KR20170099225A

KR20170099225A - Methods for counting the number of breath from a bio-signal and apparatus thereof

Info

Publication number: KR20170099225A
Application number: KR1020160021334A
Authority: KR
Inventors: 김용국
Original assignee: 주식회사 서연전자
Priority date: 2016-02-23
Filing date: 2016-02-23
Publication date: 2017-08-31
Also published as: KR101867839B1

Abstract

In one embodiment of the present invention, there is provided a method for acquiring a biological signal including a first signal synchronized with swinging of a passenger's breath and a second signal swinging on a pulse of the occupant, , Crossing the second signal with a minimum value of a filtering interval set between a maximum amplitude and a minimum amplitude of the bio-signal, and crossing the maximum value with a maximum value to confirm a vigor area; Determining a breathing frequency by crossing the value with a minimum value and crossing the breathing frequency with a minimum value, and counting the breathing area by breathing once if the breathing area and the inspiration area are consecutively arranged. Provides a method of counting.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for counting the number of respirations in a non-contact type bio-

The present invention relates to a method and apparatus for counting the number of respirations in real time in a non-contact bio-signal.

Domestic and international, the automobile industry is facing new challenges in vehicle intelligence to reflect the needs of consumers. To develop next-generation automobiles, often called intelligent cars or smart cars, automakers in each country are spurring the development of full-scale intelligent automobile technology based on electronic control by combining existing vehicle development technology and IT technology.

In recent years, as a part of such intelligent automobile technology, studies have been actively conducted to analyze driver's bio-signals during driving and actively cope with them in a dangerous situation to secure the safety of the driver.

The method of acquiring biological signals can be broadly classified into a contact type and a non-contact type. In the contact type, there is a means for acquiring a living body signal of a driver, for example, a method of acquiring a living body signal by attaching directly to a driver's body like a heart rate monitor. In contrast to a contactless type, .

In the method of acquiring the non-contact type bio-signal, the radar is mainly used to acquire the driver's bio-signal.

Radar detects the change of activity of the heart and lungs of a person and obtains the driver's bio-signal in a non-contact manner. Generally, the heart and lung of a person are shrunk and expanded by 0.2 to 0.5 mm and 4 to 12 mm respectively. It is possible to acquire the driver's biomedical signal by sensing the motion.

On the other hand, in the case of acquiring the driver's biomedical signal in a non-contact manner using a radar, it is difficult to acquire a clean biomedical signal because the heart rate of the driver, the number of breaths and the noise due to the vibration of the vehicle are mixed together. It is difficult to find the number of respiration of the passenger in real time with reference to the biological signal.

The present invention has been made in view of the above technical background, and it is an object of the present invention to accurately count the breathing frequency of a driver in real time when detecting a driver's biological signal using a radar.

According to an aspect of the present invention, there is provided a method for real-time counting of the number of respirations in a non-contact bio-signal according to an embodiment of the present invention includes a first signal synchronized with a respiration of a passenger and swinging, Acquiring a biological signal having a second signal synchronized with a swing of the occupant, the second signal having a maximum amplitude and a minimum amplitude of the biological signal, Identifying a region of interest in which the second signal crosses with a minimum value of the filtering interval, and counting the breathing region by breathing once the inspiration region and the inspiration region are consecutively arranged do.

Wherein the step of determining the vigor area comprises the steps of: counting a pulse of the second signal to be crossed with a minimum value of the filtering interval; determining a final pulse of the counted pulse as a start point of the vigor area; Determining a first pulse of the second signal that crosses with a maximum value of the filtering interval as an end point of the vigorous area in an ascending cycle that follows the starting point of the region.

Wherein the step of determining the inspiratory region comprises the steps of: determining, as a starting point of the inspiratory region, a last pulse of the second signal to be crossed with a maximum value of the filtering interval during a descending cycle of the biological signal; Counting a pulse of the second signal to be crossed with a minimum value of the filtering interval, and determining the first pulse among the counted pulses as an end point of the inspiration region.

When the bio-signal has a width greater than the average amplitude of the second signal and is input outside the noise critical section swinging in accordance with the first signal, It is possible to further include a step of replacing the signal having a period of the signal with a signal having an amplitude within the noise critical section.

An apparatus provided in another embodiment of the present invention includes a first signal synchronized with swinging of a passenger's breath and a second signal swinging on the pulse of the occupant, And a second amplifying unit that amplifies the first signal and the second amplified signal to generate a first amplified signal and a second amplified amplified signal, And a determiner for counting the inspiration area crossing with the minimum value and counting the inspiration area and the inspiration area by one respiration when the inspiration area and the inspiration area are consecutively arranged.

