CN103976737B - A kind of pulmo respiratory impedance correlation analysis and system - Google Patents

Abstract

The invention relates to the field of medical monitoring, and more specifically relates to a correlation analysis method and system for left and right lung respiratory impedance. The method comprises collecting the electrical impedance signals of the left chest and the right chest of the subject; performing analog-to-digital conversion on the collected electrical impedance signals to obtain the electrical impedance digital signals of the left chest and the right chest; The reference characteristic value is extracted from the electrical impedance digital signal of the right chest and the right chest; the correlation between the left and right lung respiratory impedance of the subject is analyzed according to the reference characteristic value. The present invention extracts the reference characteristic value according to the electrical impedance digital signal of the left chest and the electrical impedance digital signal of the right chest, and analyzes the correlation of the respiratory impedance of the left and right lungs of the subject according to the reference characteristic value. The operation is simple and can Quantitatively and accurately collect measurement data, the collected signal has good anti-interference effect, and can quickly and accurately analyze the correlation between the left and right lungs, so as to quickly and accurately evaluate the breathing coordination of the left and right lungs of the subject.

Description

A method and system for analyzing the correlation between left and right lung respiratory impedance

technical field

The present invention relates to the field of medical monitoring, in particular to a method and system for analyzing the correlation between left and right lung respiratory impedance.

Background technique

Assessing the coordination of the left and right lungs can realize the monitoring of breathing during assisted surgery and postoperative rehabilitation. At present, spirometers, ventilators and pneumotachometers are commonly used in clinical practice to directly measure respiration, but these measurement methods often require the cooperation of patients and the operation of professionals, and the respiratory coordination of the left and right lungs cannot be known. Arterial blood gas analysis, recording of airway pressure-volume curves for lung mechanics, and pulmonary plethysmography are all used to track ventilation distribution and guide adjustment of ventilator parameters. However, these techniques only reflect the overall lung function, and local abnormalities may not be found. Although imaging techniques such as MRI and CT can provide good information on the distribution of lung heterogeneity, they lack dynamic features and bedside features. monitoring capacity and require intensive care. The general chest X-ray can show the distribution of the lungs, but it lacks specificity and causes damage to the human body due to radiation.

In addition, non-invasive, non-radioactive imaging techniques such as electrical impedance tomography (EIT) is a new monitoring technique that can visualize pleural gas volumes, and the use of electrical impedance changes can reveal regional lung ventilation imbalances, providing information about the heterogeneity of the lung. However, the image resolution of this monitoring technology is low, and more electrodes need to be used, which may easily cause discomfort to the patient, thereby affecting the monitoring effect.

Contents of the invention

In order to overcome at least one defect (deficiency) described in the above-mentioned prior art, the present invention provides a method for analyzing the correlation of respiratory impedance of the left and right lungs. Analysis can quickly and accurately analyze the correlation between the left and right lungs.

The invention also provides a correlation analysis system for left and right lung respiratory impedance.

In order to solve the problems of the technologies described above, the technical solution of the present invention is as follows:

A method for analyzing the correlation between left and right lung respiratory impedance, comprising:

collecting the electrical impedance signals of the subject's left chest and right chest;

Perform analog-to-digital conversion on the collected electrical impedance signals to obtain electrical impedance digital signals of the left chest and the right chest;

Extract reference feature values from the electrical impedance digital signals of the left chest and the right chest;

The correlation between the left and right lung respiratory impedance of the subject is analyzed according to the reference characteristic value.

As a preferred solution, the acquisition method of the electrical impedance signals of the left chest and the right chest is as follows:

Collect the excitation current input to the left and right chest of the subject;

Obtain the voltage amplitude of the left and right sides of the chest of the subject;

The electrical impedance signal of the left chest and the electrical impedance signal of the right chest were calculated respectively according to the excitation current and the voltage amplitude according to Ohm's law.

As a further preferred solution, the collected excitation current is an excitation current input through a pair of excitation electrodes fixed on the left chest side and the right chest side of the subject, wherein the pair of excitation electrodes includes a positive pole and a negative pole;

The voltage amplitude obtained from the subject's left chest is:

The voltage difference of the left chest obtained by collecting the voltage value of the first measuring electrode fixed between the left and right chest and the voltage value of the third measuring electrode located below the excitation electrode on the left side;

The voltage amplitude obtained from the subject's right chest is:

The voltage difference of the right chest obtained by collecting the voltage value of the second measuring electrode fixed between the left and right chest and the voltage value of the fourth measuring electrode located below the excitation electrode on the right side and making a difference.

