JP4385650B2 - Optical fat measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical type fat measurement equipment capable of measuring the state of the fat into the optical.
[0002]
[Prior art]
FIG. 13 shows an optical fat measurement device according to the prior art (see, for example, Patent Document 1). As shown in the figure, the optical fat measurement device includes a fat measurement contact 131 that contacts the living body surface 1, a light source 132 built in the fat measurement contact 131, a plurality of light receiving elements 133a to 133d, The light quantity control circuit 134 that controls the light quantity of the light source 132 and the light receiving elements 133a to 133d are switched, and a switching circuit 135 that outputs a signal obtained from the switched light receiving elements to the amplifier 136, and a switching circuit 135 An amplifier 136 that amplifies the output from the amplifier 136, an A / D conversion circuit 137 that performs A / D conversion on the signal of the amplifier 136, an input unit 138 for a user to input for measurement, and information from the input unit 138 Alternatively, the CPU 139 that processes a signal from the A / D conversion circuit 137 and controls the light amount control circuit 134, the switching circuit 135, and the display unit 140, and the CPU 13 There has been a display unit 140 for displaying various information to be processed.
[0003]
According to such an optical fat measurement device, light that is incident on the inside of the living body composed of subcutaneous fat 2, muscle 5 and the like from the light source 132 disposed on the living body surface 1 is propagated while being scattered and absorbed inside the living body. Then, the light 141, 142, etc. again appearing on the surface of the living body is received selectively using the light receiving elements 133a-133d, and the thickness of the subcutaneous fat 2 inside the living body is measured by the CPU 139, etc. based on the received light. be able to.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-155091
[Problems to be solved by the invention]
However, in the conventional fat measuring apparatus, the soft subcutaneous fat 2 in the living tissue 1 is easily deformed by an external force. Therefore, the living body surface 1 is deformed only by gently placing the fat measuring contact 131 on the living body surface 1, and the thickness of the subcutaneous fat 2 varies with each measurement. Therefore, the measurement reproducibility was deteriorated. This problem is particularly noticeable when the subcutaneous fat 2 is thick.
[0006]
Further, when the subcutaneous fat 2 becomes thicker, the amount of light received by the light receiving elements 133a to 133d is gradually saturated, and there is a problem that thick subcutaneous fat exceeding a certain level cannot be measured.
[0007]
Accordingly, in view of the above-described conventional problems, the present invention provides an optical fat measurement device that can measure the state of fat such as subcutaneous fat with high reproducibility and high accuracy, and can measure even thicker fat. For the purpose.
[0008]
[Means for Solving the Invention]
In order to achieve the above object, the first aspect of the present invention provides a pressure applying means for applying a pressure of 7 kPa or more to the surface of the living body, and the singular or plural disposed on the living body surface including the portion to which the pressure is applied. A fat measuring contact having one or a plurality of light incident portions arranged at a predetermined distance from the light emitting portion on the surface of the living body including the light emitting portion and the portion to which the pressure is applied. ,
One or a plurality of light sources for emitting light from the light emitting portion;
One or a plurality of light receiving parts for receiving light from the light incident part,
Computation means for computing the fat state of the living body based on the amount of light received by the light receiving unit ,
The fat measuring contact has a molded part having a first contact surface in surface contact with the living body surface,
The light emitting part and the light incident part are provided on the first contact surface,
The first contact surface is an optical fat measurement device having a convex portion provided between at least a pair of the light incident portion and the light emitting portion .
[0009]
The second aspect of the present invention is the optical fat measurement apparatus according to the first aspect of the present invention, wherein the state of fat of the living body is fat thickness or fat percentage.
[0010]
Further, in the third aspect of the present invention, the calculation unit determines whether the received light amount is stable within a specified range, and performs the calculation based on the received light amount that is stable within the specified range. 1 is an optical fat measurement apparatus according to the present invention .
[0011]
Also, a fourth aspect of the present invention, the light incident portion is the light type fat measuring apparatus of the first aspect of the present invention are also provided on the main surface of the convex portion.
