WO2011129474A1 - Device and method for monitoring pulmonary function using impedance of both hands - Google Patents

Abstract

The present invention relates to a device and a method for monitoring pulmonary function using the impedance of both hands, and aims to extract an impedance pulmonary function signal (IPFS), which indicates a change in a pulmonary volume, using the bioelectrical impedance detected from both hands of an evaluation subject. To this end, the present invention provides a device for monitoring the pulmonary function and a method using same, the device comprising: a base impedance signal which obtains a measured area by a current lead-in and a voltage measurement; a bio-signal detection unit that detects the IPFS, which indicates temporal changes of the pulmonary volume according to respiration; a pulmonary function evaluation factor extraction unit, which extracts a parameter for evaluating a pulmonary function condition from the IPFS that has been detected by the bio-signal detection unit; a main control unit, which controls the action of the bio-signal detection unit and the pulmonary function evaluation factor extraction unit; and a data storage unit, which stores the IPFS that has been detected by the pulmonary function evaluation factor extraction unit and the signal that has been extracted by the extraction unit. Therefore, the present invention can solve the restraints of the conventional pulmonary function tests and be actively utilized in long-term monitoring of the pulmonary function and early diagnosis of a disease.

Description

Pulmonary function monitoring device and method using two-hand impedance

The present invention relates to a pulmonary function monitoring system capable of extracting parameters used for pulmonary function evaluation by measuring the electrical impedance of a living body, and more particularly, by measuring the bioelectrical impedance from both hands of a subject through a hand grip type electrode. Non-invasive and non-constrained extraction of the pulmonary function impedance signal (hereinafter referred to as IPFS), which shows the change in lung volume due to respiration, can be performed. It relates to a pulmonary function monitoring device and method using two-hand impedance that can solve the constraint.

Common pulmonary function tests are to check the ventilation function of the lungs by covering the nose and breathing only through the mouth, evaluating the diffusion ability of gas through alveolar capillary membrane, and pulmonary circulation function test by cardiac catheter method. In general PFT equipment, after measuring the flow of air, the value is integrated to extract the volume of the lung and the parameters FVC, FEV1 Ratio of FEV1 / FVC for the evaluation of lung function are calculated from the volume value. Extract. However, close cooperation between the examiner and the examinee is essential for accurate testing of the pulmonary function test by these methods.

However, this pulmonary function test method, of course, is not a painful and painful test, but because the pulmonary function test device is inserted into the oral cavity to check the maximum volume of breath, it is necessary to breathe quickly, much, harder, and tolerate the patient. There is a problem that can cause. In addition, there is a problem that the restraint side is followed by a long inspection time and accompanying the necessary experts.

On the other hand, conventional bioelectrical impedance detection system records changes in organs, limbs or any anatomical parts by detecting body impedance and body volume changes that detect components of the human body. Electric Impedance Plethysmography.

In order to detect the pulmonary function state through the bioelectrical impedance detection system, it is required to have a high-precision resolution within ± 5) (ohm), but the measurement resolution of a general impedance system shows a resolution of 10Ω (ohm) to 1KΩ (kohm). Therefore, since the base impedance of the human body must be used with extremely limited, the measurement resolution for change in impedance was inevitably small.

In addition, the general impedance measurement system uses a measurement method using a two-pole electrode in which current input and voltage measurement are performed at one electrode, and thus the influence of impedance due to contact impedance and frequency occurs when measuring impedance change due to respiration. There was a problem.

Technical problem to be solved by the present invention, by detecting the bioelectrical impedance from both hands of the evaluation target to extract the pulmonary function impedance signal indicating the change in lung volume due to respiration can solve the limitation of the existing pulmonary function test and lung It is an object of the present invention to provide an apparatus and method for monitoring lung function using two-hand impedance that can be actively used for long-term monitoring of function and early diagnosis of a disease.

