Method and Apparatus for Measuring Non-Contact Multiple Biosignal

Abstract

According to the present embodiment, a biosignal measuring device is provided comprising: a light source irradiation unit that radiates a first emission light of a first wavelength and a second emission light of a second wavelength toward a subject to be measured; a reflected light receiving unit that receives a first reflected light of the first wavelength and a second reflected light of the second wavelength reflected from the subject to be measured; a light absorption detection unit that detects a first light absorption for the first reflected light and a second light absorption for the second reflected light; and an oxygen saturation calculation unit that calculates the oxygen saturation of the subject to be measured according to the difference between the first light absorption and the second light absorption.

Description

Technology Field

[0001] This embodiment relates to a non-contact multi-biometric signal measurement device and method. Background Technology

[0002] The following description merely provides background information related to the present embodiment and does not constitute prior art.

[0003] It is crucial to screen for symptomatic individuals early in the event of an outbreak of infectious diseases such as COVID-19. This is because a delay in confirming a diagnosis significantly increases the risk of transmission to others.

[0004] Currently, the confirmation of infectious diseases such as COVID-19 is determined by using molecular diagnostic technology to collect a sample from the nasal cavity and test for the coronavirus. However, molecular diagnostic testing requires a long time of about 4 hours or more due to the processes of sample collection, pretreatment, and amplification. Additionally, there are disadvantages such as pain and discomfort for the subject during sample collection and a long waiting time to determine the diagnosis.

[0005] Infection with the COVID-19 virus is accompanied by a variety of complex physical symptoms, such as fever, cough, shortness of breath, and sore throat. Among these various symptoms, the only one currently used to screen for symptomatic individuals infected with the COVID-19 virus is measuring body temperature.

[0006] However, only about 25% of all infected individuals exhibit fever symptoms even after being infected with the COVID-19 virus. Therefore, simultaneously measuring multiple vital signs (body temperature, oxygen saturation, pulse, etc.) associated with the various complex physical symptoms that appear when infected with the COVID-19 virus can identify symptomatic individuals infected with the virus at an early stage with very high accuracy, making it very effective in preventing the large-scale spread of the COVID-19 virus.

[0007] Among various biological signals, oxygen saturation (SpO2) refers to the amount of oxygen bound to hemoglobin (Hb) in red blood cells. By utilizing blood oxygen saturation to assess the amount of oxygen transported by red blood cells, it is possible to determine whether respiration is effective or if oxygen is being properly delivered to the human body. Oxygen saturation is expressed as a percentage of the ratio of the concentration of oxyhemoglobin (which is bound to oxygen) to the total hemoglobin concentration. The normal range for oxygen saturation is 95% or higher; falling below this level can cause hypoxia, which can lead to a critical condition characterized by difficulty breathing.

[0008] The most accurate method for measuring oxygen saturation is to collect arterial blood and measure the oxygen saturation in the blood. However, this method has the disadvantage that blood collection is essential and it takes a certain amount of time to analyze the oxygen saturation value after blood collection.

[0009] The most representative non-invasive method that does not require blood sampling is pulse oximetry, which measures oxygen saturation through absorbance using optical elements.

[0010] The pulse oximetry method currently in use employs technology that measures oxygen saturation via contact by attaching a device to the fingertip.

[0011] However, these contact-based measurement methods are unsuitable for screening symptomatic individuals with highly contagious infectious diseases such as COVID-19. This is because contact methods make it impossible to prevent the spread of the virus through the device, as many people use the same equipment, and additional processes, such as device sterilization, are required to prevent transmission. Therefore, the development of non-contact multi-vitamin measurement technology is necessary to efficiently screen symptomatic individuals infected with COVID-19 at an early stage and to continuously monitor confirmed cases.

[0012] Currently, technologies for measuring pulse and oxygen saturation from the body in a non-contact manner are being developed using various methods such as light, electromagnetic waves, and imaging, but they are still in the basic technology development stage and have the disadvantage of low measurement accuracy. Korean Registered Patent Publication 10-2434698 (August 22, 2022) discloses matters related to the background technology of the present invention. The problem to be solved

[0013] The main purpose of this embodiment is to provide a non-contact multi-biometric signal measurement device and method. means of solving the problem

[0014] According to the present embodiment, a biosignal measuring device is provided comprising: a light source irradiation unit that radiates a first emission light of a first wavelength and a second emission light of a second wavelength toward a subject to be measured; a reflected light receiving unit that receives a first reflected light of the first wavelength and a second reflected light of the second wavelength reflected from the subject to be measured; a light absorption detection unit that detects a first light absorption for the first reflected light and a second light absorption for the second reflected light; and an oxygen saturation calculation unit that calculates the oxygen saturation of the subject to be measured according to the difference between the first light absorption and the second light absorption.