[0012]
Moreover, 5th this invention has the 2nd contact surface which the said shaping | molding part is provided in the circumference | surroundings of the said 1st contact surface, has a level | step difference with the said 1st contact surface, and contacts the said biological body surface. It is an optical fat measuring device of the 1st present invention.
[0013]
The sixth aspect of the present invention is the optical fat measurement apparatus according to the fifth aspect of the present invention, wherein the second contact surface is parallel to the first contact surface.
[0014]
Further, according to a seventh aspect of the present invention, the pressure applying means of the fat measuring contact is the fat measuring contact itself,
The pressure is the optical fat measuring device according to the first aspect of the present invention, which is the weight of the fat measuring contact.
[0015]
The eighth aspect of the present invention is the optical fat measurement device according to the fifth aspect of the present invention, wherein at least the first contact surface and / or the second contact surface of the fat measurement contactor has a light shielding property. is there.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the optical fat measuring device of the present invention will be described in detail with reference to the drawings.
[0017]
(Embodiment 1)
FIG. 1 is a configuration diagram of the optical fat measurement device according to the first embodiment of the present invention, and FIG. 2 is a top view of the molding unit 3 of the optical fat measurement device as viewed from the contact surface 3a side in contact with the biological surface 1. It is.
[0018]
On the living body surface 1 composed of three layers of skin 4, subcutaneous fat 2, and muscle 5, a forming part 3 for forming the living body surface 1 in the direction of pushing down is disposed.
[0019]
In the molding unit 3, a light source unit 6 including a light source element and a plurality of light receiving units 7 are provided. The light receiving unit 7 incorporates a light receiving element 8 for measurement and a light receiving element 9 for correction. The distance between the measurement light receiving element 8 and the light source unit 6 is 45 mm, and the distance between the correction light receiving element 9 and the light source unit 6 is 22.5 mm. The light exit from the light source unit 6 has a diameter of φ1.5 mm, and the light entrance of the measurement light-receiving element 8 and the correction light-receiving element 9 is φ1.5 mm. The distance between the measurement light receiving element 8 and the light source unit 6 is preferably between 35 mm and 80 mm, and the distance between the correction light receiving element 9 and the light source unit 6 is preferably between 15 mm and 30 mm.
[0020]
When the light source unit 6 is turned on, the correction light receiving element 9 receives the correction light reception amount (Y1), and the measurement light receiving element 8 receives the measurement light reception amount (Y2). Here, the light source unit 6 uses a laser diode having a center wavelength of 785 nm as a light source element. The light source element is not limited to the above, and a laser diode or LED having a center wavelength of 500 nm to 1000 nm is preferably used because the difference in light propagation characteristics between the subcutaneous fat 2 and the muscle 5 can be increased. . Furthermore, it is preferable that light is guided from the light source element to the living body surface 1 using a light guide component such as an optical fiber because heat generated by the light source element is not transmitted to the living body surface 1.
[0021]
A photodiode is used as the light receiving element of the light receiving unit 7. The light receiving element may be a photoelectric conversion element such as CdS. Further, light may be guided from the living body surface to the light receiving element using a light guide component such as an optical fiber.
[0022]
The molded part 3 has a disk shape with a diameter of 60 mm and has a predetermined weight as will be described later. By making the surface in contact with the biological surface 1 into a substantially planar shape, the biological surface 1 is stabilized in a planar shape and contributes to measurement reproducibility.
[0023]
The molded part 3 is made of black ABS for light shielding. The material of the molding unit 3 is low in reflectance with respect to the light from the light source unit 6, so that the light emitted from the living body surface 1 can be prevented from returning to the living body again. Only the light propagating in the deep region can be received, and the measurement accuracy is improved. In addition, disturbance light from other than the light source that causes noise can be shielded, and the measurement accuracy is improved. The molding part 3 is not limited to black ABS, and may be formed using any material as long as it has a light shielding property. Moreover, you may make it give light-shielding property only to the contact surface 3a which contacts the biological body surface 1 by processes, such as coating.
