CN105997088A - Sleep breath detection device based on flexible force sensor - Google Patents

Abstract

A sleep breathing detection device based on a flexible force-sensitive sensor, comprising a flexible force-sensitive sensor array mattress, a host computer and a controller, the flexible force-sensitive sensor array mattress is composed of an upper buffer layer, a lower buffer layer and installed on and A flexible force-sensitive sensor array between the upper and lower buffer layers, the upper and lower buffer layers are made of flexible materials, and the flexible force-sensitive sensor array includes an upper electrode layer, a middle layer and a lower electrode from top to bottom layer, the upper electrode layer and the lower electrode layer are all flexible circuit boards with uniformly distributed parallel electrodes, the N parallel electrodes of the upper electrode layer and the M parallel electrodes of the lower electrode layer intersect vertically in space, and the parallel electrodes of the upper and lower electrode layers The electrodes are respectively connected with the controller; the controller includes a DC power supply, a data acquisition device, a data processing device and a data transmission device; the upper computer is connected with the data transmission device of the controller.

Description

A sleep breathing detection device based on a flexible force-sensitive sensor

technical field

The invention belongs to the mattress in the field of medical and home nursing intelligent monitoring, in particular to a large-area mattress used for detecting sleep breathing and heart rate.

Background technique

According to epidemiological statistics, sleep apnea syndrome (Sleep Apnea Syndrome, referred to as SAS) accounts for 2-4% of the world's total population, and the prevalence rate of men over 40 years old is as high as 9%. It is closely related to the cardiovascular system, not only inducing heart disease, but also a complication of heart failure. Clinically, detecting breathing during sleep is a necessary means for diagnosing and predicting sleep apnea syndrome and related cardiovascular diseases. However, the currently used detection methods are not only complicated to operate, expensive, but also highly restrictive to people, so they cannot be used for long-term monitoring. The most critical technology in the detection method is to seek a detection device that does not bind the patient. Therefore, it is always a standby in the field of medical equipment to seek a sleep breathing detection device that is easy to operate, low in cost, unconstrained to people, and suitable for long-term monitoring. It is a cutting-edge topic that has attracted much attention. It can not only maintain and improve the health of hundreds of millions of patients in the world, but also save huge medical expenses.

The most authoritative method for the diagnosis of sleep apnea syndrome is polysomnography (PSG). However, polysomnography needs to stick various electrodes on the body of the monitored person to measure brain waves, eye movements, ECG, and leg movements. It also needs to install electrodes to measure respiratory flow, chest and abdomen movements, sleeping positions, body movements, Various sensors of oxygen concentration are not only complicated to operate, expensive, but also highly restrictive. They are not suitable for long-term monitoring at home or in hospitals. Even in hospitals, the monitored people are often unable to sleep due to restraint, resulting in diagnostic errors. Therefore, developing a unique unrestrained sleep breathing detection device in the world has become a key problem to be solved urgently in the prior art.

Contents of the invention

Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a sleep respiration monitoring device based on a flexible force-sensitive sensor. The breathing detection device based on the flexible force-sensitive sensor can eliminate the psychological pressure and foreign body discomfort brought by contact monitoring to the patient; it can meet the precise detection of the patient's sleep breathing state and the real-time data feedback to the doctor, so that the patient can get more It is better to treat it in time. It also laid a technical foundation for the development of medical breathing detection devices and home sleep monitoring systems.

The technical solution of the present invention is to provide a sleep breathing detection device based on a flexible force-sensitive sensor, which is characterized in that the detection device includes a flexible force-sensitive sensor array mattress 3, a host computer 4 and a controller 5, and the flexible force-sensitive sensor The sensitive sensor array mattress is composed of an upper buffer layer 31, a lower buffer layer 36, and a flexible force-sensitive sensor array installed between the upper and lower buffer layers. The upper and lower buffer layers are made of flexible materials. The force sensitive sensor array comprises an upper electrode layer 32, an intermediate layer 34 and a lower electrode layer 35 from top to bottom, the upper electrode layer and the lower electrode layer are all printed flexible circuit boards with uniformly distributed parallel electrodes 33, and the N of the upper electrode layer The parallel electrodes intersect vertically with the M parallel electrodes of the lower electrode layer, and the parallel electrodes of the upper and lower electrode layers are respectively connected to the controller;

Described controller comprises DC power supply 65 and data acquisition device 61, data processing device 62 and data transmission device 63, and the two poles of described DC power supply are respectively connected with the parallel electrode of upper electrode layer and the parallel electrode of lower electrode layer, and DC power supply It is also connected with the data processing device and the data transmission device and supplies power to it, the data acquisition device is respectively connected with the parallel electrodes of the upper electrode layer and the parallel electrodes of the lower electrode layer, and the data processing module is connected with the data acquisition module , the data transmission device is connected with the data acquisition device; the host computer is connected with the data transmission device of the controller.

