JP2001276000A - Bio-information measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bio-information measuring instrument which can be fitted to the portion to be measured of a living body so as to prevent the occurrence of measurement errors due to outdoor daylight and simultaneously can make battery renewal easier. SOLUTION: The housing 1 of this wrist watch-type bio-information measuring instrument having a pulse wave sensor unit 100 which detects the pulse rate of a user with a reflection type optical sensor, the housing 1 incorporating the sensor unit 100, and a wrist strap 30 is reformed. The housing 1 is constituted of a main housing 10 and a sub-housing 20, both of which are rotatably provided successively from each other adjacently to the peripheral direction of the wrist of the user. Since the successively provided angle of the housings 10 and 20 is changed in accordance with the thickness of the wrist of the user and the sensor unit 100 is always adhered closely to the portion to be measured of the user, high-accuracy results of measurements can be obtained. In addition, since the sensor unit 100 is housed in the sub-housing 20 and a battery 112 is positioned in the proximity of the back lid 12 of the instrument, the battery 112 can be renewed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological information measuring device having a form similar to a wristwatch and capable of optically measuring biological information such as a pulse rate.

[0002]

2. Description of the Related Art In order to obtain information such as the pulse rate of a living body, light from a luminous body is irradiated on the living body, and reflected light from the living body is received by a photosensor, so that the fluctuation of reflected light corresponding to the pulse is obtained. Measurement technology has already been implemented. In particular, there is a technique disclosed in Japanese Patent Application Laid-Open No. H11-235320 as a technique for measuring a change in reflected light corresponding to a pulse from a wrist of a human body. This technique is suitable for measuring the fluctuation of reflected light corresponding to a pulse from a wrist whose behavior is stable.

[0003]

However, the above technique has the following problems.

First, the thickness of the housing of the biological information measuring device is increased by stacking the pulse wave sensor unit, the battery, the main board, the liquid crystal display device, and the like. The wrist is a part that moves complicatedly in response to the movement of the human body.The thicker the housing of the biological information measuring device, the more the housing of the mounted biological information measuring device lacks stability with respect to the wrist, and the more the pulse wave sensor unit becomes. It becomes impossible to stably adhere to the wrist, and noise is added to the measurement result of the pulse wave signal detected by the pulse wave sensor unit, so that a correct measurement result cannot be obtained.

[0005] In addition, since the above-mentioned biological information measuring device consumes a large amount of current due to its structure and is often used for a long time, it is appropriate to use a primary battery having a large battery capacity as a power source. Therefore, it is necessary to replace the battery due to the exhaustion of the battery. However, when the pulse wave sensor unit and the battery, the main board, the liquid crystal display device, etc. are all laminated, a liquid crystal display panel for displaying pulse wave information on the front surface, and a pulse wave sensor unit for detecting a pulse wave signal from a living body on the back surface. Since it is necessary to dispose the battery, the battery is disposed between the liquid crystal display panel and the pulse wave sensor unit, and the biological information measuring device must have a structure in which battery replacement is troublesome.

The present invention has been made in view of the above-described circumstances, and provides high-precision measurement results and facilitates battery replacement by being mounted on a measurement site of a living body with high adhesion. It is an object to provide a biological information measuring device having a simple structure.

[0007]

In order to solve the above-mentioned problems, a living body information measuring apparatus according to the present invention comprises a luminous body for irradiating a measured portion of a living body with light, and a luminous body for irradiating the light irradiated by the luminous body. A photoreceptor that receives reflected light from a living body and generates a biological information signal according to the amount of received light, a sub-housing that supports the light emitting body and the photoreceptor, and the biological information signal detected by the photoreceptor A main board that measures biological information, a liquid crystal display device that displays the biological information, and a main housing having a battery and the like, the sub-housing, and the main housing that are connected to the main housing, and the living body near the part to be measured. Wound around, in the biological information measuring device comprising a band that fixes the sub-housing and the main housing to the living body,
The sub-housing is adjacent to the main housing in a wrist circumferential direction and is connected so as to rotate.

In the biological information measuring device according to the present invention, the main substrate, the liquid crystal display device, the battery, and the like are provided in the main housing, and the luminous body and the photoreceptor are provided in the sub housing. It is possible to reduce the total thickness of the sub-housing in which the pulse wave sensor unit configured is arranged, and the stability of the sub-housing to the living body is improved as compared with a case where all elements are stacked in one housing, Noise added to the biological information signal detected by the pulse wave sensor unit is reduced, and the accuracy of the biological information measured by the main board is improved.