[0024]
Further, the molded part 3 has a structure in which the edge is rounded so that an acute angle portion does not hit the living body surface 1, so that even if the molded part 3 is pressed against the living body surface 1, the user does not feel pain due to the edge.
[0025]
The calculation unit 10 calculates the thickness of the subcutaneous fat 2 based on the amount of light received by the light receiving unit 7. The calculated thickness of the subcutaneous fat 2 is displayed on the display unit 11 and sent as data to other devices through the communication unit 12.
[0026]
In addition, by inputting data such as height, weight, age, sex, measurement site, etc. directly from the input unit 13 or from other devices through the communication unit 12, the body fat rate correlates with the thickness of the subcutaneous fat 2. Can be calculated by the calculation unit 10 and displayed on the display unit 11, or the data can be transferred to another device by the communication unit 12.
[0027]
In the above configuration, the light source unit 6 is the light emitting unit of the present invention, the light receiving unit is the light incident unit of the present invention, the light source element is the light source of the present invention, the correction light receiving element 9 and the measurement light receiving element 8 are the present invention. The light receiving element, the calculation unit 10 corresponds to the calculation means of the present invention, the molding unit 3 corresponds to the molding unit and fat measurement contactor of the present invention, and the contact surface 3a corresponds to the first contact surface of the present invention.
[0028]
The operation of the optical fat measurement apparatus having the above-described configuration according to Embodiment 1 of the present invention will be described.
[0029]
First, the measurement principle will be described. The propagation characteristics of light are greatly different between the muscle 5 and the subcutaneous fat 2, the absorption tendency is stronger in the muscle 5, and the scattering tendency is stronger in the subcutaneous fat 2. This difference in characteristics is remarkable with light having a wavelength of 500 nm to 1000 nm. Therefore, the light incident from the biological surface 1 from the light source unit 6 is diffused in the subcutaneous fat 2 as the subcutaneous fat thickness is increased, and spreads not only in the depth direction but also in the lateral direction. Therefore, the light spreading in the lateral direction and emitted to the living body surface 1 increases as the subcutaneous fat 2 is thicker.
[0030]
The light that spreads in the lateral direction and is emitted to the living body surface 1 again is received by the light receiving unit 7, whereby the thickness of the subcutaneous fat 2 can be measured.
[0031]
Next, the measurement procedure will be described. As a first operation, in a state where the light source unit 6 is not lit, the molding unit 3 is pressed against the living body surface 1 so that the contact surface 3a is in surface contact.
[0032]
As a second operation, when the amount of light received by the light receiving unit 7 is 100 pW or less, it is confirmed that the entire light receiving unit 7 is in contact with the living body surface 1 and the living body surface 1 is pushed down, and the light source unit 6 is turned on. The light irradiates the living body surface 1.
[0033]
At this time, due to the action of pressure applied to the living body surface 1 through the contact surface 3a, the thickness of the subcutaneous fat 2 is uniformly crushed and stable until the portion corresponding to the contact surface 3a is not further deformed. Yes. The pressure is preferably 7 kPa or more because the subcutaneous fat thickness is stable.
[0034]
As a third operation, by measuring the light 14 that has reached the light-receiving element 9 for correction, a light-receiving amount for correction (light-receiving amount Y1 at the first distance) is obtained, and the light 15 that has reached the light-receiving element 8 for measurement. Is measured to obtain a measurement light reception amount (light reception amount Y2 at the second distance).
[0035]
Here, both the received light amount for correction and the received light amount for measurement fluctuate depending on the strength of pressing the molding unit 3 against the living body surface 1 and the thickness of the subcutaneous fat 2. By determining whether the received light amount is stable, it is confirmed that the pressing strength and the thickness of the subcutaneous fat 2 are stable. Thereby, measurement with high accuracy becomes possible.
[0036]
Whether the received light amount is stable is measured for each received light amount of each light receiving element at a sampling cycle of 100 Hz, and the difference between the maximum value and the minimum value of each received light amount at a sampling time of 200 ms is 10% of the maximum value. This is done by determining whether it falls within the range. In order to remove the influence of the heartbeat and the influence of the human body movement, the sampling cycle should be fast, preferably 100 Hz or more, and the sampling time should be short, preferably 500 ms or less.