As a further preferred solution, a pair of excitation electrodes is fixed at the two intersections formed by the horizontal line formed by the connection of the left and right nipples and the left and right midaxillary lines;

The first measuring electrode and the second measuring electrode are fixed at the upper and lower positions at the intersection of the horizontal line formed by connecting the left and right nipples and the midline of the manubrium.

As a preferred solution, the specific steps for extracting reference feature values from the electrical impedance digital signals of the left chest and the right chest are:

Filter the electrical impedance digital signals of the left chest and the right chest respectively;

Segment the electrical impedance digital signals of the left chest and the right chest after filtering according to time;

Calculate the absolute impedance integral value of the electrical impedance digital signal in each time period;

Perform median filtering on the electrical impedance digital signal in each time period and extract the maximum and minimum points in each time period, and use |maximum-minimum| as the resistance of each time period Anti-digital signal amplitude;

Calculate the correlation between the left chest impedance integral and the right chest impedance integral as CI, and use CI as the first reference characteristic value;

The correlation between the left chest impedance magnitude and the right chest impedance magnitude is calculated as CA, and CA is used as the second reference characteristic value.

As a further preferred solution, the specific steps for analyzing the correlation between the left and right lung respiratory impedance of the subject according to the reference characteristic value are:

Calculate mean correlation MC=(CI+CA)/2 according to the first reference eigenvalue CI and the second reference eigenvalue CA;

Compare the value of MC with the preset range threshold to judge whether the correlation between left and right lung respiratory impedance is good or bad.

A correlation analysis system for left and right lung respiratory impedance, comprising:

An electrical impedance signal acquisition module, configured to acquire electrical impedance signals of the subject's left chest and right chest;

The analog-to-digital conversion module is used to perform analog-to-digital conversion on the collected electrical impedance signal to obtain electrical impedance digital signals of the left chest and the right chest;

A reference feature value extraction module is used to extract a reference feature value from the electrical impedance digital signals of the left chest and the right chest;

The correlation analysis module is used to analyze the correlation between the left and right lung respiratory impedance of the subject according to the reference characteristic value.

As a preferred solution, the electrical impedance signal acquisition module includes:

The excitation current collection module is used to collect the excitation current input to the left and right sides of the chest of the subject;

The voltage amplitude acquisition module is used to acquire the voltage amplitude of the left and right sides of the chest of the subject;

The electrical impedance signal calculation module is used to calculate the electrical impedance signal of the left chest and the electrical impedance signal of the right chest according to Ohm's law according to the excitation current and the voltage amplitude.

As a further preferred solution, the collected excitation current is an excitation current input through a pair of excitation electrodes fixed on one side of the subject's left chest and one side of the right chest, wherein a pair of excitation electrodes includes a positive pole and a negative pole; preferably Ground, a pair of excitation electrodes are fixed at the two intersections formed by the parallel lines formed by the left and right nipples and the left and right midaxillary lines;

The voltage amplitude obtained from the subject's left chest is:

The voltage difference of the left chest obtained by collecting the voltage value of the first measuring electrode fixed between the left and right chest and the voltage value of the third measuring electrode located below the excitation electrode on the left side;

The voltage amplitude obtained from the subject's right chest is:

The voltage difference of the right chest obtained by collecting the voltage value of the second measuring electrode fixed between the left and right chest and the voltage value of the fourth measuring electrode located below the excitation electrode on the right side and making a difference.

Preferably, the first measuring electrode and the second measuring electrode are fixed at the upper and lower positions of the intersection of the parallel line formed by the left and right nipples and the midline of the manubrium.

As a preferred solution, the reference feature value extraction module includes:

A filtering module is used to filter the electrical impedance digital signals of the left chest and the right chest respectively;

The signal segmentation module is used to segment the electrical impedance digital signals of the left chest and the right chest after filtering according to time;

The impedance integral value calculation module is used to calculate the absolute value impedance integral value of the electrical impedance digital signal in each time period;

The amplitude calculation module is used to perform median filtering on the electrical impedance digital signal in each time period and extract the maximum value point and minimum value point in each time period, and the |maximum value-minimum value| As the magnitude of the electrical impedance digital signal for each time period;

The reference eigenvalue calculation module is used to calculate the correlation between the left chest impedance integral and the right chest impedance integral as CI, and take CI as the first reference eigenvalue, and calculate the left chest impedance amplitude and the right chest impedance The correlation of the impedance amplitude is CA, and CA is used as the second reference characteristic value;

Correlation analysis modules include:

Mean correlation calculation module, for calculating mean correlation MC=(CI+CA)/2 according to the first reference characteristic value CI and the second reference characteristic value CA;

The judging module is used to compare the value of MC with a preset range threshold to judge whether the correlation between left and right lung respiratory impedance is good or bad.

Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

(1) What the method of the present invention adopts is bioelectrical impedance technology, extracts the reference characteristic value according to the electrical impedance digital signal of the left chest and the electrical impedance digital signal of the right chest, according to the reference characteristic value to the subject's The analysis of the correlation between the left and right lung respiratory impedance is easy to operate, and the measurement data can be collected quantitatively and accurately. The breathing coordination of the left and right lungs of the test subject. (2) What the method of the present invention adopts is bioelectrical impedance technology, can obtain electrical impedance signal by collecting the measuring electrode that is fixed on the subject, the measuring process is convenient, and only need to use a pair of exciting electrodes and 4 measuring electrodes Fixed on the subject, compared with the EIT technology that requires the use of many measuring electrodes, the method of the present invention can reduce the discomfort of the subject and is suitable for long-term respiratory monitoring of the subject.

(3) The present invention extracts the correlation of the left chest impedance integral and the right chest impedance integral and the correlation of the left chest impedance amplitude and the right chest impedance amplitude as the reference characteristic value of the left and right lung respiratory impedance correlation, Combining the two reference parameters of impedance integral and amplitude, the correlation of left and right lung respiratory impedance can be obtained more accurately from multiple angles.

Description of drawings

FIG. 1 is a flow chart of a specific embodiment of a method for analyzing the correlation between left and right lung respiratory impedance in the present invention.

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

Fig. 3 is a structural diagram of a specific embodiment of a system for analyzing the correlation between left and right lung respiratory impedance in the present invention.

Detailed ways

The accompanying drawings are for illustrative purposes only and cannot be construed as limiting the patent;

In order to better illustrate this embodiment, some parts in the drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product;

For those skilled in the art, it is understandable that some well-known structures and descriptions thereof may be omitted in the drawings.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "left and right", "up and down", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. It is not intended to indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, the defined "first", "third", and "fourth" features may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral Ground connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary. It can be said that the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. 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.

Example 1

As shown in Figure 1, it is a flow chart of a specific embodiment of a method for analyzing the correlation of respiratory impedance of the left and right lungs in the present invention. The specific steps of a method for analyzing the correlation of respiratory impedance of the left and right lungs in this specific embodiment include:

A method for analyzing the correlation between left and right lung respiratory impedance, comprising:

Step S101: collecting electrical impedance signals of the subject's left chest and right chest;

Step S102: Perform analog-to-digital conversion on the collected electrical impedance signal to obtain electrical impedance digital signals of the left chest and the right chest;

Step S103: extracting reference feature values from the electrical impedance digital signals of the left chest and the right chest;

Step S104: Analyze the correlation between the left and right lung respiratory impedance of the subject according to the reference characteristic value.

In this specific embodiment, the method obtains the electrical impedance digital signals of the left chest and the right chest by collecting the electrical impedance signals of the left chest and the right chest of the subject and performing analog-to-digital conversion, and then The reference eigenvalues were extracted from the electrical impedance digital signal to analyze the correlation between left and right lung respiratory impedance. In this method, the bio-impedance technology is used to collect the electrical impedance signal of the subject for correlation analysis. The collection steps are simple and convenient. Based on the collected data, the correlation between the left and right lungs can be quickly and accurately analyzed. According to the correlation analysis results, the The breathing coordination of the left and right lungs of the subject, this method can continuously monitor the breathing of the subject, and can be used for medical staff to detect the subject's lung disease and assist in the monitoring of breathing during the operation and postoperative rehabilitation Treatment provides intermediate reference information.

In the specific implementation process, the electrical impedance signals of the left chest and the right chest in step S101 are generally obtained through the following acquisition methods:

Step S1011: collect the excitation current input to the left and right chests of the subject; generally, the collected excitation current is the excitation current input through a pair of excitation electrodes fixed on the left chest side and the right chest side of the subject, wherein a pair of excitation electrodes comprises a positive pole and a negative pole;

Step S1012: Obtain the voltage amplitudes of the left and right chests of the subject;

Generally, the acquisition of the voltage amplitude of the left chest of the subject is carried out by collecting the voltage value of the first measurement electrode fixed between the left and right chest and the voltage value of the third measurement electrode located below the excitation electrode on the left side The voltage difference of the left chest obtained by doing the difference;

The acquisition of the voltage amplitude of the subject's right chest is obtained by collecting the voltage value of the second measurement electrode fixed between the left and right chest and the voltage value of the fourth measurement electrode located below the excitation electrode on the right side. The resulting voltage difference across the right chest.

