KR102504784B1 - Oxygen saturation measuring method based on independent componet analysis technique and apparatus therefore - Google Patents

Abstract

A method and apparatus for measuring oxygen saturation based on independent component analysis are disclosed. An oxygen saturation measurement method according to an embodiment of the present invention is a method for measuring oxygen saturation, comprising: obtaining a received signal including an infrared signal and a red signal that have passed through a user's body; Separating an infrared signal and a red signal independent of the obtained received signal; removing noise commonly applied to the separated infrared and red signals; and calculating the oxygen saturation value of the user using the noise-removed infrared signal and the red signal, wherein the separating step uses the independent component analysis (ICA) to obtain the oxygen saturation value. Independent infrared and red signals can be separated from the received signal.

Description

Oxygen saturation measurement method and device based on independent component analysis technique

The present invention relates to a technology for measuring oxygen saturation based on an independent component analysis technique, and more particularly, a method for measuring oxygen saturation based on an independent component analysis technique capable of measuring oxygen saturation based on an independent component analysis technique (ICA), and It's about the device.

As individualization and aging progresses, individuals are interested in their own health and are conducting regular health checkups. However, since it is inconvenient to take extra time to do a health checkup, most of them go to the hospital when there is something wrong with their health. However, in the case of the elderly or handicapped with inconvenient movement or chronic disease, it is inconvenient to go to the hospital, and it is possible to cope with dangerous situations only by periodically checking the state of the body (ie, the living body state).

Oxygen saturation measurement is widely used as a measurement target for personal health. Oxygen saturation measurement is non-invasively calculating blood oxygen saturation (SpO 2 ) by measuring light absorbance for each wavelength by pulsating components of arterial blood.

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Korean Patent Publication No. 10-2005-0005661 (2005.01.14, published)

Embodiments of the present invention provide a method for measuring oxygen saturation based on independent component analysis (ICA) and an apparatus for measuring oxygen saturation based on independent component analysis (ICA).

An oxygen saturation measurement method according to an embodiment of the present invention is a method for measuring oxygen saturation, comprising: obtaining a received signal including an infrared signal and a red signal that have passed through a user's body; Separating an infrared signal and a red signal independent of the obtained received signal; removing noise commonly applied to the separated infrared and red signals; and calculating the oxygen saturation value of the user using the noise-removed infrared signal and the red signal.

In the separating, the independent infrared signal and the red signal may be separated from the obtained received signal using an independent component analysis (ICA).

The removing of the noise may include separating the separated noise signal commonly applied to the infrared signal and the red signal using an independent component analysis technique and then removing the separated noise signal using an adaptive filter. can

In the calculating of the user's oxygen saturation value, a photoplethysmography (PPG) signal may be obtained by removing the noise, and the user's oxygen saturation value may be calculated using the obtained photoplethysmography signal.

An apparatus for measuring oxygen saturation according to an embodiment of the present invention includes: an acquisition unit that obtains a received signal including an infrared signal and a red signal that have passed through a user's body; a separation unit separating an infrared signal and a red signal independent of the obtained received signal; a removal unit removing noise commonly applied to the separated infrared signal and the red signal; and a calculator configured to calculate an oxygen saturation value of the user by using the noise-removed infrared signal and the red signal.

The separating unit may separate the infrared signal and the red signal independent from the acquired received signal using an independent component analysis (ICA).

The remover may separate the separated noise signal commonly applied to the infrared signal and the red signal using an independent component analysis technique, and then remove the separated noise signal using an adaptive filter.

The operation unit may obtain a photoplethysmography (PPG) signal by removing the noise, and may calculate an oxygen saturation value of the user using the obtained photoplethysmography signal.

According to embodiments of the present invention, oxygen saturation may be measured based on Independent Component Analysis (ICA).

According to embodiments of the present invention, by measuring the oxygen saturation value using an independent component analysis technique, it is possible to improve the accuracy of the oxygen saturation measurement value.