One embodiment of the present invention for achieving the above object is made of a hand grip type mounted on the hand of one side, the first current electrode (CH) for supplying a fine current and the first voltage electrode (VH) for detecting a voltage A first impedance measuring unit having a); A second impedance measuring unit formed of a hand grip type mounted on the other hand and having a second current electrode CL for supplying a microcurrent and a second voltage electrode VL for detecting a voltage; A differential amplifier configured to differentially amplify a potential difference measured by the voltage electrode of the first impedance measuring unit and the voltage electrode of the second impedance measuring unit, and output a difference value of an impedance signal for two points of the human body; An AC / DC converter for converting the potential difference amplified by the differential amplifier into a direct current form and extracting a human body impedance signal (human impedance value) from an impedance signal amplified and DC biased through the differential amplifier; Detecting a pulmonary functional impedance signal by removing a base impedance signal of a measurement part equipped with a first current electrode and a first voltage electrode and a measurement part equipped with a second current electrode and a second voltage electrode from the human body impedance signal; The base impedance feedback unit; lung function monitoring device using a two-hand impedance, characterized in that it comprises a.

The pulmonary function monitoring device further includes a pulmonary function evaluation element extracting unit for extracting a parameter for pulmonary function state evaluation from the pulmonary function impedance signal detected by the base impedance feedback unit.

The pulmonary function evaluation element extracting unit sequentially detects the peak value and the lowest value of the pulmonary function impedance signal (IPFS) output from the base impedance feedback unit, and uses a time index and amplitude information of each value to determine a time interval between the peak value and the lowest value. Calculate the amplitude and amplitude, and try hard lung capacity (FVC), exhalation volume for 1 second (FEV1), exhalation volume for 1 second, and coercive lung capacity (FEV1 / FVC), maximum effort exhalation flow rate (FEF25-75) %) Detect the parameter.

The base impedance feedback unit may include: a first low pass filter extracting only a DC component included in the non-inverted and amplified signal by low-pass filtering the impedance signal output from the AC / DC converter to a cutoff frequency of 0.03 Hz; A first differential amplifier differentially amplifying the low pass filtered DC component at an output of the first non-inverting amplifier and a cutoff frequency of 0.03 Hz to remove only the DC component included in the non-inverted amplified impedance signal; A high pass filter for passing a frequency signal of a cutoff frequency of 0.03 Hz or more among the signals differentially amplified by the first differential amplifier; And a second low pass filter configured to pass a frequency signal having a cutoff frequency of 100 Hz or less among the output signals of the high pass filter.

The base impedance feedback unit further includes a first non-inverting amplifier between the AC / DC converter and the first low pass filter to amplify the impedance signal output from the AC / DC converter to the first low pass. And a second non-inverting amplifier after the second low pass filter to output the second low pass filter.

Another embodiment of the present invention for achieving the above object is, the basic base impedance signal of the measurement site through the current input and voltage measurement by each electrode of the hand grip form from both hands of the subject, the lung volume according to the breath (volume Physiological signal detection unit for detecting pulmonary function impedance signal (IPFS) indicating a temporal change of), pulmonary function evaluation element extraction unit for extracting parameters for pulmonary function state evaluation from pulmonary function impedance signal detected by the biosignal detection unit, Using a two-handed impedance including a main control unit for controlling the operation of the signal detection unit and the pulmonary function evaluation element extraction unit, and a data storage unit for storing the pulmonary function impedance signal detected by the biosignal detection unit and the signal extracted by the pulmonary function evaluation element extraction unit Pulmonary function monitoring device.

Another embodiment of the present invention for achieving the above object is a display that is operated by the control of the main control unit, and displays a user-induced graph that can induce the actual maximum inspiratory and maximum exhalation of the subject to detect the correct lung function data Pulmonary function monitoring device using a two-handed impedance further comprises a wealth.

In each embodiment of the present invention, the biosignal detection unit feeds back an initial base impedance detected from a measurement site to a pulmonary functional impedance signal representing a temporal change in lung volume due to respiration, thereby providing a basic base impedance signal of the measurement site. And a base impedance feedback unit for detecting the removed closed function impedance signal.

Another embodiment of the present invention for achieving the above object is a bio-signal detection unit for detecting a pulmonary functional impedance signal indicating a temporal change in the base impedance, lung volume through the current inlet and potential difference measurement, pulmonary functional impedance signal A pulmonary function monitoring method in a pulmonary function test apparatus having a pulmonary function evaluation element extracting unit extracting a plurality of parameters for pulmonary function state evaluation from Impedance detection step of detecting pulmonary functional impedance signal (IPFS) including basic base impedance and pulmonary function evaluation element of the measurement site from both hands of the subject, and detecting peak and lowest value from pulmonary functional impedance signal to evaluate lung function. Extraction of pulmonary function evaluation factors that extract parameters used A lung function monitoring method using both hands and impedance comprising a series.