[0015] According to the present embodiment, a method for measuring a biosignal is provided, comprising: a light source irradiation process of irradiating a first emission light of a first wavelength and a second emission light of a second wavelength toward a subject to be measured; a reflected light reception process of receiving a first reflected light of the first wavelength and a second reflected light of the second wavelength reflected from the subject to be measured; a light absorption detection process of detecting a first light absorption rate for the first reflected light and a second light absorption rate for the second reflected light; and an oxygen saturation calculation process of calculating the oxygen saturation of the subject to be measured according to the difference between the first light absorption rate and the second light absorption rate. Effects of the invention

[0016] The present invention is a sensor device capable of measuring biosignals reflected from the fingernail area of ​​the human body in a non-contact manner using a light source element and a photodetector, and thus has the advantage of being simple to manufacture.

[0017] In addition, according to the present invention, a biosignal measurement sensor using a light source element and a photodetector does not require a complex optical system and can be used to quantitatively detect pulse and oxygen saturation simultaneously with high sensitivity. Brief explanation of the drawing

[0018] FIG. 1 is an exemplary functional block diagram illustrating a biosignal measuring device according to the present embodiment. FIG. 2 is a diagram showing a first absorption spectrum that shows the change in light absorption of a first wavelength over time for a first reflected light. Figure 3 is a graph showing the principle of measuring oxygen saturation from the first absorption spectrum and the second absorption spectrum. Figure 4 is a flowchart illustrating a method of measuring a biosignal using a biosignal measuring device. Specific details for implementing the invention

[0019] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning identification symbols to the components of each drawing, the same components are assigned the same symbol whenever possible, even if they are shown in different drawings. Furthermore, in describing the present invention, if it is determined that a detailed description of related known components or functions could obscure the essence of the invention, such detailed description is omitted.

[0020] FIG. 1 is an exemplary functional block diagram illustrating a biosignal measuring device according to the present embodiment.

[0021] The biosignal measuring device (100) according to the present embodiment includes a light source irradiation unit (110), a reflected light receiving unit (120), a light absorption detection unit (130), a pulse rate calculation unit (140), and an oxygen saturation calculation unit (150).

[0022] The light source irradiation unit (110) radiates a first emission light of a first wavelength and a second emission light of a second wavelength toward the object to be measured (200).

[0023] Here, the subject (200) may be a fingernail part of the human body.

[0024] The light source irradiation unit (110) includes a first light source (111) and a second light source (112). The first light source (111) and the second light source (112) may each use a light-emitting diode that emits light of different wavelengths.

[0025] The first light source (111) generates a first emission light having a wavelength of 660 nm, which is the first wavelength, and the second light source (112) generates a second emission light having a wavelength of 940 nm, which is the second wavelength.

[0026] The reflected light receiving unit (120) receives a first reflected light of a first wavelength and a second reflected light of a second wavelength reflected from the object to be measured (200).

[0027] The reflected light receiving unit (120) includes a first light receiving unit (121) and a second light receiving unit (122). A CMOS (Complementary Metal-Oxide Semiconductor) image sensor may be used for each of the first light receiving unit (121) and the second light receiving unit (122).

[0028] In order to ensure that the first light source (111) and the second light source (112), and the first light receiver (121) and the second light receiver (122) are positioned so as to be at a certain distance from the position of the subject (200), respectively, in order to ensure that the pulse rate and oxygen saturation are measured in a non-contact state with the subject (200).

[0029] Here, the first light receiver (121) can be formed as a CMOS image sensor for absorbing reflected light of a first wavelength, and the second light receiver (122) can be formed as a CMOS image sensor for absorbing reflected light of a second wavelength.

[0030] The light absorption detection unit (130) detects the first light absorption for the first reflected light and the second light absorption for the second reflected light.

[0031] The light absorption detection unit (130) may be configured to include a first detection unit (131) and a second detection unit (132).

