KR100716800B1 - Measuring Method of Subcutaneous Fat Thickness - Google Patents

Abstract

The present invention relates to a method for measuring subcutaneous fat thickness, and in particular, a method for measuring subcutaneous fat thickness using light, comprising: irradiating at least one near infrared ray with a target inspector; Sensing the intensity of the reflected light after the irradiated near-infrared ray is absorbed by a target inspector; And measuring the subcutaneous fat thickness of the target inspector from the sensed light intensity, wherein the near infrared ray irradiated with the target inspector has a wavelength within a range of 900 nm to 1700 nm. In this way, by using near-infrared rays of a different wavelength band than in the related art, light penetration of the skin is further facilitated, and the thickness of the subcutaneous fat can be measured more accurately and simply.

Subcutaneous fat, measuring instrument, near infrared

Description

Measuring method of subcutaneous fat thickness {Measuring Method of Subcutaneous Fat Thickness}

1 is a cross-sectional view showing a probe of a measuring device that can be used in the method for measuring subcutaneous fat thickness according to an embodiment of the present invention,

2 is a cross-sectional view showing the distance between the light source and the detector of the method for measuring subcutaneous fat thickness according to an embodiment of the present invention,

3 is a cross-sectional view showing a state in which the detector of the subcutaneous fat thickness measurement method according to another preferred embodiment of the present invention,

4 and 5 is a cross-sectional view showing an experimental apparatus for measuring the subcutaneous fat thickness according to the present invention,

Figure 6 is a graph of the results of measuring the optical properties of various fats in the near infrared wavelength range according to the present invention,

7 is a graph showing the results of measuring the optical properties of various fats in the visible and near infrared wavelengths according to the prior art.

8 and 9 are graphs of the measurement results of the optical properties of the skin components according to the present invention,

10 is a graph showing the results of measuring the optical properties of skin, fat, and muscle according to the present invention,

Figure 11 is a photograph showing the fat penetration depth verification experiment of the near infrared ray according to the present invention.

12 is a graph showing the results of the fat penetration depth verification experiments of the near infrared ray according to the present invention,

13 and 14 are graphs showing the results of the graph of FIG. 12 in a regression curve.

15 is an experimental schematic diagram of measuring a change in distance between a light source and a detector according to the present invention;

16 to 19 are graphs showing optical property results of skin tissue according to a change in distance between a light source and a detector according to the present invention.

** Brief description of the main parts of the drawing **

1: Subcutaneous fat thickness measuring device 1a: probe

1b: main body 2: light source

3: detector 4: pressure sensor

5: shading material

The present invention relates to a method for measuring the thickness of subcutaneous fat, and in particular, a method for measuring the thickness of subcutaneous fat using light, wherein the light is a near-infrared ray within the range of 900 nm to 1700 nm, which is different from the conventional wavelength band. It relates to a method for measuring the thickness of subcutaneous fat using.

When the fats in the body of mammals, including the human body, are classified according to where they are accumulated, they can be divided into visceral fats located between organs and subcutaneous fats that accumulate under the skin. Among these, visceral fat is fat distributed in various visceral parts of the body, and is fat causing health problems such as diabetes, hypertension, hyperlipidemia and various adult diseases. Subcutaneous fat, on the other hand, is a fat layer just under the skin, and is responsible for nourishing the epidermis and dermis, determining the body shape, maintaining body temperature, absorbing external shock and protecting subcutaneous subcutaneous cells.

This subcutaneous fat does not cause a big problem metabolically, but it has become a subject of great interest in beauty with a social atmosphere that puts importance on the appearance of modern society. It is also a part that I want to pull out. Accumulation of subcutaneous fat is generally more evenly deposited than men, and both men and women are more likely to get subcutaneous fat. In northern countries where the climate is cold, local sedimentation tends to be high, and excessive nutrition leads to an increase in fat accumulation. In the human body, the back of the hand, eyelids, penis, scrotum, the anus is relatively distributed, and the lower abdomen, swelling, etc. are distributed a lot in the limbs and limbs.

Conventionally, a method of measuring fat including body fat of a human body is known in various ways as follows. First, there is a caliper (Calpers, Skinfold measurement) method to measure the thickness of the subcutaneous fat by using a caliper, and to measure the specific gravity after entering a water tank (Hydro-densitometry, Underwater) There is a weighing method, a bioelectrical resistance that measures the amount of fat in the body using the principle that a weak current flows through the body and the current flows well if there is water, and the electrical resistance value increases in the absence of water (for example, body fat). Bioelectrical Impedance (BIA) In addition, the Near-infrared Interactance (NIR) method of applying near-infrared rays to the skin and measuring the reflected light and a small amount of X-rays are used to measure the bone mass of the human body. In this case, DEXA (Dual Energy X-ray Absorptiometry (DEXA) and Magnetic Resonance Imaging (MRI), which uses medical equipment to show the distribution of hydrogen nuclei in the body using high frequency harmless to the human body.

