Pulse waveform baseline calibration device and method based on flexible pressure sensor

Abstract

The invention discloses a pulse waveform baseline calibration device and method based on a flexible pressure sensor, and the method comprises the steps: carrying out the collection of a pulse waveform signal based on the flexible pressure sensor, and uploading the collected data to a cloud platform; channel selection, data preprocessing, pulse wave trough point location traversal searching, reference period selection and reference period data comparison are carried out on collected pulse waveform data, baseline drift calibration is finally completed, baseline calibration data are generated, and the baseline calibration data are displayed on a cloud platform and a mobile terminal. According to the device and the method, the advantage that more pulse waveform detail features can be obtained through the high sensitivity of a novel sensor-flexible pressure sensor is utilized, and meanwhile the baseline drift defect that the head and the tail of the waveform fluctuate greatly due to unstable pressing force is effectively overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of pulse waveform baseline calibration, and more particularly to a device and method for pulse waveform baseline calibration based on a flexible pressure sensor. Background Art

[0002] Pulse diagnosis is one of the characteristic methods of TCM diagnosis and has important value in TCM syndrome differentiation and treatment. Pulse waveform is an important content and basis for the objectification of modern TCM pulse diagnosis. The objective data of pulse wave can provide data support for the classification of pulse waveform and provide objective indicators for TCM syndrome differentiation. The quality of pulse waveform acquisition and analysis technology determines the criteria for judgment. How to objectively, effectively and timely restore the real pulse has become a bottleneck in the modernization of pulse diagnosis research, and it is also a bottleneck restricting the modernization and intelligent development of TCM.

[0003] The piezoresistive pressure sensor of the traditional pulse instrument has low production cost and simple structure, but low sensitivity and accuracy. In addition to excellent electrical properties such as high accuracy, high sensitivity, and the ability to detect static force, the flexible pressure sensor is also bendable, wearable, portable, and can fit closely with the human body. The new pulse instrument based on flexible pressure sensor has better sensitivity and resolution, and can detect pulse fluctuations under different external pressures such as floating, medium, and sinking, and obtain more detailed features of the pulse wave.

[0004] However, due to its high sensitivity, the flexible pressure sensor made of this new material is easily affected by the external environment. In particular, when collecting pulse waves, the pulse monitor based on this type of sensor is also affected by the different pressures of different collectors on the subject, as well as the noise caused by the subject's breathing. These noises and interferences will cause baseline drift, which is mainly corrected by algorithms.

[0005] The traditional baseline drift correction algorithm mainly uses the least squares method to fit the trend term, and then subtracts the trend term from the original data to perform baseline trend correction. Its fitting effect is poor, detailed features are lost, and the hyperparameters of the fitting function need to be manually adjusted. Summary of the invention

[0006] The purpose of the present invention is to provide a device and method for pulse waveform baseline calibration based on a flexible pressure sensor to solve the problems of poor numerical stability and loss of waveform details after calibration in the prior art method. The device and method utilize the high sensitivity of a new sensor - a flexible pressure sensor to obtain more pulse waveform detail feature advantages, while effectively solving the baseline drift defect caused by unstable pressing force and excessive fluctuations in the waveform.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A pulse waveform baseline calibration method based on a flexible pressure sensor, comprising:

[0009] Collect pulse waveform signals based on flexible pressure sensors and upload the collected data to the cloud platform;

[0010] By selecting channels and preprocessing the collected pulse waveform data, traversing to find the trough points of the pulse wave, selecting the reference period and comparing the data with the reference period, the baseline drift calibration is finally completed, the baseline calibration data is generated, and displayed on the cloud platform and mobile terminal.

[0011] In some embodiments, pulse waveform signal collection is performed based on a flexible pressure sensor, including: a collector wears a pulse collection tooling based on a flexible pressure sensor, starts a pulse monitor, and collects pulse waveform signals; the flexible pressure sensors corresponding to the collector's index finger, middle finger, and ring finger should be close to the inch, guan, and chi pulse positions of the person being collected, and appropriate pressure is applied so that the beating of the pulse can cause obvious numerical changes in the flexible pressure sensor.

[0012] In some embodiments, a line graph is drawn for the pulse wave data uploaded to the cloud platform, and channel data with a relatively stable overall waveform and obvious periodic characteristics are selected as candidate data.