[0032] The first detector (131) detects the light absorption rate for a first wavelength for a certain period of time for the first reflected light received by the first light receiver (121) and stores it as a first absorption spectrum, and the second detector (132) detects the light absorption rate for a second wavelength for a certain period of time for the second reflected light received by the second light receiver (122) and stores it as a second absorption spectrum.

[0033] Light incident on the subject (200) from two light sources, a first light source (111) and a second light source (112), having different wavelengths, is absorbed by the microvessels inside the subject (200) and the remaining light that is not absorbed is reflected, and some of the reflected light is incident on the first light receiver (121) and the second light receiver (122).

[0034] FIG. 2 is a diagram showing a first absorption spectrum that shows the change in light absorption of a first wavelength over time for a first reflected light.

[0035] The graph of FIG. 2 is a graph in which the first detector (131) detects the light absorption peak values ​​(201, 202, 203, 204, 205, 206) for the first wavelength for a certain period of time with respect to the first reflected light incident on the first light receiver (121) and stores them as the first absorption spectrum.

[0036] The blood flow within the microvessels inside the subject (200) changes over time, and this change in blood flow is related to the pulse rate of the subject (200). That is, if the pulse rate of the subject (200) is fast, the change in blood flow within the microvessels is fast, and if the pulse rate of the subject (200) is slow, this change in blood flow is slow.

[0037] Referring to FIG. 2, when light is incident on a subject (200) from a first light source (111) that emits light of a first wavelength of 660 nm, the spectrum of light absorption incident on the first light receiver (121) changes according to changes in blood flow within the microvessels inside the subject (200).

[0038] Therefore, by analyzing the first absorption spectrum of the reflected light incident on the first light receiver (121), the pulse rate of the subject (200) can be calculated.

[0039] The pulse rate calculation unit (140) calculates the pulse rate of the subject (200) from the time interval of the change in the first light absorption peak value from the first absorption spectrum.

[0040] For example, in FIG. 2, the pulse rate calculation unit (140) checks the number of occurrences of light absorption peak values ​​(201, 202, 203, 204, 205, 206) and the time required corresponding to the number of occurrences, and calculates the pulse rate of the subject (200) by dividing the number of occurrences of the first light absorption peak value by the time required. For example, assuming the time between the first light absorption peak value (201) and the sixth light absorption peak value (206) is 10 seconds, the light absorption peak value occurs 5 times during the 10 seconds, so the pulse rate calculation unit (140) calculates that the pulse rate during 1 minute is 30 times using the following mathematical formula 2.

[0041]

[0042] Here, C is the number of occurrences of light absorption peak values, and T is the time required.

[0043] Figure 3 is a graph showing the principle of measuring oxygen saturation from the first absorption spectrum and the second absorption spectrum.

[0044] The second detector (132) detects the light absorption of the second wavelength for a certain period of time for the second reflected light received by the second light receiver (122) and stores it as a second absorption spectrum, and the graph shape of the second absorption spectrum is similar to the shape of the first absorption spectrum. However, as shown in FIG. 3, the magnitude of each light absorption peak value in the first absorption spectrum and the second absorption spectrum is different in the case of oxygen-bound hemoglobin and oxygen-unbound hemoglobin within the subject to measurement (200).

[0045] The oxygen saturation calculation unit (150) calculates the oxygen saturation of the subject (200) based on the difference between the first light absorption at the first wavelength and the second light absorption at the second wavelength.

[0046] After the first emission light and the second emission light are incident on the subject (200) from the first light source (111) and the second light source (112), which are two light source elements having different wavelengths (660 nm, 940 nm), the oxygen saturation calculation unit (150) can calculate the oxygen saturation inside the microvessels below the surface of the subject (200) according to the change in the peak value of the light absorption of the reflected light of two different wavelengths (660 nm, 940 nm) reflected from the subject (200).

[0047] The peak values ​​of light absorption for oxygen-bound hemoglobin and oxygen-unbound hemoglobin differ at reflected light of different wavelengths.

[0048] The oxygen saturation calculation unit (150) obtains the light absorption peak values ​​(I) of oxygen-bound hemoglobin (HbO2) and oxygen-unbound hemoglobin (Hb) from the first absorption spectrum and the second absorption spectrum. A , I B , I C , I DEach of the ) is detected to calculate the oxygen saturation of the subject (200).