In addition to the methods listed above, there are various methods such as CT (computerized tomography) and ultrasonic measurement. Among these, conventionally, as a method for measuring body fat, particularly body fat distributed throughout the body, a fat measuring method using a bioelectrical resistance analysis (BIA) method is common enough to control 90% or more of the whole body. However, although the impedance by BIA method can measure the amount of fat distribution throughout the body, there are technical limitations to measure the thickness of subcutaneous fat of the desired area.

Among the above methods, the caliper method, the DEXA method, the magnetic resonance imaging method, the CT method, the ultrasonic measurement method, the near infrared method, and the like, which can be used as a method for directly measuring the thickness of the subcutaneous fat of the localized area so far. However, the DEXA method, magnetic resonance imaging method, CT method, and ultrasonic measurement method is cumbersome and expensive because it requires an expert to operate expensive equipment at a designated place. In addition, the method of using radiation is accurate, but it is expensive and carries the risk of irradiation. Ultrasonic measuring devices have little burden on patients and doctors when measuring, and recently, ultrasound with excellent resolution has been continuously developed, but this also has disadvantages in that the price of the equipment is expensive and the results may differ depending on the skill of the measurer. . In addition, the caliper method is inaccurate, and there are limitations on its use because some parts of the skin thickness measurement are inappropriate.

Then, the conventional near-infrared measurement method which can measure the thickness of the subcutaneous fat of a local part directly is examined. The fat measuring apparatus using the conventional near-infrared measurement method is a device for measuring the percentage of body fat spread throughout the body by measuring the absorption and reflection of light by infiltrating the near-infrared ray of 938 nm to 948 nm into the body. The measurement method measures the middle part of the biceps muscle, based on the results of a study (Conway and Norris, 1986, Elia et. Al., 1990; Gullstrand) that had the highest agreement with the standardized method.

However, since the accumulation of fat varies depending on the characteristics of each individual, such as a man who accumulates a lot of fat in the abdomen and a woman who accumulates in the thighs, it is very error to measure the body fat of the whole body by measuring one place. There is a limit that there is no choice but to. In addition, as a detector for detecting near-infrared rays in the wavelength band, silicon (Si, silicon) semiconductor devices are mainly used, which exhibits insensitive reaction to wavelengths used for measurement due to the characteristics of the semiconductor material. For this reason, the conventional body fat measuring device using the near-infrared rays is very poor in accuracy, and in the case of partial body correction for the present cosmetic reasons, it is not measuring the distribution of partial subcutaneous fat, but measuring the total fat content. It may not be more suitable.

In addition, there is a lipometer as a subcutaneous fat measuring instrument for research purposes. Lipometer uses a plurality of LEDs with a wavelength of 630 nm to find the thickness of subcutaneous fat by measuring the correlation between the detected signal size and subcutaneous fat thickness according to the distance between the light source and the detector. However, the 630 nm wavelength used here is a wavelength that responds much to other skin components (collagen, melanin, etc.) in addition to fat, and has many interference factors in measuring the thickness of fat only. Therefore, a new measuring method that can accurately and easily measure the thickness of subcutaneous fat under the skin is urgently required.

The present invention has been made to solve the above problems, and aims to measure the thickness of subcutaneous fat simply and accurately by using a near infrared ray having a new wavelength range and a compound semiconductor device detecting the same by a non-invasive method. . In particular, by using near-infrared light in the range of 1000 to 1700 nm, it is intended to detect a signal using an InGaAs compound semiconductor which can measure even thick fat by improving skin penetration of light and reacting sensitively to the wavelength band. Through the present invention is harmless to the human body, it is possible to monitor the change in the thickness of subcutaneous fat by continuous use, it is intended to be useful to cultivate a good body by systematic health care.

First, the method for measuring the thickness of subcutaneous fat according to the present invention, the method for measuring the thickness of subcutaneous fat using light, comprising: irradiating at least one near infrared ray with a target inspector; Sensing the intensity of the reflected light after the irradiated near-infrared ray is absorbed by a target inspector; And measuring the subcutaneous fat thickness of the target inspector from the sensed intensity of light, wherein the near infrared ray irradiated to the target inspector has a wavelength within a range of 900 nm to 1700 nm.

Here, the near infrared rays preferably have a wavelength in the range of 1000 nm to 1300 nm, and among them, the near infrared rays may be in the range of 1050 nm to 1150 nm, and may have a wavelength in the range of 1250 nm to 1350 nm. In this case, the step of measuring the subcutaneous fat thickness according to the present invention, deriving a regression curve of the detected light intensity and the subcutaneous fat thickness, and measuring the subcutaneous fat thickness of the target examinee from the regression curve It is a more preferable subcutaneous fat thickness measuring method.

In another preferred embodiment of the present invention, there is provided a subcutaneous fat thickness measuring method for measuring the thickness of subcutaneous fat using light, the method comprising: irradiating at least two near infrared rays with a target inspector; Sensing the intensity of the reflected light after the irradiated near-infrared ray is absorbed by a target inspector; And measuring the subcutaneous fat thickness of the target inspector from the sensed intensity of light, wherein the near infrared irradiated with the target inspector has a first near infrared ray having a wavelength within a range of 1050 nm to 1150 nm and 1250 nm to 1350. Characterized in that it consists of a second near infrared ray having a wavelength in the range of nm, in this case, the step of measuring the thickness of the subcutaneous fat according to the present invention is subcutaneous fat from the difference in the intensity of light by the first near infrared ray and the second near infrared It is more preferable to measure the thickness of subcutaneous fat, which is characterized by measuring the thickness.