[0037]
Next, a method for calculating the thickness of the subcutaneous fat 2 in the calculation unit 10 will be described. FIG. 3 shows the relationship between the amount of received light for measurement and the thickness of the subcutaneous fat 2. In FIG. 3, white circles indicate the relationship between the amount of received light for measurement and the thickness of the subcutaneous fat 2. A dotted line is a linear regression line.
[0038]
As can be seen from the figure, a plurality of primary regression lines showing the correlation between the amount of received light for measurement and the thickness of subcutaneous fat 2 are obtained in advance, and the subcutaneous fat is obtained by using the primary regression line and the amount of received light for measurement. The thickness of 2 can be measured with high reproducibility and high accuracy.
[0039]
By the way, the amount of received light for measurement includes the influence of scattering and absorption variations of the skin 4 as an error factor. In order to correct the influence of the skin 4 , the correction light reception amount is used.
[0040]
FIG. 4 shows the relationship between the parameter Y2 / Y1 obtained by dividing the measurement light reception amount (light reception amount Y2 at the second distance) by the correction light reception amount (light reception amount Y1 at the first distance) and the thickness of the subcutaneous fat 2. Shown in In FIG. 4, white circles indicate the relationship between Y2 / Y1 and the thickness of subcutaneous fat 2. A dotted line is a linear regression line.
[0041]
Compared with FIG. 3, the variation is clearly reduced, and it can be seen that there is an effect of correction by the amount of received light for correction. By using the linear regression line and Y2 / Y1, it is possible to correct the influence of the skin 5 and the pressure applied to the surface of the living body, so that the subcutaneous fat thickness can be measured with high reproducibility and high accuracy. .
[0042]
As described above, according to the present embodiment, the thickness of the subcutaneous fat 2 is crushed and stabilized without further deformation by the action of the pressure applied to the living body surface 1 through the contact surface 3a, By determining that the deformed state is stable and performing the measurement, the subcutaneous fat thickness can be measured with high reproducibility and high accuracy.
[0043]
In the above description, the light source unit 6 is configured by one light source element and the light receiving unit 7 is configured by the measurement light receiving element 8 and the correction light receiving element 9 as illustrated in FIGS. As shown in FIG. 5 and a top view of the molding unit 3 in FIG. 6, the light receiving unit 7 may be configured by one light receiving element, and the light source unit 6 may be configured by the measurement light source element 16 and the correction light source element 17. In this case, when the correction light source element 17 is turned on and the measurement light source element 16 is turned off, the received light amount of the light 18 received by the light receiving unit 7 becomes the correction received light amount, and the correction light source element 17 is turned off. When the measurement light source element 16 is turned on, the received light amount of the light 19 received by the light receiving unit 7 is the received light amount for measurement. Further, the number of light source elements and light receiving elements is not limited to the above configuration. Furthermore, as long as two types of received light amounts, that is, a correction light reception amount and a measurement light reception amount can be obtained, both the light source unit 6 and the light reception unit 7 use a plurality of light source elements and a plurality of light reception elements. Also good.
[0044]
Here, as shown in the configuration diagram of FIG. 7 and FIG. 8, a convex portion 20 corresponding to the convex portion of the present invention may be provided on the contact surface 3 a of the molding portion 3. Here, the convex portion 20 has a step with the contact surface 3a, has a contact surface 3b substantially parallel to the contact surface 3a, and the correction light-receiving element 9 is disposed on the surface.
[0045]
When measurement similar to the above is performed using the molding part 3 having such a convex part 20, a part of the region between the light source part 6 and the measurement light receiving element 8 on the biological surface 1 by the convex part 20. However, by being pushed down deeper than the portion pushed down by the contact surface 3a, the step between the contact surface 3a and the contact surface 3b cuts the light 21 that has propagated through the shallow region in the living body. As a result, the light receiving unit 7 can receive only light propagating through a deeper part in the living body, and the accuracy of measuring the thickness of the subcutaneous fat 2 is improved.