In the impedance detection step according to the method of the present invention, a closed function impedance signal detected by the biosignal detection unit is fed back to an initial base impedance previously detected at a measurement site, thereby removing the basic base impedance signal of the measurement site. And a feedback processing step of detecting an impedance signal.

In the extracting of the pulmonary function evaluation element by the method of the present invention, the pulmonary function impedance signal (IPFS) detected through the biosignal detection unit is low-pass filtered to improve the signal-to-noise ratio (SNR) and have no effect on respiration. A first step of acquiring IPFS data including a second step of establishing a baseline (threshold) for an initial predetermined time using the IPFS data obtained in the first step, and a peak value of the IPFS data when the initial predetermined time elapses. In the third step of detecting the lowest value sequentially, and when the peak value and the lowest value are obtained through sequential detection, the time interval and amplitude between the peak value and the lowest value are calculated using the time index and amplitude information of each value, and the calculated Using the results of the two pieces of information, the effort-assisted lung capacity (FVC), the expiratory volume for one second (FEV1), and the ratio between the expiratory volume and the effort-related spirometry for one second are used. And a fourth step of obtaining (FEV1 / FVC), the best effort castle middle expiratory flow (FEF25-75%) parameters is characterized in that formed.

According to the pulmonary function monitoring system using the two-hand impedance according to the present invention, according to the development of the pulmonary function impedance measurement system having a high precision resolution, such as flow-volume curve, FVC, FEV1, FEV25%, etc. It is possible to detect and correlate with actual pulmonary function test clinical equipment such as Sensormedics' Vmax Encore, which makes it easier and more applicable to the detection of pulmonary function status.

In addition, the present invention detects the pulmonary functional state through the electrical impedance method according to the non-binding and non-invasive detection of the basic impedance of the human body through the bioelectrical impedance measurement system and fed back to the pulmonary functional state detection system It will be able to resolve the inconvenience of functional testers will be able to actively use for long-term monitoring of lung function and early diagnosis of the disease.

In addition, the present invention, unlike the indirect parameter detection system that can infer the pulmonary function state using the conventionally developed impedance, the same FVC, FEV1 as the pulmonary function test (Pulmonary Function Test) to evaluate the state of pulmonary function by direct breathing In addition, the FEF25-75% parameters can be detected directly, providing a high-resolution resolution impedance system that is significantly different from existing impedance systems.

1 is a block diagram schematically showing the overall configuration of a lung function monitoring apparatus using two-hand impedance according to an embodiment of the present invention.

2 and 3 are a detailed view of the electrode and the configuration example of FIG.

4 is a detailed view of the base impedance feedback unit of FIG. 1.

5 is a reference diagram illustrating a display example of the display unit of FIG. 1.

6 is an operation flowchart illustrating a data processing performed in the lung function evaluation element extractor of FIG. 1.

7 is an exemplary flow and volume graph for pulmonary function states measured through bioelectrical impedances.

8 is an exemplary diagram of a lung function evaluation graph obtained from the bioelectrical impedance measured by the present invention.

9 is a lung function evaluation result value obtained from the bioelectrical impedance measured by the present invention.

Hereinafter, the configuration and operation of a lung function monitoring apparatus using two-hand impedance according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may properly define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, since the embodiments shown in the specification and the configuration shown in the drawings is only one of the most preferred embodiment of the present invention, it is understood that there may be various equivalents and modifications that can replace them at the time of the present application shall.

1 is a block diagram schematically showing the overall configuration of a device for monitoring lung function using two-hand impedance according to an embodiment of the present invention, Figures 2 and 3 is a detailed view of the electrode portion of Figure 1, Figure 4 is Figure 1 Detailed diagram of the base impedance feedback unit.

As shown in FIG. 1, the apparatus for monitoring lung function according to an embodiment of the present invention may include a biosignal detection unit 100, a lung function evaluation element extracting unit 200, a main control unit 300, a data storage unit 400, And a display unit 500.

The biosignal detector 100 includes a base impedance detector including electrodes 101 and 102, a sine wave generator 111, a constant current source 112, a differential amplifier 113, and an AC / DC converter 114 for detecting a base impedance signal. 110 and the base impedance feedback unit 120, the current injection and voltage measurement through each electrode to measure the basic base impedance signal of the measurement site, the time change of the lung volume (volume) according to breathing Detects a closed function impedance signal (IPFS).