In the above steps, in order to obtain more accurate electrical impedance signals, further, the pair of excitation electrodes are fixed at the two intersections formed by the horizontal line formed by the connection of the left and right nipples and the left and right midaxillary lines; the first measuring electrode and the The second measuring electrode is fixed at two positions above and below the intersection of the horizontal line formed by the connection of the left and right nipples and the midline of the manubrium sternum. Specifically, refer to FIG. 2 , which is a schematic diagram of wearing the excitation electrodes and measurement electrodes in this specific embodiment.

As shown in Figure 2, the negative electrode I- of the excitation electrode can be fixed at the intersection of the horizontal line formed by the connection of the left and right nipples and the right midaxillary line, and the positive electrode I+ of the excitation electrode can be fixed at the intersection of the horizontal line formed by the connection of the left and right nipples and the left side. At the intersection point of the midaxillary line, the positions of the positive and negative poles of the excitation electrodes can be reversed, and the chest voltage signal received after the reverse becomes relatively worse, but the detection of the voltage signal is not affected; the first measuring electrode V1 is fixed on the left and right nipples to form Fix the second measuring electrode V2 at the lower end of the intersection between the parallel line formed by the left and right nipples and the midline of the manubrium and the midline of the manubrium; fix the third measuring electrode V3 on the left midaxillary line and At the intersection of the parallel lines formed by the left and right nipples, specifically, the third measurement electrode V3 is fixed below the left excitation electrode I+; the fourth measurement electrode V4 is fixed on the right midaxillary line and the left and right nipples. At the intersection of the formed parallel lines, specifically, the third measurement electrode V3 is fixed immediately below the right excitation electrode I-.

In this way, the voltage difference of the left chest of the subject is (V3-V1), and the voltage difference of the right chest is (V4-V2);

Step S1013: According to the excitation current and voltage amplitude, the electrical impedance signal of the left chest and the electrical impedance signal of the right chest are respectively calculated according to Ohm's law, that is, the voltage difference between the input excitation current and the left chest, the right chest According to the voltage difference of the chest, the electrical impedance signal of the left chest and the electrical impedance signal of the right chest are respectively calculated according to Ohm's law. Specifically, the preset input excitation current is I, then the electrical impedance signal of the left chest of the subject is RL=|(V3-V1)|/I, and the electrical impedance signal of the right chest is RR=|(V4- V2)|/I, where |(V3-V1)| is the absolute value of the voltage difference of the left chest, |(V4-V2)| is the absolute value of the voltage difference of the right chest, to ensure that the calculated The electrical impedance signal of is positive.

In the specific implementation process, an implementation manner of extracting the reference feature value from the electrical impedance digital signals of the left chest and the right chest in step S103 is as follows:

S1031: Filtering the electrical impedance digital signals of the left chest and the right chest respectively;

S1032: Segment the filtered electrical impedance digital signals of the left chest and the right chest according to time;

S1033: Calculate the absolute impedance integral value of the electrical impedance digital signal in each time period; specifically, according to the formula The obtained absolute impedance integral value, wherein, VIP represents the impedance integral signal, IP represents the electrical impedance digital signal, i represents the discrete point of collection, and T represents the subsection interval time;

S1034: Perform median filtering on the electrical impedance digital signal in each time period and extract the maximum value point and minimum value point in each time period, and use |maximum value-minimum value| as each time period The amplitude of the electrical impedance digital signal; wherein, the electrical impedance digital signal in each time period has several maximum and minimum value points, and generally the maximum value of the electrical impedance signal in each time period There is at most one difference between the maximum value point and the minimum value point, and the maximum value point and the minimum value point appear correspondingly. In the specific application, the maximum value point and the minimum value point are calculated in one-to-one correspondence, and then the extra maximum value point Value points or minimum value points are discarded, so as to obtain a series of amplitudes of the electrical impedance digital signal in each time period.

S1035: Calculate the correlation between the left chest impedance integral and the right chest impedance integral as CI, and use CI as the first reference characteristic value;

S1036: Calculate the correlation between the left chest impedance magnitude and the right chest impedance magnitude as CA, and use CA as the second reference characteristic value.