In addition, in the subcutaneous fat thickness measuring apparatus according to the present invention, the step of detecting the intensity of the light it is preferable to detect the intensity of the light using at least one or more compound semiconductor device as a detector, in particular the compound semiconductor device is indium gallium It is more preferable that it is an arsenide (InGaAs) type semiconductor element.

Further, the distance between the compound semiconductor device and the light source for irradiating at least one or more near infrared rays to the target inspector may be in the range of 5 mm to 15 mm, and the distance between the compound semiconductor device and the light source for irradiating at least one or more near infrared rays with the target inspector is Subcutaneous fat thickness measurement method is also possible, characterized in that in the range of 13mm to 14mm, the light source for irradiating at least one or more near infrared rays to the compound semiconductor device and the target inspector is located in one probe, the compound semiconductor device in the probe It is also desirable that the position can be moved. In addition, the probe may also measure the thickness of subcutaneous fat, characterized in that the pressure sensor is further included.

In another embodiment of the present invention, the step of detecting the intensity of light in the subcutaneous fat thickness measuring method, after detecting the intensity of the light, using the light detected from any compound semiconductor device of the at least one compound semiconductor device It is also possible to further include a process of determining whether or not to do so. The measuring of the thickness of subcutaneous fat may be characterized by measuring the thickness of subcutaneous fat of the target inspector after amplifying the detected light intensity. In addition, a method for measuring subcutaneous fat thickness, characterized in that for measuring the subcutaneous fat thickness of the target inspector by converting the detected light intensity into a digital signal.

In addition, the present invention having the above characteristics is not particularly limited to the method of measuring fat, but most preferably the method of measuring subcutaneous fat thickness, characterized in that the subcutaneous fat can be measured for each local part of the human body.

Hereinafter, one preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

The present invention takes advantage of the inherent optical properties of biological tissues composed of cells of different density, color, composition and size of each component of the body. Each body tissue exhibits different properties such as scattering, absorption, diffraction, refraction, and fluorescence, depending on its physical and chemical properties. In particular, when the light source is irradiated vertically, it is possible to construct an optical structure that can be observed while minimizing a single backscatter that can be observed in the bio-optic.

The skin tissue can be divided into epidermis, dermis, subcutaneous fat and muscle under the skin. The epidermis is so thin that it has almost no optical properties contributing to the measurement results, but scattering is the largest and the dermis is scattered and absorbed. In the description according to the present invention, the epidermis and the dermis are collectively called skin. The optical properties of the skin, the optical properties of fat, and the optical properties of muscle can be distinguished from each other, and the present invention measures the thickness of subcutaneous fat by analyzing such optical property differences.

The present invention for measuring the thickness of subcutaneous fat on the basis of the optical characteristics difference, the method for measuring the thickness of subcutaneous fat by using a light, comprising: irradiating near infrared rays with a target inspector; Sensing the intensity of light reflected after the near-infrared rays irradiated from the light source are absorbed by the target inspector; And measuring the subcutaneous fat thickness of the target inspector from the sensed light intensity, wherein the near infrared ray irradiated with the target inspector has a wavelength within a range of 900 nm to 1700 nm. It is a way.

This measurement method uses the new infrared light band in the 900 ~ 1700 nm range, especially 1000 ~ 1700 nm range different from the conventional frequency range band, as in the above-described subcutaneous fat thickness measuring apparatus to achieve the intrinsic optical characteristics of the subcutaneous fat Characterized by discovering, irradiating near-infrared rays with a target inspector; Sensing the intensity of light reflected after the near-infrared rays irradiated from the light source are absorbed by the target inspector; And measuring the subcutaneous fat thickness of the object inspector from the sensed light intensity is not particularly limited.

Here, first, the near-infrared ray having a new wavelength range and the light source capable of transmitting the same, which are a feature of the present invention, will be examined using a subcutaneous fat thickness measuring apparatus which can be preferably applied to the present invention, and will be described through the following experimental example. Specific embodiments of the invention will be described.

For the features of the present invention, preferably, as shown in Figure 1, a subcutaneous fat thickness measuring apparatus for measuring the thickness of subcutaneous fat using light, at least one light source (2) for irradiating near infrared rays to the target object And a probe 1a including at least one detector 3 for sensing light reflected after the near-infrared ray irradiated from the light source is absorbed by the target inspector and the intensity of the light detected by the detector. It includes a fat thickness measuring unit (not shown) for measuring the thickness of subcutaneous fat, the light source 2 may use a subcutaneous fat thickness measuring apparatus, characterized in that for irradiating near infrared rays in the range of 900nm to 1700nm. .

Conventionally, a fat measurement method using near infrared rays has selected a low frequency region in the wavelength range of 938 nm to 948 nm among near infrared rays, but the present invention is characterized by irradiating near infrared rays within a range of 900 nm to 1700 nm. As the conventional fat measurement method using near-infrared light uses only the low frequency region of the 938 nm to 948 nm wavelength as described above, in addition to the frequency region, the intrinsic response characteristic of the fat alone is desired in relation to the skin and muscle. Because I could not.

