JP2004298572A - Blood fatigue degree sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood fatigue degree sensor by which the degree of fatigue is known simply and wherein a fluctuation in precision is hardly caused by the movement etc. of a patient. <P>SOLUTION: The sensor is provided with: a first light source 4 for emitting light of a 760±5 nm wavelength; a second light source 5 for emitting light of a 840±5 nm wavelength; a photodetection part 6 opposing the first light source 4 and the second light source 5 at an interval; an arithmetic means 11 which calculates the light transmittance of the light of the 760±5 nm wavelength and the light transmittance of the light of the 840±5 nm wavelength by a light quantity emitted from the first light source 4 and the second light source 5 and a light quantity photodetected by the photodetection part 6 to obtain the ratio of the light transmittance of the light of the 760±5 nm wavelength to the light transmittance of the light of the 840±5 nm wavelength as an arithmetic result; and a display part 14 for displaying the degree of fatigue based on the arithmetic result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a blood fatigue sensor that utilizes the fact that deoxygenated hemoglobin in blood increases upon fatigue.
[0002]
[Prior art]
In recent years, there has been an increasing number of cases in which mental and physical diseases are committed due to accumulation of fatigue due to a shortage of workers due to a reduction in the number of employees, and in severe cases, death from overwork.
However, it is troublesome to have a physician check frequently to avoid illness due to overwork, so that people usually tend to overlook fatigue until their physical and mental health deteriorates considerably.
Therefore, there is a long-felt need for a device that allows even ordinary people to easily determine the degree of fatigue on their own.
[0003]
As a device that allows ordinary people to diagnose their own health status, information on the health status of the subject, such as the state of peripheral circulation, blood oxygen concentration, body fatigue, There is known a health condition analyzer that evaluates the degree of tension and presents the result to a subject (see Patent Document 1).
However, the above-mentioned conventional health condition analysis apparatus irradiates light to blood vessels such as a finger, and detects a pulse wave by receiving light reflected by the blood vessels. Therefore, the measurement may not be possible unless the subject applies an appropriate pressing force.
[0004]
[Patent Document 1]
JP-A-8-299292
[Problems to be solved by the invention]
It is an object of the present invention to provide a blood fatigue sensor that can easily know the degree of fatigue and is less likely to vary in accuracy due to the movement of the subject.
[0006]
[Means for Solving the Problems]
The blood fatigue degree sensor according to the present invention includes a first light source that emits light having a wavelength of 760 nm ± 5 nm, a second light source that emits light having a wavelength of 840 nm ± 5 nm, and the first light source and the second light source. The light receiving portion facing away at an interval, the light amount emitted from the first light source and the second light source and the light amount received by the light receiving portion determine the transmittance of light having a wavelength of 760 nm ± 5 nm and the wavelength of 840 nm ±. Calculating means for calculating the transmittance of the light having a wavelength of 5 nm, and calculating the ratio between the transmittance of the light having a wavelength of 760 nm ± 5 nm and the transmittance of the light having a wavelength of 840 nm ± 5 nm from the result; A display unit for displaying the degree.
[0007]
Alternatively, a first light source that irradiates light having a wavelength of 905 nm ± 5 nm, a second light source that irradiates light having a wavelength of 840 nm ± 5 nm, and faces the first light source and the second light source at an interval. The light transmittance of the wavelength 905 nm ± 5 nm and the transmittance of the light of wavelength 840 nm ± 5 nm are determined by the light receiving unit, the light amount irradiated from the first light source and the second light source, and the light amount received by the light receiving unit. Calculating means for calculating the ratio between the transmittance of light having a wavelength of 905 nm ± 5 nm and the transmittance of light having a wavelength of 840 nm ± 5 nm from the result, and a display section for displaying a degree of fatigue based on the calculation result. Is provided.
[0008]
When a blood vessel is irradiated with light having a wavelength of 760 nm ± 5 nm or 905 nm ± 5 nm and light having a wavelength of 840 nm ± 5 nm, the transmittance of the light having a wavelength of 760 nm ± 5 nm or 905 nm ± 5 nm fluctuates due to deoxygenated hemoglobin in blood. The transmittance of light having a wavelength of 840 nm ± 5 nm changes depending on the hemolyzed neutral fat in the blood.