The sleep breathing detection device based on a flexible force-sensitive sensor is characterized in that the data transmission device includes a USB module 631 and a Bluetooth module 632, and the digital signal matrix can be transmitted to the host computer in the form of a USB cable or a Bluetooth signal. .

The sleep breathing detection device based on a flexible force-sensitive sensor is characterized in that a fiber grating temperature sensor is also installed in the flexible force-sensitive sensor array mattress 3 . It is used to monitor the change and distribution of body temperature of sleepers.

The described sleep breathing detection device based on a flexible force sensitive sensor is characterized in that the data acquisition device is used to collect analog signals of voltage changes between the parallel electrodes of the upper and lower electrode layers, and the data processing device will collect the analog signals Convert it into an N×M digital signal matrix and transmit it to the host computer through the data transmission device. The digital signal matrix transmitted by the host computer is converted into a sleeping posture pressure image, and the sleeping posture pressure image is processed to extract sleep breathing signal data , the specific processing method of the digital signal matrix of the host computer comprises the following steps:

1) Transform the digital signal matrix transmitted from the controller into a sleeping posture pressure image

2) Extract the sleeping position pressure image in the chest area and the sleeping position pressure image in the abdominal area in the sleeping position pressure image,

2) Transform the sleeping position pressure image in the chest area and the sleeping position pressure image in the abdominal area into chest breathing time domain signal and abdominal breathing time domain signal respectively

3) Perform wavelet denoising on the chest respiration time-domain signal and abdominal respiration time-domain signal respectively to eliminate narrow-band noise in the signal,

4) Apply discrete wavelet transform (DWT) to the chest respiration time-domain signal and abdominal respiration time-domain signal processed in step 3) respectively, select the discrete wavelet type with high similarity to the respiration signal, and reconstruct based on the correlation coefficient of all details Chest respiration time-domain signal and abdominal respiration time-domain signal, and eliminate the baseline drift of the respiration signal caused by broadband noise;

5) Using Fast Fourier Transform (FFT) to process the chest respiration time-domain signal and abdominal respiration time-domain signal processed in step 4) respectively, and extract the chest respiration time-domain signal and abdominal respiration time-domain signal respectively The power spectrum of the chest respiration spectrum signal and abdominal respiration spectrum signal are obtained.

Compared with the prior art, the present invention has the beneficial effects of:

1) An unfettered flexible force-sensitive sensor is used as the medium for collecting breathing changes. The above-mentioned flexible force-sensitive sensor array mattress is not obtrusive, does not cause discomfort to the human body, and does not require any components to directly contact people. The thickness is relatively thin, and it can be laid flat on the bed like a bed sheet for sleep apnea monitoring. During the detection process, there are no constraints or special requirements for sleep apnea patients. Sleep apnea monitors can collect data only in a natural state, overcoming contact The long-term detection of the type sensor is easy to increase the psychological burden and discomfort of the sleep respiration monitor, and overcomes the shortcomings of the indirect contact type through detection of vibration or radar monitoring of respiration, low accuracy and inability to identify chest and abdomen movements.

2) The detection accuracy of respiration rate is high. Polysomnography (PSG) can accurately detect the breathing conditions of the chest and abdomen by attaching breathing belt sensors to the chest and abdomen of the human body, but the breathing movement of the chest and abdomen will have a large baseline drift. The extraction of the respiratory signal leads to low detection accuracy of the respiratory rate and the inability to make an accurate judgment on the phase relationship of the chest and abdomen. The design of the present invention adopts the unfettered flexible force-sensitive sensor, which will not have a great impact on the chest and abdomen, and the reference drift is correspondingly reduced. In the present invention, the respiratory signal processing system adopts wavelet noise reduction and wavelet variation trend to further eliminate the reference Drift, so that the detection accuracy error of respiration rate is 1-2 breaths/minute.