In the case of using such a near-infrared light source, there must be a detector that detects it. In the past, a detection device known to be excellent in effect was almost a silicon device made of silicon. However, such a silicon device has a difficulty in detecting a frequency range of the 938 nm to 948 nm wavelength band well or a wavelength having a different frequency range band. As described above, the reason why the frequency bands to be reacted differs depending on the type of detector element is that the conventional near-infrared ray using device has a limitation of using only a limited frequency band as described above.

In addition, the conventional fat measurement method using the near infrared measurement method was generally used only for the purpose of measuring the body fat percentage spread throughout the body by measuring the absorption and reflection of the near infrared rays to penetrate the body. This measurement measures the middle part of the biceps muscle because it is based on the results of a study (Conway and Norris, 1986, Elia et. Al., 1990; Gullstrand) with the highest agreement with the standardized method.

In addition, there is a method using a lipometer as a method for measuring subcutaneous fat for research purposes, but the 630 nm wavelength used here is a wavelength that responds to other skin components (collagen, melanin, etc.) in addition to fat, and is used to measure the thickness of fat only. Because of the interference factor, there was a problem that the accuracy is significantly reduced.

The present inventors have found the subcutaneous fat inherent optical properties by using a near infrared ray in the 900 ~ 1700 nm range, especially 1000 ~ 1700 nm range different from the above frequency range. The wavelength range is a frequency range of a much higher range than the conventional frequency range, and based on the fact that the longer the wavelength, the higher the penetration, the present invention provides a thicker skin penetration of light than the conventional fat measuring apparatus using near infrared rays. Even fat can be measured accurately and easily.

According to the present invention, by measuring the intensity of light detected through the fat from such a light source using a frequency in the range of 900 to 1700 nm, in particular in the range of 1000 to 1700 nm, it is distinguished from skin or muscles, thereby providing optical properties specific to subcutaneous fat only. It can be obtained, and the fact that the thickness of the subcutaneous fat can be measured using this optical property will be confirmed through the experimental example of the present invention described later.

Another embodiment of the present invention, in the step of detecting the intensity of the light reflected by the near-infrared ray irradiated by the target inspector after being absorbed by the target inspector, detecting the intensity of the light using at least one compound semiconductor device as a detector It features. The compound semiconductor device is not particularly limited, but excludes a semiconductor device having a single component as a main component, as in the conventional silicon device.

A general laser diode used as a detector can be classified into a composition of a semiconductor compound that largely determines a wavelength band. A semiconductor device suitable for use as a near-infrared detector according to the present invention is a compound of indium gallium arsenide (InGaAs) or InP. A light receiving element suitably formed is preferable. Among them, according to the present invention, indium gallium arsenide-based semiconductor devices have been found to be suitable for detecting optical signals from light sources irradiating near infrared rays within the range of 900 nm to 1700 nm.

In the optical communication detection method, it operates in the photoelectric mode and a small reverse current flows even when there is no input light under reverse bias, which is called a dark current. This current is generated by a free carrier generated thermally in the diode and is reversed in the diode. The maximum leakage current is usually called the reverse saturation current because it flows. These dark currents range from 1nA to more than a few hundred nA and typically have the lowest dark current for silicon devices. For this reason, silicon detectors have generally been used in wavelength bands with similar reactivity.

However, as described above, such a silicon device has a difficulty in detecting a frequency region having a wavelength range of 938 nm to 948 nm as well as a wavelength having a frequency range in a different range. Near-infrared rays within the range of 1700 nm were used, and compound semiconductor devices, particularly indium gallium arsenide-based semiconductor devices, were found as the optimal detectors.

Yet another embodiment of the present invention relates to a distance between the compound semiconductor device and a light source for irradiating at least one or more near infrared rays to a target inspector. That is, as shown in FIG. 2, the distance between the light source 2 and the detector 3 that irradiates and detects light. 2 is a cross-sectional view showing the distance between the light source 2 and the detector 3 of the method for measuring subcutaneous fat thickness according to an exemplary embodiment of the present invention.

As shown here, the distance between the light source 2 and the detector 3 is preferably in the range of 5 mm to 15 mm. The detector 3 is for obtaining information about the thickness of the subcutaneous fat, and in order to measure the distance to the thick subcutaneous fat, it is necessary to increase the distance between the light source 2 and the detector 3 and to thin the skin. This is because it is necessary to shorten the distance between the light source 2 and the detector 3 in order to measure the distance to the fat. If the distance is too long, the attenuation of light in the muscle tissue may increase.

Among them, it was confirmed that the distance between the light source 2 and the detector 3 according to the present invention is most preferably within the range of 13 mm to 14 mm. The optical characteristic results of the light source 2 and the detector 3 in this range are as shown in the following examples, and the light intensity results of different light intensity are evenly distributed to the subcutaneous fat thickness to obtain a linear regression graph. This is because the subcutaneous fat thickness can be measured more accurately from the light intensity.