In the specific implementation process, the correlation CI between the left chest impedance integral and the right chest impedance integral and the correlation CA between the left chest impedance amplitude and the right chest impedance amplitude can be measured by the Pearson correlation coefficient, specifically The calculation method can directly use the existing function corrcoef in the matlab software to calculate the Pearson correlation coefficient. Of course, using the function corrcoef to obtain the Pearson correlation coefficient is only one of the implementation methods. On the premise that the purpose of the present invention can be realized, the Pearson correlation coefficient can also be obtained by using other functions.

In a specific application, the above implementation method is based on the electrical impedance digital signal of the left chest, and the mean value is zero after being filtered by a filter. Then, the total time of the electrical impedance digital signal of the left chest is preset as T, which is divided into several time periods as T(t) (t=1, 2, 3 . . . ). The electrical impedance value of the left chest at the current moment k is LZ(k) (k=1, 2, 3...), first calculate the absolute impedance integral value of each time period as LI(1), LI (2), LI(3), ···, LI(k); and then carry out the median value for each time period T(1), T(2), T(3), ···, T(k) Find several extreme points after filtering, and calculate |maximum value-minimum value| as the amplitudes respectively LA(1), LA(2), LA(3),...,LA(k);

For the processing of the digital electrical impedance signal of the right chest, the average value of the electrical impedance digital signal of the right chest is zero after being filtered by a filter. The total time of the electrical impedance digital signal of the right chest is preset as T, which is evenly divided into several time periods as T(t) (t=1, 2, 3 . . . ). The electrical impedance value of the right chest at the current moment k is RZ(k) (k=1, 2, 3...), first calculate the absolute impedance integral value of each time period as RI(1), RI (2), RI(3), ···, RI(k); and then carry out the median value for each time period T(1), T(2), T(3), ···, T(k) Find several extreme points after filtering, |maximum value-minimum value| as amplitudes are RA(1), RA(2), RA(3),..., RA(k), where RA (1), RA(2), RA(3), ..., RA(k) can be an amplitude value or a set of amplitude values;

Finally, the correlation between the left chest impedance integral and the right chest impedance integral is calculated as CI, and CI is used as the first reference characteristic value; the correlation between the left chest impedance amplitude and the right chest impedance amplitude is calculated as CA , and take CA as the second reference feature value.

In the specific implementation process, the specific step of analyzing the correlation of the left and right lung respiratory impedance of the subject according to the reference characteristic value in step S104 is to calculate the mean value correlation according to the first reference characteristic value CI and the second reference characteristic value CA Sex MC=(CI+CA)/2;

Compare the value of MC with the preset range threshold to judge whether the correlation between left and right lung respiratory impedance is good or bad.

The preset range threshold can be set according to prior knowledge. For example, if the mean correlation MC≥0.9, it indicates that the left and right lungs have a good correlation in respiratory impedance, and the left and right lungs breathe well; if 0.8≤MC<0.9, it indicates that the left and right lungs The correlation of respiratory impedance is good, and the respiration of the left and right lungs is more coordinated; if 0.6≤MC<0.8, it indicates that the correlation of the respiratory impedance of the left and right lungs is average, and the respiration of the left and right lungs is not coordinated; if the mean correlation MC<0.6, it indicates that the respiration of the left and right lungs The impedance correlation is poor, and the breathing of the left and right lungs is very uncoordinated.

Example 2

According to the left and right lung respiratory impedance correlation analysis method in Embodiment 1, the present invention also provides a left and right lung respiratory impedance correlation analysis system. The specific example of the left and right lung respiratory impedance correlation analysis system of the present invention will be described in detail below.

As shown in Figure 3, it is a structure diagram of a left and right lung respiratory impedance correlation analysis system in this specific embodiment 2, which specifically includes:

An electrical impedance signal acquisition module 201, configured to acquire electrical impedance signals of the subject's left chest and right chest;

An analog-to-digital conversion module 202, configured to perform analog-to-digital conversion on the collected electrical impedance signal to obtain electrical impedance digital signals of the left chest and the right chest;

A reference feature value extraction module 203, configured to extract a reference feature value from the electrical impedance digital signals of the left chest and the right chest;

The correlation analysis module 204 is configured to analyze the correlation between the left and right lung respiratory impedance of the subject according to the reference characteristic value.