The main housing and the sub-housing are adjacent to each other in the circumferential direction of the wrist and connected so as to rotate, so that the angle of the connecting portion changes according to the variation in the wrist diameter due to the variation in the size of the living body. Since the sub-housing is always in close contact with the living body, noise added to the biological information signal detected by the pulse wave sensor unit is reduced, and the accuracy of the biological information measured by the main board is improved.

Further, by disposing the pulse wave sensor unit in the sub-housing, the battery can be arranged on the back side of the main housing, that is, in the immediate vicinity of the back cover. It can be structured.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

(1) Embodiment (1-1) Outline of Apparatus As shown in FIG. 1, a biological information measuring apparatus according to an embodiment of the present invention is of a wristwatch type and includes various electric or electronic components. A main housing 10 and a sub-housing 20 which are built in and connected so as to rotate, and are connected to the main housing 10 and the sub-housing 20;
A wristband 30 is provided around the wrist to fix the main housing 10 and the sub-housing 20 to the arm.

In this embodiment, the connecting method between the main housing 10 and the sub-housing 20 is a known method using a spring bar 25 as shown in FIG.

Incidentally, the connection system between the main housing 10 and the sub-housing 20 is not limited to this example.
For example, as shown in FIG. 3, the main housing 10 and the sub-housing 20 may be connected to each other by insert molding a resin having a low elastic modulus, for example, a silicone rubber connecting body 26.

The wristband 30 in this embodiment has two band pieces 31, 33. One end of the band piece 31 is connected to the upper end of the main housing 10.
One end of the band piece 33 is connected to the lower end of the sub housing 20. Main housing 1 of band pieces 31, 33
The connection method to the 0 and the sub-housing 20 is a known method using a spring bar (not shown). Band piece 3
Materials that do not transmit light are selected as materials 1 and 33 in order to suppress a measurement error of a pulse wave sensor unit described later.

At the end of the band piece 31 connected to the main housing 10, a buckle 36 and a tongue 37 are attached in a known manner. On the other hand, in the band piece 33,
A plurality of small holes 38 are formed along the longitudinal direction. By inserting the band piece 33 into the buckle 36 and passing the tongue 37 through any of the small holes 38, the living body information measuring device is fixed to the living body, and the back surface of the sub-housing 20 adheres to the living body. And the small hole 3 through which the tongue 37 passes
By selecting 8, the circumference of the biological information measuring device is adjusted.

The mechanism for adjusting the circumference of the wristband 30 is not limited to this example, and may be, for example, Velcro.
ro) Tapes or buttons may be used.

FIG. 4 shows the main housing 10 of the present embodiment.
And a sectional view of the sub-housing 20. As shown in those figures, the main housing 10 has an outer case 11 arranged on the front side and a back cover 12 arranged on the back side. The outer case 11 and the back cover 12 are combined and fixed to each other, and form a space for accommodating various electric components or electronic components therein. Similarly, the sub housing 20 also has a sub case 21 arranged on the front side and a sub back cover 22 arranged on the back side. The sub case 21 and the sub back cover 22 are combined and fixed to each other to form a space for accommodating various electric components or electronic components inside. Outer case 11, back cover 12, sub case 21, and sub back cover 22
A material that does not allow light to pass through is selected as the material.

The sub-housing 20 supports a pulse wave sensor unit 100. Pulse wave sensor unit 10
Reference numeral 0 denotes a reflection type optical sensor, which is a circuit board 101 disposed on the sub-back cover 22 and an LED (Light Emitting Diode) which is a light emitting body mounted on the back surface of the circuit board 101.
102 and a photodiode 103 which is a light receiving body (biological information detecting means). The light emitted from the LED 102 travels downward in the figure and irradiates the wearer's wrist. The irradiation light is absorbed by the tissues and blood vessels of the wrist, and the irradiation light that has escaped absorption is reflected. The reflected light is received by the photodiode 103 and the photodiode 10
3 generates an electric signal according to the intensity of the received light.

A through hole is formed at the approximate center of the sub-back cover 22, and the transparent glass 104 is formed so as to cover the through hole.
Has been fixed. The transparent glass 104 is
And the photodiode 103 to allow light transmission and protect them. Also, the transparent glass 104
And an optical filter 105 is arranged between the LED 102 and the photodiode 103. Therefore, LE
The irradiation light from D102 irradiates the wrist through the optical filter 105, and the reflected light is received by the photodiode 103 through the optical filter 105. These LEDs 102,
The arrangement of the photodiode 103 and the transparent glass 104 is also shown in FIG.