Yet another preferred embodiment of the present invention is characterized in that a light source for irradiating at least one or more near infrared rays to the compound semiconductor device and the target inspector is located in one probe, and the compound semiconductor device may be moved in a probe. That is, as shown in FIG. 3, the light source 2 and the detector 3, which is a compound semiconductor element, are positioned in one probe, and the detector 3 has a form in which a position can be moved in the probe 1a. will be. 3 is a cross-sectional view showing a state in which the detector 3 of the method for measuring subcutaneous fat thickness according to another preferred embodiment of the present invention moves.

As shown, when one detector 3 can be moved in the probe 1a, it is possible to reduce the demand for the required compound semiconductor device used as the detector 3. This is because a compound semiconductor device that can be preferably used in the present invention rather than a conventional silicon device is relatively expensive. If the detector 3 can be moved in this way, the distance to the light source can be adjusted in various ways with one detector 3, and in the case where the light receiving element can be moved in this way, the number of detectors as the small number of detectors 3 can be adjusted. It can have an effect with (3). In addition, the movement of the detector 3 may use a micro motor.

In addition, in the case of measuring the thickness of the subcutaneous fat using the present invention as described above, the subcutaneous fat measuring device should be abutted on the surface of the target object we want, and in this case between the measuring device and the surface of the object body May be affected by pressure. Therefore, in the present invention, in order to check such a pressure, it is also possible to form a pressure sensor 4 is further included in the probe (1a) as shown in FIG.

Further, the probe 1a according to the present invention includes a light source 2 for transmitting near infrared rays as shown in the drawing, and a detector 3 and a pressure sensor 4 for sensing the intensity of light, which are absorbed and reflected from fat. The outer periphery of the probe 1a may further include a light blocking material 5 for blocking light from the outside.

Meanwhile, the method for measuring subcutaneous fat thickness according to the present invention determines whether to use the light detected from the at least one compound semiconductor device among the at least one compound semiconductor device after detecting the light intensity in the step of detecting the light intensity. It is also possible to further include a process. The measuring of the thickness of subcutaneous fat may be characterized by measuring the thickness of subcutaneous fat of the target examinee after amplifying the detected light intensity. In addition, a method for measuring subcutaneous fat thickness, characterized in that for measuring the subcutaneous fat thickness of the target inspector by converting the detected light intensity into a digital signal.

Here, to determine whether to use the light sensed from the compound semiconductor device may use a selection circuit unit, and to amplify the intensity of the detected light it is possible to use an amplifier, converting the intensity of the detected light into a digital signal It is preferable to use an A / D conversion circuit section.

In addition, it is preferable that the selection circuit unit, the amplifier, and the A / D conversion circuit unit sequentially process and transmit the optical signal from the detector in the above order. In the method according to the invention, the step of measuring the subcutaneous fat thickness may include the function of the selection circuit section, the amplifier and the A / D conversion circuit section, and is transmitted from the selection circuit section, the amplifier and the A / D conversion circuit section. And finally processing the signal. That is, the optical signal in the detector is selected by the selection circuit section, and the selected signal is first amplified by the amplifier and then converted into a digital signal by the A / D conversion circuit. Subsequently, this value is finally received by the fat thickness measurement unit, which can serve as a CPU, to calculate the thickness of subcutaneous fat.

Here, although the detector is selected by the selection circuit unit, when a light receiving process is performed at a higher speed, a method of separately measuring an amplifier and an A / D conversion circuit may be possible.

Furthermore, the present invention uses a frequency in the range of 900 to 1700 nm, in particular in the range of 1000 to 1700 nm, and measures the intensity of light detected through fat from such a light source, thereby distinguishing it from skin or muscles, which is specific to subcutaneous fat. Optical characteristics can be obtained. That is, the present invention having the above characteristics is not particularly limited to a device for measuring fat, but it is a subcutaneous fat thickness measuring apparatus, characterized in that the subcutaneous fat can be measured for each local part of the human body.

The wavelength range is a frequency range of a much higher range than the conventional frequency range, and based on the fact that the longer the wavelength, the higher the penetration, the present invention provides a thicker skin penetration of light than the conventional fat measuring apparatus using near infrared rays. Even fat can be measured accurately and easily, and can be detected more easily by using an indium gallium arsenide (InGaAs) -based semiconductor device.

< Experimental Example  1: Fabrication of Experiment Device>

According to the present invention, various experimental devices have been fabricated to find the frequency range of a light source emitting light intensity specific to fat. The experimental apparatus used the absorbance method for the precise measurement of the basic optical properties of fat components and the diffusion reflection method was used to measure the optical properties of the tissues.

The device as shown in Figure 4 is a light source for irradiating white light and an optical fiber for moving the light, a light reduction filter for attenuating the light intensity without changing the wavelength, a holder for holding the sample, the light reacted with the sample wavelength It consists of a spectrometer that separates stars, an InGaAs detector that converts the light intensity into an electrical signal, and a computer that receives and processes the signal, and measured the wavelength range from 1000 to 1700 nm.

The experimental apparatus shown in FIG. 5 is an experimental apparatus that is changed into a holder capable of measuring diffuse reflection of light by changing a sample holder into a biological tissue in the apparatus configuration as shown in FIG. 4.

