WO2008029978A1

WO2008029978A1 - Non-invasive measuring apparatus of subcutaneous fat thickness and method thereof

Info

Publication number: WO2008029978A1
Application number: PCT/KR2007/000981
Authority: WO
Inventors: Young-Bin Kim; Young-Seok Bae
Original assignee: Planet82 Inc.
Priority date: 2006-09-08
Filing date: 2007-02-26
Publication date: 2008-03-13
Also published as: KR20080022923A

Abstract

The present invention provides a non-invasive measurement device of a subcutaneous fat thickness, which measures an absolute thickness of subcutaneous fat present in topical parts of a human body by using light, and a method thereof. The device of the present invention comprises: a power supplying part; a light source which generates light generated from a light source element having a wavelength between 400nm -2500nm; an optic filter which only allows light within a near- infrared bandwidth of 1000nm-1400nm to be passed therethrough, among the light which has been absorbed to and reflected from a part desired to be measured after being irradiated from said light source to the part; a detector which can only detect light within a specific wavelength range which passed through the optic filter; and a data processing part which measures the subcutaneous fat present in topical parts of a human body, based on the light intensity detected by said detector.

Description

NON-INVASIVE MEASURING APPARATUS OF SUBCUTANEOUS FAT THICKNESS AND METHOD THEREOF

Technical Field

[1] The present invention relates to a device for measuring a subcutaneous fat thickness by using light, and a method thereof, which comprises irradiation of electromagnetic rays within the bandwidth of visible light (450nm ~ 750nm) and infrared (750nm ~ 2500nm). Specifically, the present invention relates to a device for measuring a subcutaneous fat thickness and a method thereof, by passing light which is obtained after being absorbed into and reflected from a subject to be measured (a part of a body), through an optic filter which only allows light within a certain wavelength band to be penetrated, and detecting the light passed the optic filer by a detector that is a semiconductor device made of an indium-galium arsenide(InGaAs) compound, wherein the InGaAs only responds to light within a near-infrared region. Background Art

[2] As for general behaviors of the skin relative to light, when light is irradiated to the skin, some of the light beam is reflected and the other penetrates into the skin including epidermis, dermis and a subcutaneous fat layer. The ratio of the reflected light or specular reflectance is typically about 4-7% of the irradiated light over the spectrum of 250-3000nm [J. Parrish, R. Anderson, F. U RBACH, D. Pitts, UV-A: Biologic Effects of Ultraviolet Radiation with Emphasis on Human Response to Longwave Ultraviolet, New York, Plenum Press(1978)]. Meanwhile, 93-96% of the incident beam penetrating into the skin become reduced owing to light scattering and absorption during the penetration through various layers of the skin.

[3] The epidermis is a very thin layer, as compared to a subcutaneous fat layer or muscle, so that it hardly has unique optical characteristics which could affect the measurement. However, in the epidermis, light scattering is mostly occurred, and in the dermis, light scattering and absorption are occurred.

[4] Each optical characteristic of the skin, subcutaneous fat and muscle differ from each other. Fig. 1 is a plot showing the adsorption band of tissue components in the transmittance spectrum of woman breast tissues, for an application of a conventional device for measuring subcutaneous fat [F.A.Marks, "Optical Determination of the Hemoglobin Oxygenation State of Breast Biopsies and Human Breast Cancer Xenografts in Nude Mice(1992)], wherein the numbers 1, 2 and 3 represent the characteristics of hemoglobin, fat, and water in this order, respectively, providing representative examples of the above-mentioned description. [5] The present invention studies such differences in optical characteristics so as to measure a subcutaneous fat thickness.

[6] In the meantime, light absorption in tissues is occurred by three basic components, i.e. water, protein and fat. As a major component, water governs the adsorption of a near-infrared ray having a wavelength of 1 lOOnm or more, which can be confirmed by a significant light absorption band. Various types of proteins, particularly collagen are strong light absorbing materials in the dermis.

