Optical system for measuring metabolism in a body and imaging method

• US 6,282,438 B1
• Filed: 12/02/1998
• Issued: 08/28/2001
• Est. Priority Date: 10/06/1994
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ito, Yoshitoshi, Yamashita, Yuichi, Maki, Atsushi, Koizumi, Hideaki, Kawaguchi, Fumio
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): MANTIS MERCADER, ELENI M
• Application Number:
  US09/203,610
• Time in Patent Office: 1,000 Days
• Field of Search: 600/310, 600/476, 600/473, 356/340, 356/342
• US Class Current: 600/476
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• 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 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: A61B 6/03 Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: A61B 6/507 for determination of haemodynamic parameters, e.g. perfusion CT

Abstract

Light rays of a plurality of wavelengths which are modulated in intensity with a plurality of different frequencies are irradiated on a plurality of irradiation positions on the surface of a living body, and time-variable changes in living body transmitting light intensity levels corresponding to the respective wavelengths and the respective irradiation positions are measured at different positions on the surface of the living body. After completion of the measurement or during the measurement, changes in concentration values of absorbers in the living body are determined from the living body transmitting light intensity levels of the plurality of wavelengths detected at the respective detection points and a measuring point is set on a perpendicular extending through an intermediate point between the incident point and each detection point so as to image a function of the living body. In living body optical measurement system and method, the measuring time is shortened by estimating fluctuation attributable to the living body, the presence or absence of a change in measured signal can be decided easily by displaying an estimation signal and a measured signal at a time, and a local change in. hemodynamic movement can be measured by detecting light rays transmitting through the interior of the living body by the two light detectors disposed at different two sites (equidistant from the light incident point) on a subject and by separating only the local change in hemodynamic movement from an overall change in hemodynamic movement in the living body in accordance with a logarithmic difference between the two detection signals.

Claims

1. An optical measurement system comprising:

a plurality of light irradiators for irradiating light rays on a subject;

a plurality of light receivers for receiving light rays passing through said subject;

wherein said plurality of light irradiators and said plurality of light receivers are disposed in lattice form alternatively; and

a display control unit for displaying a predetermined area on a display screen corresponding to presumptive measuring points on or in said subject, each presumptive measuring point being determined on a basis of a set of one of said light irradiators and one of said light receivers adjacent to each other, by a color or brightness corresponding to a data value detected by said one of the light receivers.

2. An optical measurement system according to claim 1, wherein a value at a position between said presumptive measuring points is determined through interpolation on a basis of data values detected by said light receivers corresponding to said presumptive measuring points, and wherein said display control unit displays said predetermined area by color or brightness corresponding to said value determined through the interpolation.

3. An optical measurement system according to claim 1, wherein a light propagation characteristic in said subject as determined by said set of said one of the light irradiators and said one of the light receivers adjacent to each other is calculated by numerical calculation, and wherein said display control unit displays an image on a basis of a calculated result.

4. An optical measurement system according to claim 1, wherein said each presumptive measuring point is an intermediate point between said one of the light irradiators and said one of the light receivers.

5. An optical measurement system according to claim 1, wherein said predetermined area is a square pixel having a center of gravity at said each presumptive measuring point.

6. An optical measurement system comprising:

a plurality of light irradiators for irradiating light rays on a subject;

a plurality of light receivers for receiving light rays passing through said subject;

wherein said plurality of light irradiators and said plurality of light receivers are disposed in lattice form alternatively; and

a display control unit for displaying as an image predetermined areas on a display screen corresponding to presumptive measuring points on or in said subject as determined on a basis of sets of ones of said light irradiators and ones of said light receivers adjacent to each other, by color or brightness corresponding to data values detected by said light receivers, wherein said display control unit displays said image in an order of measuring time points.

7. An optical measurement system according to claim 6, wherein each of said presumptive measuring points is an intermediate point between one of the light irradiators and one of the light receivers adjacent to each other.

8. An optical measurement system according to claim 6, wherein each area of said predetermined areas is a square pixel having a center of gravity at a corresponding one of said presumptive measuring points.

9. An optical measurement system comprising:

a plurality of light irradiators for irradiating light ray on a subject;

a plurality of light receivers for receiving light rays passing through said subject;

a plurality of signal separators for separating detected signals by said receivers into each signal coming from said each irradiator;

a display controller for providing pixels on the basis of the separated signals by said signal separators; and

a display unit for displaying an image on the basis of pixels.

10. An optical measurement system comprising:

a plurality of light irradiators for irradiating light ray on a subject;

a plurality of light receivers for receiving light rays passing through said subject;

a plurality of signal separators for separating detected signals by said receivers into respective signals, each respective signal being resultant from a differing light-irradiator/light-receiver combination;

a display controller for providing pixels on the basis of the separated signals by said signal separators; and

a display unit for displaying an image on the basis of pixels.

11. An optical measurement system comprising:

a plurality of light radiators for irradiating light ray on human body;

a plurality of light detectors for detecting light rays from the human body to generate electric signals;

a separator for separating a specific electric signals from said electric signals, said specific electric signal corresponding to one of said electric signals resulting from a specific one of said plurality of light irradiators; and

a display unit for displaying an image picture formed on the basis of the separated specific electric signal.

12. An optical measurement system comprising:

a plurality of light irradiators for irradiating light rays on human body, each of which has a specific wavelength;

a plurality of light detectors for detecting the light ray scattered by said human body, said detectors being disposed at a plurality of positions on said human body, and

a display controller for displaying the images on the basis of the signals detected in accordance with said plurality of positions.

13. An optical measurement method comprising steps of:

irradiating light ray on a plurality of portions of human body;

detecting light rays passed through the human body at a plurality of portions; and

displaying a moving picture relating to a state of blood of said human body on the basis of the detected light rays and the portions of the human body through which the detected light rays passed.