KR20240076279A - Bio-signal measurement system and method using terahertz wave - Google Patents

Abstract

The present invention provides a terahertz wave detection sensor; an imaging unit that converts the terahertz wave incident to the terahertz wave detection sensor into an electrical signal and generates an image using the electrical signal; and a bio-signal detection unit that detects the breathing rate of the human body by detecting movement of the lung portion of the human body in the image generated by the imaging unit.

Description

Biosignal measurement system and measurement method using terahertz waves {BIO-SIGNAL MEASUREMENT SYSTEM AND METHOD USING TERAHERTZ WAVE}

The present invention relates to a biosignal measurement system and measurement method, and particularly to a biosignal measurement system and measurement method for measuring biosignals using terahertz waves.

Terahertz waves (THz waves) are electromagnetic waves corresponding to frequencies ranging from 0.1 THz to 10 THz (wavelength 1 mm to 30 ㎛) and are located in the middle area between millimeter waves (radio waves) and light waves (far infrared range). Thanks to the rapid development of terahertz wave generation/detection technology in recent years, a variety of applied research related to terahertz waves is being conducted in various fields such as life, chemistry, machinery, and communications.

Terahertz waves have the characteristics of having both the straight-line nature of light waves and the permeability of radio waves, while possessing the advantages of both areas. Terahertz waves have both the penetrability of radio waves and the straight path of light waves, so they do not require direct contact with the material like existing ultrasonic non-destructive testing, and do not require intermediate media such as water, so they have infinite potential as a next-generation non-contact/non-destructive testing imaging technology. .

Terahertz waves optically have a very low dielectric constant for almost all materials (plastics, wood, paper, fabric, etc.) except metals, so they easily penetrate the inside of the material with almost no loss. Terahertz waves have the disadvantage of being difficult to use for long-distance communication in the atmosphere due to their large absorption by moisture, but they have the advantage of being able to diagnose and analyze the unique characteristics of living organisms, which are mostly made up of moisture, without damaging them.

In addition, unlike electromagnetic waves, it is not affected by magnetic or electric fields, and has a strong penetrating power, but its major advantage is that it does not damage biological tissue like x-rays, ultraviolet rays, or high-power lasers. Specifically, terahertz waves have energy (4.1meV) that is one millionth of the energy of existing x-rays, so they do not destroy the cellular structure of the human body, and the wavelength is small enough in the ㎛ range to create bio-friendly high-resolution images. It is also possible.

Using these characteristics of terahertz waves, transmission images of the human body and biological tissues can be obtained even without the examinee being aware of it. Additionally, due to these characteristics of terahertz waves, they are also called T-rays as a relative concept to x-rays. Figure 1 shows the range of various molecular vibrations in the frequency domain of terahertz waves. Referring to Figure 1, the terahertz region is deeply involved in large molecular vibrations related to biological functions, which are relatively slow among general molecular vibrations, and materials showing characteristic fingerprint spectra (finger print) have been discovered.

A variety of methods have been proposed to measure biosignals (respiration, heart rate, etc.) in a non-contact manner. The method using radar transmits radar, detects signals reflected from the human body, and obtains biometric information from signal changes that occur due to the movement of internal organs. The method using a camera (2D image sensor) continuously photographs the upper body of the human body, detects movement of the abdomen, chest, etc., and measures heart rate or breathing. The method using radar has the disadvantage of having a relatively low resolution compared to the method using a camera, and the method using a camera has the problem that privacy issues may occur because it requires continuous filming.

Therefore, there is a need for a biosignal measurement system that can cover both the shortcomings of the radar-based method and the camera-based method.

Korean Patent Publication No. 10-2017-0036079

The purpose of the present invention is to provide a bio-signal measurement system and method using terahertz waves, which detects the movement of the lungs and heart inside the human body by imaging terahertz waves and measures bio-signals through this.

In order to achieve the above object, the present invention includes a terahertz wave detection sensor; an imaging unit that converts the terahertz wave incident to the terahertz wave detection sensor into an electrical signal and generates an image using the electrical signal; and a bio-signal detection unit that detects the breathing rate of the human body by detecting movement of the lung portion of the human body in the image generated by the imaging unit.

Preferably, the terahertz wave detection sensor is installed on the back of the human body to acquire images at a location close to the human body, thereby improving the detection accuracy of the bio-signal detection unit.

Preferably, the terahertz wave detection sensor is installed in a vehicle and may be located on the back of the backrest of a chair in the vehicle.