[7] Further, a near-infrared ray having a certain wavelength, which infiltrates into the subcutaneous tissue, is mostly absorbed by fat. Muscles under the subcutaneous fat layer absorb light in almost all wavelength range.

[8] The structure and composition of the skin greatly differ from each individual organism. Even in the same individual organism, they have different characteristics depending on the location in the body.

[9] The skin is made up of epidermis and dermis, and under the dermis, a layer of subcutaneous fat or fat tissue and then muscle thereunder are present.

[10] The epidermis which has a thickness of 10~150um together with stratum corneum, is a barrier penetrating infection and water loss, and the dermis which is a thick inner layer provides mechanical strength and elasticity [F. Ebling. The Normal Skin, Textbook of Dermatology, 2nd ed.;A. Rook; D. Wilkinson, F. Ebling, Eds,;Blackwell scientific, Wxford, pp 4-24(1972)]. In a human, the thickness of dermis differ with the location in the body, for example from 0.5mm on the eyelid to 4mm on the back, but averagely, it is about 1.2mm in the human body [S.Wilson, V. Spence, Phys. Med.Biol., 33: 894-897(1988)].

[11] Body fat can be divided, depending on the location, into visceral fat and subcutaneous fat.

[12] Subcutaneous fat means fat accumulated beneath the skin, and has functions of heat insulation for keeping the body temperature constant, and cushioning impacts from the outside.

[13] Surplus nutrients are stored in the body as fats, which can be used as a source of energy, when necessary. Therefore, the fat content changes with exercises or changes in physiological functions. Such change in fat content is first found in the face, and then the legs and arms, and the trunk of the body is relatively less affected by such change.

[14] It is known that subcutaneous fat, although it may cause a problem in aesthetic point of view, does not cause any direct health problems such as adult diseases.

[15] In human, the subcutaneous fat is well developed in an adult woman, forming a characteristic body shape of a woman, by being deposited in mass amount over the whole body. [16] In women, subcutaneous fat is stored in the following order: first from the back of thigh, the side of thigh, body, diaphragm and the upper body, while fat loss proceeds vice versa. Said parts of the body greatly affect the whole body shape in aesthetic point of view, and thus they are the mostly targeted parts for being on a diet.

[17] Particularly, in this modern society, desires for better appearance is getting more increased and naturally efforts to make a good-looking body figure are also increased.

[18] In the meantime, the fat deposited around the internal organs (visceral fat) becomes the cause of adult diseases, increasing health risks. It can be confirmed by the fact that, when checking the health condition, in most cases, many of persons with visceral fat obesity suffer from hyperlipidemia, diabetes and hypertension, while persons with subcutaneous fat obesity do not have a disease.

[19] In the above, obesity refers to a condition in which body fat is excessively present, which is increased to a point where it becomes hazardous to health, without concerning an aesthetic point of view.

[20] Until mid-90 s, obesity was considered as a cause of diseases or one of symptoms of certain diseases, however in 1997, it was defined as a disease which requires medical treatment, by WHO.

[21] Since then, obesity has been loomed large as one of the most significant health problems worldwide, and accordingly various diagnosing methods therefor have been developed.

[22] Under such circumstances, so far many devices for fat related measurements have been developed vigorously. Fat measurement methods currently used may be divided into methods for a total body fat measurement and a topical fat measurement.

[23] As for the methods which have been most widely used for fat measurement, bio- electrical impedance analysis (BIA) wherein a micro-electric current is flown to a human body for measurement; an underwater weighing method which uses specific gravity of a human body; and heavy water method wherein a solution is infused into a body and the concentration of a sample recovered from the body after a certain period of time.

[24] Methods for measuring topical body fat, include a skinfold measurement wherein the skin including subcutaneous fat is raised as a double layer and measured with a caliper; a bio-impedance measurement which measures body fat present in topical area of a body by flowing a micro-electric current through the body; an ultrasonic wave measurement; near-infrared interactance (NIR) using a light; DEXA method using a very low level of X-ray; and magnetic resonance imaging (MRI) using a magnetic field.

