CN104138259B - The chest breath signal acquisition method not affected by sleeping posture and system - Google Patents

Abstract

A method and system for collecting chest breathing signals not affected by sleeping positions, the method is: separately collecting the electrical impedance signal of the chest of the subject in the supine, left lying and right lying positions and the breathing flow rate measured by BIOPAC TSD117 signal; perform analog-to-digital conversion on the collected electrical impedance signal, and obtain the electrical impedance digital signal of the subject's chest when lying on the back, left side, and right side respectively; according to the obtained electrical impedance digital signal and respiratory flow rate signal, respectively extract A reference eigenvalue; the chest respiration signals collected by the subject in different sleep positions are calibrated according to the reference eigenvalue. The system includes: electrical impedance signal acquisition device and BIOPAC TSD117. The method of the present invention is simple and easy to operate, and the system has a simple structure and good anti-interference effect, and can quickly and accurately collect the chest breathing signal of the subject without being affected by the sleeping posture, thereby realizing the early diagnosis and treatment of certain lung diseases. detection.

Description

Chest respiration signal acquisition method and system not affected by sleeping posture

technical field

The invention relates to the technical field of medical monitoring, in particular to a method and system for collecting chest breathing signals that are not affected by sleep postures.

Background technique

At present, techniques such as forced dynamic spirometry, forced oscillation, and interrupter techniques are often used clinically to obtain mechanical parameters of the airway. The equipment required for these methods is not only bulky and difficult to move but also requires the patient's active and patient cooperation. Standard polysomnography can only be used in sleep laboratories, which greatly limits its popularization and application. Respiratory flow meter is the gold standard for measuring respiratory flow rate signal, but it is easy to cause insomnia or discomfort for patients because it needs to use nose clip or breathing mask to prevent air leakage. In addition, respiration measuring thermal element is also a popular tool to measure respiration signal, but it is still unreliable in quantitative measurement. Thoracic impedance plethysmography, a convenient respiratory monitoring technique, has been used since the middle of the last century. However, recent research has found that it has some drawbacks for monitoring sleep disturbances. Brouillette et al. reported some typical disturbances when using thoracic impedance plethysmography, such as cardiac-induced variability. In addition, Larsen et al. pointed out that small movements of the body can also greatly interfere with respiratory monitoring. Therefore, one of the problems in monitoring the respiratory condition is how to accurately measure the respiratory signal without causing discomfort to the patient.

Contents of the invention

The object of the present invention is to address the above-mentioned problems and deficiencies, and provide a method and system for collecting chest breathing signals that are simple and feasible in technology and accurate in measurement and are not affected by sleeping postures.

Technical scheme of the present invention is realized like this:

The chest respiration signal acquisition method not affected by sleep posture of the present invention is characterized in that it comprises the following steps:

S1. Collect the electrical impedance signal of the subject's chest and the respiratory flow rate signal measured by BIOPAC TSD117 in the supine, left and right lying positions;

S2. Perform analog-to-digital conversion on the collected electrical impedance signals of the subject's chest in the supine, left and right lying positions, and obtain the electrical impedance numbers of the subject's chest in the supine, left and right lying positions respectively. Signal;

S3. According to the obtained electrical impedance digital signal and respiratory flow rate signal of the subject's chest when lying on his back, lying on his left side and lying on his right side, respectively extract reference characteristic values;

S4. Calibrate the electrical impedance signals of the chest collected by the subject in different sleep positions according to the obtained reference characteristic values.

Wherein, the specific operation method of the above step S1 is as follows:

S11. Fix the excitation electrode and the positive electrode of the measuring electrode at the upper and lower ends of the intersection point between the left and right nipples and the left midaxillary line respectively Fix the negative pole of the excitation electrode and the measurement electrode;

S12. When the subject is in a supine position, clamp the nose with a nose clip, and then measure the respiratory flow rate signal of the subject in different sleep positions through BIOPAC TSD117, and input the excitation current to the subject through the excitation electrode at the same time;

S13. According to the excitation current and the measurement voltage, calculate the electrical impedance signal of the subject's chest in different sleep positions according to Ohm's law.