In this specific embodiment, the system collects the electrical impedance signal of the subject's left chest and the electrical impedance signal of the right chest through the electrical impedance signal acquisition module 201, and uses the analog-to-digital conversion module 202 to perform analog-to-digital conversion to obtain the left The electrical impedance digital signals of the chest and the right chest, and then the reference feature value is extracted from the electrical impedance digital signal through the reference feature value extraction module 203 and combined with the correlation analysis module 204 to perform a correlation analysis of the respiratory impedance of the left and right lungs. In this system, bio-impedance technology is integrated to collect the electrical impedance signals of the subjects for correlation analysis. The system structure is simple, and the processing process is fast and convenient. The results of sex analysis can evaluate the breathing coordination of the left and right lungs of the subject. This system can continuously monitor the breathing of the subject, and can be used by medical staff to detect lung diseases of the subject and monitor breathing during the auxiliary operation. , Provide intermediate reference information for postoperative rehabilitation.

In a specific implementation process, the electrical impedance signal acquisition module 201 generally includes:

The excitation current collection module is used to collect the excitation current input to the left and right chests of the subject; generally, the collected excitation current is input through a pair of excitation electrodes fixed on the left chest side and the right chest side of the subject The excitation current, wherein a pair of excitation electrodes include a positive pole and a negative pole;

The voltage amplitude acquisition module is used to acquire the voltage amplitude of the left and right sides of the chest of the subject;

Generally, the acquisition of the voltage amplitude of the left chest of the subject is carried out by collecting the voltage value of the first measurement electrode fixed between the left and right chest and the voltage value of the third measurement electrode located below the excitation electrode on the left side The voltage difference of the left chest obtained by doing the difference;

The acquisition of the voltage amplitude of the subject's right chest is obtained by collecting the voltage value of the second measurement electrode fixed between the left and right chest and the voltage value of the fourth measurement electrode located below the excitation electrode on the right side. The resulting voltage difference across the right chest.

Further, in order to obtain more accurate electrical impedance signals, the pair of excitation electrodes are fixed at the two intersections formed by the horizontal line formed by the connection of the left and right nipples and the left and right midaxillary lines; the first measuring electrode and the second measuring electrode are fixed Two locations above and below the intersection of the horizontal line formed by the connection of the left and right nipples with the midline of the manubrium sternum. Specifically, refer to FIG. 2 , which is a schematic diagram of wearing the excitation electrodes and measurement electrodes in this specific embodiment.

As shown in Figure 2, the negative electrode I- of the excitation electrode can be fixed at the intersection of the horizontal line formed by the connection of the left and right nipples and the right midaxillary line, and the positive electrode I+ of the excitation electrode can be fixed at the intersection of the horizontal line formed by the connection of the left and right nipples and the left side. At the intersection of the midaxillary line, the positions of the positive and negative electrodes of the excitation electrode can be reversed; the first measurement electrode V1 is fixed at the upper end of the intersection of the horizontal line formed by the connection of the left and right nipples and the midline of the manubrium; the second measurement electrode V2 Fix it at the lower end of the intersection of the horizontal line formed by the connection of the left and right nipples and the midline of the manubrium sternum; fix the third measuring electrode V3 at the intersection of the horizontal line formed by the connection of the left midaxillary line and the left and right nipples, specifically, close to the The third measurement electrode V3 is fixed under the left excitation electrode I+; the fourth measurement electrode V4 is fixed at the intersection of the horizontal line formed by the connection between the right midaxillary line and the left and right nipples, specifically, close to the right The third measurement electrode V3 is fixed under the side excitation electrode I-.

In this way, the voltage difference of the left chest of the subject is (V3-V1), and the voltage difference of the right chest is (V4-V2);

The electrical impedance signal calculation module is used to calculate the electrical impedance signal of the left chest and the electrical impedance signal of the right chest according to the excitation current and voltage amplitude according to Ohm's law, which is used to calculate the electrical impedance signal of the left chest according to the input excitation current and the left chest According to Ohm's law, the electrical impedance signal of the left chest and the electrical impedance signal of the right chest are respectively calculated. Specifically, the preset input excitation current is I, then the electrical impedance signal of the left chest of the subject is RL=|(V3-V1)|/I, and the electrical impedance signal of the right chest is RR=|(V4- V2)|/I, where |(V3-V1)| is the absolute value of the voltage difference of the left chest, |(V4-V2)| is the absolute value of the voltage difference of the right chest, to ensure that the calculated The electrical impedance signal of is positive.