[0013] In some embodiments, the candidate data is downsampled to eliminate waveform aliasing.

[0014] In some embodiments, the down-sampled data is low-pass filtered to eliminate high-frequency noise; and the low-pass filtered data is smoothed to eliminate waveform glitches.

[0015] In some embodiments, for the smoothed data, a suitable window size is set according to the sampling rate and sampling time, as well as the heart rate range of a normal person, and all data points in the window are traversed to find the minimum value until the minimum value of all windows is found and recorded in the trough value list.

[0016] In some embodiments, in the trough value list, the smallest point is selected as the trough point of the reference period, and the period in which the smallest point is located is used as the reference period.

[0017] In some embodiments, the points in the trough value list are used as the dividing points of each cycle, the minimum trough value of each cycle except the reference cycle is numerically compared and calculated with the minimum point of the reference cycle, and the difference is recorded in the comparison list.

[0018] In some embodiments, all data except the reference period are subtracted period by period from the data corresponding to the period in the comparison list to generate new data, which are then concatenated with the reference period to obtain baseline-calibrated data.

[0019] This embodiment also provides a pulse waveform baseline calibration device based on a flexible pressure sensor, comprising:

[0020] Sampling tooling, used for flexible pressure sensor to collect pulse signals;

[0021] Signal acquisition processing and transmission module, used for processing and transmitting the collected original signals;

[0022] The mobile terminal is used to connect to the sensor to collect data and upload it to the cloud platform or to visualize the raw data collected by the cloud platform and the data after baseline calibration;

[0023] The cloud platform is used for data storage, distribution, display of raw data, processing, generation and display of baseline calibration data.

[0024] The device and method for pulse waveform baseline calibration based on a flexible pressure sensor provided in this application have beneficial effects including but not limited to:

[0025] A device and method for pulse waveform baseline calibration based on a flexible pressure sensor. Compared with traditional devices and methods, this device and method utilizes the high sensitivity of a new sensor - a flexible pressure sensor to obtain more pulse waveform detail characteristics, while effectively solving the baseline drift defect caused by unstable pressing force and excessive waveform fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart of the pulse waveform baseline calibration method based on a flexible pressure sensor disclosed in Example 1 of the present invention.

[0027] Figure 2 Alternative original data.

[0028] Figure 3 Preprocessed data.

[0029] Figure 4 Data generated after baseline calibration.

[0030] Figure 5 Flexible pressure sensor device tooling. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0032] The following will be combined Figure 1-5 It is worth noting that the following embodiments are only used to explain the present application and do not constitute a limitation on the present application.

[0033] Example

[0034] The present invention proposes a device and method for pulse waveform baseline calibration based on a flexible pressure sensor, so as to solve the problems of poor numerical stability and loss of waveform details after calibration in the prior art method.

[0035] The technical solution adopted by the present invention is to provide a baseline calibration method for pulse waveform periodicity based on a flexible pressure sensor, comprising:

[0036] The collector wears a flexible pressure sensor to collect the pulse wave data of the person being collected.

[0037] Specifically, the collector wears flexible pressure sensors on the index finger, middle finger and ring finger respectively. The collector finds the Cun, Guan and Chi pulse positions of the person being collected. The collector places the index finger, middle finger and ring finger on the Cun, Guan and Chi pulse positions of the person being collected. The collector applies appropriate pressure to the three channels of the index finger, middle finger and ring finger respectively, so that the beating of the pulse can cause obvious changes in the value of the flexible pressure sensor.

[0038] Pulse wave data upload: Upload the collected data based on the flexible pressure sensor to the cloud platform for data analysis and processing.

[0039] Select the data channel for data uploaded to the cloud platform.

[0040] Specifically, a line graph is drawn for each channel data uploaded to the cloud platform each time. Channel data with relatively stable pulse waveform and obvious periodic characteristics are found as candidate data for subsequent data preprocessing. Data preprocessing is performed on the selected high-quality data.

[0041] In some embodiments, downsampling is performed according to the sampling rate of the flexible pressure sensor and the actual waveform of the data, so that the pulse waveform does not look like a combination of multiple curves, but a single curve.

[0042] The pulse wave data after downsampling is low-pass filtered to eliminate high-frequency noise. The pulse wave data after low-pass filtering is smoothed to eliminate waveform glitches.

[0043] Retrieve the coordinates of the valley values ​​of the preprocessed waveform.