The specific operation method of the above step S3 is as follows:

S31. According to the obtained electrical impedance digital signal IP _DD and respiratory flow velocity signal PNT _DD of the subject's chest when lying on the back, the electrical impedance digital signal IP _LD and the respiratory velocity signal PNT _LD of the subject's chest when lying on the left side, and the right lying position The electrical impedance digital signal IP _RD and the respiratory flow rate signal PNT _RD of the subject's chest are filtered by a filter, and the mean value is zero, and then according to The breathing volume signals VPNT _DD , VPNT _LD , VPNT _RD under different sleep postures are calculated respectively; wherein, the variable T is the time interval;

S32. According to the electrical impedance digital signal IP _DD and respiratory volume signal VPNT _DD of the subject's chest when lying on the back, the electrical impedance digital signal IP _LD and the respiratory volume signal VPNT _LD of the subject's chest when lying on the left side, and the subject's chest when lying on the right side. The electrical impedance digital signal IP _RD and the respiratory volume signal VPNT _RD of the subject's chest are respectively subjected to linear regression analysis and recorded as: y ₁ =k ₁ x ₁ +b ₁ , y ₂ =k ₂ x ₂ +b ₂ , y ₃ = k ₃ x ₃ +b ₃ , then take k ₁ as the first reference characteristic value, k ₂ as the second reference characteristic value, and k ₃ as the third reference characteristic value; where, y is the respiratory volume signal, x is the electrical impedance number Signal, b is the parameter generated when doing linear regression.

In the above step S4, the average value is taken according to the above reference characteristic values k ₁ , k ₂ , k ₃ , which is k=( k ₁ + k ₂ + k ₃ )/3, and then k is used as the correction coefficient.

The chest respiratory signal acquisition system not affected by sleep posture according to the present invention is characterized in that it includes an electrical impedance signal acquisition device for acquiring the electrical impedance signal of the subject's chest and a device for detecting the subject's respiratory flow rate signal. BIOPAC TSD117, wherein the electrical impedance signal acquisition device includes a power supply module, a constant current source module, a multi-channel switch module, a data acquisition module, a signal processing module, an excitation electrode and a measurement electrode, and the constant current source module is used for the measurement electrode Provide current excitation, the multi-channel switch module is respectively connected with the excitation electrode, the measurement electrode, the constant current source module and the data acquisition module and is used to control the excitation current of the excitation electrode fixed at different positions on the chest of the subject and receive the measurement electrode Voltage signal and transmit the received voltage signal to the data acquisition module, the data acquisition module calculates the electrical impedance signal of the subject's chest according to the received voltage signal, and the signal processing module is connected with the data acquisition module for Perform analog-to-digital conversion on the electrical impedance signal transmitted by the data acquisition module and analyze and process the signal. Each module is powered.

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

Because the present invention utilizes bioelectrical impedance technology to measure the chest breathing signal, it is not only simple and easy to implement, but also has good anti-interference effect, can quantitatively and accurately collect measurement data, can effectively reduce the number of measuring instruments used, and is simple to operate, and can be fast and accurate Accurately collect the chest breathing signal of the subject without being affected by the sleeping position, and then realize the early detection of certain lung diseases.

The present invention will be further described below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a schematic structural diagram of an electrical impedance signal acquisition device in the present invention.

Fig. 2 is a schematic diagram of wearing excitation electrodes and measurement electrodes in the present invention.

detailed description

The chest respiration signal acquisition method not affected by sleep posture of the present invention comprises the following steps:

S1. Collect the electrical impedance signal of the subject's chest and the respiratory flow rate signal measured by BIOPAC TSD117 in the supine, left and right lying positions;

S2. Perform analog-to-digital conversion on the collected electrical impedance signals of the subject's chest in the supine, left and right lying positions, and obtain the electrical impedance numbers of the subject's chest in the supine, left and right lying positions respectively. Signal;

S3. According to the obtained electrical impedance digital signal and respiratory flow rate signal of the subject's chest when lying on his back, lying on his left side and lying on his right side, respectively extract reference characteristic values;

S4. Calibrate the chest electrical impedance signals (that is, chest breathing signals) collected by the subject in different sleep positions according to the obtained reference characteristic values.

