JPH06154177A - Pulsometer - Google Patents

Abstract

PURPOSE:To measure accurately a pulse rate while taking exercise. CONSTITUTION:A pulsimeter is to detect pulses from a change in a light absorbing quantity in a human body part sandwiched between sandwiching members by arranging a light emitting element 21 and a light receiving element 22 oppositely in the sandwiching members 11 and 12 whose interval is made variable. Measuring means 23 and 24 to measure a distance between the light emitting element 21 and the light receiving element 22 and a correcting means to correct a light receiving quantity by the light receiving element according to a distance detected by these measuring means, are arranged, and influence of an interval change between the light emitting element 21 and the light receiving element 22 caused by a thickness change in a pulse measuring part of the human body such as an earlobe, is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse rate meter, and more particularly to a pulse rate meter for measuring a pulse rate of a bicycle ergometer, a treadmill, etc. when performing a certain exercise.

[0002]

2. Description of the Related Art As shown in FIG. 4, a bicycle ergometer has a handle 30, a saddle 31, a pedal 32, and a pedal 3.
2 is composed of a load mechanism section 33 for applying a predetermined load and a controller 34. The controller 34 is connected to a pulse meter 1 for measuring the pulse of an exerciser, and the load of exercise is increased or decreased according to the pulse rate. And estimating the maximum oxygen uptake amount from the measured pulse rate and calorie consumption, the pulse meter 1 used here is pivoted on the axis 10 as shown in FIG. A pair of sandwiching members 11, 12
In addition, the light emitting element 21 and the light receiving element 22 are arranged so as to face each other. The light emitting element 21 and the light receiving element 22 are attached to the exerciser such that the earlobe of the exerciser is sandwiched by the sandwiching members 11 and 12. The pulse rate is detected and the pulse rate is measured based on the fluctuation of the absorption amount of light having a wavelength of 4000 to 10000Å entering the light receiving element 22 due to hemoglobin in the blood. This is based on the fact that the amount of transmitted light is increased / decreased in synchronization with the pulse, and the current flowing through the light receiving element 22 is increased / decreased accordingly.
As shown in 0, a current change is detected as a voltage change Vs by a resistor R connected in series to the light receiving element 22, noise cut by the high-pass filter 32, pulse signal generation by a peak hold circuit 34, amplification by an amplifier 35, The pulse rate is calculated by pulsing by the comparator 36 and measuring the pulse interval by the microcomputer 33.

[0003]

Here, with this type of pulse meter, a clean pulse pulse can be obtained in the stationary state, and the pulse rate can be measured accurately, but during exercise, the pulse rate can be measured. Noise with a frequency almost the same as the frequency of 1 was generated, which sometimes prevented accurate pulse rate measurement.

As a cause of this, it is conceivable that smooth blood flow is disturbed by the movement of blood vessels due to swaying of the earlobe, but the following points have been clarified as more serious causes. That is, due to body movement during exercise, as compared with the stationary state shown in FIG. 11A, the portion of the earlobe 9 that is sandwiched by the sandwiching members 11 and 12 becomes thicker, as shown in FIG. As shown in FIG. 11 (c), the state of thinning occurs randomly, and this causes the interval between the light emitting element 21 and the light receiving element 22 to constantly fluctuate. Here, as shown in FIG. 12 (a), the amount of light from the light emitting element 21 to the light receiving element 22 is proportional to the square of the distance therebetween, so the amount of light received by the light receiving element 22 is absorbed by the hemoglobin. In addition to the amount, this distance also affects the distance, and when the earlobe 9 becomes thicker, it falls to the level L2 when the earlobe 9 becomes thicker even though the level is L1 in FIG. When becomes thin, it goes up to level L3. This variation in the thickness of the earlobe 9 is considered to be a cause of noise having substantially the same frequency as the pulse frequency, and the influence of the variation in the thickness of the earlobe 9 is essentially one pulse. In this case, two pulse pulses occur and are measured as two pulses, or the pulse pulse is canceled and is not measured as a pulse.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a pulse meter capable of accurately measuring a pulse rate during exercise.