Hemoglobin in blood increases when fatigued, so that the transmittance of light having a wavelength of 760 nm ± 5 nm or 905 nm ± 5 nm decreases, but the transmittance of light having a wavelength of 840 nm ± 5 nm changes little.
Accordingly, when the ratio of the transmittance of the light having the wavelength of 760 nm ± 5 nm or 905 nm ± 5 nm to the transmittance of the light having the wavelength of 840 nm ± 5 nm is significantly reduced, it can be understood that the accumulation of fatigue tends to progress. Display and inform.
[0009]
The blood fatigue degree sensor of the present invention includes a light source that emits light having a wavelength of 760 nm ± 5 nm, a light receiving unit facing the light source at an interval, a light amount emitted from the light source, and light received by the light receiving unit. Calculating means for calculating the transmittance of light having a wavelength of 760 nm ± 5 nm based on the amount of light, and obtaining a temporal change in the transmittance of light having a wavelength of 760 nm ± 5 nm from the result; and a display for displaying the degree of fatigue based on the calculation result. May be provided.
[0010]
Alternatively, a light source that emits light having a wavelength of 905 nm ± 5 nm, a light receiving unit facing the light source at an interval, and a light source having a wavelength of 905 nm ± 5 nm depending on the amount of light emitted from the light source and the amount of light received by the light receiving unit. An arithmetic unit for calculating the light transmittance and obtaining a temporal change in the transmittance of the light having a wavelength of 905 nm ± 5 nm from the result as an operation result, and a display unit for displaying the operation result or the degree of fatigue based on the operation result. .
When the transmittance of light having a wavelength of 760 nm ± 5 nm or 905 nm ± 5 nm is sharply reduced, it is known that fatigue is progressing and hemoglobin in blood is increasing.
[0011]
The light source and the light receiving section may be provided on the inner surface of the finger insertion tube. With this configuration, it is possible to measure the transmittance of light that has passed through the blood simply by inserting a finger into the finger insertion tube.
It is also possible to use a fingerprint recognition unit of the fingerprint authentication device and install a light source and a light receiving unit here.
If an alarm is issued when the calculation result reaches a predetermined value, even a test subject who cannot understand the displayed contents can recognize that fatigue is progressing.
It is good to mount it on an electronic device such as a mobile phone or a computer terminal device (for example, a keyboard) so that it can be easily used at any time.
It is desirable that the light source and the light receiving unit are installed at positions corresponding to a distance of 11.5 mm ± 0.5 mm from the fingertip so that the degree of fatigue can be known by accurately measuring the light transmittance.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 3 show a first embodiment of the present invention.
As shown in FIG. 1, the blood fatigue degree sensor includes a sensor unit 1 and a measuring device main body 2.
The sensor unit 1 includes a finger insertion tube 3 (FIGS. 2 and 3), a first light source including a light emitting diode 4 for emitting light having a wavelength of 760 nm ± 5 nm or light having a wavelength of 905 nm ± 5 nm, and a light source having a wavelength of 840 nm ± 5 nm. It has a second light source composed of a light emitting diode 5 for irradiating light, and a light receiving section composed of a photodiode 6.
[0013]
As shown in FIGS. 2 and 3, the finger insertion tube 3 is formed in a slightly thin cylindrical shape in accordance with the shape of the fingertip.
At a distance of 11.5 mm ± 0.5 mm from the back end of the finger insertion tube 3, a light emitting diode 4 and a light emitting diode 5 are mounted on one side of the inner surface, and a photodiode 6 is mounted on the other side of the inner surface. , 5 are installed.
Further, a connector 10 is attached to a distal end of a lead wire 9 extending from the finger insertion tube 3.
[0014]
The measuring device main body 2 is incorporated in a case, and is detachably connected to the memory unit 1 via a connector 10.