During the specific implementation, a chest breathing signal acquisition system that is not affected by the sleeping posture is used to calibrate the chest breathing signal of the subject that is not affected by the sleeping posture. The electrical impedance signal of the lower chest is collected and the respiratory flow rate signal measured by BIOPAC TSD117, and the electrical impedance signal is converted into a digital signal and then analyzed and processed according to the obtained electrical impedance digital signal of the chest under different sleep positions. and breathing volume signals, extracting reference feature values, and calibrating the chest breathing signals collected by the subject in different sleeping positions according to the reference feature values.

In this embodiment, the specific operation method of the above step S1 is as follows:

S11. Fix the excitation electrode and the positive electrode of the measuring electrode at the upper and lower ends of the intersection point between the left and right nipples and the left midaxillary line respectively Fix the excitation electrode and the negative pole of the measurement electrode. Specifically, as shown in Figure 2, the negative electrode I- _of the excitation electrode can be fixed at the upper end of the intersection point between the left and right nipples and the right midaxillary line, and the positive electrode I ₊ of the excitation electrode can be fixed on the connection line between the left and right nipples and the right midaxillary line. The upper end of the intersection of the left midaxillary line; fix the negative electrode V _- of the measuring electrode at the lower end of the intersection of the line connecting the left and right nipples and the right midaxillary line, specifically, below the right excitation electrode I _- Fix the measurement electrode V- _; fix the positive pole of the measurement electrode V ₊ at the lower end of the intersection of the line connecting the left and right nipples and the left midaxillary line; specifically, it is close to the left excitation electrode I ₊ Fixing the measuring electrode V ₊ ;

S12. When the subject is in a supine position, clamp the nose with a nose clip, and then measure the respiratory flow rate signal of the subject in different sleep positions through BIOPAC TSD117, and input the excitation current to the subject through the excitation electrode at the same time;

S13. According to the excitation current and the measurement voltage, calculate the electrical impedance signal of the subject's chest in different sleep positions according to Ohm's law. Specifically, the voltage difference of the subject's chest is collected through the measuring electrodes, the voltage difference of the subject's chest is (V ₊ - V _- ), and the excitation current input to the subject is I, and according to the voltage difference between the excitation current and the left chest, the electrical impedance signal of the left chest is respectively calculated according to Ohm's law. Specifically, the electrical impedance signal of the chest of the subject is R=|(V ₊ - V _- )|/I, and |(V ₊ - V _- )| is the absolute value of the voltage difference of the chest, so as to ensure that the calculated The electrical impedance signal is positive. And in this embodiment, the specific operation method of the above step S3 is as follows:

S31. According to the obtained electrical impedance digital signal IP _DD and respiratory flow velocity signal PNT _DD of the subject's chest when lying on the back, the electrical impedance digital signal IP _LD and the respiratory velocity signal PNT _LD of the subject's chest when lying on the left side, and the right lying position The electrical impedance digital signal IP _RD and the respiratory flow rate signal PNT _RD of the subject's chest are filtered by a filter, and the mean value is zero, and then according to The breathing volume signals VPNT _DD , VPNT _LD , VPNT _RD under different sleep postures are calculated respectively; wherein, the variable T is the time interval;

S32. According to the electrical impedance digital signal IP _DD and respiratory volume signal VPNT _DD of the subject's chest when lying on the back, the electrical impedance digital signal IP _LD and the respiratory volume signal VPNT _LD of the subject's chest when lying on the left side, and the subject's chest when lying on the right side. The electrical impedance digital signal IP _RD and the respiratory volume signal VPNT _RD of the subject's chest are respectively subjected to linear regression analysis and recorded as: y ₁ =k ₁ x ₁ +b ₁ , y ₂ =k ₂ x ₂ +b ₂ , y ₃ = k ₃ x ₃ +b ₃ , then take k ₁ as the first reference characteristic value, k ₂ as the second reference characteristic value, and k ₃ as the third reference characteristic value; where, y is the respiratory volume signal, x is the electrical impedance number Signal, b is the parameter generated when doing linear regression. Moreover, in the above step S4, the average value is taken according to the reference feature values k ₁ , k ₂ , k ₃ , that is, k=( k ₁ + k ₂ + k ₃ )/3, and then k is used as the correction coefficient. That is to say, the present invention obtains the electrical impedance digital signal and the respiratory flow velocity signal of the subject's chest when lying on the back, the electrical impedance digital signal and the respiratory flow velocity signal of the subject's chest when lying on the left side, and the subject's breathing velocity signal when lying on the right side. After the electrical impedance digital signal of the chest and the respiratory flow rate signal, the first reference characteristic value, the second reference characteristic value and the third reference characteristic value are extracted, and then the first reference characteristic value, the second reference characteristic value and the third reference characteristic value are calculated. The mean value of the eigenvalues is used to calibrate the acquired chest breathing signal that is not affected by the sleeping posture.

