axis are used as paired light sources and the measured light signals are converted into electrical signals to form graphic signals, the amplitude signals at the same time point are superimposed on each other and integrated into a group of graphic signals.

[0093] In this way, three groups of signals are formed, namely data one from monitoring components A and D, data two from monitoring components B and E, and data three from monitoring components C and F.

[0094] The three sets of data are first sorted by weight, and the data are arranged in a weighted manner in such a way that the weaker the light signal, the greater the weight. Since the blood flow near the arteriovenous fistula is large, the weaker the light signal reflected by the measurement light source, the stronger the blood flow signal at the measured site, and the more thoroughly the light signal is absorbed, which indicates that the measurement point is most closely related to the arteriovenous fistula. Therefore, it is given a greater weight when fitting the signal.

[0095] If the monitoring components are multiple monitoring components that are set asymmetrically, there is no need to superimpose the data. Instead, the data are weighted according to the signal strength. Similarly, the data are weighted in such a way that the weaker the optical signal, the greater the weight.

[0096] In this way, the focus can be focused on the arteriovenous fistula, and the blood flow change signal at the arteriovenous fistula can be amplified, while the blood flow changes in other forearm blood vessels can be reduced, thereby improving the accuracy and sensitivity of monitoring.

[0097] The above is a specific implementation of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A wearable monitoring device suitable for monitoring arteriovenous fistula, characterized in that: It includes a monitoring component, a controller, and a memory, wherein the monitoring component is composed of a light-emitting diode and a light-sensitive photodiode, the light-sensitive photodiode is connected to the memory and the controller respectively, the memory is connected to the controller, the monitoring component, the controller, and the memory are all fixed on a wearable base, and the monitoring component is fixed on the side of the wearable base close to the skin; The wearable base is a sleeve, and the monitoring component is fixed inside the sleeve; The monitoring components are greater than two and are fixedly arranged in a ring shape on the inner side of the cuff; The monitoring components are arranged in pairs in a ring shape and fixed inside the cuff, and the two monitoring components in a pair are respectively arranged at two end points of the diameter; the data of the two monitoring components arranged in a pair are integrated into one data.

2. The wearable monitoring device for monitoring arteriovenous fistula according to claim 1, characterized in that: A communication device is also included, and the communication device is connected to the controller.

3. The wearable monitoring device for monitoring arteriovenous fistula according to claim 2, characterized in that: The communication device is Bluetooth.

4. The wearable monitoring device for monitoring arteriovenous fistula according to claim 1, characterized in that: Also included is an alarm device, which is connected to the controller.

5. The wearable monitoring device for monitoring arteriovenous fistula according to claim 4, characterized in that: The alarm device includes a sound-generating device and / or a light-emitting device.

6. The wearable monitoring device for monitoring arteriovenous fistula according to claim 5, characterized in that: The sound-generating device is a buzzer, and the light-emitting device is an alarm light.

7. The wearable monitoring device for monitoring arteriovenous fistula according to claim 1, characterized in that: The controller is a CPU controller.

8. The wearable monitoring device for monitoring arteriovenous fistula according to claim 1, characterized in that: The sleeve is a hypoallergenic breathable elastic sleeve.

9. The wearable monitoring device for monitoring arteriovenous fistula according to claim 1, characterized in that: The monitoring component is embedded in the cuff.

10. The wearable monitoring device for monitoring arteriovenous fistula according to claim 1, characterized in that: The thickness of the sleeve is 5 mm or more.

11. The wearable monitoring device for monitoring arteriovenous fistula according to claim 9, characterized in that: The thickness of the sleeve is 5mm.

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