The optical filter 105 has a wavelength of 500 nm to 600 nm.
Transmits light in the nm wavelength range. That is, the measurement wavelength of this measurement optical system is in the range of 500 nm to 600 nm. This range is the range with the highest measurement accuracy of the pulse wave when measuring the tissue of the wrist found by the collaborator of the present inventors.

On the front side of the circuit board 101, an OP amplifier 106 and a circuit element 107 are mounted. The OP amplifier 106 amplifies the electric signal output from the photodiode 103. The circuit element 107 includes the OP amplifier 10
6 and a later-described resistor 107 connected to the LED 102
a, 107b, etc. are provided.

In addition, a main board 110 is disposed in the internal space of the main housing 10. Main board 11
0 is provided with a data processing circuit 111 including an IC component such as a CPU (Central Processing Unit) described later. On the back side of the main board 110, a battery 112 serving as a power supply of the biological information measuring device is arranged, and the battery 112 is connected to a circuit on the main board 110. further,
On the front side of the main substrate 110, a liquid crystal display device 113 is arranged. On the front side of the liquid crystal display device 113, a transparent glass 114 that allows the liquid crystal display device 113 to be viewed and protects the liquid crystal display device 113 is arranged. The transparent glass 114 is supported by the outer case 11 of the main housing 10. The liquid crystal display device 113 includes a pulse wave sensor unit 10
The pulse rate (biological information) as the measurement result of 0 is displayed.

In this embodiment, the main board 11
The circuit provided at 0 is similar to a normal digital watch,
It has a function to count time and date. The liquid crystal display device 113 can also display time and date in addition to the pulse rate. In the liquid crystal display device 113 shown in FIG. 1, “10:08” indicates time, and “127” indicates a pulse rate. As shown in FIG.
The outer case 11 is provided with button switches 116 and 117 for adjusting the time and switching the display contents.

The main board 110 and the pulse wave sensor unit 100 are connected to each other by a cable 40 as shown in FIG. Thereby, the main board 110
Power is supplied to the pulse wave sensor unit 110 from the
The pulse wave signal is transmitted to.

(1-2) Pulse Detection FIG. 6 shows details of the pulse wave sensor unit 100. As shown in the figure, a positive voltage + V is applied to the anode of the LED 102, and its cathode is grounded via the resistor 107a. Since the resistor 107a functions as a current limiting resistor, a desired current flows to the LED 102.

A positive voltage + V is applied to the cathode of the photodiode 103, and the anode of the
6 negative input terminal. The output signal of the OP amplifier 106 is fed back to the negative input terminal via the resistor 107b. The input impedance of the OP amplifier 106 is extremely high and the gain is large.

Since the positive input terminal of the OP amplifier 106 is grounded, the anode of the photodiode 103 is imaginarily shorted to ground. Therefore, the photodiode 103 is reverse-biased, and when light enters there, a current flows according to the amount of light. This current increases as the incident light increases. The OP amplifier 106 and the resistor 107b convert the current from the photodiode 103 into a voltage and amplify it. That is, the OP amplifier 1
The output signal Vm of 06 varies according to the amount of incident light.

Referring to FIG. 7, pulse wave sensor unit 100
The principle of will be described. In the figure, T is the epidermis of the living body to be detected, and C is the capillaries and arterioles. Living tissue is formed between the epidermis T and the blood vessel C. Then, blood flows inside the blood vessel C.

A part of the light emitted from the LED 102 is
Absorbed by hemoglobin in living tissues and blood,
Another part is reflected by the tissue of the living body, and the reflected light is received by the photodiode 103.
The photodiode 103 outputs an electric signal according to the amount of received light. Therefore, the output signal of the photodiode 103 reflects the absorption by the tissue of the living body and the absorption by hemoglobin in the blood.

FIG. 8 is a graph showing the change over time in the absorbance when light is externally applied to a human blood vessel, where I2 is the light-absorbing component due to tissue, I3 is the light-absorbing component due to venous blood,
Reference numeral 4 denotes a light absorption component due to arterial blood. The light absorption component I2 due to the tissue is constant since the tissue concentration does not change. Also,
The light absorption component I3 due to venous blood is also constant. This is because there is no pulsation in the vein and no change in concentration.

As shown in FIG. 9, the blood pressure related to the pulsation of the blood sent from the heart is generally higher and more variable in blood vessels closer to the heart, and is lower and less variable in veins. Therefore, the output current of the photodiode 103 fluctuates according to the pulsation of the artery. Therefore, the output signal Vm of the OP amplifier 106 that has amplified the output of the photodiode 103 can be regarded as a pulse wave signal.