< Experimental Example  2: various local Optical properties  Measurement Experiments>

Fat is divided into animal oil and vegetable oil depending on where it is extracted. Among them, commercially available pork oil, butter, and olive oil were used to measure the optical properties of oil. It was measured in the wavelength range of 1000 ~ 1700 nm and all the samples were measured by heating to about 55 ℃ since the pig oil is a solid at room temperature. Lard 1, 2, and 3 in Fig. 6 are the results measured at different temperatures (55, 36, 23 ° C.), respectively.

6 is to check the optical properties of various fats. As you can see in the graph, there is a slight degree of difference, but the overall appearance is the same. In the case of olive oil, it can be seen that the visible light region (see FIG. 7, about 500 to 700 nm region) has a different optical characteristic from other animal oils. Olive oil also has characteristics similar to animal oil in the region of 1000 to 1700 nm. You can see that. Based on these optical properties, the inventors were able to select the appropriate wavelength most effective when observing the change in fat thickness.

That is, when measuring the wavelength of the light source in the range of 1000 ~ 1700 nm according to the present invention, it can be seen that the optical properties of various fats have very similar properties in the measurement range as shown. It can be seen that the strong absorbance is shown at around 1200 nm and near 1400 nm, and has a relatively weak absorbance at around 1100 nm and near 1300 nm. Thus, the present inventors were able to obtain constant optical properties regardless of the type of fat when using near-infrared light in the range of 1000 to 1700 nm as a light source.

Although shown as a light transmittance with reference to FIG. 6, the light transmittance can be converted into an absorbance. That is, since T = P / P ₀ and A = -logT = log (P ₀ / P), the transmittance can be converted into absorbance as much as possible. 6 is converted into a light transmittance and an absorbance when compared with a state in which no sample is included as raw data (P _{0 in the} above formula). Referring to FIG. 6, the concave part is a part that does not pass much light, and the fat absorbs light, and the convex part that passes through the light well means that the absorbance is low.

< Experimental Example  3: of various skin components Optical properties  Measurement Experiments>

The present invention is to measure the thickness of the subcutaneous fat, in order to determine the effect of the skin layer present above the subcutaneous fat was carried out experiments to measure the optical properties of the skin components.

Through this experiment, the optical properties of collagen, which accounts for about 70% of the dermis and skin melanin, were determined. Here, the absorbance is measured with a spectrophotometer different from the above Experimental Example 2, and when the graph is convex, it means that the absorbance is high. As shown in Figure 8 (collagen) and Figure 9 (melanin), both components showed a relatively high absorption near 1500 nm, and a relatively weak absorption in the 1000 ~ 1300 nm range. This means that there is less interference in light passing through the optical measurements in that range. Therefore, if you measure the optical characteristics of the fat using a wavelength in this range, it can be seen that less interference than other wavelengths. Accordingly, another embodiment of the present invention utilizes a light source having a frequency in the range of 1000-1300 nm, which is preferred for achieving the object of the present invention.

< Experimental Example  4: skin tissue Optical properties  Experiment>

The present invention is to measure the thickness of the subcutaneous fat, in order to determine the effect of the skin layer present above the subcutaneous fat and the muscles present under the subcutaneous fat, for each skin component consisting of only skin, fat, muscle Optical characteristics measurement experiment was performed.

As a result of measuring the optical properties of the skin (epidermis + dermis), fat, and muscle constituting the skin tissue are shown in FIG. In FIG. 10, the y-axis represents the intensity of light emitted after light penetrates into the tissue and passes a certain distance.

First, looking at the optical properties of the NIR region of the skin, it can be seen that the absorbance is low at around 1100 nm and around 1300 nm, and the absorbance is lowered at around 1600 nm. When comparing the absorbance near 1100 nm and the absorbance near 1300 nm, the absorbance near 1300 nm is relatively smaller compared to fat or muscle. Looking at the optical properties of fat, it can be seen that the absorbance is low at around 1100 nm and around 1300 nm as well as the optical properties of the skin, and high absorbance at 1200 nm, which is the intrinsic property of fat observed in FIG. have. The optical properties of the muscles are generally uniformly high in absorbance over the entire wavelength range (less light intensity for muscles of the same thickness compared to skin or fat, ie larger absorbances), and in the vicinity of 1300 nm It can be seen that it has a different high absorbance. As such, it can be seen that each skin tissue has its own optical properties at around 1100 nm and around 1300 nm, respectively.

In this way, the different optical properties of skin tissues can be used to predict what influences strong or weak absorbance in a given area, and in particular, in relation to intensity at other wavelengths. The light intensity of the range can also be converted to the thickness of fat.

< Experimental Example  5: Near infrared  Fat Penetration Depth Confirmation Experiment>

Through the above experimental examples, it was confirmed that using the frequency light source in the range of 1000 nm to 1700 nm in accordance with the present invention can obtain a result specific to the optical properties. In this experimental example, the change in the light intensity or absorbance according to the thickness of the subcutaneous fat was confirmed centering around the frequency range of 1000 nm to 1700 nm, especially 1100 nm and 1300 nm.