Further, as shown in FIG. 1, the measuring device main body 2 controls the entire circuit of the blood fatigue degree sensor, and stores a CPU 11 serving as a calculating means, a ROM 12 storing a control program of the CPU 11 and the like, a calculation result of the CPU 11 and the like. A data memory 13 for storing, a display 14 serving as a display unit installed on the outer surface of the case, a display control circuit 15 for controlling display contents on the display 14 based on a calculation result of the CPU 11, and a data transmitted from the memory unit 1. A / D converter 16 for digitally converting the converted signal.
A power switch is provided in the case of the measuring device main body 2.
[0015]
The blood fatigue sensor according to the present embodiment measures the fatigue as follows.
The subject inserts the finger of the hand into the finger insertion tube 3 to the far end. Then, the light emitting diodes 4 and 5 and the photodiode 6 face each other across a portion of 11.5 mm ± 0.5 mm from the fingertip.
When the subject turns on the power switch in this state, the light emitting diodes 4 and 5 start emitting light toward the photodiode 6.
[0016]
The light emitting diodes 4 and 5 are pulsed under the control of the CPU 11. The light emitting diode 4 repeatedly emits light having a wavelength of 760 nm ± 5 nm or light having a wavelength of 905 nm ± 5 nm for 40 ms and turns off the light for 200 ms (a in FIG. 4), and the light emitting diode 5 emits light having a wavelength of 840 nm ± 5 nm for 40 ms. And turning off the light for 200 ms is repeated (b in FIG. 4). Further, the lighting timings of the light emitting diode 4 and the light emitting diode 5 are shifted so that the light emitting diode 5 is turned on at the same time as the light emitting diode 4 is turned off.
Although the light emitting diodes 4 and 5 vary depending on the device used, for example, the maximum current is 20 mA, and light emission usually starts from 7 mA, and is changed to 20 mA according to the deterioration of the light emitting diodes 4 and 5.
[0017]
A part of the light emitted from the light emitting diodes 4 and 5 passes through the finger and is received by the photodiode 6.
The photodiode 6 transmits a detection signal corresponding to the amount of received light to the A / D converter 16, and the A / D converter 16 converts the received signal into a digital signal. The digital signal is read by the CPU 11 and the difference between the amount of light emitted from the light emitting diodes 4 and 5 is used to determine the transmittance of light having a wavelength of 760 nm ± 5 nm, or the transmittance of light having a wavelength of 905 nm ± 5 nm and the light having a wavelength of 840 nm ± 5 nm. And the transmittance are calculated.
[0018]
By the way, the light having a wavelength of 760 nm ± 5 nm or the light having a wavelength of 905 nm ± 5 nm emitted from the light emitting diode 4 changes in transmittance due to deoxygenated hemoglobin in blood, and the wavelength 840 nm ± emitted from the light emitting diode 5. The transmittance of 5 nm light changes depending on the hemolyzed neutral fat in blood.
In addition, hemoglobin in the blood increases when fatigue occurs, whereas the neutral fat concentration hardly changes.
In FIG. 5, the solid line indicates the light transmittance in a normal state (non-fatigue state), and the broken line indicates the light transmittance during fatigue. From FIG. 5, it can be seen that the transmittance of light having a wavelength of 760 nm ± 5 nm or light having a wavelength of 905 nm ± 5 nm decreases when fatigue occurs, but the transmittance of light having a wavelength of 840 nm ± 5 nm does not easily change.
[0019]
Therefore, for example, when the transmittance of light having a wavelength of 760 nm ± 5 nm is used, the CPU 11 uses the CPU 11 to determine the ratio (Δ760) of the transmittance of light having a wavelength of 760 nm ± 5 nm (Δ760) to the transmittance of light having a wavelength of 840 nm ± 5 nm (Δ840). When Δ840) is obtained and log (Δ760 / Δ840), which is the amount of inclination, is obtained based on the transmittance ratio, the degree of fatigue increases as the amount of inclination increases.
Δ760 / Δ840 and log (Δ760 / Δ840) obtained by the CPU 11 are stored in the data memory 13, further taken out from the data memory 13 by the CPU 11, and passed to the display control circuit 15 as display information. The display control circuit 15 converts the display information into display data of a preset format and displays the display data on the display 14 as the degree of fatigue.