[0049] That is, in the 660nm wavelength region, the absorption of oxygen-bound hemoglobin (I B ) is the peak light absorption value (I) of oxygen-unbound hemoglobin A Much larger than ), and in the 940nm wavelength region, the peak value of light absorption of unbound oxygen hemoglobin (I D ) peak light absorption value of oxygen-bound hemoglobin (I C It is much larger than ). Therefore, the peak values ​​of light absorption at different wavelengths (660nm, 940nm) (I A , I B , I C , I D By utilizing the change in ), the oxygen saturation level within the microvessels inside the surface of the subject (200) can be accurately and quantitatively calculated.

[0050] As illustrated in FIG. 3, the oxygen saturation calculation unit (150) can calculate the oxygen saturation by analyzing the relative intensity change of the first reflected light and the second reflected light having wavelengths of 660 nm and 940 nm, respectively.

[0051] The oxygen saturation calculation unit (150) calculates the oxygen saturation by calculating a first statistical indicator of the first light absorption peak value in the first spectrum and a second statistical indicator of the second light absorption peak value in the second spectrum in order to analyze the relative intensity change of two reflected lights.

[0052] Here, the value obtained by dividing the standard deviation of multiple first light absorption peak values ​​in the first spectrum by the average of the first light absorption peak values ​​is determined as the first statistical indicator. Additionally, the value obtained by dividing the standard deviation of multiple second light absorption peak values ​​in the second spectrum by the average of the second light absorption peak values ​​is determined as the second statistical indicator.

[0053] The oxygen saturation calculation unit (150) calculates the oxygen saturation based on the ratio between the first statistical indicator and the second statistical indicator.

[0054] That is, the oxygen saturation calculation unit (150) can calculate the oxygen saturation SpO2 according to the following mathematical formula 2.

[0055]

[0056] Here, K1 and K2 can be set as proportionality constants of 110 and 25, respectively, but the present invention is not limited thereto.

[0057] In addition, a1 represents the value obtained by dividing the standard deviation of multiple first light absorption peak values ​​by the average of the first light absorption peak values ​​as a first statistical indicator, and a2 represents the value obtained by dividing the standard deviation of multiple second light absorption peak values ​​by the average of the second light absorption peak values ​​as a second statistical indicator.

[0058] Figure 4 is a flowchart illustrating a method of measuring a biosignal using a biosignal measuring device.

[0059] Hereinafter, a method for measuring biosignals will be described with reference to FIGS. 1 to 4.

[0060] The light source irradiation unit (110) radiates a first emission light of a first wavelength and a second emission light of a second wavelength toward the object to be measured (200) (S410).

[0061] The reflected light receiving unit (120) receives a first reflected light of a first wavelength and a second reflected light of a second wavelength reflected from the object to be measured (200) (S420).

[0062] The first detector (131) detects the light absorption of the first wavelength for the first reflected light received by the first light receiver (121) for a certain period of time and stores it as the first absorption spectrum (S430).

[0063] The second detector (132) detects the light absorption of the second wavelength for the second reflected light received by the second light receiver (122) for a certain period of time and stores it as the second absorption spectrum (S440).

[0064] The pulse rate calculation unit (140) calculates the pulse rate of the subject (200) from the time interval of the change in the first light absorption peak value from the first absorption spectrum (S450).

[0065] The oxygen saturation calculation unit (150) calculates the oxygen saturation of the subject (200) based on the difference between the first light absorption peak value at the first wavelength and the second light absorption peak value at the second wavelength (S460).

[0066] The oxygen saturation calculation unit (150) determines the value obtained by dividing the standard deviation of the first light absorption peak value in the first spectrum by the average of the first light absorption peak value as the first statistical indicator in order to analyze the change in intensity of the relative peak values ​​of the two reflected lights.

[0067] Additionally, the oxygen saturation calculation unit (150) determines the value obtained by dividing the standard deviation of the second light absorption peak value in the second spectrum by the average of the second light absorption peak values ​​as the second statistical indicator.

[0068] The oxygen saturation calculation unit (150) calculates the oxygen saturation based on the value obtained by dividing the first statistical indicator by the second statistical indicator as in the aforementioned mathematical formula 2.

[0069] The operation of the pulse rate calculation unit (140) and the oxygen saturation calculation unit (150) has been described above, so further explanation regarding this is omitted.