The base impedance detection unit 110 is an H / W that measures the basic base impedance of the measurement site before the parameter detection for pulmonary function evaluation through impedance, and has 1kΩ [kohm] ~ 3k 가 of the existing impedance hardware. Anything with a range of [kohm] can be used.

The sine wave generator 111 is a device for generating a sine wave signal for supplying to an electrode, and may be configured as a wein bridge oscillator or the like for generating a high frequency signal required for current injection into a human body.

The constant current source 112 converts a sine wave signal output from the sine wave generator 111 into a constant current source and injects the measured current through the current electrode. The constant current source 112 converts the output of the sine wave generator into a constant current and sends it out to the current electrode.

The electrodes 101 and 102 are sensor devices consisting of a tetrapolar electrode in the form of a hand grip, and include a first current electrode CH, a first voltage electrode VH, a second current electrode CL, and a second voltage electrode ( VL) to inject a current directly into the measurement site and to measure the voltage change according to the change in the bioelectrical impedance, and to form an electrode of the hand grip type as shown in FIGS. 2 and 3. Such an electrode supplies a constant current supplied from the constant current source 112 to the measurement site of the subject through the first current electrode CH and the second current electrode CL, and thus is generated at the two measurement sites. The potential difference is measured through the first voltage electrode VH and the second voltage electrode VL. Through this, in the present invention, it is possible to minimize the influence of the impedance according to the contact impedance and the frequency when measuring the impedance change due to respiration, in particular the output impedance of the constant current source and the input impedance of the AC Volt meter between the electrode impedance and the electrode and skin If the contact resistance is considerably larger than the impedance of the electrode and the contact resistance of the electrode can be minimized.

The differential amplifier 113 differentially amplifies the potential difference measured by the two voltage electrodes VH and VL and outputs a difference value of an impedance signal for two points of the human body.

The AC / DC converter 114 converts the potential difference amplified by the differential amplifier 113 into a DC form and outputs it. In other words, by converting the amplified potential difference in the form of direct current, the human body impedance value is extracted from the amplified and DC biased impedance signal through the differential amplifier.

As shown in FIG. 4, the base impedance feedback unit 120 includes a first non-inverting amplifier 121, a first differential amplifier 122, a high pass filter (HPF) 123 having a cutoff frequency of 0.03 Hz, and a cutoff frequency of 100 Hz. And a low pass filter (LPF) 124, a second non-inverting amplifier 125, and a low pass filter (LPF) 126 having a cutoff frequency of 0.03 Hz, indicating a temporal change in lung volume due to respiration. The initial base impedance detected from the measurement site is fed back to the lung function impedance signal, and the lung function impedance signal from which the basic base impedance signal of the measurement site is removed is detected and supplied to the lung function evaluation element extracting unit 200. Here, it can be seen that the change in lung volume is a value representing volume, and the change in impedance is also a voltage value representing change in lung volume, so that the two values are values that maintain correlation with each other.

The first non-inverting amplifier 121 amplifies the closed function impedance signal detected from the measurement site.

The low pass filter 126 low-pass filters the output of the first non-inverting amplifier 121 at a cutoff frequency of 0.03 Hz to extract only a DC component included in the non-inverted amplified signal.

The first differential amplifier 122 differentially amplifies the low-pass filtered DC component at an output of the first non-inverting amplifier 121 and a cutoff frequency of 0.03 Hz to remove and output only the DC component included in the non-inverted amplified impedance signal. . That is, the first differential amplifier 122 amplifies the difference between the signal amplified by the first non-inverting amplifier 121 and the initial base impedance signal fed back (the output signal of the low pass filter) to remove the base impedance. Output an impedance signal.

The high pass filter (HPF) 123 is a filter for passing all frequency signals above the cutoff frequency and attenuating all other frequency signals among the signals differentially amplified through the first differential amplifier 122. The AC signal passes through an amplifier 122 having a cutoff frequency of 0.03 Hz or more.

The low pass filter (LPF) 124 is a filter that passes all frequency signals below the cutoff frequency and attenuates all other frequency signals among the high pass filtered signals. In the present invention, the low pass filter (LPF) is filtered through the high pass filter (HPF). Pass a DC signal with a cutoff frequency of 100 Hz or less among the signals.

The second non-inverting amplifier 125 sequentially non-inverts and amplifies the high-pass filtered and low-pass filtered signals again through the two filters, and outputs a pulmonary functional impedance signal IPFS including a pulmonary function evaluation element.