Preferably, the terahertz wave detection sensor is m It consists of n array antennas, and some of the array antennas can be used to measure distance to the human body.

Preferably, the bio-signal detection unit may detect the heart rate of the human body by detecting movement of the heart part of the human body in the image generated by the imaging unit.

Preferably, a laser source that irradiates terahertz waves toward the human body may be further included.

Preferably, the laser source may be driven in a manual mode in which the user can manually turn it on and off depending on the power situation, and in an automatic mode in which the laser source is turned off when the applied power amount is less than or equal to a preset power amount, and turned on when it is exceeded.

In addition, the present invention includes a terahertz wave detection step of detecting terahertz waves using a terahertz wave detection sensor; An imaging step of converting the terahertz waves detected in the detection step into an electrical signal and generating an image using the electrical signal; and a bio-signal detection step of detecting the breathing rate of the human body by detecting the movement of the lung portion of the human body in the image generated in the imaging step.

Preferably, it may further include a terahertz wave irradiation step of irradiating terahertz waves toward the human body using a laser source.

Preferably, the terahertz wave irradiation step can be operated in a manual mode in which the user can manually turn on and off depending on the power situation, and in an automatic mode in which the device is turned off when the applied amount of power is less than or equal to a preset amount of power, and turned on when it exceeds the preset amount of power. .

The present invention has the advantage of being able to obtain highly accurate biosignals by measuring respiratory rate and heart rate through the movement of the lungs and heart, which directly generate breathing and heart rate, rather than through the external movement of the human body.

Additionally, the present invention has the advantage of being able to detect heart rate or respiratory rate due to the permeability of terahertz waves even in situations where it is difficult to detect chest movement due to thick clothing, etc.

Additionally, the present invention can generate clear images using a laser source that generates terahertz waves.

In addition, the present invention uses some of the antennas constituting the terahertz wave detection sensor to measure distance, and can detect biosignals of the human body and simultaneously detect the position of the human body.

Figure 1 shows the range of various molecular vibrations in the frequency domain of terahertz waves.
Figure 2 shows the configuration of a biosignal measurement system using terahertz waves according to an embodiment of the present invention.
Figure 3 shows the angle of view of a terahertz wave detection sensor according to an embodiment of the present invention.
Figure 4 shows a configuration diagram of a terahertz wave detection sensor according to an embodiment of the present invention.
Figure 5 shows a bio-signal measurement system using terahertz waves to which a laser source is applied according to an embodiment of the present invention.
Figure 6 shows an operation algorithm of a laser source according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the exemplary embodiments. The same reference numerals in each drawing indicate members that perform substantially the same function.

The purpose and effect of the present invention can be naturally understood or become clearer through the following description, and the purpose and effect of the present invention are not limited to the following description. Additionally, in describing the present invention, if it is determined that a detailed description of known techniques related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Figure 2 shows a configuration diagram of a biosignal measurement system 10 using terahertz waves according to an embodiment of the present invention. Referring to FIG. 2, the biosignal measurement system 10 using terahertz waves may include a terahertz wave detection sensor 100, an imaging unit 300, a biosignal detection unit 500, and a laser source 700. You can.

It is a previously used biosignal measurement system that measures respiratory rate and heart rate by detecting human body movements (particularly the chest and abdomen) from images captured using a 2D camera. The biosignal measurement system 10 using terahertz waves according to the present invention measures respiratory rate and heart rate through the movement of the lungs and heart, which directly generates breathing and heartbeat, rather than the external movement of the human body, and produces highly accurate biosignals. can be obtained.

The biological signal measurement system 10 using terahertz waves is not affected by magnetic or electric fields, and although it has strong penetrating power, it does not damage biological tissue like x-rays, ultraviolet rays, or high-power lasers. The biosignal measurement system (10) using terahertz waves has an energy level of one millionth of the existing x-ray energy (4.1meV), so it can realize bio-friendly high-resolution images without destroying the cellular structure of the human body. You can.

The biosignal measurement system 10 using terahertz waves has a relatively high resolution compared to the method using radar, and can solve the problem of invasion of privacy, which is a problem of the method using cameras. The biosignal measurement system 10 using terahertz waves can detect biosignals of the human body and the position of the human body at the same time by using some of the antennas constituting the terahertz wave detection sensor 100 to measure distance. there is.