1 shows the configuration of a ring-shaped oxygen saturation measuring device.
2 shows an exemplary view for explaining a semi-convex lens applied to a light transmitter and a light receiver.
FIG. 3 shows a picture of a state in which the device of FIG. 1 is worn on a user's finger.
4 is an operational flowchart for a method for measuring oxygen saturation based on an independent component analysis technique according to an embodiment of the present invention.
FIG. 5 shows an exemplary diagram for explaining the method of FIG. 4 .
6 illustrates a configuration of a device for measuring oxygen saturation based on an independent component analysis technique according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various forms different from each other, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

Terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" means that a stated component, step, operation, and/or element is present in the presence of one or more other components, steps, operations, and/or elements. or do not rule out additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. The same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

An object of the present invention is to provide a method and apparatus capable of measuring oxygen saturation based on Independent Component Analysis (ICA).

At this time, the device applied to the present invention can measure oxygen saturation during daily life in a worn state, and stably detects signals by closely adhering the light transmitter and light receiver to the skin surface touched by the user's finger regardless of the thickness of the finger. Thus, the measurement accuracy of oxygen saturation can be improved. For example, the device applied to the present invention can reduce the driving current of the diode, that is, the light transmitter and the light receiver by about 50% by applying a semi-convex lens to the light transmitter and the light receiver, regardless of the thickness of the finger. A control unit capable of adjusting the elastic force of a curved shape capable of adjusting the contact force so as to be in close contact with the contact unit may be provided.

The present invention will be described with reference to FIGS. 1 to 6 as follows.

1 shows the configuration of a ring-shaped oxygen saturation measuring device, FIG. 1a is a front view of the ring-shaped oxygen saturation measuring device, and FIG. 1b is a perspective view of the ring-shaped oxygen saturation measuring device. .

Referring to FIG. 1 , a ring-shaped oxygen saturation measuring device 100 includes a main body 110, a first body 120, a second body 130, a contact unit 140, a light transmitter 150, and a light receiver. (160).

The body 110 controls the light transmitter 150 and the light receiver 160, and measures the oxygen saturation of the user based on the output signal of the light receiver 160 that receives the light transmitted by the light transmitter 150. contains the module

At this time, the main body 110 further includes a charging terminal 111 for charging the built-in battery of the main body using an external charging means and a display means (not shown) for displaying the user's oxygen saturation measured by the measurement module. can be provided Here, the charging terminal may be configured in a terminal form corresponding to a cable form with the charging means.

The body 110 may be electrically connected to the light transmitting unit 150 and the light receiving unit 160 disposed on the inner surfaces of the first body 120 and the second body 130, and the electrical connection of the present invention It may be determined by a business operator or an individual who provides technology, and since the relevant part may distract from the technical gist of the present invention, a detailed description thereof will be omitted.

The first body portion 120 is formed to contact at least a portion of the skin surface of a user's finger inserted into the device 100 . For example, the first body is physically connected to the main body and is formed of an elastic material on the left side, and either the light transmitter 150 or the light receiver 160 is formed or disposed on the inner surface of the first body 130. can

The second body 130 is formed to contact at least another part of the skin surface of the user's finger inserted into the device 100 . For example, the second body part 130 is physically connected to the main body 110 and is formed of an elastic material on the right side, and among the light transmitter 150 and the light receiver 160 on the inner surface of the second body part 130 Any other may be formed or disposed.

The contact part 140 is formed by being connected to the end of the first body part 120 and the end of the second body part 130, and the distance between the first body part 120 and the second body part 130 is elastically formed. , so that the first body part 120 and the second body part 130 come into close contact with the user's finger contact skin surface regardless of the thickness of the user's finger.

At this time, the contact part 140 is connected to the end of the first body part 120 and the end of the second body part 130 and is formed in a 'U'-shaped curved shape, and may be formed of an elastic material. there is. Of course, the contact part is not limited to a curved shape of a 'U' shape, and the first body part 120 and the second body part 130 can be brought into close contact with the user's finger contact skin surface regardless of the thickness of the user's finger. It can be formed into all kinds of possible shapes.

Although the first body portion 120, the second body portion 130, and the contact portion 140 have been described as independent configurations, the first body portion 120, the second body portion 130, and the contact portion 140 Is not limited or limited to being configured independently, the first body portion 120, the second body portion 130 and the contact portion 140 may be integrally formed of an elastic material, for example, a silicon material. That is, the first body part 120, the second body part 130, and the contact part 140 may be integrally formed in a ring shape.

The light transmitter 150 is a means for transmitting light, and includes a diode (eg, light emitting diode) that emits infrared light and a specific color, for example, red light, and as shown in FIG. A convex lens is formed.