[0044] Specifically, according to the actual cycle of the waveform, the sampling rate and the sampling time, as well as the heart rate range of a normal person, a suitable window size is set. According to the set window size, all data points in the window are traversed, the minimum value in the window range is obtained, and the minimum value is recorded. The minimum value is the trough value.

[0045] Repeat the above steps to find the trough values ​​of all windows and record them in the trough value list.

[0046] In the trough value list, find the trough value with the smallest value, use this period as the base period, and compare the data period by period.

[0047] Find the minimum valley value, and use the cycle where the minimum valley value is located as the reference cycle. Divide the waveform into cycles according to the valley points found. Compare the data of each cycle. For all cycle data except the reference cycle, compare the data of each cycle with the reference cycle one by one. Compare the minimum valley point in each cycle with the minimum value of the reference cycle, and record the difference in the comparison list.

[0048] New waveform data is generated using the comparison results and original data.

[0049] Specifically, subtract the difference value recorded in the cycle from all the data in the original cycle to get the new calibrated waveform data. Since the reference cycle does not need to be calibrated, when the reference cycle is traversed, the data of the reference cycle can be directly spliced. Traverse all cycles until all cycles of calibration data are generated.

[0050] The present invention also provides a pulse waveform baseline calibration device based on a flexible pressure sensor, comprising:

[0051] For the sampling tooling, with reference to the area of ​​the fingertips of human fingers, the area of ​​the flexible pressure sensors of the three channels should be less than or equal to the fingertips of the index finger, middle finger, and ring finger of an adult.

[0052] Taking advantage of the bendable property of the flexible pressure sensor, the bending curvature of the flexible pressure sensor should be similar to that of a fingertip to achieve a close fit with the fingertip.

[0053] The signal acquisition, processing and transmission module processes the collected signals and transmits them to the cloud.

[0054] The sensor data collected from each channel is processed by an amplification circuit and a filtering circuit.

[0055] The processed data of each channel is transmitted wirelessly to the mobile terminal or cloud platform.

[0056] On the mobile side, you can connect to sensors to collect data and upload it to the cloud platform. You can also visualize the original data collected by the cloud platform and the data after baseline calibration.

[0057] The cloud platform is used for data storage, distribution, display of raw data, processing, generation and display of baseline calibration data.

[0058] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0059] Embodiment 1:

[0060] In this embodiment, a three-channel flexible sensor is used as a pulse wave data acquisition device to collect pulse wave signals, process, analyze and calibrate the pulse waveform as shown in the following process: Figure 1 shown.

[0061] Figure 1 The collector wears a flexible pressure sensor to collect pulse waves. The collector wears three-channel flexible pressure sensors on the index finger, middle finger, and ring finger to collect pulse wave data at the Cun, Guan, and Chi pulse positions of the person being collected.

[0062] Figure 1 The pulse waveform data collected by 101 is uploaded to the Pulse Cloud Platform for storage.

[0063] Figure 1 103 pulse data channel selection. Draw a line graph for each channel and select the channel data with relatively stable pulse wave and obvious periodic characteristics as candidate data. Figure 2 .

[0064] Figure 1104 pulse data preprocessing. Downsample the candidate data to a single waveform curve, not a combination of multiple waveforms. After downsampling, low-pass filter the data to remove noise with a frequency greater than 3Hz. Then smooth the data to eliminate waveform burrs. Figure 3 .

[0065] Figure 1 In step 105, the trough point of the pulse wave is retrieved. According to the sampling rate, sampling time, and the heart rate range of a normal person, an appropriate window size is set, and the minimum value of the data in the window is retrieved to find the trough point. The data between the trough points is a complete pulse wave cycle data. Repeat the above operation to find the trough values ​​of all windows and record them in the trough value list.

[0066] Figure 1 In step 106, a reference period is selected. The point with the minimum value in all the trough value lists is found, and the data between the point and the previous trough point is used as a reference period.

[0067] Figure 1 The data is compared with the reference period in 107. The minimum valley points of all waveform periods except the reference period are periodically compared with the minimum value of the reference period and recorded in the comparison list.

[0068] Figure 1 In step 108, baseline calibration data is generated. All waveform data except the reference period are subtracted one by one from the data of the corresponding period in the comparison list in the order of periods to generate new period data, and then the reference period data is spliced. Finally, the data is the baseline calibration data. Figure 4 .