In a specific application, the existing constant current source module can be used to provide current excitation for the measurement electrodes, and the multi-channel switch module is connected to the electrodes, constant current source module and data acquisition module respectively to control the electrodes fixed at different positions on the chest. The excitation current of the excitation electrode and the voltage signal of the reception measurement electrode.

In the specific implementation process, the reference feature value extraction module 203 generally includes:

A filtering module is used to filter the electrical impedance digital signals of the left chest and the right chest respectively;

The signal segmentation module is used to segment the electrical impedance digital signals of the left chest and the right chest after filtering according to time;

The impedance integral value calculation module is used to calculate the absolute value impedance integral value of the electrical impedance digital signal in each time period;

The amplitude calculation module is used to perform median filtering on the electrical impedance digital signal in each time period and extract the maximum value point and minimum value point in each time period, and the |maximum value-minimum value| As the magnitude of the electrical impedance digital signal for each time period;

The reference eigenvalue calculation module is used to calculate the correlation between the left chest impedance integral and the right chest impedance integral as CI, and take CI as the first reference eigenvalue, and calculate the left chest impedance amplitude and the right chest impedance The correlation of the impedance amplitude is CA, and CA is used as the second reference characteristic value;

The correlation analysis module 204 generally includes:

Mean correlation calculation module, for calculating mean correlation MC=(CI+CA)/2 according to the first reference characteristic value CI and the second reference characteristic value CA;

The judging module is used to compare the value of MC with a preset range threshold to judge whether the correlation between left and right lung respiratory impedance is good or bad.

The preset range threshold can be set according to prior knowledge. For example, if the mean correlation MC≥0.9, it indicates that the left and right lungs have a good correlation in respiratory impedance, and the left and right lungs breathe well; if 0.8≤MC<0.9, it indicates that the left and right lungs The correlation of respiratory impedance is good, and the respiration of the left and right lungs is more coordinated; if 0.6≤MC<0.8, it indicates that the correlation of the respiratory impedance of the left and right lungs is average, and the respiration of the left and right lungs is not coordinated; if the mean correlation MC<0.6, it indicates that the respiration of the left and right lungs The impedance correlation is poor, and the breathing of the left and right lungs is very uncoordinated.

The same or similar reference numbers correspond to the same or similar components;

The positional relationship described in the drawings is only for illustrative purposes and cannot be construed as a limitation to this patent;

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (8)

1. a pulmo respiratory impedance correlation analysis, is characterized in that, comprising:

Gather the left side chest of experimenter and the electrical impedance signal of right side chest;

The electrical impedance digital signal that analog digital conversion obtains left side chest and right side chest is carried out to the electrical impedance signal collected;

Fixed reference feature value is extracted from the electrical impedance digital signal of left side chest and right side chest;

Analyze according to the pulmo respiratory impedance dependency of fixed reference feature value to described experimenter;

The concrete steps extracting fixed reference feature value from the electrical impedance digital signal of left side chest and right side chest are:

Respectively filtering is carried out to the electrical impedance digital signal of left side chest and right side chest;

The electrical impedance digital signal of filtering rear left thoracotomy and right side chest is carried out segmentation according to the time;

Calculate the absolute value impedance integrated value of the electrical impedance digital signal in each time period;

Medium filtering is carried out and the maximum point extracted in each time period and minimum point to the electrical impedance digital signal in each time period, will | maximum-minimum | as the amplitude of the electrical impedance digital signal of each time period;

The dependency calculating chest impedance integration on the right side of the chest impedance anomalous integral of left side is CI, and using CI as the first fixed reference feature value;

The dependency calculating left side chest impedance amplitude and right side chest impedance amplitude is CA, and using CA as the second fixed reference feature value.

2. pulmo respiratory impedance correlation analysis according to claim 1, is characterized in that,

The acquisition mode of the electrical impedance signal of left side chest and right side chest is as follows:

The exciting current of Gather and input experimenter left and right sides chest;

Obtain the voltage magnitude of experimenter left and right sides chest;

The left side electrical impedance signal of chest and the electrical impedance signal of right side chest is calculated respectively according to Ohm's law according to exciting current and voltage magnitude.