The pulmonary function evaluation element extracting unit 200 is a device for extracting a parameter for pulmonary function state evaluation from the pulmonary function impedance signal detected by the biosignal detection unit 100, and the pulmonary function impedance signal output from the biosignal detection unit 100. Effort spirometry (FVC), used for pulmonary function evaluation by detecting peaks and troughs (IPFS) sequentially and calculating time intervals and amplitudes between peaks and troughs using time index and amplitude information for each value. Initial expiratory volume (FEV1), ratio of exhaled volume and cooperative spirometry for 1 second (FEV1 / FVC), and hardest peak expiratory flow rate (FEF25-75%) parameters are obtained. FVC stands for Forced Vital Capacity, which means the maximum amount of air that can be exhaled to the maximum after inhaling maximum breathing capacity, and FEV1 stands for Forced Expiratiory Volume in 1s. Air volume (air quality indicator,% PRED is 80-100% normal), FEV1 / FVC is the ratio of FEV1 and FVC, FEF25-75% is the slope of 25-75% of FEV1. (Medium / small airway evaluation index, and% PRED is 75 ~ 100% normal).

The main control unit 300 controls the operations of the biosignal detection unit 100 and the lung function evaluation element extraction unit 200.

The data storage unit 400 stores the lung function impedance signal detected by the biosignal detection unit 100 and the signals extracted by the lung function evaluation element extraction unit 200.

The display unit 500 is operated under the control of the main controller 300, and as shown in FIG. 5, a user-induced graph capable of inducing the actual maximum inspiration and the maximum exhalation of the subject to detect the correct lung function data. Display. In addition, the display unit 500 is a current source that is introduced into the current measurement site through the electrode in the bio-signal detection unit 100, AC impedance, base impedance, lung volume measured directly from both hands in the bio-signal detection unit Displays a pulmonary function impedance signal representing the temporal change of the signal.

Meanwhile, the pulmonary function monitoring method according to another embodiment of the present invention includes a basic base impedance and pulmonary function evaluation element of the measurement site from both hands of the subject through current input and voltage measurement through each electrode in the biosignal detection unit. Impedance detection step of detecting each of the pulmonary function impedance signal (IPFS), and the pulmonary function evaluation element extraction step of extracting the parameters used for pulmonary function evaluation by detecting the peak value and the lowest value from the pulmonary function impedance signal.

The impedance detection step feeds back the initial base impedance previously detected at the measurement site to the lung function impedance signal detected by the biosignal detection unit, and detects the lung function impedance signal from which the basic base impedance signal of the measurement site is removed. It is preferred to include a treatment step.

FIG. 6 is an operation flowchart illustrating a data processing process performed in the lung function evaluation element extractor of FIG. 1. FIG. 7 is an exemplary view illustrating a flow and volume graph of a lung function state measured through bioelectrical impedance. Pulmonary function evaluation graph obtained from the bioelectrical impedance measured by the present invention is an exemplary view, Figure 9 is a lung function evaluation result obtained from the bioelectrical impedance measured by the present invention.

The data processing performed in the lung function evaluation element extracting unit 200 of the monitoring apparatus of FIG. 1 according to the present invention includes a lung function impedance signal (IPFS) detected through the biosignal detection unit as shown in the operation flowchart of FIG. 6. The first step (S101 ~ S103) of acquiring IPFS data including the pulmonary function evaluation factor that improves the signal-to-noise ratio and does not affect the breathing by low-pass filtering, using the IPFS data obtained in the first step, the base for an initial constant time. A second step (S104, S105) of setting a line (threshold value), a third step (S106-S110) of sequentially detecting peak and minimum values of IPFS data after an initial predetermined time elapses, and the peak value and When the lowest value is obtained, the time interval and amplitude between the peak value and the lowest value are calculated using the time index and amplitude information of each value, and the result of the calculated two information is used. Efficacy spirometry (FVC), exhalation volume for 1 second (FEV1) and ratio of exhalation volume and exertion spirometry for 1 second (FEV1 / FVC), highest intermediary exhalation flow rate (FEF25-75%) It comprises a fourth step (S111, S112) to obtain a.

The first step is to feed back the lung function impedance signal detected by the biosignal detection unit to an initial base impedance previously detected at the measurement site, thereby detecting the lung function impedance signal from which the basic base impedance signal of the measurement part is removed. It is preferably configured to include a feedback processing step.