The chest respiratory signal acquisition system not affected by sleep posture according to the present invention includes an electrical impedance signal acquisition device for acquiring the electrical impedance signal of the subject's chest and a BIOPACTSD117 for detecting the subject's respiratory flow rate signal, wherein The electrical impedance signal acquisition device includes a power supply module, a constant current source module, a multi-channel switch module, a data acquisition module, a signal processing module, an excitation electrode and a measurement electrode, and the constant current source module is used to provide current excitation for the measurement electrode, The multi-channel switch module is respectively connected with the excitation electrode, the measurement electrode, the constant current source module and the data acquisition module and is used to control the excitation current of the excitation electrode fixed at different positions on the chest of the subject and receive the voltage signal of the measurement electrode and The received voltage signal is transmitted to the data acquisition module, and the data acquisition module calculates the electrical impedance signal of the subject's chest according to the received voltage signal, and the signal processing module is connected with the data acquisition module to perform Perform analog-to-digital conversion on the transmitted electrical impedance signal and analyze and process the signal. The power supply module is electrically connected to the constant current source module, multi-channel switch module, data acquisition module and signal processing module to supply power to each module. . As shown in FIG. 1 , it is a schematic structural diagram of an electrical impedance signal acquisition device.

During specific implementation, the chest breathing signal acquisition method not affected by sleep posture provided by the present invention can adopt the chest breathing signal acquisition system not affected by sleep posture as shown in FIG. 1 to test the subjects. Wherein, the excitation electrodes are used to input excitation current to the chest, and the measurement electrodes are used to collect the voltage amplitude of the chest. The chest respiratory signal acquisition system not affected by sleep posture provided by the present invention utilizes bioelectrical impedance technology to collect the electrical impedance signal of the subject's chest in a supine position and the respiratory flow rate signal measured by BIOPAC TSD117, and to the described The electrical impedance signal of the subject's chest in the supine position is converted from analog to digital to obtain the digital signal of the electrical impedance of the chest in the supine position; the electrical impedance signal of the subject's chest in the left lying position and the respiratory flow rate measured by BIOPAC TSD117 are collected signal; the electrical impedance signal of the chest of the subject under the left lying position is analog-to-digital converted to obtain the electrical impedance digital signal of the chest when lying on the left side; the electrical impedance of the chest of the subject under the right lying position is collected signal and the respiratory flow rate signal measured by BIOPAC TSD117; the electrical impedance signal of the chest of the subject under the right lying position is analog-to-digital converted to obtain the electrical impedance digital signal of the chest when lying on the right side; according to the supine The electrical impedance digital signal and respiratory velocity signal of the chest when lying on the left side, the electrical impedance digital signal and the respiratory velocity signal of the chest when lying on the left side, and the electrical impedance digital signal and the respiratory velocity signal of the chest when lying on the right side, extract the reference characteristic value; according to the With reference to the eigenvalues, the chest breathing signals collected by the subject in different sleeping positions are calibrated. The method provided by the present invention is simple and easy to implement, has good anti-interference effect, can quantitatively and accurately collect measurement data, can effectively reduce the number of measuring instruments used, is simple to operate, and can quickly and accurately collect the subject’s body temperature without being affected by the sleeping posture. Chest breathing signal, thereby realizing the early detection of certain lung diseases.

The present invention is described by the embodiment, but does not constitute limitation to the present invention, with reference to the description of the present invention, other changes of the disclosed embodiment, if it is easy to imagine for those skilled in the art, such changes should belong to Within the scope defined by the claims of the present invention.