[0006]

SUMMARY OF THE INVENTION In the present invention, however, a pulse is generated from a change in the amount of light absorbed in a human body part in which a light-emitting element and a light-receiving element are arranged in opposition to a sandwiching member having a variable spacing and sandwiched by the sandwiching member. The pulse rate detecting device includes a measuring unit that measures the distance between the light emitting element and the light receiving unit, and a correcting unit that corrects the amount of light received by the light receiving unit according to the distance detected by the measuring unit. It has a special feature.

[0007]

According to the present invention, it is possible to eliminate the influence of the change in the distance between the light emitting element and the light receiving element due to the thickness variation of the human body part such as the earlobe.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the illustrated embodiment. In the embodiment shown in FIG. 1, a light emitting element 21 is provided on one end side of a pair of sandwiching members 11 and 12 pivotally mounted on a shaft 10. And the light receiving element 22 are opposed to each other, and the light emitting element 23 and the light receiving element 24 are also opposed to each other on the other end side. here,
The light-emitting element 21 and the light-receiving element 22 are for measuring the pulse, as described in the above-mentioned conventional example.
3 and the light receiving element 24 are for measuring the distance between the light emitting element 21 and the light receiving element 22.
2, 24 are connected to the microcomputer 30. The amount of light received by the light receiving element 22 is in a state in which the amount of pulse fluctuation and the amount of thickness change of the earlobe 9 are combined, but the amount of light received by the light receiving element 24 is via the earlobe 9. Since it does not exist, it reflects only the distance change due to the thickness change of the earlobe 9, so that the light receiving element 2
By subtracting the measured distance change from the two outputs, only the pulse change is taken out, and the pulse rate is measured by the D / A converter 31, the high-pass filter 32, and the microcomputer 33.

That is, the distance from the shaft 10 to the light emitting element 21 and the light receiving element 22 in the pair of sandwiching members 11 and 12 pivotally attached to the shaft 10 and the distance from the shaft 10 to the light emitting element 23 and the light receiving element 24. If they are equal to each other, the distance between the light emitting element 21 and the light receiving element 22 changes from R1 to R1 + r as the thickness of the earlobe changes, and as shown in FIG.
When the output voltage Vs1 of the light receiving element 22 changes from A1 to a1, the distance between the light emitting element 23 and the light receiving element 24 changes from R2 to R.
2−r and the output voltage Vs2 of the light receiving element 24 is shown in FIG.
As shown in (d), the output voltage changes from A2 to a2. At this time, the output voltage is proportional to the amount of light received and the light emitting element −
Since it is inversely proportional to the square of the distance between the light receiving elements, R1 = R
When the value of 2 is R0, the output voltage Vs2 at this time is A0, and the fluctuation of A1, a1 due to the pulse is ignored, R1 ² · A1 = (R1 + r) ² · a1 (1) R2 ² · A2 = ( R2-r) ² · a2 = R0 ² · A0 (2) R1 + R2 = 2R0 (3).

Therefore, in the microcomputer 30, R0 and A0 are stored in advance as eigenvalues, and then A when the earlobe is sandwiched and is stationary.
1 and A2 are measured and R2 and R1 are calculated from the equations (2) and (3).
To calculate. Then, when the distance changes due to body movement, a2 is detected from the output of the light receiving element 24, and the variable distance r is calculated from the equation (2). Further, a1 can be calculated by the equation (1). Therefore, a1
The signal variation due to the distance variation can be obtained by -A1, and the actual signal variation of the light receiving element 22 is the sum of the pulse variation and the distance variation a1-A1.
By subtracting the value of, only the pulse fluctuation component can be extracted. The microcomputer 30
Although there is a time delay for the calculation time due to the above, if the pulse width is widened to about several hundreds μs, it is possible to sufficiently follow up.