Wherein the determining unit counts a pulse of the second signal to be crossed with a maximum value of the filtering interval during an ascending cycle of the bio-signal, determines a final pulse of the counted pulse as a starting point of the inspiration region, In the descending cycle immediately following the cycle, the first pulse of the second signal that crosses with the minimum value of the filtering interval is determined as the end point of the inspiration region.

Wherein the determination unit determines a start pulse of the vital area as a last pulse of the second signal that crosses the minimum value of the filtering interval during a falling cycle of the bio-signal, and, in an ascending cycle immediately following the descending cycle, Counts the pulse of the second signal to be crossed with the maximum value of the filtering interval, and determines the first pulse of the counted pulse as the end point of the vigor area.

Wherein the determination unit determines that the bio-electrical signal has a width greater than the average amplitude of the second signal and acquires the bio-electrical signal when the bio-electrical signal is out of the noise critical period that swings according to the first signal, The signal having the amplitude within the noise critical section may be replaced with a signal having the period of the noise critical section.

The details of other embodiments are included in the detailed description and drawings.

According to the embodiment of the present invention, even when the first signal, the second signal, and the noise are mixed in the biological signal, the biological signal is filtered using the noise critical section, and the inspiration region and the exhalation region are checked And it is possible to monitor the respiration of the occupant without any error in real time by counting the inspiration area and the breathing area successively with one breath.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

FIG. 1 shows an inside of a vehicle equipped with an apparatus according to an embodiment of the present invention.
2 shows a block diagram of an apparatus according to an embodiment of the present invention.
Figure 3 shows the flow of a method according to an embodiment of the present invention.
4 illustrates a bio-signal acquired through a radar and a noise critical section set on the bio-signal.
5 illustrates the lifting cycle and the lifting cycle of the living body signal.
Fig. 6 shows an enlarged view of the portion "A" in Fig.
Fig. 7 shows an enlarged view of the portion "B" in Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

FIG. 1 is a block diagram of a counting apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram of a vehicle in which a counting apparatus is installed.

Referring to these figures, the counting apparatus 100 of this embodiment may be configured to include a radar unit 110 and a determination unit 120.

The radar unit 110 radiates a microwave (300 MHz or more) to the vehicle occupant, receives a reflected radio wave reflected from the occupant, measures the time taken for the reflected radio wave to be received, and acquires the biological signal in a noncontact manner.

The biosignal has a first signal swinging to sink into the passenger's breath and a second signal carried on the first signal and swinging in sync with the passenger's pulse. The first signal acquired by the radar signal also has a pulse that rises and falls in accordance with the respiration of the occupant, because the person expands and contracts as the respiration proceeds. Likewise, because the heart expands and contracts with the pulse of the heartbeat, the second signal also has pulses rising and falling in line with the passenger's pulse.

Here, the first signal and the second signal are obtained by the same radar, and the second signal is acquired by the first signal because the human breath has a larger period than the pulse and has an amplitude.

The determination unit 120 identifies the inspiration area and the breathing area in the non-contact type bio-signal of the occupant acquired by the radar unit 110. If the inspiration area and the breathing area are continuously arranged, the passenger counts )do.

The determination unit 120 refers to the filtering period when determining the vigor area and the inspiration area. This filtering interval is set to default in the device and is set to the interval between the maximum amplitude and the minimum amplitude of the biological signal so that the maximum value and the minimum value of the filtering interval are crossed with only some of the pulses of the bio signal .

Meanwhile, in order to check the real-time breathing state of the passenger, it is necessary to know the period of the first signal stored in the acquired bio-signal. However, in addition to the first signal, the biosignal also has a second swinging second signal, so it is difficult to count the period of the first signal.

However, in this embodiment, the filtering interval is set as described above, and the breathing frequency of the passenger can be counted in real time by checking the breathing area and the breathing area using the filtering interval.

The determination unit 120 counts pulses of the second signal to be crossed with the maximum value of the filtering interval during the ascending cycle of the biological signal, determines the last pulse among the counted pulses as the starting point of the inspiration region, In the proceeding descent cycle, the first pulse of the second signal which crosses with the minimum value of the filtering interval is determined as the end point of the inspiration region to determine the inspiration region.