In particular, the data processing process of the monitoring apparatus according to the present invention is a fifth step (S104-1 ~ S104-) to obtain the flow curve change through the first derivative of the IPFS data with improved signal-to-noise ratio (SNR) through the first step It may also comprise 2).

Operation of the pulmonary function monitoring method and pulmonary function evaluation element extracting unit 200 according to the present invention having such a configuration will be described in detail.

First, the biosignal detection unit 100 generates a pulmonary functional impedance signal (IPFS) including basic base impedance and pulmonary function evaluation elements of the measurement site from both hands of the subject through current input and voltage measurement through each electrode. Detect. In the impedance detection step, the lung function impedance signal detected by the biosignal detection unit may be fed back to the initial base impedance previously detected at the measurement site, and the basic function of the impedance signal may be removed to detect the lung function impedance signal. Will be.

Next, in the pulmonary function evaluation element extraction step, first, the pulmonary function parameter extraction unit 200 reads the pulmonary function parameter detection signal IPFS using impedance (S101) and low-pass filtering (a minimum frequency of 1 Hz without affecting respiration). Through the SNR to obtain the IPFS data is improved (S102, S103).

Next, in the second step, a baseline (Threshold) is set for an initial predetermined time (for example, 3 seconds) by using the IPFS data obtained in the first step (S104, S105). At this time, the data for the initial constant time (for example, data for 3 seconds) is the data for the stable time of the signal for the transient response, during which the initial baseline value is determined.

Next, in the third step, IPFS data is read afterwards and the IPFS data is compared with the baseline value (S106). If the IPFS data is larger than the preset baseline value as a result of the comparison, the peak value detection process is called to determine the IPFS data. Peak values are detected (S107, S108). When the detection of these peak values is completed, the lowest value detection process is called again to detect the lowest values of the IPFS data (S109, S110).

When the peak value and the lowest value of the IPFS data are obtained through the sequential detection as described above, the fourth step calculates the time interval and the amplitude between the peak value and the lowest value using the respective time index and amplitude information (S111). Using the result of the two pieces of information, FVC, FEV1, Ratio of FEV1 / FVC, etc., which are parameters used for pulmonary function evaluation, are determined and detected (S112).

In addition, in the fifth step, it is possible to obtain a change in flow with respect to the impedance volume change through the first derivative of the IPFS data with the improved SNR in the first step (S104-1, S104-2).

Through such a process, in the present invention, a flow-volume curve appearing in a general PFT device can also be detected through an impednace. In other words, impedance is a quantitative change of the air entering and exiting the lungs, that is, measuring the volume, so that when the volume is differentiated, the flow can be extracted, and as a result, the flow-volum curve of the PFT used in the existing clinic is detected in the same way. It is possible to maintain the measurement more easily.

Therefore, the evaluation of the pulmonary function state using the electrical impedance method according to the present invention can replace the evaluation of the state of pulmonary function using the PFT sufficiently, and thus may cause patient's rejection and fatigue, and long examination time and expert companion are essential. It can be said to have a significant advantage over PFT inspection.

In the present invention, the output of the AC / DC converter 114 is amplified once more, and the difference between the amplified signal and the fed back base impedance signal is amplified again. As well as a resolution of ˜3 kΩ [kohm] as well as a high resolution within ± 5 ohm (ohm) can be detected, it is possible to extract the parameters for detecting the lung function state.

Pulmonary function monitoring system using the two-hand impedance of the present invention has a high precision resolution, it is possible to detect the flow parameters such as flow-volume curve, FVC, FEV1, FEV25%, which is a direct parameter used for pulmonary function evaluation, easier and more accurate lung function state Can be detected and actively utilized for long-term monitoring of lung function and early diagnosis of disease.