Claims (4)

1. a chest breathing signal acquisition method not affected by sleep posture, is characterized in that comprising the steps: S1. Collect the electrical impedance signal of the chest and the respiratory flow rate signal measured by BIOPACTSD117 in the supine, left and right lying positions of the subject; S2. Perform analog-to-digital conversion on the collected electrical impedance signals of the subject's chest in the supine, left and right lying positions, and obtain the electrical impedance numbers of the subject's chest in the supine, left and right lying positions respectively. Signal; S3. According to the obtained electrical impedance digital signal and respiratory flow rate signal of the subject's chest when lying on his back, lying on his left side and lying on his right side, respectively extract reference characteristic values; S4. Calibrate the electrical impedance signals of the chest collected by the subject in different sleep positions according to the obtained reference characteristic value; The specific operation method of the above step S3 is as follows: S31. According to the obtained electrical impedance digital signal IP _DD and respiratory flow velocity signal PNT _DD of the subject's chest when lying on the back, the electrical impedance digital signal IP _LD and the respiratory velocity signal PNT _LD of the subject's chest when lying on the left side, and the right lying position The electrical impedance digital signal IP _RD and the respiratory flow rate signal PNT _RD of the subject's chest are filtered by a filter, and the mean value is zero, and then according to The breathing volume signals VPNT _DD , VPNT _LD , VPNT _RD under different sleep postures are calculated respectively; wherein, the variable T is the time interval; S32. According to the electrical impedance digital signal IP _DD and respiratory volume signal VPNT _DD of the subject's chest when lying on the back, the electrical impedance digital signal IP _LD and the respiratory volume signal VPNT _LD of the subject's chest when lying on the left side, and the subject's chest when lying on the right side. The electrical impedance digital signal IP _RD and the respiratory volume signal VPNT _RD of the subject's chest are respectively subjected to linear regression analysis and recorded as: y ₁ =k ₁ x ₁ +b ₁ , y ₂ =k ₂ x ₂ +b ₂ , y ₃ = k ₃ x ₃ +b ₃ , then take k ₁ as the first reference characteristic value, k ₂ as the second reference characteristic value, and k ₃ as the third reference characteristic value; where, y is the respiratory volume signal, x is the electrical impedance number Signal, b is the parameter generated when doing linear regression. 2. according to the described chest respiration signal collection method that is not affected by sleep posture according to claim 1, it is characterized in that the specific operation method of above-mentioned step S1 is as follows: S11. Fix the excitation electrode and the positive electrode of the measuring electrode at the upper and lower ends of the intersection point between the left and right nipples and the left midaxillary line respectively Fix the negative pole of the excitation electrode and the measurement electrode; S12. When the subject is in a supine position, clamp the nose with a nose clip, and then measure the respiratory flow rate signal of the subject in different sleep positions through BIOPAC TSD117, and input the excitation current to the subject through the excitation electrode at the same time; S13. According to the excitation current and the measurement voltage, calculate the electrical impedance signal of the subject's chest in different sleep positions according to Ohm's law. 3. according to claim 1, the chest respiration signal acquisition method that is not affected by sleep posture is characterized in that in the above-mentioned step S4, according to the above-mentioned reference characteristic value k ₁ , k ₂ , k ₃ get the average value, which is k=( k ₁ + k ₂ + k ₃ )/3, and then use k as the correction factor. 4. A chest breathing signal acquisition system not affected by sleep posture, which is used in the chest breathing signal collection method not affected by sleep posture according to any one of the above claims, characterized in that it includes the method for collecting the subject The electrical impedance signal acquisition device of the electrical impedance signal of the chest and the BIOPAC TSD117 used to detect the respiratory flow rate signal of the subject, wherein the electrical impedance signal acquisition device includes a power module, a constant current source module, a multi-channel switch module, and a data acquisition module. module, a signal processing module, an excitation electrode and a measurement electrode, the constant current source module is used to provide current excitation for the measurement electrode, and the multi-channel switch module is respectively connected with the excitation electrode, the measurement electrode, the constant current source module and the data acquisition module And it is used to control the excitation current of the excitation electrodes fixed at different positions on the chest of the subject, receive the voltage signal of the measurement electrode and transmit the received voltage signal to the data acquisition module, and the data acquisition module calculates according to the received voltage signal The electrical impedance signal of the chest of the subject is output, and the signal processing module is connected with the data acquisition module to perform analog-to-digital conversion on the electrical impedance signal transmitted from the data acquisition module and analyze and process the signal. The power module is connected with the The constant current source module, the multi-channel switch module, the data acquisition module and the signal processing module are electrically connected to supply power to each module.