The determining unit 120 determines the starting point of the vigor area as the last pulse of the second signal that crosses the minimum value of the filtering interval and the minimum value of the filtering interval during the descending cycle of the biological signal. Counts the pulse of the second signal to be crossed with the maximum value, and determines the exhalation region by determining the first pulse among the counted pulses as the end point of the exhalation region.

The determination unit 120 replaces the input signal with a signal in the noise critical section immediately after the biological signal is input after the biological signal is input beyond the noise critical section to prevent the biological signal from being distorted by the noise.

Here, the noise critical section is a predetermined section for filtering the noise mixed in the biological signal, and is set to the default in the apparatus. The noise critical section has a width greater than the average amplitude of the second signal and swings in accordance with the first signal. The average amplitude of the second signal may be predetermined based on the data collected during the simulation and actual operation.

The radar unit 110 and the determination unit 120 configured as described above may be installed in the interior of the vehicle, and may preferably be installed in the backrest of the seat closest to the occupant, or in a cluster, a sunvisor, or the like, which is the front of the occupant.

Hereinafter, referring to FIG. 3, a method of counting the number of respirations in real time in a non-contact bio-signal according to an embodiment of the present invention will be described.

The counting method includes a step (S10) of acquiring a bio-signal, a step of removing noise (S20), a step of determining a breathing area (S30), a step of determining an inspiration area (S40) (step S50).

First, step S10 is a step of acquiring a biological signal from a passenger on a vehicle in real time using a radar. The biological signal is obtained as a signal having a waveform as shown in Fig. 4 (A).

The biological signal has a first signal synchronized with the respiration of the passenger and swinging, and a second signal S2 carried on the first signal S1 and swinging in sync with the pulse of the occupant. Accordingly, the period of the first signal corresponds to the number of respirations of the occupant, and the period of the second signal corresponds to the pulse rate of the occupant.

If the second signal S2 swings on the first signal S1 and the pulse of the signal is a pulse for one period, if the intermediate value of each pulse of the second signal S2 is connected to each other , This cycle corresponds to the first signal S1.

The noise critical section Nt has a width larger than the average amplitude of the second signal S2 and swings in synchronization with the first signal S1.

The vital signal oscillates in accordance with the ascending cycle and the descending cycle, and the ascending cycle refers to a period in which the vital signal rises from the lowest point to the highest point, and the descending cycle refers to a period in which the vital signal falls from the highest point to the lowest point.

Biological signals can be seen as signals that continuously draw the rising and falling cycles.

Next, in step S20, noise is removed from the acquired bio-signal (FIG. 4 (B)). This noise may be a signal distorted by the vibration of the vehicle, and may be a signal largely deviated from the normal amplitude.

In this step S20, the noise critical section Nt is used for noise reduction. When the biological signal deviates from the maximum value or the minimum value of the noise critical section, the acquired biological signal is determined as noise, and the noise is replaced with a biological signal that is already set and does not deviate from the noise critical section.

Or may be replaced with a biological signal that is input in the previous section that is the same as the input section of noise and does not deviate from the noise critical section.

In this step, the noise is replaced with a normal bio-signal to prevent the biosignal from being distorted by the noise.

Next, in step S30, the living area is determined with the bio-signal acquired in real time.

In step S30, a pulse of the second signal to be crossed with a minimum value of the filtering interval is counted during an ascending cycle of the biological signal, and a final pulse of the counted pulse is determined as a starting point of the vigorous area. The first pulse of the second signal crossing with the maximum value is determined as the end point of the vigor area.

In this embodiment, since the first signal S1 and the second signal S2 are mixed in the living body signal, it is difficult to count the period of the first signal S1 in order to know the respiration of the occupant, And the inspiration area, and counts the number of respirations of the passenger on the basis thereof. Then, a filtering interval Ft is used to determine the inspiration area and the breathing area.

As illustrated in FIG. 5, the filtering interval Ft is set so as to partially intersect with the second signal S2 in a period in which the rising cycle and the falling cycle of the biological signal change, or a period in which the falling cycle and the rising cycle change.

FIG. 6 is a partially enlarged view of an interval A in which the second signal S2 crosses the maximum value of the filtering interval Ft.

As shown, the second signal S2 rises in accordance with the rising cycle and falls again in the falling cycle. Since the second signal S2 is composed of pulses having an amplitude, some of the pulses cross the maximum value of the filtering period Ft.

In FIG. 6, the first to fourth pulses PU1 to PU4 of the second signal S2 cross the maximum value of the filtering interval Ft during the rising cycle.