FIG. 10 is a functional block diagram of the data processing circuit 111 of the main board 110. The pulse wave signal Vm generated by the pulse wave sensor unit 100 is
The pulse wave signal converter 120 supplies the pulse wave signal Vm
Is converted from an analog signal to a digital signal (pulse wave data MD). The pulse wave data MD is transferred to a storage unit 121 including a RAM (random access memory) or the like, and the storage unit 121 stores the pulse wave data MD for a predetermined period.

The pulse wave data MD is read from the storage unit 121 at a constant cycle, and the read pulse wave data MD is transferred to the frequency analysis unit 122. The frequency analysis unit 122 performs a frequency analysis on the pulse wave data MD to generate pulse wave analysis data MKD. There are various frequency analysis methods. In this example, FFT (Fast Fourier Transform) is used so that analysis can be performed in a short calculation time.

Next, the pulse wave analysis data MKD is supplied to the pulse rate calculator 123, and the pulse rate calculator 123 calculates the pulse rate HR based on the pulse wave analysis data MKD. In this calculation, the pulse rate calculation unit 123 outputs the pulse analysis data MKD
Is specified, and the frequency Fh is calculated based on the time between the peaks. Frequency F
Since h is the fundamental frequency of the pulse wave signal Vm, the pulse rate calculation unit 123 calculates the pulse rate HR, which is the number of pulses per minute, by the following equation.

HR = 60Fh When the SN ratio of the pulse wave signal Vm is sufficiently high, the pulse wave signal Vm is simply shaped and converted into a rectangular wave without depending on the frequency analysis, and the period of the rectangular wave is calculated. And the pulse rate HR may be displayed.

The pulse rate HR calculated in this way is displayed on the liquid crystal display device 113. The subject's pulse can be known in this way.

(1-3) Details of Biological Information Measuring Device The housing 1 of this biological information measuring device is composed of the main housing 10 and the sub-housing 20 as described above. As shown in FIG. 1, the main housing 10 and the sub-housing 20 are fixed to a living body by band pieces 31 and 33 connected to each other. Main housing 10, sub housing 20, wristband 30
In order to suppress a measurement error of the pulse wave sensor unit 100 as an optical sensor, a sensor that does not transmit light is selected.

Main housing 10 and sub housing 2
0 is connected so as to rotate. For example, as shown in FIG. 2, they are connected by a known spring bar.

The main board 110 housed in the main housing 10 and the circuit board 101 housed in the sub-housing 20 are connected by a cable 40. Power consumed by the circuit board 101 is supplied from a battery 112 connected to the main board 110 via the cable 40. On the other hand, the pulse wave sensor unit 1 connected to the circuit board 101
The signal detected by 00 is transmitted to the main board 110 via the cable 40 via the circuit board 101 and is subjected to data processing.

The gap between the main housing 10 and the sub-housing 20 and the cable 40 is sealed with a packing or a waterproof sealing material, so that the waterproofness in the main housing 10 and the sub-housing 20 is maintained.

Since the sub-housing 20 has the pulse wave sensor unit 100, the battery 112 of the main housing 10 is located immediately near the back cover 12. Therefore, as shown in FIG. 4, the battery 112 can be easily replaced by opening and closing the battery cover 13 provided on the back cover 12. Even when the battery cover 13 is not installed, the back cover 12
The battery 112 can be replaced only by removing the battery.

Next, the effect of dividing the housing 1 into the main housing 10 and the sub-housing 20 and connecting them so as to rotate will be described with reference to FIGS. 11 and 12. FIG.

FIG. 11A shows a state in which a living body information measuring device having a structure in which a liquid crystal display device 113, a main substrate 110, and a battery 112 are stacked on one housing 1 is mounted on a wrist W of a subject. In this case, the housing 1 has the wrist W
A substantially uniform pressure is applied to a portion where the pulse wave sensor unit 100 and the wristband 30 arranged at positions in contact with each other are in contact. However, when twisting the wrist W,
As shown in FIG. 11B, the pulse wave sensor unit 100
May be separated from the wrist W. In such a case, a gap is generated between the pulse wave sensor unit 100 and the wrist W, and external light enters the gap.

In this case, the influence of measurement errors due to external light cannot be ignored. This problem is likely to occur if the subject exercises because the wrist is an easily twisted part. on the other hand,
If the pressure when the biological information measuring device is worn on the wrist W is strong, it is possible to prevent the wrist W and the housing 1 from separating, but since the living body inevitably feels a high pressure, it is necessary to use for a long time. difficult. In addition, the influence of measurement error due to blood fluctuation cannot be ignored. This problem tends to occur when the subject exercises, since the part before the wrist is a part that moves frequently.