[0046]
Moreover, although the method of applying a pressure via the contact surface 3a may use the external force which is not shown in figure, you may utilize the dead weight of the shaping | molding part 3. FIG. At this time, the weight of the molded part 3 is preferably 1 kg. Moreover, although this Embodiment demonstrated as what measures body fat thickness, as a fat state of this invention, you may measure states other than body fat thickness.
[0047]
For example, the body fat percentage indicating the proportion of body fat in the living body is correlated with the subcutaneous fat thickness of each part of the living body, and the body fat percentage increases as the subcutaneous fat is thicker. However, even with the same subcutaneous fat thickness, if the muscle mass is large, the body weight increases and the body fat percentage decreases.
[0048]
Therefore, by inputting information such as the measurement site and weight from the input unit 13 or the communication unit 12, the calculation unit 10 can determine the body fat percentage. For the calculation in the calculation unit 10, a plurality of specimens whose body fat percentages are known are prepared in advance, and the relationship between the value obtained by dividing the subcutaneous fat thickness of the predetermined measurement site by the weight of the specimen and the known body fat percentage is calculated. Plot on the graph and use the calculation formula obtained from the linear approximation line . It is possible to calculate body fat percentage with higher accuracy by inputting height, sex, age, etc. in addition to body weight and facilitating individual calculation formulas for each condition.
[0049]
(Embodiment 2)
FIG. 9 is a configuration diagram of the optical fat measurement device according to the second embodiment of the present invention, and FIG. 10 is a top view of the molding unit 3 of the optical fat measurement device viewed from the contact surface 3a side in contact with the biological surface 1. It is.
[0050]
Description of the same parts as those in the first embodiment will be omitted, and different parts will be described. On the contact surface 3a of the molding part 3 that molds the living body surface 1 in the direction of pressing down, a convex part 22 that further presses down locally is provided. The convex portion 22 is also made of black ABS in order to block light like the molded portion 3. The convex portion 22 has a contact surface 3c parallel to the contact surface 3a having a width of 5 mm and a length of 55 mm, and protrudes from the contact surface 3a with a step of 5 mm in height. A light source unit 6 and a light receiving unit 7 are provided on the contact surface 3c. The contact surface 3c does not necessarily have to be parallel to the contact surface 3a. There should be a step. The light receiving unit 7 includes a measurement light receiving element 8 (second light receiving element) and a correction light receiving element 9 (first light receiving element). The distance between the measurement light receiving element 8 and the light source unit 6 is 45 mm, the distance between the correction light receiving element 9 and the light source unit 6 is 22.5 mm, and the light source unit 6 and each light receiving unit 7 are arranged substantially in a straight line. Has been. In the above configuration, the contact surface 3c corresponds to the second contact surface of the present invention.
[0051]
The difference from the first embodiment is that the convex portion 22 deforms the subcutaneous fat 2 to a greater extent locally than the portion where the contact surface 3a is in contact. Therefore, when the subcutaneous fat 2 is thick, the subcutaneous fat 2 that is thinner by the height of the convex portion 22 is measured than when the convex portion 22 is not provided. Further, when the subcutaneous fat 2 is thin, the subcutaneous fat 2 is not deformed, so that the thickness of the measured subcutaneous fat 2 does not change. Therefore, the thicker subcutaneous fat 2 can be measured by the height of the convex portion 22.
[0052]
FIG. 11 shows the relationship between the amount of received light for measurement and the subcutaneous fat thickness, and FIG. 12 shows the relationship between the skin correction parameter Y2 / Y1 and the subcutaneous fat thickness. By using the regression line and the received light amount for measurement or the parameter Y2 / Y1, the subcutaneous fat thickness can be measured locally thin, and the original subcutaneous fat thickness can be converted from the thinned subcutaneous fat thickness. Therefore, a thicker subcutaneous fat thickness can be measured with high reproducibility and high accuracy, and the measurement range of the subcutaneous fat thickness can be increased.