The method of measuring bio-signals using a 2D camera has limitations in measuring bio-signals because it is difficult to determine the movement of the chest or abdomen when the person to be measured is covered in a blanket or wearing thick clothes. The biosignal measurement system 10 using terahertz waves can detect heart rate or respiratory rate due to the permeability of terahertz waves even in situations where it is difficult to detect chest movement due to thick clothes, etc.

The terahertz wave detection sensor 100 can detect incident terahertz waves. There are numerous radio signals caused by sunlight (1) in the air. Among the radio signals generated by sunlight (1), we can see with our eyes the signals in which visible light is struck by objects, etc. and reflected. 2D cameras convert visible light into electrical signals and create images. The terahertz wave detection sensor 100 according to the present invention can detect terahertz waves transmitted through or reflected by the human body. The terahertz wave detected by the terahertz wave detection sensor 100 may be converted into an electrical signal in the imaging unit 300 and imaged.

The terahertz wave detection sensor 100 uses a photoconductive antenna method, an all-optical sampling method, a bolometer, a Golay cell, a Shottky barrier photodiode, or a superconductor-insulator-superconductor (SIS) mixer. Terahertz waves can be detected using a THz wave detector. In particular, the terahertz wave detection sensor 100 may be configured as a bolometer sensor that operates at room temperature without using a cooler and is characterized by low cost, small size, light weight, and low power consumption. Bolometer sensors generally use VOx sensing materials with low thermal noise and detect THz waves when combined with an antenna, making them easy to manufacture as two-dimensional array sensors.

The terahertz wave detection sensor 100 is installed on the back of the human body and can acquire images at a location close to the human body, thereby improving the detection accuracy of the bio-signal detection unit 500. Terahertz waves reflected or transmitted by the human body are weak signals and may be vulnerable to noise. Accordingly, the terahertz wave detection sensor 100 may be installed on the back of the human body to detect terahertz waves at a location close to the human body.

The terahertz wave detection sensor 100 is installed in a vehicle and may be located on the back of the backrest of a chair in the vehicle. When placed in front of the human body, the terahertz wave detection sensor 100 can detect terahertz waves containing a significant amount of noise due to hand movement, movement of objects or people between the sensor and the measuring person, etc. The terahertz wave detection sensor 100 according to the present invention can be installed on the back of a chair's backrest or the bottom of a bed so that obstacles cannot pass between the sensor and the measuring person.

The terahertz wave detection sensor 100 can remove noise by applying a moving average filter that accumulates incident terahertz waves.

Figure 3 shows the angle of view of the terahertz wave detection sensor 100 according to an embodiment of the present invention. Referring to FIG. 3, the angle of view of the terahertz wave detection sensor 100 may be set to image both the heart and lungs within the human body. When measuring only the heart rate, the terahertz wave detection sensor 100 may have an angle of view set to image the heart within the human body, and when measuring only the breathing rate, the angle of view may be set to image the lungs within the human body.

Figure 4 shows a configuration diagram of a terahertz wave detection sensor 100 according to an embodiment of the present invention. Referring to FIG. 4, the terahertz wave detection sensor 100 is m It consists of n array antennas, and some of the array antennas can be used to measure distance to the human body. The terahertz wave detection sensor (100) is m When configured as an n array antenna, the array antenna may include a terahertz wave detection antenna 110 and a distance detection antenna 130. The terahertz wave detection antenna 110 is used to detect and image terahertz waves, and the distance detection antenna 130 can be used to measure the distance to a specific object or human body.

The imaging unit 300 may convert the terahertz wave incident to the terahertz wave detection sensor 100 into an electrical signal and generate an image using the electrical signal. The imaging unit 300 can use both passive imaging and active imaging methods. Here, the passive imaging method is a technology that images using terahertz waves emitted directly from the sample to be observed without an external terahertz light source or generated by scattering from the sample by a black body radiation light source in the atmosphere, and the active imaging method is This is a technology that creates an image of an object by making a terahertz light source incident on the object to be observed and detecting terahertz waves that pass through or are reflected from the object. The imaging unit 300 uses a passive imaging method when the laser light source 700 does not operate, and uses a passive + active imaging method when the laser light source 700 operates.

The imaging unit 300 may generate an electrical signal with an intensity proportional to the intensity of the incident terahertz wave and assign a pixel value according to the intensity of the electrical signal. For example, the imaging unit 300 may assign a high pixel value when the intensity of the electrical signal is large, and may assign a small pixel value when the intensity of the electrical signal is low. The imaging unit 300 may image by assigning pixel values according to the intensity of terahertz waves received by each antenna included in the array antenna. The imaging unit 300 may perform imaging by performing imaging in real time.