Here, the light transmitter 150 may be disposed on an inner surface of any one of the first body part 120 and the second body part 130, and infrared rays and red light emitted through the semi-convex lens transmit through the finger. and can be transmitted to the light receiver.

At this time, as shown in FIG. 2, the semi-convex lens may include a primary refracting surface 151 formed as a concave surface based on the diode and a secondary refracting surface 152 formed as a convex surface convex outward. . For example, the light emitted by the light transmitter 150 spreads in all directions through the primary refracting surface 151 of the semi-convex lens, and the light spread in this way passes through the secondary refracting surface 152 formed to be convex outward. By doing so, it spreads once more. That is, the light refracted in the direction of diffusion while passing through the primary refracting surface 151 is refracted once more in the direction of diffusion while passing through the secondary refracting surface 152, and as a result, it is diffused and bent twice and irradiated with the user's finger. will do

Here, the radius of curvature of the primary refracting surface 151 of the semi-convex lens may be larger than the radius of curvature of the secondary refracting surface 152 .

The light receiving unit 160 is a means for receiving light, and infrared rays emitted from the light transmitting unit 150 and a specific color, for example, red light transmit through the user's finger and receive the transmitted light.

In this case, the light receiving unit 160 may include a photodiode and the semi-convex lens shown in FIG. 2 . That is, in the light receiving unit 160, a semi-convex lens is formed on the photodiode.

Here, the light receiver 160 may be disposed on the inner surface of the other of the first body 120 and the second body 130, and infrared and red light received through the semi-convex lens are received by the photodiode. It can be.

At this time, the light receiving unit 160 collects the light passing through the finger through the secondary refracting surface of the semi-convex lens and then focuses it once more through the primary refracting surface. That is, light that is focused while passing through the secondary refracting surface is focused once more while passing through the primary refracting surface, and as a result, is double focused and bent and received by the photodiode. Similarly, the radius of curvature of the primary refracting surface of the semi-convex lens applied to the light receiving unit 160 may be greater than the radius of curvature of the secondary refracting surface.

As shown in FIG. 3, the ring-shaped oxygen saturation measuring device 100 is applied to the user's finger skin surface to be worn regardless of the thickness of the user's finger by adjusting the elastic force by the contact unit when applied to the user's finger. By close contact, the light transmitted by the light transmitter 150 passes through the finger and is received by the light receiver 160, and thus the user's oxygen saturation can be measured using the light signal received by the light receiver 160 in the measurement module. there is.

That is, the ring-shaped oxygen saturation measuring device elastically holds the first body part 120 and the second body part 130 according to the thickness of the user's finger into which the device is fitted by the contact part 140, The inner surface of the body part 120 and the second body part 130 are brought into close contact with the user's finger contact skin surface regardless of the thickness of the user's finger, and thus the light transmitter and light receiver adhere closely to the finger contact skin surface to measure signals. Accuracy can be improved.

In addition, the ring-shaped oxygen saturation measurement device applies the semi-convex lens shown in FIG. 2 to the light transmitter and the light receiver, thereby reducing the driving current of the diode by about 50% and driving the device with low power. It may be possible to live a lifetime while wearing it without a separate cable.

In addition, since the first body part 120 and the second body part 130 of the ring-shaped oxygen saturation measurement device are physically connected to the main body 110, they may perform a function of supporting the main body.

The present invention is a technology for measuring oxygen saturation of a user wearing such a device, and is not limited to or limited to the above-described ring-shaped oxygen saturation measuring device, and transmits a light signal including an ultraviolet signal and a red signal to the user's body, for example. For example, after obtaining a received signal that is received through the finger, that is, a received signal including an infrared signal and a red signal that has passed through the user's body, the user's oxygen saturation value can be measured through these received signals. Applicable to devices.

4 is an operational flowchart for a method for measuring oxygen saturation based on an independent component analysis technique according to an embodiment of the present invention.

Referring to FIG. 4 , in the oxygen saturation measurement method according to an embodiment of the present invention, a received signal including an infrared signal (IR signal) and a red signal (RD signal) passing through the user's body is obtained (S410).

Here, in step S410, a received signal may be obtained through the light receiving unit shown in FIG. 1 .

When the received signal including the IR signal and the RD signal is obtained in step S410, the IR signal and the RD signal passing through the user's body are separated from the obtained received signal (S420).

At this time, step S420 may separate the IR signal and the RD signal included in the received signal using Independent Component Analysis (ICA), and the separated IR and RD signals include a noise signal. .

