Optical system for measuring metabolism in a body

• US 20040006260A1
• Filed: 06/03/2003
• Published: 01/08/2004
• Est. Priority Date: 07/08/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd., Hitachi Medical Corporation (Hitachi, Ltd.)
• Original Assignee: HITACHI, LTD. AND HITACHI MEDICAL CORPORATION.
• Inventors: Sato, Hiroki, Maki, Atsushi, Kiguchi, Masashi
• Granted Patent: US 6,907,279 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0042 for the brain
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00

Abstract

The invention provides optical technique for measuring metabolism in a living body that can further reduce an error in measurement even if distance between irradiation and detection is fixed. The living body is classified into measurement regions and different measuring wavelengths are set according to the classification. For example, the head is classified into four regions of a parietal region, a frontal region, a temporal region and an occipital region and a wavelength according to each tissue is set in a wavelength selecting system. In measurement, wavelengths according to each measurement region are selected by multiple wavelengths-light radiating means. Besides, for a region having large personal difference, premeasurement is made using plural combinations of wavelengths and wavelengths are selected using a calculated error in measurement as a criterion.

Claims

1. An optical system for measuring metabolism in a body based upon an optical system for measuring metabolism in a body in which light radiating means for radiating light on the living body and light receiving means for detecting transmitted light radiated from the light radiating means and propagated in the living body are arranged on the living body and which is configured so that information in the living body is measured based upon a signal detected by the light receiving means with a substantial middle point of the light radiating means and the light receiving means as a measurement point, wherein:

the light radiating means is provided with plural light sources respectively having a different wavelength; and

the light source having a wavelength according to the tissue of a measurement region in the living body and its optical property is selected out of the plural light sources.

2. An optical system for measuring metabolism in a body according to claim 1, wherein:

for the selection of wavelengths, an object of measurement is classified into measurement regions and suitable wavelengths are selected out of wavelengths preset every measurement region.

3. An optical system for measuring metabolism in a body according to claim 1, wherein:

for the selection of wavelengths, premeasurement is made beforehand using plural measuring wavelengths, an error of a signal to be detected is calculated and wavelengths are selected based upon the calculated error.

4. An optical system for measuring metabolism in a body according to claim 1, wherein:

a display for displaying a wavelengths selecting method according to an object of measurement according a preset criterion is provided.

5. An optical system for measuring metabolism in a body according to claim 1, wherein:

the light radiating means is provided with a wavelength variable light source that can radiate light of an arbitrary wavelength; and

wavelengths according to the tissue of a measurement region in the living body and its optical property can be selected by selecting any light source of the plural light sources and the wavelength variable light source.

6. An optical system for measuring metabolism in a body based upon an optical system for measuring metabolism in a body in which light radiating means for radiating light on the living body and light receiving means for detecting transmitted light radiated from the light radiating means and propagated in the living body are arranged on the living body and which is configured so that information in the living body is measured based upon a signal detected by the light receiving means with a substantial middle point of the light radiating means and the light receiving means as a measurement point, wherein:

the light radiating means is provided with a wavelength variable light source that can radiate light of an arbitrary wavelength; and

the wavelengths of light radiated from the light source are selected according to the tissue of a measurement region in the living body and its optical property.

7. An optical system for measuring metabolism in a body according to claim 6, wherein:

for the selection of wavelengths, an object of measurement is classified into measurement regions and suitable wavelengths are selected out of wavelengths preset every measurement region.

8. An optical system for measuring metabolism in a body according to claim 6, wherein:

for the selection of wavelengths, premeasurement is made beforehand using plural measuring wavelengths, an error of a signal to be detected is calculated and wavelengths are selected based upon the calculated error.

9. An optical system for measuring metabolism in a body according to claim 6, wherein:

a display for displaying a wavelengths selecting method according to an object of measurement according to a preset criterion is provided.

10. An optical system for measuring metabolism in a body based upon an optical system for measuring metabolism in a body in which light radiating means for radiating light on the living body and light receiving means for detecting transmitted light radiated from the light radiating means and propagated in the living body are arranged on the living body and which is configured so that information in the living body is measured based upon a signal detected by the light receiving means with a region determined by an incident position by the light radiating means and a detection position by the light receiving means as a measurement region, wherein:

the light radiating means comprises;

a first group of light sources respectively having a different wavelength;

a second light source having a wavelength further different from the first group of light sources;

selecting means for selecting light of the light source having a wavelength according to the tissue of a measurement region in the living body and its optical property in the first group of light sources; and

an optical coupler for coupling an optical path of light selected by the selecting means and an optical path of light from the second light source and conducting it to the incident position.