[25] Disclosure of Invention

Technical Problem

[26] These methods have some advantages and disadvantages in terms of cost, volume and preciseness. In case of the bioelectrical impedance analysis, when measuring body fat, it is not possible to measure the fat content at a certain part of the body desired to know, while measuring topical fat, only its distribution relative to the part can be measured to a certain extent . It further has a problem of an expensive price and bulky size of a device therefor, limiting its use as a portable device. The underwater weighing method and heavy water merhod require complex and time-consuming processes. The skin-fold method cannot achieve precise measurement since the measured value varies, depending on the measured part, a person who measures and every measurement. For the ultrasonic wave method, DEXA method and MRI, these methods are not economical, and need the use of bulky devices and a skilled operator therefor.

[27] There are other methods such as near-infrared measurement, wherein a near- infrared beam within the wavelengths of 938~948nm is irradiated to a certain part of a body, for example biceps, and a body fat ratio is deduced from the relation of the irradiated beam responding to a fat thickness. However, it also has a limitation to precise measurement since it deduces the total body fat ratio based on the measurement information of just one certain part of a body. Thus, it is not considered as a device for measuring subcutaneous fat of a certain topical part of a body. Technical Solution

[28] The present invention has been designed to solve the above-mentioned problems of conventional techniques. The object of the invention is to achieve precise measurement of a subcutaneous fat thickness in non-invasive and safe way, by using an optic filter which only allows a near-infrared ray in a certain wavelength range to pass through, and a semiconductor element made up of indium-galium-arsenide (InGaAs) compounds.

[29] According to the present invention, provided are non-invasive device for measuring a subcutaneous fat thickness and a method for measuring a subcutaneous fat thickness by using said device, which make it possible to report main changes in absolute subcutaneous fat thicknesses in certain topical body part desired to know such as biceps, triceps, sides, thighs, calves or the like, for body maintenance, thereby being useful for making a good-shaped body.

[30] The non-invasive measurement device of a subcutaneous fat thickness of the present invention is a device which measures an absolute thickness of subcutaneous fat by using near-infrared, and characteristically comprises: a power supplying part; a light source which generates light generated from a light source element having a wavelength between 400nm -2500nm; an optic filter which only allows light within a near- infrared bandwidth of 1000nm-1400nm to be passed therethrough, among the light which has been absorbed to and reflected from a part desired to be measured after being irradiated from said light source to the part; a detector which can only detect a light within a specific wavelength range which passed through the optic filter; and a data processing part which measures the subcutaneous fat present in topical parts of a human body, based on the light intensity detected by said detector.

[31] Preferably, the data processing part comprises: an amplifier(AMP) for amplifying a signal detected by the detector; an analog-digital(A/D) converter for converting the detected signal to a digital signal; a digital signal processor for processing the converted signal; a memory storing an algorithm which comprises data used for estimating a subcutaneous fat thickness at a certain part of a human body; a microprocessor for controlling the estimation of a subcutaneous fat thickness by comparing the data outputted from the digital signal processor and the data from the memory and a display part for displaying the subcutaneous fat thickness estimated by the microprocessor.

[32] Preferably, the light source is a tungsten halogen lamp, and the detector uses a semiconductor device made of indium-galium-arsenide compound(InGaAs), which only responds to the wavelengths in near-infrared region, i.e. between 900nm and 1700nm.

[33] Further, it is preferred to derive a calibration curve from the relation between the absorbance and intensity of light sensed by the detector and a subcutaneous fat thickness, and determine a thickness of subcutaneous fat in the area desired to be measured, based on the calibration curve.

[34] In the above, the distance between the light source and the detector is preferably 10

~ 15mm.

[35] Further, it is preferred that the display part further comprises an input part which senses the generation of light.

[36] Such device having the forgoing constitution may be used as a carry-along device, or for a data back-up and customer relationship management, by establishing a network based on a Line communication using a PC and a cable, infrared or RF co mmunication.