For example, in step S420, the received signal may be separated into an IR signal and an RD signal including noise as shown in FIG. 5A using ICA.

When the IR signal including noise and the RD signal including noise are separated by step S420, the noise commonly applied to the separated IR signal and the RD signal is removed (S430).

Here, step S430 may separate the noise signal commonly applied to the separated IR signal and the RD signal using ICA, and remove the separated noise signal using a filter, for example, an adaptive filter can do.

For example, in step S430, when a noise signal commonly applied to the separated IR signal and RD signal is separated as shown in FIG. 5B, the noise signal may be removed using an adaptive filter.

When the noise signal commonly applied to the IR signal and the RD signal is removed in step S430, the oxygen saturation value of the user is calculated using the noise-removed IR signal and the RD signal (S440).

At this time, in step S440, a photoplethysmography (PPG) signal from which noise has been removed by step S430 may be obtained as shown in FIG. can be calculated.

Here, step S440 may calculate the user's oxygen saturation value based on the ratio of the noise-removed IR signal and the RD signal, and since it is calculated based on the ratio of the noise-removed IR signal and the RD signal, the gain of the adaptive filter (gain) is not affected.

That is, the present invention separates the IR signal and the RD signal included in the received signal based on ICA, separates the noise signal commonly applied to the separated IR signal and the RD signal, and then removes these noise signals using an adaptive filter. By removing, the noise signal included in the received signal is removed, and the PPG signal from which the noise has been removed is obtained, thereby accurately measuring the oxygen saturation value of the user.

The method of the present invention may be applied to a transmission type oxygen saturation measurement device, but is not limited or limited thereto, and may also be applied to a reflection type oxygen saturation measurement device depending on circumstances. Of course, the method of the present invention can be applied to the ring-shaped oxygen saturation device described in FIGS. 1 to 3, and can also be applied to other types of oxygen saturation devices other than the ring-shaped one.

As such, the method according to the embodiment of the present invention can improve the accuracy of the measured oxygen saturation value by measuring the oxygen saturation based on Independent Component Analysis (ICA).

6 shows a configuration of an independent component analysis method-based oxygen saturation measuring device according to an embodiment of the present invention, and shows a conceptual configuration of a device performing the methods of FIGS. 4 and 5 . Here, FIG. 6 may be a configuration included in the body of the device described in FIGS. 1 to 3 .

Referring to FIG. 6 , the oxygen saturation measuring device 600 according to an embodiment of the present invention includes an acquisition unit 610, a separation unit 620, a removal unit 630, and a calculation unit 640.

The acquisition unit 610 acquires a received signal including an IR signal and an RD signal that have passed through the user's body.

The separation unit 620 separates the IR signal and the RD signal that have passed through the user's body from the received signal obtained by the acquisition unit 610 .

At this time, the separation unit 620 may separate the IR signal and the RD signal included in the received signal using an independent component analysis (ICA), and the separated IR and RD signals include a noise signal.

That is, the separation unit 620 may separate the IR signal and the RD signal including a common noise signal using ICA.

The removal unit 630 removes noise commonly applied to the separated IR and RD signals.

At this time, the removal unit 630 separates the noise signal commonly applied to the separated IR signal and the RD signal using ICA, and then removes the commonly applied noise signal using an adaptive filter can do.

The calculation unit 640 calculates the user's oxygen saturation value by using the noise-removed IR and RD signals.

At this time, the calculation unit 640 may obtain a photoplethysmography (PPG) signal by removing noise, and calculate the user's oxygen saturation value using the obtained photoplethysmography signal.

Although the description of the device of FIG. 6 is omitted, each component constituting FIG. 6 may include all of the contents described in FIGS. 1 to 5, which is apparent to those skilled in the art.

The devices described above may be implemented as hardware components, software components, and/or a combination of hardware components and software components. For example, devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. A processing device may run an operating system (OS) and one or more software applications running on the operating system. A processing device may also access, store, manipulate, process, and generate data in response to execution of software. For convenience of understanding, there are cases in which one processing device is used, but those skilled in the art will understand that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that it can include. For example, a processing device may include a plurality of processors or a processor and a controller. Other processing configurations are also possible, such as parallel processors.

