BIOLOGICAL INFORMATION MEASUREMENT APPARATUS AND METHOD

• US 20100030066A1
• Filed: 07/23/2009
• Published: 02/04/2010
• Est. Priority Date: 07/30/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: IDA, Ichirou
• Granted Patent: US 8,679,017 B2
• Time in Patent Office: Days
• US Class Current: 600/425
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0097 by applying acoustic waves and detecting light, i.e. acoustooptic measurements
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00

Abstract

A biological information measurement apparatus includes an electromagnetic wave applying unit configured to apply, to a living body, a first electromagnetic wave and a second electromagnetic wave having a frequency different from a frequency of the first electromagnetic wave; a reflected wave receiver configured to receive a first reflected wave corresponding to the first electromagnetic wave and a second reflected wave corresponding to the second electromagnetic wave; a correlation value configured to calculate unit calculating a correlation value between the first and second reflected waves; a correlation value evaluating unit configured to determine whether the correlation value satisfies a given condition; and a biological information measuring unit configured to measure biological information based on the first or second reflected wave when the correlation value evaluating unit determines that the correlation value satisfies the given condition.

Claims

1. A biological information measurement apparatus comprising:

an electromagnetic wave applying unit configured to apply, to a living body, a first electromagnetic wave and a second electromagnetic wave having a frequency different from a frequency of the first electromagnetic wave;

a reflected wave receiver configured to receive a first reflected wave corresponding to the first electromagnetic wave and a second reflected wave corresponding to the second electromagnetic wave;

a correlation value calculating unit configured to calculate a correlation value between the first and second reflected waves;

a correlation value evaluating unit configured to determine whether the correlation value satisfies a given condition; and

a biological information measuring unit configured to measure biological information based on at least one of the first and second reflected wave when the correlation value evaluating unit determines that the correlation value satisfies the given condition.

2. The biological information measurement apparatus according to claim 1, wherein

the correlation value evaluating unit determines whether the correlation value is greater than a given correlation value threshold, and

the biological information measuring unit measures the biological information when the correlation value evaluating unit determines that the correlation value is greater than the correlation value threshold.

3. The biological information measurement apparatus according to claim 1, wherein

when the correlation value evaluating unit determines that the correlation value does not satisfy the given condition, the electromagnetic wave applying unit applies a third electromagnetic wave having a frequency different from frequencies of the first and second electromagnetic waves to the living body,

the reflected wave receiver receives a third reflected wave corresponding to the third electromagnetic wave,

the correlation value calculating unit calculates another correlation value between the second and third reflected waves,

the correlation value evaluating unit determines whether the another correlation value satisfies the given condition, and

when the correlation value evaluating unit determines that the another correlation value satisfies the given condition, the biological information measuring unit measures the biological information based on at least one of the second and third reflected wave.

4. The biological information measurement apparatus according to claim 3, wherein

when the correlation value evaluating unit determines that the correlation value is less than or equal to the correlation value threshold, the electromagnetic wave applying unit applies the third electromagnetic wave to the living body,

the correlation value evaluating unit determines whether the another correlation value is greater than the given correlation value threshold and

when the correlation value evaluating unit determines that the another correlation value is greater than the correlation value threshold, the biological information measuring unit measures the biological information.

5. The biological information measurement apparatus according to claim 1, wherein

the biological information measuring unit measures, as the biological information, the average value of the biological information measured based on each of the two reflected waves used for calculating the correlation value.

6. The biological information measurement apparatus according to claim 1, wherein

the biological information measuring unit measures, as the biological information, the pulsation of the living body.

7. The biological information measurement apparatus according to claim 1, further comprising:

an ultrasound applying unit configured to apply ultrasound to the living body, wherein

the electromagnetic wave applying unit applies the electromagnetic waves to the living body while the ultrasound applying unit is applying ultrasound to the living body.

8. The biological information measurement apparatus according to claim 7, further comprising:

a calculation count checking unit configured to count correlation value calculations performed by the correlation value calculating unit and determine whether the calculation count is greater than a given calculation count threshold;

wherein

the correlation value calculating unit calculates the correlation value and stores, in a correlation value storage unit, the calculated correlation value and frequencies of the two electromagnetic waves corresponding to the calculated correlation value,

the ultrasound applying unit changes a frequency of ultrasound to be applied to the living body when the calculation count checking unit determines that the calculation count is greater than the calculation count threshold, and

the electromagnetic wave applying unit obtains frequencies corresponding to the highest correlation value from the correlation value storage unit and applies two electromagnetic waves having the obtained frequencies to the living body when the calculation count checking unit determines that the calculation count is greater than the calculation count threshold.

9. The biological information measurement apparatus according to claim 7, wherein

the biological information measuring unit measures the blood pressure of the living body as the biological information.

10. A biological information measurement method used in a biological information measurement apparatus, comprising:

applying a first electromagnetic wave to a living body;

receiving a first reflected wave corresponding to the first electromagnetic wave;

applying to the living body a second electromagnetic wave having a frequency different from a frequency of the first electromagnetic wave;

receiving a second reflected wave corresponding to the second electromagnetic wave;

calculating a correlation value between the first and second reflected waves;

determining whether the correlation value satisfies a given condition; and

measuring biological information based on at least one of the first and second reflected wave when the determining determines that the correlation value satisfies a given condition.

11. The biological information measurement method according to claim 10, wherein

the determining includes determining whether the correlation value is greater than a given correlation value threshold, and

the measuring includes measuring the biological information when the determining determines that the correlation value is greater than the correlation value threshold.

12. The biological information measurement method according to claim 10, comprising:

applying to the living body a third electromagnetic wave having a frequency different from the frequencies of the first and second electromagnetic waves when the determining determines that the correlation value does not satisfy the given condition,

receiving a third reflected wave corresponding to the third electromagnetic wave,

calculating another correlation value between the second and third reflected waves,

determining whether the another correlation value satisfies the given condition, and

measuring the biological information based on at least one of the second and third reflected wave when the determining determines that the another correlation value satisfies the given condition.

13. The biological information measurement method according to claim 12, wherein

the applying includes applying the third electromagnetic wave to the living body when the determining determines that the correlation value is less than or equal to the correlation value threshold,

the determining includes whether the another correlation value is greater than the given correlation value threshold, and

the measuring includes measuring the biological information when the determining determines that the another correlation value is greater than the correlation value threshold.

14. The biological information measurement method according to claim 10, wherein

the biological information measuring unit measures, as the biological information, the average value of the biological information measured based on each of the two reflected waves used for calculating the correlation value.

15. The biological information measurement method according to claim 10, wherein

the measuring includes measuring, as the biological information, the pulsation of the living body.

16. The biological information measurement method according to claim 10, further comprising:

applying ultrasound to the living body;

wherein

the applying includes applying the electromagnetic waves to the living body while applying ultrasound to the living body.

17. The biological information measurement method according to claim 16, further comprising:

counting correlation value calculations;

determining whether the calculation count is greater than a given calculation count threshold;

storing, in a correlation value storage unit, the calculated correlation value and the frequencies of the two electromagnetic waves corresponding to the calculated correlation value;

changing a frequency of ultrasound to be applied to the living body when the determining determines that the calculation count is greater than the calculation count threshold;

obtaining frequencies corresponding to the highest correlation value from the correlation value storage unit; and

applying two electromagnetic waves having the obtained frequencies to the living body when the determining determines that the calculation count is greater than the calculation count threshold.

18. The biological information measurement method according to claim 16, wherein

the measuring includes measuring the blood pressure of the living body as the biological information.