Figure 11 shows the change in the penetration depth of light according to the wavelength using a pig oil mass. White light was put in the upper part using the optical fiber, and the light intensity was measured by moving the optical fiber from the near to the far light source along the side surface.

As a result, the light penetrates more than 28 mm, and as shown in FIG. 12, it can be seen that the light tends to penetrate according to the wavelength when the light decrease trends at 1172 nm and 1230 nm are shown. In the graph of FIG. 12, the y-axis represents the light intensity, and the light intensity is calculated and displayed in inverse proportion to the absorbance in the graph. In other words, as the size of the y-axis increases, the intensity of light increases and the absorbance decreases.

As shown in FIG. 12, it can be seen that the present invention evenly changes the light intensity or absorbance according to the thickness of the subcutaneous fat, centering on the frequency in the range of 1000 nm to 1700 nm, especially around 1100 nm and around 1300 nm. Accordingly, the present invention preferably uses near infrared rays within the range of 1050 nm to 1150 nm or within the range of 1250 nm to 1350 nm.

FIG. 13 is a graph showing a change at 1172 nm as a regression curve among the graph results of FIG. 12, and FIG. 14 is a graph showing a change at 1230 nm as a regression curve among the graph results of FIG. 12. As shown in FIG. 13 and FIG. 14, it can be seen that the transition at each wavelength is different according to the change in the thickness of subcutaneous fat as can be seen from the shape of the curve. In the above-described change graph at 1172 nm and change graph at 1230 nm, the change graph at 1172 nm (FIG. 13) has a more linear regression curve shape, and thus predicts subcutaneous fat thickness according to light intensity or absorbance. Below, the shape of the change graph at 1172 nm is more preferable.

As described above, the present invention derives a regression curve between the intensity of the light detected by the detector and the fat thickness through the fat thickness measuring unit, and enables a subcutaneous fat thickness measuring apparatus capable of measuring the fat thickness of the target examinee from the regression curve. Do.

< Experimental Example  6: light source Detector  Of skin tissue according to distance Optical properties  Change experiments>

In the present experimental example, as shown in FIG. 15, the optical properties of the skin tissues according to the distance between the light source and the detector were confirmed. 15 is an experimental schematic diagram of measuring a change in distance between a light source and a detector according to the present invention.

As shown in FIG. 15, an experiment was conducted to find a distance where the influence of the change in fat thickness was best while changing the distance between the light source and the detector. The results can be confirmed in the graphs of FIGS. 16 to 19 which show optical property results of the skin tissue according to the distance change between the light source and the detector according to the present invention.

16 illustrates a case where the distance between the light source and the detector is 6.5 mm, FIG. 17 is 10 mm, FIG. 18 is 13.5 mm, and FIG. 19 is 17 mm. In FIGS. 16 to 19, the size of the y-axis is proportional to the size of the absorbance. Accordingly, the thickness of the subcutaneous fat is large when the uppermost convex curve is large. The reason for this is known as Beer-Lambert Law, which is represented by A = εbc. Where A is the absorbance, ε is the absorption coefficient, b is the optical path length, and c is the concentration. In this experiment, only b (fat thickness) was changed assuming that ε and c did not change. If ε and c are fixed, A and c are directly proportional to each other, so that the thicker the fat is, the higher the b is, and the higher the b, the greater the absorbance.

As can be seen from the graphs of FIGS. 16 to 19, it can be seen that the change in absorbance occurs at around 1100 nm and around 1300 nm. As the distance between the light source and the detector increases, the absorbance near 1300 nm rather than around 1100 nm is observed. It can be seen that increases. These results are identical to the ability of light to propagate or penetrate the skin, depending on the characteristics of the wavelengths seen in the near-infrared fat penetration depth test. It can be seen that the distance between the light source and the detector that can best represent the change in fat thickness is about 13.5 mm compared to other distances. That is, the change in thickness at a distance of 13.5 mm is well represented as thicker than other distances. In the graph of intensity change around 1300 nm with the change of thickness, the graph of 13.5 mm distance has a linear smooth regression curve, and the graphs of other distances show the change of curve of steep slope. A gentle change in the slope of the graph is a good representation of the change in thickness over a wider area.

As described above, the present invention derives a regression curve of the intensity and the thickness of light detected by the detector through the fat thickness measuring unit in each frequency range, as can be seen from the absorbance graph around 1100 nm or around 1300 nm. From the regression curve, the fat thickness of the target inspector can be measured. That is, in the present invention, the step of measuring the thickness of the subcutaneous fat derives a regression curve between the intensity of the detected light and the thickness of the subcutaneous fat, and measures the subcutaneous fat thickness of the target examinee from the regression curve. Subcutaneous fat thickness measurement method is possible.

In addition, the near-infrared irradiated to the target inspector may use each of the two near-infrared rays such as a first near infrared ray having a wavelength in the range of 1050 nm to 1150 nm and a second near infrared ray having a wavelength in the range of 1250 nm to 1350 nm, It is also possible to measure the thickness of subcutaneous fat from the difference in the intensity of light caused by the first near infrared ray and the second near infrared ray. Further, based on the absorbance of the fat of 1208 nm as a reference, it is also possible to quantify the absorbance change around 1300 nm, which changes according to the change in fat thickness, and convert it to the thickness of fat.