3) Easy to install and set up. The flexible force-sensitive sensor array mattress can be laid flat on the bed, and the receiving device and data transmission device are installed in the form of a quick interface, which facilitates the operation of the tester. The upper computer is quickly connected to the device through the USB interface or Bluetooth module, which does not affect the rest of the sleeper, and the upper computer can be an industrial computer, PC or mobile smart terminal, which can be used in hospitals, nursing homes and other institutions, and can also be used in homes. .

4) The signal processing method of the middle and upper computer of the detection device provided by the present invention is to detect the sleep breathing status of the sleep apnea without restraint, by converting the generated sleep posture pressure image into a time domain signal, and after wavelet denoising and off-line wavelet transform and fast Fourier transform. The narrow-band noise and reference drift in the original signal are eliminated, the respiratory signal is extracted, and the respiratory power spectrum is obtained, which realizes accurate data extraction of sleep breathing state and provides data support for professional medical diagnosis.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of a sleep breathing detection device based on a flexible force-sensitive sensor of the present invention.

2 is a schematic structural view of a flexible force-sensitive sensor array mattress of an embodiment of a sleep breathing detection device based on a flexible force-sensitive sensor of the present invention;

3 is a structural schematic diagram of a controller of an embodiment of a sleep breathing detection device based on a flexible force-sensitive sensor of the present invention;

Fig. 4 is the time-domain signal diagram of chest sleeping position obtained when adopting a kind of embodiment of the sleep breathing detection device based on flexible force sensitive sensor of the present invention to carry out sleep detection;

Fig. 5 is the signal diagram obtained after wavelet denoising processing to chest sleep position time domain signal shown in Fig. 4;

Fig. 6 is the signal diagram obtained after applying the discrete wavelet transform (DWT) to the signal shown in Fig. 5,

FIG. 7 is a chest respiration spectrum signal diagram obtained after extracting the power spectrum from the signal shown in FIG. 6 .

Fig. 8 is a phase relationship diagram of chest and abdomen breathing under chest and abdomen breathing movement when adopting an embodiment of a sleep breathing detection device based on a flexible force sensitive sensor of the present invention, (a) is the chest and abdomen in a normal breathing state Respiratory spectrum signal diagram; (b) is the chest and abdomen respiratory spectrum signal diagram in apnea state.

In the figure, 1. the subject to be tested, 3. the flexible force-sensitive sensor array mattress, 4. the upper computer, 5. the controller, 6. the mattress; 31. the upper buffer layer, 32. the upper electrode layer, 33. the electrodes, 34. Middle layer, 35. Lower electrode layer, 36 Lower buffer layer, 37. Wires; 64. DC power supply, 61. Data acquisition device, 62. Data processing device, 63. Data transmission device, 631. USB module, 632. Bluetooth module.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The sleep breathing detection device (hereinafter referred to as the detection device) based on the flexible force-sensitive sensor provided by the present invention is characterized in that the detection device includes a flexible force-sensitive sensor array mattress 3, a host computer 4 and a controller 5, and the flexible The force-sensitive sensor array mattress is composed of an upper buffer layer 31, a lower buffer layer 36, and a flexible force-sensitive sensor array installed between the upper and lower buffer layers. The upper and lower buffer layers are made of flexible materials. The flexible force sensitive sensor array comprises an upper electrode layer 32, an intermediate layer 34 and a lower electrode layer 35 from top to bottom, the upper electrode layer and the lower electrode layer are all printed flexible circuit boards with uniformly distributed parallel electrodes 33, and the N parallel electrodes vertically intersect with the M parallel electrodes of the lower electrode layer, and the parallel electrodes of the upper and lower electrode layers are respectively connected to the controller through wires 37;

Described controller comprises DC power supply 64 and data acquisition device 61, data processing device 62 and data transmission device 63, and the two poles of described DC power supply are respectively connected with the parallel electrode of upper electrode layer and the parallel electrode of lower electrode layer, and DC power supply It is also connected with the data processing device and the data transmission device and supplies power to it, the data acquisition device is respectively connected with the parallel electrodes of the upper electrode layer and the parallel electrodes of the lower electrode layer, and the data processing module is connected with the data acquisition module , the data transmission device is connected with the data acquisition device;

The host computer is connected with the data transmission device of the controller.

