KR20170043360A - Pulse measurement apparatus and method for controlling operation thereof - Google Patents

Abstract

The present invention relates to a pulse measuring apparatus capable of minimizing power consumption by controlling an on-state period of a light source based on a pulse period and an operation control method thereof. The pulse measuring apparatus according to the present invention allows a light emitting part to emit light for a predetermined time, measures the amount of light penetrating the skin of a user when the light emitting part emits light, and controls a duty so that the light emitting part repeats on and off operations based on the measured amount of light.

Description

TECHNICAL FIELD [0001] The present invention relates to a pulsation measuring apparatus,

The present invention relates to a pulse measuring apparatus and its operation control method capable of minimizing power consumption by a light source based on a pulse period.

In recent years, products capable of measuring pulse signals around wearable devices have been released and are used to estimate the user's condition such as momentum and stress. PPG (Photo-PlethysmoGraphy) method, which is an optical pulse-wave measuring method, is used, and a pulse measurement signal of a wrist wearable device can be used to estimate the driver's condition in a vehicle.

Such a PPG pulse measuring apparatus shortens the use time of the wearable apparatus because power consumption is high because the light source used for pulse measurement is always operated or the PWM (pulse width modulation) control is performed.

Conventionally, the pulse measurement apparatus performs pulse measurement only when there is an instruction to operate the wearable apparatus, or causes a pulsation to be measured using a green LED (light emitting diode) with a relatively low power consumption.

However, when continuous pulse measurement is performed, the light source of the pulse measurement device must be kept in an ON state constantly, resulting in high power consumption. In this case, since the power consumed by the light source during the power consumption required for the pulse measurement is 95% or more, a strategy of minimizing the on time of the light source is required in order to minimize the power consumption.

KR 100786277 B1

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art described above, and it is an object of the present invention to provide a pulse measuring apparatus and an operation control method thereof that can minimize power consumption by controlling an on period of a light source based on a pulse period do.

According to an aspect of the present invention, there is provided a method for controlling an operation of a pulse measurement apparatus, including the steps of emitting light for a predetermined period of time, measuring an amount of light transmitted through a user's skin And controlling the duty so that the light emitting portion repeats on and off operations based on the measured light amount.

The duty control step includes the steps of determining a pulse period based on the measured light amount, and controlling the duty based on the determined pulse period.

The present invention is characterized in that it comprises the steps of checking whether the amount of light measured in the current pulse period after the duty control of the light emitting part changes to be equal to or less than a reference ratio with respect to the amount of light measured in a previous pulse period, .

Wherein the on period controlling step increases the on period of the light emitting unit when the light amount measured in the current pulse period changes to be equal to or less than the reference ratio with respect to the light amount measured in the previous pulse period.

Wherein the on period controlling step decreases the on period of the light emitting unit when the light amount measured in the current pulse period changes to a value exceeding the reference rate in comparison with the light amount measured in the previous pulse period.

According to the present invention, there is provided a method of controlling a light emitting device, comprising: driving a light emitting unit when a pulse cycle is reached from a light emitting unit operation time after a warm cycle control; confirming whether a light quantity measured when driving the light emitting unit is a reference value; And a step of determining whether or not the image is displayed.

Wherein the step of determining whether or not the pulse period fluctuates is determined to be that there is no variation in the pulse period when the measured light amount is a reference value.

Wherein the step of determining whether the pulse period fluctuates is determined to have a pulse period variation if the measured light amount is not the reference value.

And the reference value is a maximum light amount or a minimum light amount.

The light emitting unit operation time is a time point when the light amount is the lowest or a time point when the light amount is the maximum.

According to another aspect of the present invention, there is provided a pulse measurement apparatus including a light emitting unit for generating light and irradiating the user's skin, a light receiving unit for measuring a light amount transmitted through the skin of the user, And a control unit for controlling the duty so as to repeat the OFF operation.

The present invention minimizes the light source operation time of the pulse measurement device based on the pulse period, so that the power consumed by the pulse measurement by software control without additional parts or costs can be reduced by more than 70% in comparison with the conventional continuous operation of the light source.

In addition, according to the present invention, it is possible to measure a pulse at a low power and to deviate from the use time limit due to the capacity of the battery.

In addition, according to the present invention, it is possible to increase the charging period of the pulse measurement window built in the wearable device, thereby reducing the hassle of the conventional frequent charging.

