Body activity measurement device

• US 20050171435A1
• Filed: 01/11/2005
• Published: 08/04/2005
• Est. Priority Date: 01/14/2004
• Status: Active Grant

• Current Assignee: National Institute of Information and Communications Technology
• Original Assignee: National Institute of Information and Communications Technology
• Inventors: Eda, Hideo, Sugai, Katsuo, Maesako, Takanori, Kuroda, Yasufumi
• Granted Patent: US 7,386,335 B2
• Time in Patent Office: Days
• US Class Current: 600/475
• CPC Class Codes: G01N 2021/3144 for oxymetry
• CPC Class Codes: G01N 21/49 within a body or fluid

Abstract

A body activity measurement device is provided with a light irradiation unit that irradiates near infrared light of a specified wavelength on a specified measurement site of a brain of a subject; a light detector that detects the intensity of the light exiting from the measurement site; a light absorbance data generator that from the time sequence changes of the intensity of the exiting light generates light absorbance time sequence data suggesting the changes in the concentration of oxyHb, deoxyHb and totalHb; and multiple baseline correction units that correct baselines that mutually differ in relation to the light absorbance time sequence data obtained when the subject performs specified assignments; and configured such that the baseline correction of the light absorbance time sequence data can be conducted using the baseline correction units corresponding to the assignment performed by the subject.

Claims

1. A body activity measurement device comprising:

a light irradiation unit that irradiates light of a specified wavelength on a specified measurement site of the body of a subject;

a light detector that detects the intensity of the light exiting from the aforementioned measurement site based on the irradiated light of the light irradiation unit;

a time sequence data generator that, based on the time sequence changes of the intensity of the exiting light that the light detector detects, generates time sequence data suggesting the changes in amount or changes in concentration of a specified body substance pertaining to the body activity; and

multiple baseline correction units that correct baselines that mutually differ in relation to the aforementioned time sequence data obtained when the aforementioned subject performs specified assignments;

configured such that the aforementioned baseline correction of the time sequence data can be conducted using one or multiple baseline correction units corresponding to the assignment performed by the subject.

2. The body activity measurement device according to claim 1 wherein the aforementioned multiple baseline correction units correct by subtracting the baseline data indicating the baseline from the aforementioned time sequence data, and

the aforementioned baseline data is expressed by a function related to time that refers to all or part of the values of the time sequence data generated by the aforementioned time sequence data generator.

3. The body activity measurement device according to claim 2 wherein, when the subject repeatedly performs the specified assignment, the aforementioned multiple baseline correction units comprise at least a baseline correction unit in which the aforementioned baseline data is expressed by a function referencing the values of the time sequence data of a specified time during performance of the various assignments.

4. The body activity measurement device according to claim 3 wherein the aforementioned specified assignment comprises a specified task and a rest period when that task is not given;

and the aforementioned baseline data is expressed by a linear function set up for each task and rest period, and determined by the values of the time sequence data at the initial times of the respective tasks and rest periods, and by the values of the time sequence data at the final times of the respective tasks and rest periods.

5. The body activity measurement device according to claim 3 wherein the aforementioned specified assignment comprises a specified task and a rest period when that task is not given;

and the aforementioned baseline data is expressed by a constant function that is set up for each task and rest period, and that takes as a constant the values of the time sequence data at the initial times of the respective tasks and rest periods.

6. The body activity measurement device according to claim 3 wherein the aforementioned specified assignment comprises a specified task and a rest period when that task is not given;

and the aforementioned baseline data is expressed by a linear function set up between each specified time of a rest period, and determined by the values of the time sequence data at specified times of specified rest periods, and the values of the time sequence data of specified times of the following rest periods.

7. The body activity measurement device according to claim 2 wherein, when the subject continues to perform assignments with two or more differing contents, the aforementioned multiple baseline correction units comprise at least a baseline correction unit that expresses the aforementioned baseline data with a function that references the values of the time sequence data at specified times during performance of the assignments.

8. The body activity measurement device according to claim 7 wherein the aforementioned baseline data is expressed by a constant function that is set up for each assignment, and that takes as the constant the values of the time sequence data at the initial times of the assignments.

9. The body activity measurement device according to claim 1 wherein baseline correction unit extraction means are provided to extract from the aforementioned multiple baseline correction units the baseline correction units corresponding to the assignment the subject is made to perform, and the time sequence data is corrected by the baseline correction units extracted by this baseline correction unit extraction means.

10. The body activity measurement device according to claim 1 wherein the measurement site is set up in the brain, and brain activity is measured as the body activity.

11. The body activity measurement device according to claim 1 wherein the light of a specified wavelength that is irradiated by the aforementioned light irradiation unit is near infrared light.

12. The body activity measurement device according to claim 1 wherein the specified body substance participating in the aforementioned body activity is serum, oxyHb and deoxyHb.

13. A body activity measurement system comprising:

a light irradiation unit that irradiates light of a specified wavelength on a specified measurement site of the body of a subject to provide a measurement of a characteristic of the body;

a light detector that detects the intensity of the light exiting from the aforementioned measurement site based on the irradiated light of the light irradiation unit;

a predetermined assigned task material to require activity by the body of the subject;

a stored table of correction values related to predetermined baseline values associated with the predetermined assigned task;

a time sequence data generator that, based on the time sequence changes of the intensity of the exiting light that the light detector detects, generates time sequence data representative of changes in the characteristics of the body during and after the predetermined assigned task; and

a baseline correction assembly for determining from the time sequence data a baseline value corrected by a correction value relisted from the stored table of correction values appropriate to the body of the subject and the predetermined assigned task.

14. The body activity measurement system of claim 13 wherein the light detection measures oxygenated hemoglobin and deoxygenated hemoglobin of the subject.

15. A body activity measurement device comprising:

a detector unit operatively connected to a body of a subject for providing measurement signals characteristic of the body during and after a predetermined activity of the subject;

a time sequence generator that, based on the time sequence changes of signals that the detector unit detects, generates time sequence data of the changes in the characteristic of the body during the body activity; and

multiple baseline correction units that correct baselines that mutually differ in relation to the aforementioned time sequence data obtained when the aforementioned subject performs a specified assignment, wherein the aforementioned baseline correction of the time sequence data can be conducted using one or more multiple baseline correction units corresponding to the assignment performed by the subject.

16. The body activity measurement system of claim 15 wherein the detector unit measures the characteristics of the body during the specified assignment and during a subsequent rest period.

17. The body activity measurement device of claim 16 wherein the multiple baseline correction units include correction values related to the specified assignment.