The biosignal detection unit 500 may detect the breathing rate of the human body by detecting the movement of the lung portion of the human body in the image generated by the imaging unit 300. The biosignal detection unit 500 may detect heart movement by fixing (enlarging) only the lung portion of the human body in the image generated by the imaging unit 300. The biosignal detector 500 determines the difference in lung size that changes with breathing, and when the difference between the smallest and largest lungs is considered the maximum value, the difference in lung size greater than a preset ratio (< 1) from the maximum value is determined. In this case, it can be detected as one breath.

The biosignal detection unit 500 may detect the heart rate of the human body by detecting the movement of the heart part of the human body in the image generated by the imaging unit 300. The biosignal detection unit 500 can detect heart movement by fixating (enlarging) only the heart part of the human body in the image generated by the imaging unit 300. The biosignal detection unit 500 determines the difference in heart size that changes according to the heartbeat, and when the difference between the smallest and largest heart states is called the maximum value, the heart size difference is greater than a preset ratio (< 1) from the maximum value. When occurs, it can be detected that the heart beats once.

Since the biosignal detection unit 500 tracks and observes only the heart or lung portion of the image generated by the imaging unit 300, it can be free from noise caused by human body movement. The biosignal detection unit 500 can detect biosignals from images of the heart or lungs inside the human body according to the transmission characteristics of terahertz waves, so biosignals can be detected even when the measurer is covered with a blanket or wearing thick clothes. It can be easily detected. Existing thermal imaging sensors can also detect people covered by blankets, etc., but on hot days, the temperature inside the vehicle can be very high, and in this case, the sensing range can be exceeded. However, the present invention does not cause problems due to temperature. No.

Figure 5 shows a bio-signal measurement system 10 using terahertz waves to which a laser source 700 is applied according to an embodiment of the present invention. Referring to FIG. 5, the laser source 700 can irradiate terahertz waves toward the human body.

The biosignal measurement system 10 using terahertz waves according to the present invention can generally operate without the laser source 700. In other words, the biosignal measurement system 10 using terahertz waves can perform imaging by receiving only the incident terahertz waves, without radiating terahertz waves. However, in this case, if the signal of the terahertz wave generated by scattering by the black body radiation source in the air is weak, the difference in pixel value for each pixel is very small, and imaging may not be performed properly. Accordingly, the laser source 700 can serve to reinforce insufficient terahertz wave signals.

The laser source 700 can be understood on the same principle as a flash used in a general 2D camera. If you shoot with a regular 2D camera at night with the lights off, it is difficult to distinguish the subject from the captured image because the strength of the signal you want to see is too weak. However, if you turn on the lights at night and shoot with a regular 2D camera, the subject is clearly distinguishable in the captured image. The laser source 700 can be understood as playing the role of fire.

The laser source 700 can be driven in a manual mode in which the user can manually turn it on and off depending on the power situation, and in an automatic mode in which it is turned off when the amount of power applied is less than or equal to a preset amount of power, and turned on when it exceeds the preset amount of power.

In the case of diagnostic medical devices, measuring biological signals continuously and stably is an important challenge. The laser source 700 can consume a lot of power, so when the biosignal measurement system 10 using terahertz waves is operated with limited energy, a power shortage problem may occur. When the bio-signal measurement system 10 using terahertz waves is operated without the laser source 700, the power consumption of the bio-signal measurement system 10 using terahertz waves is several microwatts. Accordingly, the laser source 700 can be configured to turn on and off depending on the power situation.

Figure 6 shows an operation algorithm of the laser source 700 according to an embodiment of the present invention. Referring to FIG. 6, when the laser source 700 is in manual mode, the user can directly turn it on and off as needed. That is, the user can turn off the laser source 700 when the available power is sufficient or when imaging is easy without the laser source 700. The user can turn on the laser source 700 if there is insufficient power or if imaging is difficult without the laser source 7000.

When the laser source 700 is in automatic mode, a reference power amount can be set by the user. The laser source 700 may be automatically turned off when the remaining power of the energy source of the bio-signal measurement system 10 using terahertz waves is less than the standard power amount (preset power amount). The laser source 700 may be automatically turned off when the remaining power of the energy source of the bio-signal measurement system 10 using terahertz waves exceeds the reference power amount (preset power amount).

