JPH119563A - Vibrationproof pulse ear sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable accurate measurement of pulses by eliminating wrong detection caused by noises such as vibration without impairing advantage of a smaller size and a lighter weight in a pulse ear sensor having a detecting section in which an earlap is pinched between a light emitting element for emitting infrared rays and a photodetector to obtain a pulse detection signal based on a transmittance of light through the earlap. SOLUTION: A detection piece 12 of a detecting section 2 is provided with an acceleration sensor 4 which is build in a smaller size with a lighter weight to detect vibration generated during the period of using a training machine or the like. Detection signals of the detecting section 2 and the acceleration sensor 4 are introduced into a differential part 7a of a microcomputer 7 through an amplifier 5 and an A/D converter 6. The differential part 7a performs a computation of subtracting a vibration component from a pulse detection signal containing vibration to obtain a correct pulse signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse ear sensor which measures a pulse by wearing it on an earlobe of a subject.

[0002]

2. Description of the Related Art A pulse ear sensor is used to measure a pulse when worn on a subject's earlobe when various training machines such as a running machine, a bicycle, and a stair climbing machine are used. It is widely used in fields such as physical strength measurement by force training, data collection in hospitals and laboratories, and analysis of sports medicine.

[0003] The pulse ear sensor is characterized in that it is small and lightweight, and mainly adopts an infrared modulation light transmission system.
The pulse rate is measured based on a change in the transmittance of light (infrared rays) penetrating the subject's earlobe.

[0004]

When the pulse ear sensor is used at the time of measuring athletic ability by a training machine such as a running machine, a bicycle, and a stair climbing machine, the pulse ear sensor picks up noise such as vibration due to the exercise, The pulse is erroneously detected. For this reason, there has been a problem that accurate pulse measurement cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to eliminate a false detection due to noise such as vibration without impairing the advantages of small size and light weight, and to provide a pulse ear sensor capable of accurate pulse measurement. Is to provide.

[0006]

[Means for Solving the Problems]

(1) The present invention provides a pulse ear sensor for measuring a pulse of a subject, the pulse ear sensor having a pulse detection unit for obtaining a pulse detection signal based on the transmittance of light passing through an earlobe of the subject. An acceleration sensor provided in the unit and detecting vibration;
A differential section for subtracting a vibration detection signal of the acceleration sensor from a pulse detection signal of the pulse detection section, and obtains a pulse measurement signal from which unnecessary vibration components have been removed.

(2) When the pulse ear sensor is worn on the earlobe and exercise is performed by the training machine, vibration components due to the machine and exercise are input to the acceleration sensor. The pulse detection signal of the pulse detector includes a pulse signal and the vibration component. Since the vibration component in the pulse detection signal is canceled by the detection signal of the acceleration sensor in the differential section, only an accurate pulse signal can be obtained as a pulse measurement signal.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an earlobe of a subject, and 2 denotes a detection unit of a pulse ear sensor which is attached to the earlobe 1. The detection unit 2 includes a detection piece 12
And a light-emitting element 3a and a light-receiving element 3b provided on a holding portion of the detection piece 12 which holds the earlobe from both sides.

An acceleration sensor 4 is provided on the detection piece 12 and detects vibration. Reference numeral 5 denotes an amplifier that amplifies the pulse detection signal and the vibration detection signal input via the lead 2a of the pulse ear sensor and the lead 4a of the acceleration sensor 4, respectively. The pulse detection signal and the vibration detection signal amplified by the amplifier 5 are converted into digital signals by an A / D converter 6 and input to a microcomputer 7. This microcomputer 7
Has a differential unit 7a that performs a digital operation of subtracting the vibration detection signal detected by the acceleration sensor 4 from the pulse detection signal detected by the detection unit 2 of the pulse ear sensor.

Next, the operation of the apparatus configured as described above will be described. When exercise is performed by a training machine or the like with the detection unit 2 of the pulse ear sensor attached to the earlobe 1, a pulse detection signal introduced from the detection unit 2 through the lead wire 2a is as shown in FIG. The vibration during exercise is picked up as indicated by X in the figure.

The vibration during the movement indicated by the portion X is also detected by the acceleration sensor 4 as shown in FIG.
Since the signal of the section (signal with vibration) has the same phase in FIGS. 2A and 2B, the vibration component can be canceled in the differential section 7a.

That is, the differential unit 7a of the microcomputer 7 subtracts the vibration detection signal shown in FIG. 2B from the pulse detection signal containing the vibration component shown in FIG. Calculate the signal. As a result, erroneous detection due to vibration during exercise can be prevented, and an accurate pulse signal can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As the acceleration sensor 4, for example, a piezoelectric ceramic type shock sensor as shown in FIG. 3 is used. As shown in FIG. 3A, this shock sensor detects electric charges generated by bending of the piezoelectric elements 21a and 21b when an impact is applied, and has an appearance as shown in FIG. 3B. .

In FIG. 3 (b), reference numeral 22 denotes a case made of a high heat-resistant liquid crystal resin whose interior is shield-plated to improve noise resistance. In the case 22, a bimorph type piezoelectric ceramic 21 (piezoelectric element 21a) is provided. , 21b) are stored.

The shock sensor constructed as described above is formed to have a height of, for example, 1.2 mm, a length of 6.4 mm, and a width of 2.6 mm, and is very small and lightweight. The sensor can be attached to the detecting section 2 of the sensor without any problem, and the vibration can be accurately detected.

The acceleration sensor of the present invention is not limited to the shock sensor shown in FIG. 3, but may use another sensor having the same operation and effect.

[0017]

As described above, according to the present invention, there is provided a pulse detector for obtaining a pulse detection signal based on the transmittance of light passing through the earlobe of the subject, and the pulse of the subject is measured. In a pulse ear sensor, the pulse detection unit is provided with an acceleration sensor that detects vibration, and a differential unit that subtracts a vibration detection signal of the acceleration sensor from a pulse detection signal of the pulse detection unit, and includes an unnecessary vibration component. Since the removed pulse measurement signal is obtained, the following excellent effects can be obtained.

(1) Since a vibration component in a pulse detection signal can be removed, erroneous detection of a pulse due to vibration can be prevented and accurate pulse measurement can be performed.

(2) The detection unit mounted on the earlobe is small,
Since the configuration is such that a lightweight acceleration sensor is added, it can be used in the same atmosphere as a conventional pulse ear sensor, and the configuration is extremely simple.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of the present invention.

2A is a waveform diagram of a pulse detection signal of a pulse ear sensor, and FIG. 2B is a waveform diagram of a vibration detection signal of an acceleration sensor.

3A and 3B show an embodiment of the present invention, wherein FIG. 3A is an explanatory diagram showing the principle of detection of a shock sensor, and FIG. 3B is a perspective view of the shock sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Earlobe 2 ... Detection part of a pulse ear sensor 3a ... Light emitting element 3b ... Light receiving element 4 ... Acceleration sensor 5 ... Amplifier 6 ... A / D converter 7 ... Microcomputer 7a ... Differential part 21a, 21b ... Piezoelectric element 21 ... Bimorph type piezoelectric ceramic 22 ... Case

Claims (1)

[Claims] 1. A pulse ear sensor for measuring a pulse of a subject having a pulse detection unit for obtaining a pulse detection signal based on a transmittance of light passing through an earlobe of the subject, wherein the pulse detection unit An acceleration sensor that detects vibration, and a differential unit that subtracts the vibration detection signal of the acceleration sensor from the pulse detection signal of the pulse detection unit, and obtains a pulse measurement signal from which unnecessary vibration components have been removed. And pulse ear sensor.