The data acquisition device is used to collect the analog signal of the voltage change between the parallel electrodes of the upper and lower electrode layers. The data processing device converts the collected analog signal into an N×M digital signal matrix and transmits it to the host computer through the data transmission device. The digital signal matrix transmitted by the host computer is converted into a sleeping posture pressure image, and the sleeping posture pressure image is processed to extract sleep breathing signal data.

Example

In this embodiment, N=M=64, and the signal collection frequency is 10 Hz. A fiber optic grating temperature sensor is also installed in the flexible force-sensitive sensor array mattress 3 to monitor the change and distribution of the sleeper's body temperature.

The data transmission device includes a USB module 631 and a Bluetooth module 632, which can transmit the digital signal matrix to the host computer by using a USB cable or a Bluetooth signal respectively.

The overall structural diagram of the detection device provided in this embodiment is shown in FIG. 1 , the structural diagram of the flexible force-sensitive sensor array mattress is shown in FIG. 2 , and the structural diagram of the controller is shown in FIG. 3 .

The specific processing method of the host computer to the digital signal matrix comprises the following steps

1) Transform the digital signal matrix transmitted from the controller into a sleeping posture pressure image

2) Extract the sleeping position pressure image in the chest area and the sleeping position pressure image in the abdominal area in the sleeping position pressure image,

2) Transform the sleeping position pressure image in the chest area and the sleeping position pressure image in the abdominal area into chest breathing time domain signal and abdominal breathing time domain signal respectively

3) Perform wavelet denoising on the chest respiration time-domain signal and abdominal respiration time-domain signal respectively to eliminate narrow-band noise in the signal,

4) Apply discrete wavelet transform (DWT) to the chest respiration time-domain signal and abdominal respiration time-domain signal processed in step 3) respectively, select the discrete wavelet type with high similarity to the respiration signal, and reconstruct based on the correlation coefficient of all details Chest respiration time-domain signal and abdominal respiration time-domain signal, and eliminate the baseline drift of the respiration signal caused by broadband noise;

5) Using Fast Fourier Transform (FFT) to process the chest respiration time-domain signal and abdominal respiration time-domain signal processed in step 4) respectively, and extract the chest respiration time-domain signal and abdominal respiration time-domain signal respectively The power spectrum of the chest respiration spectrum signal and abdominal respiration spectrum signal are obtained.

The experimental situation of using the detection device provided in this embodiment to detect the subject 1 is as follows

Lay the flexible force-sensitive sensor array mattress of the detection device on a commercially available nursing bed, and place an ordinary mattress 7 between the bed body of the nursing bed and the flexible force-sensitive sensor array mattress. The purpose of this experiment is to evaluate the effectiveness of extracting apnea signals in a general soft bed environment. During the experiment, subjects were allowed to choose their comfortable position, simulating apnea and maintaining their usual habit of lying down. According to the visible thoracoabdominal movement, the entire experimental process was recorded and recorded, and respiratory events were counted and marked in the video for identification. When the subject is in the supine position, breathing as usual, and does not make any major posture changes, the signal generated by the flexible force-sensitive sensor array is recorded, and the sampling rate is 10 Hz.

Process the sleeping posture pressure images detected by the subject, extract the sleeping posture pressure images in the abdominal region from the sleeping posture pressure images and convert them into chest breathing time domain signals, as shown in Figure 4, from which it can be seen that , the signal is fuzzy and complex, and is interfered by a large amount of noise, which affects the accuracy of respiratory rate extraction. It is necessary to extract useful signals. The narrow-band noise in the signal is noise centered at 60Hz (or 50Hz). The signal obtained after wavelet denoising is shown in Figure 5; the signal shown in Figure 5 is processed by discrete wavelet transform (DWT), and the discrete wavelet type with high similarity to the respiratory signal is selected. Based on the correlation coefficient of all details The reconstructed respiratory signal is shown in Figure 6, which eliminates the reference drift of the respiratory signal caused by the ECG signal and makes the waveform of the respiratory signal clearer; the signal shown in Figure 6 is transformed using Fast Fourier Transform (FFT) Carry out signal processing, extract the power spectrum of the chest breathing time domain signal, and obtain the chest breathing spectrum signal as shown in Figure 7. From Figure 7, it can be seen that the breathing frequency of the experimenter appears at 0.36Hz, and the breathing rate can be accurately judged About 22 times/min.