On the other hand, FIG. 12A shows a state in which the biological information measuring device having the main housing 10 and the sub-housing 20 of the above embodiment is mounted on the wrist W of the subject. In this case, since the main housing 10 and the sub-housing 20 are connected so as to rotate, when the wrist W is twisted, the main housing 10 and the sub-housing 20 are connected as shown in FIG. By moving following the shape of the wrist W, it can exhibit high adhesion to the wrist W and reduce the thickness of the main housing 10 and the sub housing 20. The behavior of the housing 1 with respect to the wrist W is stabilized, and the adhesion of the housing 1 to the wrist W is kept high.

Therefore, the pulse wave sensor unit 100 is hardly affected by external light, and the occurrence of measurement errors is suppressed.

Since the main housing 10 and the sub-housing 20 are arranged adjacent to each other in the circumferential direction of the wrist, by adjusting the wrist band 30, both can be held without wobbling on the wrist W. , The addition of noise to the detection result of the pulse sensor unit 100 due to the movement can be minimized.

In addition, by a simple adjustment of the wristband 30, it is possible to apply an appropriate pressing force to the pulse sensor unit 100, and it is possible to prevent external light from entering the pulse sensor unit 100.

Therefore, the wrist W can be attached to the site to be measured with high adhesion, and the measurement accuracy of the biological information measuring device is improved.

(2) Modifications (2-1) First Modification In the above embodiment, the case where the battery 112 is provided in the main housing 10 has been described, but the battery 112 may be provided in the sub-housing 20. .

In this case, since the battery 112 is located in the immediate vicinity of the sub case 21, the replacement of the battery can be facilitated by providing the sub case 21 with a battery cover.

(2-2) Second Modification In the above-described embodiment, considering the visibility of the liquid crystal display device 113, when the display of the liquid crystal display device 113 can be read normally, Although the housing 20 is arranged to be on the lower side, the sub-housing 2
The same effect can be obtained by disposing 0 in the upper side of the main housing 10.

[0054]

As described above, according to the present invention,
By mounting with high adhesion to a measurement site of a living body, a highly accurate measurement result can be obtained, and a biological information measuring device having a structure in which a battery can be easily replaced can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a biological information measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a connecting portion between a main housing and a sub housing in the biological information measuring device.

FIG. 3 is a cross-sectional view showing a connecting portion between a main housing and a sub-housing in the biological information measuring device.

FIG. 4 is a sectional view of the biological information measuring device.

FIG. 5 is a perspective view showing a back side of the biological information measuring device.

FIG. 6 is a circuit diagram showing details of a pulse wave sensor unit of the biological information measuring device.

FIG. 7 is a diagram showing a principle of pulse wave measurement by the biological information measuring device.

FIG. 8 is a diagram showing a change in absorbance when light is externally applied to a human blood vessel portion.

FIG. 9 is a graph showing blood pressure distribution of a human body.

FIG. 10 is a functional block diagram of a data processing circuit that processes an output signal of the pulse wave sensor unit.

FIG. 11 is a side view showing a conventional biological information measuring device worn on a wrist of a subject.

FIG. 12 is a side view showing the biological information measuring device mounted on a wrist of a subject.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing 10 ... Main housing 11 ... Outer case 12 ... Back cover 13 ... Battery cover 20 ... Sub housing 21 ... Sub case 22 ... Sub back cover 30 ... Wrist bands 31, 33 ... Band pieces 100 ... Pulse wave sensor unit 102 ... LED 103: photodiode 110: main substrate 111: data processing circuit 112: battery 113: liquid crystal display

Claims (1)

[Claims] 1. A light emitter for irradiating a measured portion of a living body with light, and a light receiver for receiving reflected light from the living body related to the light emitted by the light emitter and generating a biological information signal corresponding to a received light amount A body, a sub-housing that supports the light-emitting body and the light-receiving body, a main substrate that measures biological information from the biological information signal detected by the light-receiving body, a liquid crystal display device that displays the biological information, and a battery. And a main housing having the same. The sub housing and the main housing are connected to each other, and are wound around the living body in the vicinity of the part to be measured to fix the sub housing and the main housing to the living body. In a biological information measurement device including a band, the sub-housing is adjacent to the main housing in a wrist circumferential direction and is connected to rotate. Biological information measuring device, characterized in that there.