Claims (16)

1. A first impedance measuring unit formed of a hand grip type mounted on one hand and having a first current electrode CH for supplying a microcurrent and a first voltage electrode VH for detecting a voltage;

   A second impedance measuring unit formed of a hand grip type mounted on the other hand and having a second current electrode CL for supplying a microcurrent and a second voltage electrode VL for detecting a voltage;

   A differential amplifier configured to differentially amplify a potential difference measured by the voltage electrode of the first impedance measuring unit and the voltage electrode of the second impedance measuring unit, and output a difference value of an impedance signal for two points of the human body;

   An AC / DC converter for converting the potential difference amplified by the differential amplifier into a direct current form and extracting a human body impedance signal (human impedance value) from an impedance signal amplified and DC biased through the differential amplifier;

   Detecting a pulmonary functional impedance signal by removing a base impedance signal of a measurement part equipped with a first current electrode and a first voltage electrode and a measurement part equipped with a second current electrode and a second voltage electrode from the human body impedance signal; A base impedance feedback unit;

   Lung function monitoring device using a two-hand impedance, characterized in that it comprises a.
2. The method of claim 1,

   And a lung function evaluation element extracting unit for extracting a parameter for pulmonary function state evaluation from the lung function impedance signal detected by the base impedance feedback unit.
3. The method of claim 2,

   The pulmonary function evaluation element extracting unit sequentially detects the peak value and the lowest value of the pulmonary function impedance signal (IPFS) output from the base impedance feedback unit, and uses a time index and amplitude information of each value to determine a time interval between the peak value and the lowest value. Calculate the amplitude and amplitude, and try hard lung capacity (FVC), exhalation volume for 1 second (FEV1), exhalation volume for 1 second, and coercive lung capacity (FEV1 / FVC), maximum effort exhalation flow rate (FEF25-75) %) Pulmonary function monitoring device using two-hand impedance, characterized in that for detecting the parameter.
4. The method of claim 3,

   The base impedance feedback unit

   A first low pass filter extracting only DC components included in the non-inverted and amplified signal by low-pass filtering the impedance signal output from the AC / DC converter to a cutoff frequency of 0.03 Hz;

   A first differential amplifier differentially amplifying the low pass filtered DC component at an output of the first non-inverting amplifier and a cutoff frequency of 0.03 Hz to remove only the DC component included in the non-inverted amplified impedance signal;

   A high pass filter for passing a frequency signal of a cutoff frequency of 0.03 Hz or more among the signals differentially amplified by the first differential amplifier;

    A second low pass filter configured to pass a frequency signal having a cutoff frequency of 100 Hz or less among the output signals of the high pass filter;

   Pulmonary function monitoring device using two-hand impedance, characterized in that consisting of.
5. The method of claim 4, wherein

   The base impedance feedback unit

   A first non-inverting amplifier is further provided between the AC / DC converter and the first low pass filter to amplify the impedance signal output from the AC / DC converter to output the first low pass filter.

   And a second non-inverting amplifier after the second low pass filter to output the second low pass filter.
6. Through the current input and voltage measurement by each electrode from both hands of the subject, the basic base impedance signal of the measurement site and the pulmonary functional impedance signal (IPFS) representing the temporal change of the lung volume due to respiration are detected. A biosignal detection unit;

   A pulmonary function evaluation element extracting unit for extracting a parameter for pulmonary function state evaluation from the pulmonary function impedance signal detected by the biosignal detection unit;

   A main control unit controlling an operation of the biosignal detection unit and the pulmonary function evaluation element extracting unit;

   And a data storage unit for storing the lung function impedance signal detected by the biosignal detection unit and the signal extracted by the lung function evaluation element extracting unit.
7. The method of claim 6,

   And a display unit which is operated by the control of the main control unit and displays a user induction graph that can induce the actual maximum inspiration and the maximum exhalation of the subject for correct lung function data detection. Pulmonary function monitoring device using.
8. The method of claim 7, wherein the display unit,

   The biosignal detection unit displays a pulmonary function impedance signal representing a current source introduced into the measurement site through an electrode, an AC impedance measured by the biosignal detection unit, a base impedance, and a temporal change in lung volume due to respiration. Pulmonary function monitoring device using two-hand impedance.
9. The method of claim 6, wherein the bio-signal detection unit,

   A sine wave generator for generating a high frequency signal for injection of current into the human body;

   A constant current source for converting the output of the sine wave generator into a constant current;

   A first current electrode CH and a second current electrode CL for introducing a constant current supplied from the constant current source into a measurement site of the subject;

   A first voltage electrode (VH) and a second voltage electrode (VL) for measuring a voltage difference across the two measurement sites into which current is drawn by each of the current electrodes;

   A differential amplifier for amplifying a potential difference measured by the two voltage electrodes and outputting a difference value of an impedance signal for two points of the human body;