[37] Hereinafter, the present invention is further illustrated by the following examples with referencing the drawings attached hereto. The present invention will be better understood by the following examples, which only has illustrative purposes without any intention to limit the scope of the right to be protected by the claims attached thereto.

[38] Fig. 2 is a cross-sectional view showing a part of a device for measuring a sub- cutaneous fat thickness according to one embodiment of the present invention, which comprises at least one light source having a filter settled therein and a detector; Fig. 3 is a cross-sectional view showing transmission of light between a light source and a detector in a non-invasive device for measuring a subcutaneous fat thickness according to one embodiment of the present invention; Fig. 4 is a circuit diagram illustrating the structure of a non-invasive device for measuring a subcutaneous fat thickness according to the present invention; Fig. 5 is a perspective view of a test device showing a display part according to one embodiment of the present invention.

[39] Generally, fat measurement devices utilizing a near- infrared beam specifically use a near- infrared beam having wavelengths ranged between 940nm to 950nm, among the near-infrared wavelength range. These body fat measuring devices have been only used for roughly estimating the body fat ratio distributed over the entire body, by inputting various factors which may affect the body fat, such as gender, age, height/ weight of a subjected individual. This method is mainly used for the center of the biceps, based on a study result that, when using this method, that part has the greatest consistency with the result measured by a standard method (Conway and Norris, 1986, Elia et. al., 1990; Gullstrand).

[40] On the contrary, the present inventors have found an intrinsic optical property of subcutaneous fat, which responds to certain wavelengths within a near-infrared wavelength range, other than the above-said wavelength range.

[41] The wavelength range of the present invention is 1000~1700nm, which is a much wider wavelength range, and such range has been obtained based on the fact that the longer wavelength have greater penetration capability. Therefore, it is possible to measure a thicker fat layer in precise and convenient manner, owing to the light being capable of deeper penetration into the skin, as compared to the conventional body fat measurement devices using a near-infrared beam.

[42]

[43]

Brief Description of the Drawings

[44] Fig. 1 is a plot showing the adsorption band of tissue components in the transmittance spectrum of woman breast tissues, for an application of a conventional device for measuring subcutaneous fat.

[45] Fig. 2 is a cross-sectional view showing a part of a device for measuring a subcutaneous fat thickness according to one embodiment of the present invention, which comprises at least one light source having a filter settled therein and a detector.

[46] Fig. 3 is a cross-sectional view showing transmission of light between a light source and a detector in a non-invasive device for measuring a subcutaneous fat thickness according to one embodiment of the present invention.

[47] Fig. 4 is a circuit diagram illustrating the structure of a non-invasive device for measuring a subcutaneous fat thickness according to the present invention.

[48] Fig. 5 is a perspective view of a test device showing a display part according to one embodiment of the present invention.

[49] Fig. 6 is a flowchart showing a process of measuring a subcutaneous fat thickness in non-invasive way according to the present invention.

[50] Fig. 7 is a standard calibration curve according to one embodiment of the present invention.

[51] <Numerals used in the drawings>

[52] 10: light source 20: detector

[53] 30: optic filter 40: data processing part

[54] 41: microprocessor 42: A/D converter

[55] 43: digital signal processor 44: memory

[56] 45: amplifier 50: display part

[57] 51 : operating panel 52: LCD

[58] 60: power 70: head part of a sensor

[59]

Mode for the Invention

[60] As shown in Figs. 2 to 4, the non-invasive device for measuring a subcutaneous fat thickness according to the present invention comprises a sensor head part(70) comprising: one or more light sources(lθ) (hereinafter, also referred as a tungsten halogen lamp); one or more detectors (20) for detecting the light absorbed to and reflected from the subjected body; and an optical filter(30) which only allows a near- infrared beam to pass therethrough.

[61] As shown in Fig. 2, the device for measuring a subcutaneous fat thickness representing one of embodiments of the present invention, which comprises one or more tungsten halogen lamps(lθ) and filters(30) placed thereon and detectors (20), is possible to adjust the distance to the tungsten halogen lamp(lθ), variously owing to the use of one or more detectors (20).