The pair of sandwiching members 11 and 12 may be pivotally mounted so as to cross each other as shown in FIG. 3 (a), and also as shown in FIG. 3 (b).
As shown in FIG. 2, the other pinching member 12 is slidably engaged with the plurality of pins 15 and 15 protruding from the one pinching member 11 and is urged by the springs 16 and 16 so that both pins are pinched. The members 11 and 12 may be moved in parallel, and further, as shown in FIG. 3 (c), a pair of clamping members 1 pivotally attached to each other.
Light emitting elements 21 and 23 and a light receiving element 2 are provided on one end side of
2, 24 may be attached together. In the embodiment shown in FIGS. 3B and 3C, when the distance between the light emitting element 21 and the light receiving element 22 increases, the distance between the light emitting element 23 and the light receiving element 24 increases by the same amount. Will be easier to calculate.

FIG. 6 shows that the connection cord 19 with the controller 34 does not get in the way when the pulse meter 1 constructed as described above is attached to the bicycle ergometer.
7 shows the handle 30 pulled out from the terminal or the saddle 31. FIG. 7 shows the handle 30 with the end portion of the pulse meter 1 stored therein, and FIG. 8 shows the saddle 31.
The inside of the pulse meter 1 is shown as a storage part. In the figure, reference numeral 18 is a post for winding the connection cord 19. Further, FIG. 9 shows a cord reel 40 around which the connection cord 19 is wound and the controller 40 is housed inside the controller 34 or inside the saddle 31. The cord reel 40 may be attached to the controller 34 as needed. Reference numeral 41 in the drawing denotes an output terminal of the cord reel 40.

[0013]

As described above, in the present invention, the measuring means for measuring the distance between the light emitting element and the light receiving element, and the amount of light received by the light receiving element is corrected according to the distance detected by the measuring means. It is possible to eliminate the influence of the change in the distance between the light emitting element and the light receiving element due to the thickness variation of the human body part such as the earlobe, for this reason. Measurement can be performed accurately.

[Brief description of drawings]

1A is a cross-sectional view of an embodiment, and FIG. 1B is a block circuit diagram of the same.

2A and 2B are explanatory diagrams of the same operation as above, and FIGS. 2C and 2D are explanatory diagrams of an output voltage of the same.

3A and 3B are cross-sectional views of other embodiments, and FIG. 3C is a perspective view of another embodiment.

FIG. 4 is a perspective view of an example of a bicycle ergometer.

FIG. 5 is a cutaway side view of a conventional pulse rate monitor used in the above.

6 (a) and 6 (b) are perspective views showing the pulled out form of the connection cord of the pulse rate monitor.

7 (a) and 7 (b) are perspective views showing an example of a stored form of a pulse rate monitor.

8 (a) and 8 (b) are broken side views showing another storage form of the pulse rate monitor.

9A is a perspective view of a cord reel, and FIGS. 9B and 9C are explanatory views showing a storage form of the cord reel.

FIG. 10 is a block circuit diagram of a conventional example.

11 (a), (b) and (c) are explanatory diagrams of thickness variation in a pulse measurement portion.

12A is an explanatory diagram of a distance between a light emitting element and a light receiving element and a light receiving amount, and FIG. 12B is an explanatory diagram of an output voltage of the light receiving element.

[Explanation of symbols]

 11, 12 sandwiching member 21 light emitting element 22 light receiving element 23 light emitting element 24 light receiving element

Claims (3)

[Claims] 1. A pulse meter for detecting a pulse from a change in the amount of light absorbed in a human body part sandwiched by a sandwiching member in which a light emitting element and a light receiving element are opposed to a pair of sandwiching members with variable spacing, and a light emitting element is provided. A pulse meter comprising: a measuring unit that measures the distance between the light receiving element and the light receiving element; and a correcting unit that corrects the amount of light received by the light receiving element according to the distance detected by the measuring unit. 2. A pair of sandwiching members are pivotally mounted on a shaft,
2. The pulse meter according to claim 1, wherein the light emitting element and the light receiving element are arranged on one end side, and the measuring means is arranged on the other end side which spreads when the one end side narrows. 3. The pulse rate monitor according to claim 1, wherein the pair of sandwiching members are connected so as to be movable in parallel.