The spectrum signal of the chest and abdomen breathing of the tested subject is shown in Figure 8 (curve 0 is the chest breathing signal and curve 1 is the abdominal breathing signal), which can clearly reflect the tester's breathing intensity and breathing changes. Fig. 8 (a) is the thoracoabdominal respiration spectrum signal diagram under the normal breathing state, and Fig. 8 (b) is the thoracoabdominal respiration spectrum signal diagram during apnea simulation. From Fig. 8, it can be seen that breathing effort and The change of respiratory frequency is very prominent. Before apnea, the breathing is uniform, the respiratory frequency is small, and the breathing effort is small. However, the breathing frequency of the tested subjects after the simulated apnea becomes faster and the breathing effort is enhanced. This provides a basis for subsequent research on apnea. data support.

What is not mentioned in the present invention is applicable to the prior art. .

Claims (4)

1. A sleep breathing detection device based on a flexible force-sensitive sensor, characterized in that the detection device comprises a flexible force-sensitive sensor array mattress, a host computer and a controller, and the flexible force-sensitive sensor array mattress is buffered by the upper layer, a lower buffer layer, and a flexible force-sensitive sensor array installed between the upper and lower buffer layers, the upper and lower buffer layers are made of flexible materials, and the flexible force-sensitive sensor array includes from top to bottom The upper electrode layer, the middle layer and the lower electrode layer, the upper electrode layer and the lower electrode layer are flexible circuit boards with uniformly distributed parallel electrodes, and the N parallel electrodes of the upper electrode layer intersect vertically with the M parallel electrodes of the lower electrode layer. The parallel electrodes of the upper and lower electrode layers are respectively connected to the controller; The controller includes a DC power supply, a data acquisition device, a data processing device, and a data transmission device. The two poles of the DC power supply are respectively connected with the parallel electrodes of the upper electrode layer and the parallel electrodes of the lower electrode layer, and the DC power supply is also connected with the data processing device. The device is connected with the data transmission device and supplies power to it, the data acquisition device is respectively connected with the parallel electrodes of the upper electrode layer and the parallel electrodes of the lower electrode layer, the data processing module is connected with the data acquisition module, and the data The transmission device is connected with the data acquisition device; the host computer is connected with the data transmission device of the controller. 2. A sleep breathing detection device based on a flexible force-sensitive sensor as claimed in claim 1, wherein said data transmission device comprises a USB module and a Bluetooth module. 3. A kind of sleep breathing detection device based on flexible force-sensitive sensor as claimed in claim 1, it is characterized in that fiber grating temperature sensor is also installed in flexible force-sensitive sensor array mattress, for monitoring sleeper's body temperature Variation and distribution. 4. A sleep breathing detection device based on a flexible force-sensitive sensor according to any one of claims 1 to 4, wherein the data acquisition device is used to collect analog signals of voltage changes between the parallel electrodes of the upper and lower electrode layers , the data processing device converts the collected analog signal into an N×M digital signal matrix and transmits it to the host computer through the data transmission device, and converts the digital signal matrix transmitted by the host computer into a sleeping posture pressure image, and monitors the sleeping posture. Posture and pressure images are processed to extract sleep respiration signal data, and the specific processing method of the digital signal matrix by the host computer comprises the following steps: 1) Transform the digital signal matrix transmitted from the controller into a sleeping posture pressure image 2) Extract the sleeping position pressure image in the chest area and the sleeping position pressure image in the abdominal area in the sleeping position pressure image, 2) Transform the sleeping position pressure image in the chest area and the sleeping position pressure image in the abdominal area into chest breathing time domain signal and abdominal breathing time domain signal respectively 3) Perform wavelet denoising on the chest respiration time-domain signal and abdominal respiration time-domain signal respectively to eliminate narrow-band noise in the signal, 4) Apply discrete wavelet transform (DWT) to the chest respiration time-domain signal and abdominal respiration time-domain signal processed in step 3) respectively, select the discrete wavelet type with high similarity to the respiration signal, and reconstruct based on the correlation coefficient of all details Chest respiration time-domain signal and abdominal respiration time-domain signal, and eliminate the baseline drift of the respiration signal caused by broadband noise; 5) Using Fast Fourier Transform (FFT) to process the chest respiration time-domain signal and abdominal respiration time-domain signal processed in step 4) respectively, and extract the chest respiration time-domain signal and abdominal respiration time-domain signal respectively The power spectrum of the chest respiration spectrum signal and abdominal respiration spectrum signal are obtained.