In the above description, it should be understood that those skilled in the present invention can only make modifications and changes to the present invention without changing the gist of the present invention as merely illustrative of a preferred embodiment of the present invention.

According to the present invention as described above, the subcutaneous fat thickness measuring method for measuring the thickness of the subcutaneous fat using light, the method comprising: irradiating at least one or more near infrared rays with a target inspector; Sensing the intensity of the reflected light after the irradiated near-infrared ray is absorbed by a target inspector; And measuring the subcutaneous fat thickness of the target inspector from the detected intensity of light, wherein the near infrared ray irradiated with the target inspector has a wavelength within a range of 900 nm to 1700 nm. Measurement method can be provided.

According to the present invention, by using near-infrared rays of a different wavelength band than in the prior art, the skin can easily penetrate the light, and thus the thickness of the subcutaneous fat can be measured more accurately and simply. In addition, the present invention has the effect of measuring the thickness of subcutaneous fat simply and accurately by non-invasive method using near-infrared and compound semiconductor. By using near-infrared rays in the range of 1000 ~ 1700 nm, the skin can penetrate light to measure thick fats and detect signals using InGaAs compound semiconductors sensitive to the wavelength range. Since it is harmless to human body, it can manage health by monitoring the change of subcutaneous fat thickness through continuous use, and it can be useful for cultivating good looking body.

Claims (17)

delete delete delete delete delete In the subcutaneous fat thickness measuring method of measuring the thickness of subcutaneous fat using light, Irradiating at least two near infrared rays with a subject examinee; Sensing the intensity of the reflected light after the irradiated near-infrared ray is absorbed by a target inspector; And And measuring the subcutaneous fat thickness of the object inspector from the sensed intensity of light. The near infrared ray irradiated to the target inspector is composed of a first near infrared ray having a wavelength within a range of 1050 nm to 1150 nm and a second near infrared ray having a wavelength within a range of 1250 nm to 1350 nm, The subcutaneous fat thickness measuring method of measuring subcutaneous fat thickness, characterized in that for measuring the subcutaneous fat thickness from the difference in the intensity of light by the first near infrared ray and the second near infrared ray. delete The method of claim 6, The detecting of the intensity of light may include measuring subcutaneous fat thickness using at least one compound semiconductor device as a detector. In the subcutaneous fat thickness measuring method of measuring the thickness of subcutaneous fat using light, Irradiating at least one near infrared ray with a subject examinee; Sensing the intensity of light reflected after the irradiated near-infrared ray is absorbed by a target inspector using at least one compound semiconductor device as a detector; And And measuring the subcutaneous fat thickness of the object inspector from the sensed intensity of light. The near infrared ray irradiated to the target inspector has a wavelength in the range of 900 nm to 1700 nm, The compound semiconductor device is a subcutaneous fat thickness measuring method, characterized in that the indium gallium arsenide (InGaAs) -based semiconductor device. The method for measuring subcutaneous fat thickness according to claim 8, wherein the distance between the compound semiconductor device and the light source for irradiating at least one or more near infrared rays to the target inspector is within a range of 5 mm to 15 mm. The method for measuring subcutaneous fat thickness according to claim 8, wherein a distance between the compound semiconductor device and the light source for irradiating at least one or more near infrared rays to the target inspector is within a range of 13 mm to 14 mm. In the subcutaneous fat thickness measuring method of measuring the thickness of subcutaneous fat using light, Irradiating at least one near infrared ray with a subject examinee; Sensing the intensity of light reflected after the irradiated near-infrared ray is absorbed by a target inspector using at least one compound semiconductor device as a detector; And And measuring the subcutaneous fat thickness of the object inspector from the sensed intensity of light. The near infrared ray irradiated to the target inspector has a wavelength in the range of 900 nm to 1700 nm, And a light source for irradiating at least one or more near infrared rays to the compound semiconductor device and the target inspector in one probe, and the compound semiconductor device may be moved in a probe. The method of claim 12, wherein the probe further includes a pressure sensor. In the subcutaneous fat thickness measuring method of measuring the thickness of subcutaneous fat using light, Irradiating at least one near infrared ray with a subject examinee; Sensing the intensity of light reflected after the irradiated near-infrared ray is absorbed by a target inspector using at least one compound semiconductor device as a detector; And And measuring the subcutaneous fat thickness of the object inspector from the sensed intensity of light. The near infrared ray irradiated to the target inspector has a wavelength in the range of 900 nm to 1700 nm, The sensing of the light intensity further includes determining whether to use the light detected from the at least one compound semiconductor device among the at least one compound semiconductor device after detecting the light intensity. Fat thickness measurement method. The method of claim 8, wherein the measuring of the thickness of subcutaneous fat comprises measuring a thickness of subcutaneous fat of the target inspector after amplifying the detected light intensity. The method for measuring subcutaneous fat thickness according to claim 8, wherein the subcutaneous fat thickness measurement is performed by measuring the subcutaneous fat thickness of the target object by converting the detected light intensity into a digital signal. The method for measuring subcutaneous fat thickness according to claim 8, wherein the subcutaneous fat can be measured for each local part of the human body.

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