Software may include a computer program, code, instructions, or a combination of one or more of the foregoing, which configures a processing device to operate as desired or processes independently or collectively. You can command the device. Software and/or data may be any tangible machine, component, physical device, virtual equipment, computer storage medium or device, intended to be interpreted by or provide instructions or data to a processing device. can be embodied in Software may be distributed on networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer readable media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program commands recorded on the medium may be specially designed and configured for the embodiment or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. - includes hardware devices specially configured to store and execute program instructions, such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler.

As described above, although the embodiments have been described with limited examples and drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques may be performed in an order different from the method described, and/or components of the described system, structure, device, circuit, etc. may be combined or combined in a different form than the method described, or other components may be used. Or even if it is replaced or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

Claims (8)

In the method for measuring oxygen saturation in which each step is performed by a device for measuring oxygen saturation,
obtaining a received signal including an infrared signal and a red signal that have passed through the user's body by an acquisition unit of the apparatus for measuring oxygen saturation;
Separating an infrared signal and a red signal independent of the obtained received signal by a separation unit of the apparatus for measuring oxygen saturation;
removing noise commonly applied to the separated infrared signal and the red signal by a removal unit of the apparatus for measuring oxygen saturation; and
Calculating, by a calculator of the device for measuring oxygen saturation, a value of oxygen saturation of the user using the noise-removed infrared signal and the red signal,
The step of obtaining
Obtaining the received signal based on an output signal of a light receiving unit receiving light transmitted by the light transmitting unit of the apparatus for measuring oxygen saturation;
The separation step
Separating independent infrared and red signals from the obtained received signal using Independent Component Analysis (ICA);
The step of removing the noise is
After separating a noise signal commonly applied to the separated infrared signal and red signal using the independent component analysis technique, removing the separated noise signal using an adaptive filter;
The step of calculating the oxygen saturation value of the user
characterized in that a photoplethysmography (PPG) signal is obtained by removing the noise, and an oxygen saturation value of the user is calculated using the obtained photoplethysmography signal;
The light transmitter and the light receiver
Transmitting and receiving light through a semi-convex lens including a primary refracting surface formed as a concave surface and a secondary refracting surface formed as an outwardly convex convex surface based on the photodiode,
The light emitted by the light transmitter is refracted in the direction of diffusion through the primary refracting surface, and the refracted light passes through the secondary refracting surface and is further refracted in the direction of diffusion. become,
The light received by the light receiving unit is double-focused and bent to be received by the photodiode because light focused while passing through the secondary refracting surface is additionally focused while passing through the primary refracting surface.
Characterized in that the radius of curvature of the primary refracting surface is formed larger than the radius of curvature of the secondary refracting surface, oxygen saturation measuring method.
delete delete delete In the device for measuring oxygen saturation,
an acquisition unit that obtains a received signal including an infrared signal and a red signal that have passed through a user's body;
a separation unit separating an infrared signal and a red signal independent of the obtained received signal;
a removal unit removing noise commonly applied to the separated infrared signal and the red signal; and
A calculation unit for calculating the oxygen saturation value of the user using the noise-removed infrared signal and the red signal,
the acquisition unit
Obtaining the received signal based on an output signal of a light receiving unit receiving light transmitted by the light transmitting unit of the apparatus for measuring oxygen saturation;
the separating part
Separating independent infrared and red signals from the obtained received signal using Independent Component Analysis (ICA);
the removal part
Separating a noise signal commonly applied to the separated infrared signal and red signal using an independent component analysis technique and then removing the separated noise signal using an adaptive filter;
the calculation unit
characterized in that a photoplethysmography (PPG) signal is obtained by removing the noise, and an oxygen saturation value of the user is calculated using the obtained photoplethysmography signal;
The light transmitter and the light receiver
Transmitting and receiving light through a semi-convex lens including a primary refracting surface formed as a concave surface and a secondary refracting surface formed as an outwardly convex convex surface based on the photodiode,
The light emitted by the light transmitter is refracted in the direction of diffusion through the primary refracting surface, and the refracted light passes through the secondary refracting surface and is further refracted in the direction of diffusion. become,
The light received by the light receiving unit is double-focused and bent to be received by the photodiode because light focused while passing through the secondary refracting surface is additionally focused while passing through the primary refracting surface.
Characterized in that the radius of curvature of the primary refracting surface is formed larger than the radius of curvature of the secondary refracting surface, oxygen saturation measuring device.
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