1 is a block diagram showing a configuration of a pulse measuring apparatus according to an embodiment of the present invention;
2 is a flowchart illustrating a method of controlling an operation of a pulse measurement apparatus according to an embodiment of the present invention.
FIG. 3 and FIG. 4 are diagrams for explaining the operation of the pulse measuring apparatus according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention provides a method for minimizing power consumption of a pulse measuring apparatus using a photoelectric pulse wave (PPG) measuring method.

Here, the PPG measurement method is to irradiate a light source to the skin to measure the amount of light transmitted to grasp the blood flow and estimate the pulse of the user. At this time, the light to be irradiated is absorbed by the blood, bone, and tissue. In particular, the amount of light (amount of light) transmitted through the biotissue varies depending on the heartbeat in the blood vessel.

In PPG measurement, power consumption is mostly consumed in operating the light source. In order to reduce power consumption, it is necessary to minimize the operation time of the light source. Accordingly, the present invention proposes a method for minimizing the light source operation time based on the Matter period (interval).

1 is a block diagram showing the configuration of a pulse measuring apparatus according to an embodiment of the present invention.

1, the pulse measuring apparatus includes a light emitting portion 11, a light receiving portion 12, and a control portion 12. [

The emitter 11 emits light to the medium and includes a light source such as an LED (Light Emitting Diode) for generating infrared rays. Although the LED is used as a light source in this embodiment, the present invention is not limited to this, and a light source that generates light that transmits the living tissue can be used. The light emitting portion 11 is attached to the skin such as the user's finger, earlobes and toes, and irradiates light toward the skin.

The detector 12 is attached to the skin of the user like the light emitting unit 11 and receives light (light) transmitted through the user's skin while the light emitting unit 11 emits light, ). In the present embodiment, the amount of light transmitted through the living tissue by the light receiving unit 12 is described as an example. However, the present invention is not limited to this, and the amount of light reflected on the living tissue may be measured.

The light receiving unit 120 is implemented as a light receiving element such as a photodiode or a phototransistor.

The control unit 13 controls the light emitting unit 11 to emit light for a predetermined time and measures the amount of light transmitted through the user's skin through the light receiving unit 12 to measure the pulse tendency. Here, the pulse tendency detects the pulse period, the peak, the lowest point and the midpoint of the PPG signal.

The control unit 13 controls the on-off duration (duty) of the light emitting unit 11 according to the measured pulse tendency. The light emitting unit 11 performs the on or off operation according to the duty control of the control unit 13. [

Further, the control unit 13 confirms whether the light amount measured in this pulse period is a change in the light amount measured in the preceding period or less than the reference rate. The control unit 13 controls the on period of the light emitting unit 11 according to the result of the check.

2 is a flowchart illustrating an operation control method of a pulse measurement apparatus according to an embodiment of the present invention.

First, the control unit 13 controls the light emitting unit 11 to emit light for a predetermined time (S11). The light emitting unit 11 generates light under the control of the control unit 13 and irradiates the skin (living tissue) of the user.

The control unit 13 measures the amount of light transmitted through the skin of the user through the light receiving unit 12 while irradiating light to the user's skin with the light emitting unit 11 (S12).

The control unit 13 determines (determines) a pulse period based on the measured light amount (S13). The control unit 13 detects the pulse period and the change of the PPG signal while the light emitting unit 11 is operating in the ON state as shown in FIG. At this time, the control unit 13 detects the highest point, the lowest point, and the midpoint (the lowest point, the highest point, and the middle point of the blood flow volume) of the PPG signal.

The control unit 13 controls the ON period of the light emitting unit 11 according to the pulse period (S14).

The control unit 13 determines whether the rate of change of the amount of light measured in the present pulse period relative to the amount of light measured in the previous pulse period is less than or equal to the reference rate (S15). Here, the reference ratio is predetermined.

The control unit 13 increases the on period of the light emitting unit 11 when the measured light amount in the current pulse period is less than the reference rate in comparison with the light amount measured in the previous period (S16). That is, if the pulse rate change rate is lower than the reference pulse rate, the control unit 13 increases the ON period of the light emitting unit 11 to reduce the number of pulse measurement times.

The control unit 13 drives the light emitting unit 11 when the pulse period is reached from the operating point of the light emitting unit 11 (S17). In other words, the control unit 13 turns on the light emitting unit 11 to illuminate the living tissue (skin of the user) when the light amount reaches the lowest point or when the light amount reaches the pulse period from the highest point.

The control unit 13 confirms whether the light quantity measured by the light receiving unit 12 through the living tissue irradiated by the light emitting unit 11 is a reference value (S18). Here, the reference value may be the light amount minimum value or the light amount maximum value.