[62] From the light intensity sensed by the detector(20), a thickness of subcutaneous fat of a subjected body can be measured.

[63] In the above, general photodiodes used as a detector(20), may be a composition of semiconductor compounds which determine the wavelength band. A semiconductor element suitably used for a near-infrared detector according to the present invention is preferably a light receiving element comprised of indium-galium-arsenide (InGaAs) or InP compounds in suitable ratio. Among them, particularly preferred is an indium- galium-arsenide semiconductor element for sensing a light signal from a light source(lθ) which emits a near- infrared beam in the wavelength range of 1000nm-1700nm.

[64] As illustrated in Fig. 3, in transmission of light from a tungsten halogen lamp(lθ) to the non-invasive device for measuring subcutaneous fat which represents one embodiment of the present invention, it is necessary to lengthen the distance between the tungsten halogen lamp (10) and the detector (20) in order to obtain information on the thicker subcutaneous fat thickness.

[65] Most preferred distance is in the range between 10mm and 15mm. Since the light intensity results varied with a subcutaneous fat thickness are evenly distributed, it is possible to measure a subcutaneous fat thickness more precisely with said light intensity.

[66] As illustrated in Fig. 4, the non-invasive device for measuring subcutaneous fat according to the present invention is comprised of: a power source(60); a light source part(lθ) which generates light; an optic filter(30) which allows a light within a near- infrared bandwidth, among the light which is irradiated from the light source part, and absorbed into and reflected from the part desired to be measured, to pass therethrough; a detector(20) which can only detect a light in a specific wavelength range, which passed through the optic filter; and a data processing part(40) which measures the subcutaneous fat present in topical parts of a human body, based on the light intensity detected by said detector.

[67] In the above, the data processing part(40) is comprised of: an amplifier(44) (AMP) which amplifies a signal detected by the detector(20); an analog-digital (A/D) converter (42) which converts the detected signal to a digital signal; a digital signal processor(43) for processing the converted signal; a memory(44) which stores an algorithm which comprises data used for estimating a subcutaneous fat thickness at a certain part of a human body; a microprocessor (41) which controls the estimation of a subcutaneous fat thickness by comparing the data outputted from the digital signal processor(43) and the data from the memory; and a display part(50) which displays the estimated subcutaneous fat thickness.

[68] The power source(60) has a battery (not shown) therein so as to supply a voltage of

3~6V to each component by inputted control signals.

[69] The tungsten halogen lamp(lθ) is formed to operate by the voltage supplied from the battery in a power source(60) by responding to the inputted signals, and then to generate a visible light and infrared ray within the wavelengths of 400-2500nm.

[70] The optic filter(30) is fixed to the light receiving part of the detector(20) so as to allow a near- infrared beam within the wavelength range of 1000nm-1400nm, among the light (400-2500nm) which is absorbed into and reflected from the skin and sub- cutaneous fat, after being generated from the tungsten halogen lamp (10) to have a wide frequency band.

[71] The detector(20) is formed to sense the light absorbed into and reflected from the skin and subcutaneous fat by inputted control signals and then to convert the sensed light to an electrical signal.

[72] The amplifier(45, AMP) is connected to the detector(20) so as to amplify the electrical signal outputted from the detector(20) to a certain level or more, by control signals.

[73] The microprocessor (41) generally controls each component of the system. Particularly, when a user operates an optional function key on an operating panel(51) for measuring a subcutaneous fat thickness, it controls the tungsten halogen lamp (10) and the detector(20) so as to generate light and detect the light. Further, it compares the digital signal which is outputted from the detector(20)via the amplifier(45) and A/D converter(42) with standard calibration curve data (Fig. 7) which have been already stored in the memory(44), then with the compared result, finds a subcutaneous fat thickness and displays the result on a LCD.