3. pulmo respiratory impedance correlation analysis according to claim 2, is characterized in that,

The described exciting current collected is the exciting current of the pair of exciting input by being fixed on experimenter left chest side and right chest side, and wherein pair of exciting comprises positive pole and negative pole;

On the left of described acquisition experimenter, the voltage magnitude of chest is:

The voltage difference doing the left side chest that difference obtains is carried out by the magnitude of voltage gathering the 3rd measurement electrode below the magnitude of voltage being fixed on the first measurement electrode between the chest of left and right and the exciting electrode being positioned at left side;

On the right side of described acquisition experimenter, the voltage magnitude of chest is:

The voltage difference doing the right side chest that difference obtains is carried out by the magnitude of voltage gathering the 4th measurement electrode below the magnitude of voltage being fixed on the second measurement electrode between the chest of left and right and the exciting electrode being positioned at right side.

4. pulmo respiratory impedance correlation analysis according to claim 3, is characterized in that, pair of exciting is fixed on left and right nipple and connects two point of intersection that the horizontal line that formed and left and right sides midaxillary line formed;

Described first measurement electrode and the second measurement electrode are fixed on two positions up and down that left and right nipple is connected the point of intersection of formed horizontal line and presternum center line.

5. pulmo respiratory impedance correlation analysis according to claim 1, is characterized in that, according to the concrete steps that the pulmo respiratory impedance dependency of fixed reference feature value to described experimenter is analyzed is:

Average dependency MC=(CI+CA)/2 is calculated according to the first fixed reference feature value CI and the second fixed reference feature value CA;

The value of MC and default range threshold are compared the good job judging pulmo respiratory impedance dependency.

6. a pulmo respiratory impedance correlation analysis system, is characterized in that, comprising:

Electrical impedance signal acquisition module, for the electrical impedance signal of the left side chest and right side chest that gather experimenter;

Analog-to-digital conversion module, obtains the electrical impedance digital signal of left side chest and right side chest for carrying out analog digital conversion to the electrical impedance signal collected;

Fixed reference feature value extraction module, for extracting fixed reference feature value in the electrical impedance digital signal from left side chest and right side chest;

Correlating module, for analyzing according to the pulmo respiratory impedance dependency of fixed reference feature value to described experimenter.

7. pulmo respiratory impedance correlation analysis system according to claim 6, it is characterized in that, electrical impedance signal acquisition module comprises:

Exciting current acquisition module, for the exciting current of Gather and input experimenter left and right sides chest;

Voltage magnitude acquisition module, for obtaining the voltage magnitude of experimenter left and right sides chest;

Electrical impedance signal computing module, for calculating the left side electrical impedance signal of chest and the electrical impedance signal of right side chest according to exciting current and voltage magnitude respectively according to Ohm's law;

Fixed reference feature value extraction module comprises:

Filtration module, for carrying out filtering to the electrical impedance digital signal of left side chest and right side chest respectively;

Signal subsection module, for carrying out segmentation by the electrical impedance digital signal of filtering rear left thoracotomy and right side chest according to the time;

Impedance integrated value computing module, for calculating the absolute value impedance integrated value of the electrical impedance digital signal in each time period;

Amplitude computing module, for carrying out medium filtering and the maximum point extracted in each time period and minimum point to the electrical impedance digital signal in each time period, will | maximum-minimum | as the amplitude of the electrical impedance digital signal of each time period;

Fixed reference feature value computing module, be CI for calculating the dependency of chest impedance integration on the right side of the chest impedance anomalous integral of left side, and using CI as the first fixed reference feature value, and the dependency calculating left side chest impedance amplitude and right side chest impedance amplitude is CA, and using CA as the second fixed reference feature value;

Correlating module comprises:

Average correlation calculations module, for calculating average dependency MC=(CI+CA)/2 according to the first fixed reference feature value CI and the second fixed reference feature value CA;

Judge module, for comparing the value of MC and default range threshold the good job judging pulmo respiratory impedance dependency.

8. pulmo respiratory impedance correlation analysis system according to claim 7, is characterized in that,

The described exciting current collected is the exciting current of the pair of exciting input by being fixed on experimenter left chest side and right chest side, and wherein pair of exciting comprises positive pole and negative pole;

On the left of described acquisition experimenter, the voltage magnitude of chest is:

The voltage difference doing the left side chest that difference obtains is carried out by the magnitude of voltage gathering the 3rd measurement electrode below the magnitude of voltage being fixed on the first measurement electrode between the chest of left and right and the exciting electrode being positioned at left side;

On the right side of described acquisition experimenter, the voltage magnitude of chest is:

The voltage difference doing the right side chest that difference obtains is carried out by the magnitude of voltage gathering the 4th measurement electrode below the magnitude of voltage being fixed on the second measurement electrode between the chest of left and right and the exciting electrode being positioned at right side.