[0020]
The calculated log (Δ760 / Δ840) may be displayed on the display 14 as a diagonal line, and may be displayed together with the diagonal line indicating the log (Δ760 / Δ840) in a normal state. Alternatively, Δ760 / Δ840 may be directly used as a numerical value and compared with a normal numerical value. May be displayed. Then, the subject can recognize that he / she is tired when the measurement result is largely separated from the normal state.
Further, when Δ760 / Δ840 is within a certain range, the range can be displayed in characters and displayed as, for example, “energy”, “very tired”, “attention required”, and the like. It is.
When Δ760 / Δ840 reaches a certain value, it may be considered that the vehicle is in an overworked state, and a warning by lighting or sound may be issued.
[0021]
FIG. 6 shows a second embodiment.
The sensor unit 1 is provided with only a light source composed of a light emitting diode 4 that emits light having a wavelength of 760 nm ± 5 nm or light having a wavelength of 905 nm ± 5 nm, and is not irradiated with light having a wavelength of 840 nm ± 5 nm.
When the photodiode 6 receives light having a wavelength of 760 nm ± 5 nm or light having a wavelength of 905 nm ± 5 nm and transmits a detection signal to the A / D converter 16, the digital signal converted by the A / D converter 16 is transmitted. In response, the CPU 11 calculates the transmittance of the light having the wavelength of 760 nm ± 5 nm or the light having the wavelength of 905 nm ± 5 nm, and stores the calculated transmittance in the data memory 13.
[0022]
Then, the CPU 11 compares the transmittance at each measurement time, and displays a change with time of the transmittance on the display 14 as a graph or a numerical value.
The subject looks at the display 14 and, when the light transmittance sharply decreases, can recognize that the accumulation of fatigue is progressing.
Further, when the difference between the transmittance at a certain measurement time point and the transmittance at the next measurement time point becomes equal to or more than a certain value, it is preferable to consider that it is too much work and to issue a warning by lighting or sound.
[0023]
The fingerprint recognition unit of the fingerprint authentication device when logging in to the personal computer can be used as a sensor unit, and a light source and a light receiving unit can be installed in the fingerprint recognition unit to measure the degree of fatigue at the time of login. In this case, the personal computer fulfills the function of the measuring instrument body.
In addition, the sensor unit 1 in the first embodiment or the second embodiment is connected to electronic devices such as a mobile phone, a keyboard, and various terminal devices, and a computer connected to the mobile phone and the terminal device is used as a measuring instrument main body. It is also possible.
In any of these cases, it is desirable to dispose the light source and the light receiving portion at a position corresponding to a distance of 11.5 mm ± 0.5 mm from the fingertip so that the light transmittance can be accurately measured.
Further, by changing the shape of the sensor unit, the light transmittance may be measured at a part other than the finger, for example, at a blood vessel such as a toe or a wrist.
[0024]
【The invention's effect】
According to the first to fourth aspects of the present invention, since the fatigue level can be easily and objectively known, it is possible to prevent overwork due to exercise or labor by checking the fatigue level at any time. .
In addition, since the measurement accuracy does not easily change due to the pressing force of pressing a finger or the like against the sensor portion, the degree of fatigue can be accurately measured simply by inserting the finger or the like between the light source and the light receiving unit.
[0025]
According to the invention according to claim 5, it is possible to measure the transmittance of light that has passed through the blood simply by inserting a finger into the finger insertion tube.
According to the invention of claim 6, it is possible to simultaneously measure the degree of fatigue when performing fingerprint authentication, such as when logging in to a personal computer.
According to the invention according to claim 7, it is possible to notify a subject who cannot understand the displayed contents that the fatigue is progressing.
According to the invention according to claim 8, the degree of fatigue can be easily measured at any time by using a nearby mobile phone, keyboard, terminal device, or the like.
According to the ninth aspect of the present invention, since the light transmittance can be measured with high accuracy, it is possible to reliably know the degree of fatigue.