[74] Fig. 7 is a standard calibration curve data showing the difference in absorbance depending on a subcutaneous fat thickness, which were obtained by test results of subcutaneous fat thickness measurements according to one embodiment of the present invention. The standard calibration curve can be further upgraded later in continual manner.

[75] To the memory, various data required to the system are stored, which are upgradable. Specifically, data of a standard calibration curve (Fig. 7) and corrected data are stored.

[76] In the calibration data, the relationship between absorbance(A) and a subcutaneous fat thickness (mm) can be represented as a linear equation in the form of y = ax + b, wherein y is the absorbance at a certain part, and x is a subcutaneous fat thickness corresponding to the absorbance.

[77] Absorbance(A) can be determined by the following equality:

[78] A = log ( P / P )

[79] (Po: reference signal level (Steps P1-P2 in Fig. 6),

[80] P: signal level obtained by measuring a part of a body(Step P3 in Fig. 6)).

[81] Hereinafter, a method using a non-invasive measurement device of a subcutaneous fat thickness having the above constitution is described.

[82] As it is shown in Fig. 6, the method for non-invasively measuring a subcutaneous fat thickness according to the present invention comprises the following steps: a first step of measuring the light intensity of the light generated from a light source, by using a standard reflectance material; a second step of, when the measured light intensity reached to a certain level or more, irradiating a certain part of a human body with the light; a third step of calculating a relative absorbance by comparing the intensity of light, which has been absorbed into, reflected from the irradiated part of the body, with the light intensity measured in the first step; a fourth step of measuring a subcutaneous fat thickness by comparing the calculated absorbance and data stored in the memory; and a fifth step of displaying the measured subcutaneous fat thickness.

[83] In the above steps, preferably the third step comprises: a first process of, among the light which has been obtained after absorption and reflection at the irradiated part, passing the light only having a wavelength in the near- infrared band between lOOOnm and 1400nm through an optic filter; a second process of sensing the near-infrared ray passed through the optic filter by a detector, and then amplifying it in the form of a corresponding electric signal; and a third process of converting the amplified electric signal to a digital signal by an analog-digital converter, and calculating a relative absorbance.

[84] Further describing the above steps, based on Fig. 6, the first step is a step [Pl] for finding the light intensity wherein the light is the reflection of a light instantly generated from the tungsten halogen lamp, to the standard reflectance material.

[85] When the reference signal level is determined to have a suitable degree of light intensity [P2], a part of a subjected body is irradiated with the light [P3].

[86] The intensity of the light which is obtained after being absorbed to and reflected from the measured area, i.e. the irradiated part of the subjected body, is compared with a reference signal level, and then a relative absorbance is calculated from the comparison result [P4]. The light which is obtained after being absorbed to and reflected from the irradiated part of the subjected body is subjected to the optic filter which only allows the light having the wavelengths within the near-infrared band, i.e. between lOOOnm and 1400nm, to pass through. The infrared ray passed through the optic filter is sensed by the detector, amplified in the form of an electric signal by the amplifier, and outputted.

[87] Such amplified electric signal is converted to a digital signal through the analog- digital converter, and then the calibrated calculation value is compared with the standard calibration curve data stored in a memory [P5] so as to measure a subcutaneous fat thickness [P6]. Completing the measurement, the subcutaneous fat thickness is displayed on an LCD panel as illustrated in Fig. 5 [P7].

[88] The non-invasive measurement device of a subcutaneous fat thickness and the method thereof, as so far described, make it possible to measure a thickness of subcutaneous fat present in the deeper part of a human body in more convenient way, by measuring a thickness of subcutaneous fat topically present in the human body with a near- infrared ray in the range of lOOOnm- 1400nm. [89] It should be understood that the forgoing description is only to illustrate the preferred embodiments of the present invention, without limitative purposes, and thus various modifications or variations may be made to the present invention by persons skilled in the art, without departing from the scope of the present invention.