The control unit 13 determines that there is no change (fluctuation) in the pulse period when the measured light amount is a reference value (S19).

In step S15, the control unit 13 decreases the on period of the light emitting unit 11 when the light amount measured in the current pulse period exceeds the reference rate in comparison with the light amount measured in the previous period (S20). That is, the control unit 13 decreases the ON period of the light emitting unit 11 to increase the number of pulse measurement times when the pulse rate change rate exceeds the reference value. Thereafter, the control unit 13 performs step S17.

On the other hand, if the light amount measured in S18 is not the reference value, the controller 13 determines that the pulse period has changed (S21). If the pulse period fluctuates, the control unit 13 returns to S11 to measure the pulse tendency and adjust the on-time of the light emitting unit 11. [

3 is a diagram illustrating an operation control method of a pulse measurement apparatus according to an embodiment of the present invention.

First, as shown in FIG. 3, the control unit 13 turns on the light emitting unit 11 for a predetermined time to detect the pulse period and the lowest value of the PPG signal.

Then, the control unit 13 determines the lowest value of the PPG signal as the operating point of the light emitting unit 11. [ The control unit 13 operates the light emitting unit 11 every pulse period from the operation timing to irradiate the living tissue and measures the amount of light passing through the living tissue through the light receiving unit 12. [ That is, the control unit 13 turns on the light emitting unit 11 every time the PPG signal is at the lowest value to perform the pulse measurement.

The control unit 13 decreases the on period of the light emitting unit 11 as shown in FIG. 3 when the ratio of the amount of light measured in the current pulse period to the amount of light measured in the previous pulse period exceeds the reference ratio, Increase the number of measurements.

On the other hand, when the light amount measured in this pulse period changes to be equal to or less than the reference ratio with respect to the light amount measured in the previous pulse period, the control unit 13 increases the on period of the light emitting unit 11 as shown in FIG. Reduce the number of measurements.

As described above, according to the present invention, if there is no change in the pulse period, the pulse measurement period is increased to decrease the pulse measurement frequency, and if there is a pulse period variation, the pulse measurement period is decreased to increase the measurement frequency.

The pulse measuring apparatus according to the present invention can be applied to a mobile device, a wearable device, a medical device, and the like. Such a pulse measuring device optimizes light source control to minimize power consumption, but it can perform continuous measurement in situations where continuous pulse measurement is required.

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Claims (11)

A step in which the light emitting portion emits light for a predetermined time,
Measuring an amount of light transmitted through the user's skin when the light emitting unit emits light; and
And controlling the duty so that the light emitting unit repeats on and off operations based on the measured light amount.
The method according to claim 1,
The duty control step includes:
Determining a pulse period based on the measured light amount, and
And controlling the duty based on the determined pulse period.
The method according to claim 1,
Confirming whether the amount of light measured in the present pulse period after the duty control of the light emitting unit changes to be less than a reference ratio with respect to the amount of light measured in a previous pulse period,
And controlling the ON period of the light emitting portion according to the result of the checking.
The method of claim 3,
Wherein the on-
Wherein the on period of the light emitting portion is increased when the light amount measured in the current pulse period is less than or equal to the reference ratio with respect to the light amount measured in the previous pulse period.
The method of claim 3,
Wherein the on-
Wherein the on period of the light emitting unit is decreased when the light amount measured in the current pulse period is changed to exceed the reference rate in comparison with the light amount measured in the previous pulse period.
The method of claim 3,
After the on period control, driving the light emitting portion when the pulse period is reached from the operation point of the light emitting portion,
Confirming whether the light amount measured when driving the light emitting portion is a reference value, and
And determining whether the pulse period fluctuates according to the result of the determination.
The method according to claim 6,
Wherein the step of determining whether the pulse period fluctuates comprises:
Wherein if the measured light amount is a reference value, it is determined that there is no variation in the pulse period.
The method according to claim 6,
Wherein the step of determining whether the pulse period fluctuates comprises:
And determines that the pulse rate fluctuates if the measured light amount is not the reference value.
9. The method according to any one of claims 6 to 8,
The reference value,
And a light quantity peak value or a light quantity minimum value.
The method according to claim 6,
The light emitting unit operation time point
And the light amount is the time point when the light amount is the minimum value or the time point when the light amount is the maximum value.
A light emitting portion for generating light and irradiating the user's skin,
A light-receiving portion for measuring the amount of light transmitted through the user's skin, and
And a control unit for controlling the duty so that the light emitting unit repeats on and off operations based on the measured light amount.

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