In steps S30 and S40, the determination unit 120 counts pulses in which the second signal S2 crosses the maximum value of the filtering period Ft during the rising cycle.

The first pulse PU1 intersecting with the maximum value of the filtering interval Ft in the double ascending cycle is determined as the end point of the exhalation region and the last pulse PD3 crossing the maximum value of the filtering interval Ft in the descending cycle As shown in FIG.

When the first signal PF1 of the second signal S2 in which the second signal S2 crosses the minimum value of the filtering section Ft is found in the falling cycle, the pulse is determined as the end point of the inspiration region And determines the last pulse PC4 crossing the minimum value of the filtering interval Ft in the ascending cycle as the starting point of the breathing area. If the start and end points of the exhalation are consecutive, the interval is determined as the exhalation interval, and if the beginning and end points of the inspiration are consecutive, the interval is determined as the inspiratory interval.

Through the process described above, the determination unit 120 counts the inspiration area, the vigor area, the vigor area, and the inspiration area in a single breathing process in step S50.

In this way, even if the first signal and the second signal are mixed in the bio-signal, the inspiration region and the exhalation region can be checked using the second signal as described above, so that the breathing frequency of the passenger can be counted in real time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

Acquiring a first signal synchronized with swinging of the passenger's breath and a second signal carried on the first signal and having a second signal swinging in sync with a pulse of the occupant;
Crossing the second signal with a minimum value of a filtering interval set between a maximum amplitude and a minimum amplitude of the bio-signal, and crossing the maximum value with a maximum value;
Crossing the second signal with a maximum value of the filtering interval, and crossing the second signal with a minimum value to check an inspiration region; And
Counting the breathing area and the inspiration area in succession;
And counting the number of times of breathing in real time in the non-contact type bio-signal.

The method according to claim 1,
Wherein the step of determining the vigor area comprises:
Counting a pulse of the second signal that crosses with a minimum value of the filtering interval during an ascending cycle of the biological signal;
Determining a last pulse of the counted pulses as a start point of the vigor area;
Determining, in the ascending cycle, a first pulse of the second signal that crosses with a maximum value of the filtering interval as an end point of the vomiting region;
And counting the number of times of breathing in real time in the non-contact type bio-signal.

The method according to claim 1,
Wherein said determining the inspiration region comprises:
Determining, as a starting point of the inspiratory region, a last pulse of the second signal to be crossed with a maximum value of the filtering interval during a descending cycle of the biological signal;
Counting a pulse of the second signal crossing with a minimum value of the filtering interval in the falling cycle;
Determining a first pulse of the counted pulses as an end point of the inspiration region;
And counting the number of times of breathing in real time in the non-contact type bio-signal.

The method according to claim 1,
After acquiring the bio-signal,
Wherein when the biological signal has a width greater than an average amplitude of the second signal and is input outside the noise critical section swinging in accordance with the first signal, the input signal is divided into an amplitude within the noise critical section The method further comprising: replacing the non-contact bio-signal with a signal having a non-contact bio-signal.

A radar unit for acquiring a first signal synchronized with the respiration of the occupant and swinging and a second signal carried on the first signal and swinging in sync with the pulse of the occupant,
Wherein the second signal is a minimum value among a filtering interval set between a maximum amplitude and a minimum amplitude of the bio signal and a vigor area where a maximum value is crossed after crossing, a determination unit for checking the minimum value after crossing and the inspiration area to be crossed and counting the inspiration area and the inspiration area by breathing once,
And counting the number of respirations in real time.

The method of claim 5,
Wherein the determination unit counts a pulse of the second signal to be crossed with a minimum value of the filtering interval during an ascending cycle of the bio-signal, determines a last pulse of the counted pulse as a starting point of the vomiting region, The first pulse of the second signal to be crossed with the maximum value of the filtering interval is determined as the end point of the vomiting region, and the breathing count is counted in real time in the non-contact type bio-signal.

The method of claim 5,
Wherein the determining unit determines a starting point of the inspiratory region as a starting point of the inspiratory region during a descending cycle of the biological signal and a last pulse of the second signal that crosses the maximum value of the filtering interval, And counting the number of times of breathing in the non-contact type bio-signal in real time.

The method of claim 5,
Wherein the determination unit determines that the bio-electrical signal has a width greater than the average amplitude of the second signal and acquires the bio-electrical signal when the bio-electrical signal is out of the noise critical period that swings according to the first signal, Wherein the non-contact bio-signal is a signal having an amplitude within the noise critical section, the non-contact bio-signal having an amplitude within the noise critical section.