[90]

Industrial Applicability

[91] As it has been described so far, according to the device for measuring a subcutaneous fat thickness in non-invasive way of the present invention, and the method thereof, the light penetration into the skin can be done to the deeper part of the skin, thereby being possible to carry out precise measurement of a thick fat layer in convenient manner, since the present invention utilizes a characteristic feature of subcutaneous fat which responds to a specific wavelength range, i.e. a near-infrared wavelength range, other than different conventional wavelength range.

Claims

[1] A non-invasive measurement device of a subcutaneous fat thickness which measures an absolute thickness of subcutaneous fat present in topical parts of a human body by using light, characterized by comprising: a power supplying part; a light source which generates light generated from a light source element having a wavelength between 400nm -2500nm; an optic filter which only allows light within a near- infrared bandwidth of

1000nm-1400nm to be passed therethrough, among the light which has been absorbed to and reflected from a part desired to be measured after being irradiated from said light source to the part; a detector which can only detect a light within a specific wavelength range which passed through the optic filter; and a data processing part which measures the subcutaneous fat present in topical parts of a human body, based on the light intensity detected by said detector.

[2] The non-invasive measurement device of a subcutaneous fat thickness according to claim 1, wherein the data processing part comprises: an amplifier(AMP) for amplifying a signal detected by the detector; an analog-digital(A/D) converter for converting the detected signal to a digital signal; a digital signal processor for processing the converted signal; a memory storing an algorithm which comprises data used for estimating a subcutaneous fat thickness at a certain part of a human body; a microprocessor for controlling the estimation of a subcutaneous fat thickness by comparing the data outputted from the digital signal processor and the data from the memory; and a display part for displaying the subcutaneous fat thickness estimated by the microprocessor.

[3] The non-invasive measurement device of a subcutaneous fat thickness according to claim 1, wherein the light source is a tungsten halogen lamp.

[4] The non-invasive measurement device of a subcutaneous fat thickness according to claim 1, wherein the detector is a semiconductor device made of indium- galium- arsenide compound(InGaAs), which only responds to the wavelengths in near-infrared region, i.e. between 900nm and 1700nm.

[5] The non-invasive measurement device of a subcutaneous fat thickness according to claim 1, which derives a calibration curve from the relation between the absorbance and intensity of light sensed by the detector and a subcutaneous fat thickness, and determines a thickness of subcutaneous fat in the area desired to be measured, based on the calibration curve.

[6] The non-invasive measurement device of a subcutaneous fat thickness according to claim 1, wherein the distance between the light source and the detector is 10 ~ 15mm.

[7] The non-invasive measurement device of a subcutaneous fat thickness according to claim 2, wherein the display part further comprises an input part which senses the generation of light.

[8] The non-invasive measurement device of a subcutaneous fat thickness according to claim 1 or 2, which is used as a carry-along device, or for a data back-up and customer relationship management, by establishing a network based on a Line communication using a PC and a cable, infrared or RF communication.

[9] A method for non-invasively measuring a subcutaneous fat thickness, which measures an absolute thickness of subcutaneous fat present in a topical part of a human body by using light in non-invasive way, characterized by comprising the following steps: a first step of measuring the light intensity of the light generated from a light source, by using a standard reflectance material; a second step of, when the measured light intensity reached to a certain level or more, irradiating a certain part of a human body with the light; a third step of calculating a relative absorbance by comparing the intensity of light, which has been absorbed into, reflected from the irradiated part of the body, with the light intensity measured in the first step; a fourth step of measuring a subcutaneous fat thickness by comparing the calculated absorbance and data stored in the memory; and a fifth step of displaying the measured subcutaneous fat thickness.

[10] The method for non-invasively measuring a subcutaneous fat thickness according to claim 9, wherein the third step comprises: a first process of, among the light which has been obtained after absorption and reflection at the irradiated part, passing the light only having a wavelength in the near- infrared band between lOOOnm and 1400nm through an optic filter; a second process of sensing the near-infrared ray passed through the optic filter by a detector, and then amplifying it in the form of a corresponding electric signal; and a third process of converting the amplified electric signal to a digital signal by an analog-digital converter, and calculating a relative absorbance.