[Brief description of the drawings]
FIG. 1 is a block diagram of a blood fatigue degree sensor showing a first embodiment. FIG. 2 is a side view of a sensor unit. FIG. 3 is a plan view of a sensor unit. FIG. 4 is a diagram of a first light source and a second light source. FIG. 5 is a diagram showing light emission timing. FIG. 5 is a diagram showing a relationship between light wavelength and transmittance. FIG. 6 is a block diagram of a blood fatigue degree sensor according to the first embodiment.
DESCRIPTION OF SYMBOLS 1 Sensor part 2 Measuring instrument main body 3 Finger insertion tube 4 Light emitting diode 5 Light emitting diode 6 Photodiode 9 Lead wire 10 Connector 11 CPU
12 ROM
13 Data Memory 14 Display 15 Display Controller 16 A / D Converter

Claims (9)

A first light source for irradiating light with a wavelength of 760 nm ± 5 nm, a second light source for irradiating light with a wavelength of 840 nm ± 5 nm, and a light receiving device facing the first light source and the second light source at intervals. The light transmittance of a wavelength of 760 nm ± 5 nm and the light transmittance of a wavelength of 840 nm ± 5 nm are calculated based on the light amount emitted from the first light source and the second light source and the light amount received by the light receiving unit. A calculating means for obtaining, as an operation result, a ratio between a transmittance of light having a wavelength of 760 nm ± 5 nm and a transmittance of light having a wavelength of 840 nm ± 5 nm; and a display section for displaying a degree of fatigue based on the calculation result. Blood fatigue sensor. A light source for irradiating light having a wavelength of 760 nm ± 5 nm, a light receiving portion facing the light source at an interval, and a light having a wavelength of 760 nm ± 5 nm depending on the amount of light emitted from the light source and the amount of light received by the light receiving portion. A blood device comprising: a calculating means for calculating a transmittance and obtaining a temporal change in transmittance of light having a wavelength of 760 nm ± 5 nm from the result as a calculation result; and a display unit for displaying the calculation result or a degree of fatigue based on the calculation result. Fatigue degree sensor. A first light source for irradiating light with a wavelength of 905 nm ± 5 nm, a second light source for irradiating light with a wavelength of 840 nm ± 5 nm, and a light receiving device facing the first and second light sources at an interval The light transmittance of a wavelength of 905 nm ± 5 nm and the light transmittance of a wavelength of 840 nm ± 5 nm are calculated based on the light amount emitted from the first light source and the second light source and the light amount received by the light receiving unit. A calculation means for obtaining, as an operation result, a ratio between a transmittance of light having a wavelength of 905 nm ± 5 nm and a transmittance of light having a wavelength of 840 nm ± 5 nm, and a display section for displaying a degree of fatigue based on the calculation result. Blood fatigue sensor. A light source that emits light having a wavelength of 905 nm ± 5 nm, a light receiving unit facing the light source at an interval, and light having a wavelength of 905 nm ± 5 nm based on the amount of light emitted from the light source and the amount of light received by the light receiving unit. A blood device comprising: calculating means for calculating a transmittance, and obtaining a temporal change in transmittance of light having a wavelength of 905 nm ± 5 nm as a calculation result from the result; and a display unit for displaying the calculation result or a degree of fatigue based on the calculation result. Fatigue degree sensor. The blood fatigue degree sensor according to any one of claims 1 to 4, wherein the light source and the light receiving unit are provided on an inner surface of the finger insertion tube. The blood fatigue sensor according to any one of claims 1 to 4, wherein the light source and the light receiving unit are provided in a fingerprint recognition unit of the fingerprint authentication device. 7. The blood fatigue sensor according to claim 1, wherein an alarm is issued when the calculation result reaches a predetermined value. The blood fatigue degree sensor according to any one of claims 1 to 7, which is mounted on an electronic device. 9. The blood fatigue sensor according to claim 1, wherein the light source and the light receiving unit are installed at a position corresponding to a distance of 11.5 mm ± 0.5 mm from a fingertip.

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