[0069] Embodiment: 2:

[0070] This embodiment discloses a pulse waveform device based on a flexible pressure sensor, comprising:

[0071] Figure 5 The softness of the flexible pressure sensor of the tooling should be similar to that of the fingertip, and the bendability of the flexible pressure sensor should be greater than the curvature of the fingertip surface, so that the sensor can fit tightly between the finger.

[0072] Figure 5 The signal acquisition and transmission module in 502. This module filters and amplifies the signal collected by the flexible pressure sensor, and transmits the signal to the mobile terminal or cloud platform through wireless transmission.

[0073] On the mobile side, the mobile phone is connected to the pulse monitor via wireless for data collection and result display.

[0074] Cloud platform, the data collected by the 502 module is uploaded to the cloud platform through the network for data storage. In addition, the platform can realize data visualization, preprocessing analysis and baseline calibration of pulse waveform.

[0075] The above embodiments propose a device and method for pulse waveform baseline calibration based on a flexible pressure sensor. The device and method utilize the high sensitivity of a new sensor - a flexible pressure sensor to obtain more pulse wave detail features, and propose a pulse waveform baseline calibration method to solve the problem of pulse waveform instability and waveform signal baseline drift caused by the high sensitivity of the flexible pressure sensor, which is susceptible to interference from the external environment, the heartbeat and breathing interference of the person being collected, and the different pressure intensity interference of the collector. Compared with the traditional baseline calibration method, this method can retain more waveform detail features and provide data support for the standardization and intelligent development of traditional Chinese medicine.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calibration of pulse waveform based on flexible pressure sensor, characterized in that include: Pulse waveform signal acquisition is carried out based on flexible pressure sensors, and the collected data is uploaded to the cloud platform; By selecting channels and preprocessing the collected pulse waveform data, traversing to find the trough points of the pulse wave, selecting the reference period and comparing the data with the reference period, the baseline drift calibration is finally completed, the baseline calibration data is generated, and displayed on the cloud platform and mobile terminal.

2. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 1, characterized in that, The pulse waveform signal is collected based on the flexible pressure sensor, including: the collector wears the pulse collection tooling based on the flexible pressure sensor, starts the pulse meter, and collects the pulse waveform signal; the flexible pressure sensors corresponding to the collector's index finger, middle finger, and ring finger should be close to the inch, guan, and chi pulse positions of the person being collected, and appropriate pressure is applied so that the beating of the pulse can cause obvious numerical changes in the flexible pressure sensor.

3. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 1, characterized in that, The pulse wave data uploaded to the cloud platform is plotted in a line chart, and the channel data with a relatively stable overall waveform and obvious periodic characteristics can be observed as alternative data.

4. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 3, characterized in that, Desample alternative data to eliminate waveform confusion.

5. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 4, characterized in that, Low-pass filtering of the downsampling process is performed to eliminate high-frequency noise; smoothing of the low-pass filtering data is eliminated to eliminate waveform glitches.

6. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 5, characterized in that, For the smoothed data, set the appropriate window size according to the sampling rate and sampling time, as well as the heart rate range of a normal person, traverse all data points in the window, and search for the minimum value until the minimum value of all windows is found and recorded in the trough value list.

7. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 6, characterized in that, In the trough value list, select the smallest point as the trough point of the reference period, and the period where it is located is used as the reference period.

8. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 7, characterized in that, The points in the trough value list are used as the dividing points of each period. The minimum trough value of each period except the benchmark period is numerically compared with the minimum point of the benchmark period, and the difference is recorded in the comparison list.

9. The baseline calibration method based on the flexible pressure sensor pulse waveform according to claim 7, characterized in that, Subtract all data except the reference period from the corresponding data in the comparison list period by period, one by one, to generate new data, which are then spliced ​​with the reference period to obtain the baseline-calibrated data.

10. A pulse waveform baseline calibration device based on a flexible pressure sensor, characterized in that, include Sampling tool parts for flexible pressure sensors to collect pulse signals; The signal acquisition processing and transmission module is used to process and transmit the collected original signals; Mobile terminal, used to connect sensors to collect data and upload it to the cloud platform or visualize the original data collected by the cloud platform and the data calibrated by the baseline; Cloud platform, used for data storage, issuance, display of original data, processing and generating baseline calibration data and displaying.

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