In particular, when the bio-signal measurement system 10 using terahertz waves according to the present invention is installed in a vehicle, it is operated with limited battery capacity. Patent: In the case of electric vehicles, the vehicles are driven by batteries, so if the batteries are consumed during non-operation times by the bio-signal measurement system 10 using terahertz waves, actual driving efficiency may decrease. Accordingly, the laser source 700 can be set in mode and on/off, thereby solving the battery problem.

In another embodiment of the present invention, a bio-signal measurement method using terahertz waves may include a terahertz wave detection step, an imaging step, a bio-signal detection step, and a terahertz wave irradiation step.

In the terahertz wave detection step, terahertz waves can be detected using a terahertz wave detection sensor. The terahertz wave detection step refers to an operation performed by the above-described terahertz wave detection sensor 100.

In the imaging step, the terahertz waves detected in the detection step can be converted into electrical signals and images can be created using the electrical signals. The imaging step refers to an operation performed by the above-described imaging unit 300.

The biosignal detection step can detect the breathing rate of the human body by detecting the movement of the lung portion of the human body in the image generated in the imaging step. In the biosignal detection step, the heart rate of the human body can be detected by detecting the movement of the heart part of the human body in the image generated by the imaging unit 300. The bio-signal detection step refers to the operation performed by the bio-signal detection unit 500 described above.

In the terahertz wave irradiation step, terahertz waves can be irradiated toward the human body using the laser source 100. The terahertz wave irradiation stage can be operated in a manual mode in which the user can manually turn it on and off depending on the power situation, and in an automatic mode in which it is turned off if the applied power amount is less than a preset amount of power and turned on if it is exceeded. The terahertz wave irradiation step refers to an operation performed by the laser source 100 described above.

Although the present invention has been described in detail through representative embodiments above, those skilled in the art will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention. will be. Therefore, the scope of rights of the present invention should not be limited to the described embodiments, but should be determined not only by the claims described later, but also by all changes or modified forms derived from the claims and the concept of equivalents.

1: solar power
10: Biosignal measurement system using terahertz waves
100: Terahertz wave detection sensor
110: Terahertz wave detection antenna
130: Distance detection antenna
300: Imaging unit
500: Biosignal detection unit
700: Laser source

Claims (10)

Terahertz wave detection sensor;
an imaging unit that converts the terahertz wave incident to the terahertz wave detection sensor into an electrical signal and generates an image using the electrical signal; and
a bio-signal detection unit that detects the breathing rate of the human body by detecting movement of the lung portion of the human body in the image generated by the imaging unit;
A biosignal measurement system using terahertz waves, comprising:
According to claim 1,
The terahertz wave detection sensor,
A bio-signal measurement system using terahertz waves, which is installed on the back of the human body and acquires images at a location close to the human body, thereby improving the detection accuracy of the bio-signal detection unit.
According to claim 2,
The terahertz wave detection sensor,
A biosignal measurement system using terahertz waves that is installed in a vehicle and located on the back of the backrest of a chair in the vehicle.
According to claim 1,
The terahertz wave detection sensor,
m It consists of n array antennas,
A biosignal measurement system using terahertz waves, wherein some of the array antennas are used to measure distances to the human body.
According to claim 1,
The biosignal detection unit,
A biosignal measurement system using terahertz waves, characterized in that it detects the heart rate of the human body by detecting the movement of the heart part of the human body from the image generated by the imaging unit.
According to claim 1,
A biosignal measurement system using terahertz waves, further comprising a laser source that irradiates terahertz waves toward the human body.
According to claim 6,
The laser source is,
A manual mode where the user can manually turn on and off depending on the power situation,
A biosignal measurement system using terahertz waves, characterized in that it is operated in an automatic mode that turns off when the applied power amount is less than a preset amount of power and turns on when it exceeds the preset power amount.
A terahertz wave detection step of detecting terahertz waves using a terahertz wave detection sensor;
An imaging step of converting the terahertz waves detected in the detection step into an electrical signal and generating an image using the electrical signal; and
A bio-signal detection step of detecting the breathing rate of the human body by detecting the movement of the lung portion of the human body from the image generated in the imaging step;
A bio-signal measurement method using terahertz waves, comprising:
According to claim 8,
A bio-signal measurement method using terahertz waves, further comprising a terahertz wave irradiation step of irradiating terahertz waves toward the human body using a laser source.
According to clause 9,
The terahertz wave irradiation step is,
A manual mode where the user can manually turn on and off depending on the power situation,
A bio-signal measurement method using terahertz waves, characterized in that it is driven in an automatic mode that turns off when the applied power amount is less than a preset amount of power and turns on when it exceeds the preset power amount.