[0053]
In the above description, the living body is a human body, but may be another animal.
[0054]
【The invention's effect】
As is clear from the above, according to the present invention, the state of fat can be measured with high reproducibility and high accuracy.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an optical fat measurement device according to a first embodiment of the present invention. FIG. 2 is a top view of a molding part of the optical fat measurement device as viewed from the side in contact with a living body surface. FIG. 4 is a graph showing the relationship between the amount of received light for measurement and fatiness determined by the optical fat measurement device in one embodiment of the present invention. FIG. 4 shows the relationship between the parameter Y2 / Y1 determined by the optical fat measurement device and the subcutaneous fat thickness. FIG. 5 is a configuration diagram of an optical fat measuring device in which the configuration of the light source unit and the light receiving unit is different in the embodiment. FIG. 6 is a side of the molded fat measuring device in contact with the living body surface. FIG. 7 is a configuration diagram of an optical fat measurement device provided with a protrusion in the same embodiment. FIG. 8 is a view of a molding portion of the optical fat measurement device viewed from the side in contact with the living body surface. FIG. 9 is a top view of an optical fat measurement apparatus according to another embodiment of the present invention. Fig. 10 is a top view of the molding part of the optical fat measuring device as seen from the side in contact with the surface of the living body. Fig. 11 is a relationship between the amount of received light for measurement and the thickness of subcutaneous fat obtained by the optical fat measuring device. FIG. 12 is a graph showing the relationship between the parameter Y2 / Y1 obtained by the optical fat measurement device and the subcutaneous fat thickness. FIG. 13 is a configuration diagram of a conventional optical fat measurement device.
DESCRIPTION OF SYMBOLS 1 Living body surface 2 Subcutaneous fat 3 Molding part 4 Skin 5 Muscle 6 Light source part 7 Light receiving part 8 Measurement light receiving element 9 Correction light receiving element 10 Calculation part 11 Display part 12 Communication part 13 Input part 14 Photon which a correction light receiving element receives 15 Photons received by the measurement light receiving element 16 Measurement light source element 17 Correction light source element 18 Light from the correction light source element 19 Light from the measurement light receiving element 20 Convex part 21 Light propagating through a shallow part of the living body 22 Convex part

Claims (8)

A pressure applying means for applying a pressure of 7 kPa or more to the surface of the living body, one or a plurality of light emitting portions arranged on the surface of the living body including the portion to which the pressure is applied, and a portion to which the pressure is applied On the surface of the living body, a fat measuring contact having one or a plurality of light incident portions arranged at a predetermined distance from the light emitting portion,
One or a plurality of light sources for emitting light from the light emitting portion;
One or a plurality of light receiving parts for receiving light from the light incident part,
Computation means for computing the fat state of the living body based on the amount of light received by the light receiving unit ,
The fat measuring contact has a molded part having a first contact surface in surface contact with the living body surface,
The light emitting part and the light incident part are provided on the first contact surface,
The optical fat measuring device, wherein the first contact surface has a convex portion provided between at least a pair of the light incident portion and the light emitting portion .   The optical fat measuring device according to claim 1, wherein the fat state of the living body is fat thickness or fat percentage.   The optical fat measurement according to claim 1, wherein the calculation unit determines whether the received light amount is stable within a specified range, and performs the calculation based on the received light amount that is stable within the specified range. apparatus. The optical fat measuring apparatus according to claim 1 , wherein the light incident part is also provided on a main surface of the convex part . The forming section, the first provided around the contact surface, the having a first contact surface and the step, optical type fat according to claim 1 having a second contact surface in contact with the living body surface measuring device. The optical fat measurement device according to claim 5 , wherein the second contact surface is parallel to the first contact surface . The pressure applying means of the fat measuring contact is the fat measuring contact itself,
The optical fat measuring device according to claim 1, wherein the pressure is the weight of the fat measuring contact . The optical fat measurement device according to claim 5 , wherein at least the first contact surface and / or the second contact surface of the fat measurement contactor has light shielding properties .

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