   And an AC / DC converter for converting the amplified potential difference into a direct current form and extracting a human body impedance value from an amplified and DC biased impedance signal through an amplification unit.
10. The method of claim 6, wherein the bio-signal detection unit,

    Base impedance feedback which detects the pulmonary function impedance signal from which the basic base impedance signal of the measurement site is removed by feeding back the initial base impedance detected from the measurement site to the pulmonary function impedance signal representing the temporal change of lung volume due to respiration. Lung function monitoring apparatus using a two-hand impedance, characterized in that it comprises a.
11. The method of claim 6, wherein the base impedance feedback unit,

    A first non-inverting amplifier 121 for amplifying the closed function impedance signal detected from the measurement site;

    A low pass filter 126 for low pass filtering the output of the first non-inverting amplifier to extract only a DC component included in the non-inverted amplified signal;

    A first differential amplifier 122 for differentially amplifying the output of the first non-inverting amplifier and the low-pass filtered DC component to remove only the DC component included in the non-inverted amplified impedance signal and outputting the DC component;

    The high pass filter 123 and the low pass filter 124 and the low pass filter 123 for outputting a pulmonary function impedance signal (IPFS) including a pulmonary function evaluation element by sequentially high-pass filtering, low-pass filtering and non-inverted amplification of the differentially amplified signal 2 non-inverting amplifier (125); lung function monitoring device using a two-hand impedance, characterized in that consisting of.
12. The method of claim 6, wherein the lung function evaluation element extracting unit,

    Evaluate the peak value and the lowest value of the pulmonary functional impedance signal (IPFS) output from the biosignal detection unit sequentially, and calculate the time interval and amplitude between the peak value and the lowest value using time index and amplitude information of each value to evaluate the lung function. It is characterized by acquiring the coercive spirometry (FVC), the exhalation volume for 1 second (FEV1), the ratio of exhalation volume and coercive lung capacity for 1 second (FEV1 / FVC), and the highest coercive expiratory flow rate (FEF25-75%). Pulmonary function monitoring device using two-hand impedance.
13. The biosignal detection unit detects a pulmonary functional impedance signal indicating a temporal change in base impedance and lung volume through current inflow and potential difference measurement, and a lung extracting a plurality of parameters for pulmonary functional state evaluation from the pulmonary functional impedance signal. In the pulmonary function monitoring method in the pulmonary function tester having a function evaluation element extraction unit,

    Impedance detection for detecting the pulmonary function impedance signal (IPFS) including the basic base impedance and pulmonary function evaluation elements of the measurement site from both hands of the subject through current input and voltage measurement through each electrode in the biosignal detection unit step;

    The lung function monitoring method using two-hand impedance, characterized in that it comprises a; extracting the lung function evaluation element for extracting the parameters used for the lung function evaluation by detecting the peak value and the lowest value from the lung function impedance signal.
14. The method of claim 13, wherein the impedance detection step comprises:

    A feedback processing step of feeding back the initial base impedance previously detected at the measurement site to the lung function impedance signal detected by the biosignal detection unit to detect the lung function impedance signal from which the basic base impedance signal of the measurement site is removed; Pulmonary function monitoring method using a two-handed impedance comprising a.
15. The method of claim 13 or 14, wherein the pulmonary function evaluation element extraction step,

    Performing a low pass filtering of the pulmonary function impedance signal (IPFS) detected through the biosignal detection unit to obtain IPFS data including a pulmonary function evaluation element having an improved signal-to-noise ratio (SNR) and having no effect on respiration;

    A second step of setting a baseline (threshold) for an initial predetermined time using the IPFS data obtained in the first step;

    Detecting a peak value and a lowest value of IPFS data sequentially after the initial constant time elapses; And,

    When the peak value and the lowest value are obtained through the sequential detection, the time interval and the amplitude between the peak value and the lowest value are calculated using the time index and amplitude information of each value, and the lung function evaluation is performed using the results of the calculated two informations. Fourth to obtain the parameters of coherent spirometry (FVC) used, exhalation volume for 1 second (FEV1) and the ratio of exhalation volume and coercive lung capacity for 1 second (FEV1 / FVC), and peak effort middle expiratory flow rate (FEF25-75%) Pulmonary function monitoring method using a two-hand impedance, characterized in that comprises a.
16. The method of claim 15,

    And a fifth step of acquiring a change curve of the flow for the change in the lung volume through the first derivative of the IPFS data with the improved SNR through the first step. Way.

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