[0070] Meanwhile, the various functions or methods described in this disclosure may be implemented as instructions stored in a non-transient recording medium that can be read and executed by one or more processors. A non-transient recording medium includes, for example, any type of recording device in which data is stored in a form readable by a computer system. For example, a non-transient recording medium includes storage media such as EPROM (Erasable Programmable Read Only Memory), flash drives, optical drives, magnetic hard drives, and solid-state drives (SSDs).

[0071] It should be understood that the exemplary embodiments described above may be implemented in many different ways. The functions described in one or more examples may be implemented in hardware, software, firmware, or any combination thereof. It should be understood that the functional components described herein are labeled as "...unit" to particularly emphasize their implementation independence.

[0072] The above description is merely an illustrative explanation of the technical concept of the present embodiment, and a person skilled in the art to which the present embodiment belongs would be able to make various modifications and variations within the scope of the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain, not limit, the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment. Explanation of the symbols

[0073] 100: Biosignal measuring device 110: Light source irradiation unit 111: First light source 112: Second light source 120: Reflected light receiver 121: First light receiver 122: Second optical receiver 130: Optical absorption detector 131: First detection unit 132: Second detection unit 140: Pulse rate calculation unit 150: Oxygen saturation calculation unit 201, 202, 203, 204, 205, 206: Light absorption

Claims

Claim 1 A light source irradiation unit that radiates a first emitted light of a first wavelength and a second emitted light of a second wavelength toward a subject to measurement; a reflected light receiving unit that receives the first reflected light of the first wavelength and the second reflected light of the second wavelength reflected from the subject to measurement; and a light absorption detection unit that detects a first light absorption for the first reflected light and a second light absorption for the second reflected light; A biosignal measuring device comprising an oxygen saturation calculation unit that calculates the oxygen saturation of a subject according to the first light absorption and the second light absorption, wherein the light source irradiation unit and the reflected light receiving unit are each configured to be at a certain distance from the subject, and the oxygen saturation calculation unit calculates a first value obtained by dividing the standard deviation of a plurality of first light absorptions by the average of the first light absorptions and a second value obtained by dividing the standard deviation of a plurality of second light absorptions by the average of the second light absorptions, and calculates the oxygen saturation based on the ratio between the first value and the second value, wherein the oxygen saturation is calculated based on the following formula K1 - K2 * [a1 / a2] (where K1 and K2 are constants, a1 is the first value, and a2 is the second value). Claim 2 A biosignal measuring device according to claim 1, further comprising a pulse rate calculation unit that calculates the pulse rate of the subject from the time interval of the first change in light absorption. Claim 3 A biosignal measuring device according to claim 1, wherein the light absorption detection unit detects the first light absorption and the second light absorption over time. Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 A biosignal measuring device according to claim 1, characterized in that the first wavelength is 660 nm and the second wavelength is 940 nm. Claim 9 A method for measuring a biosignal using a biosignal measuring device comprising a light source irradiation unit, a reflected light receiving unit, a light absorption detection unit, and an oxygen saturation calculation unit, wherein the light source irradiation unit irradiates a first emitted light of a first wavelength and a second emitted light of a second wavelength toward a subject to be measured; a reflected light receiving unit receives a first reflected light of the first wavelength and a second reflected light of the second wavelength reflected from the subject to be measured; and a light absorption detection unit detects a first light absorption for the first reflected light and a second light absorption for the second reflected light. A biosignal measurement method comprising: an oxygen saturation calculation unit including an oxygen saturation calculation process that calculates the oxygen saturation of the subject according to the first light absorption and the second light absorption; wherein the light source irradiation unit and the reflected light receiving unit are each configured to be at a certain distance from the subject, and the oxygen saturation calculation process calculates a first value obtained by dividing the standard deviation of a plurality of first light absorptions by the average of the first light absorptions and a second value obtained by dividing the standard deviation of a plurality of second light absorptions by the average of the second light absorptions, and calculates the oxygen saturation based on the ratio between the first value and the second value, wherein the oxygen saturation is calculated based on the following formula K1 - K2 * [a1 / a2] (where K1 and K2 are constants, a1 is the first value, and a2 is the second value). Claim 10 A biosignal measurement method according to claim 9, further comprising a pulse rate calculation process for calculating the pulse rate of the subject from the time interval of the first change in light absorption. Claim 11 A biosignal measurement method according to claim 9, characterized in that the first light absorption and the second light absorption are each detected over time. Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 A biosignal measurement method according to claim 9, characterized in that K1 is 110 and K2 is 25.

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