Optical measurement instrument for living body

• US 20060184046A1
• Filed: 03/10/2006
• Published: 08/17/2006
• Est. Priority Date: 10/06/1995
• Status: Abandoned Application

• Current Assignee: Atsushi Maki, Hideaki Koizumi, Yuichi Yamashita
• Original Assignee: Atsushi Maki, Hideaki Koizumi, Yuichi Yamashita
• Inventors: Yamashita, Yuichi, Maki, Atsushi, Koizumi, Hideaki
• Application Number:
  US11/371,918
• Publication Number:
  US 20060184046A1
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 2562/046 in a matrix array
• 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 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• 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 6/03 Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B

Abstract

An optical measurement instrument for a living body including a first light irradiator for irradiating light from a first irradiation position in a small region as considered as a plan on the surface of a head of a subject into the inside of the head in the region in the direction of depth, a second light irradiator for irradiating light from a second irradiation position in the region into the inside of the head, a first detecting for detecting the first irradiated light to pass through the head in a first detection position in the region, a second detector for detecting the second irradiated light to pass through the head in a second detection position in the region, and a calculator for multiplication or addition of a first signal and a second signal in a calculator.

Claims

1. An optical measurement instrument for a living body comprising:

a first light irradiation means for irradiating a first irradiated light from a first irradiation position in a small region as considered as a plan on the surface of a head of a subject into the inside of the head in the region in the direction of depth;

a second light irradiation means for irradiating a second irradiated light from a second irradiation position in the region into the inside of the head;

a first detection means for detecting the first irradiated light to pass through the head in a first detection position in the region;

a second detection means for detecting the second irradiated light to pass through the head in a second detection position in the region; and

means for multiplication or addition of a first signal and a second signal in a calculator;

wherein the first signal is based on a signal of a first transmitted light of the light irradiated from the first light irradiation means detected by the first detection means and the second signal is based on a signal of a second transmitted light of the light irradiated from the second light irradiation means detected by the second detection means;

wherein the first and the second irradiation positions and the first and the second detection positions are predetermined such that a first transmitted light path and a second transmitted light path are overlapped in a certain region in the head, the first transmitted light path being from the first irradiation position to the first detection position, the second transmitted light path being from the second irradiation position to the second detection position; and

wherein a first straight line linking the first irradiation position with the first detection position and a second straight line linking the second irradiation position with the second detection position, are nonparallel line.

2. An optical measurement instrument for a living body comprising:

first light irradiation means and first light detection means arranged in a point symmetry position in which a point symmetry center is the center of a circle having a diameter of a certain size in on the surface region as considered as a plan on the surface of a head of a subject;

second light irradiation means and second light detection means arranged in a point symmetry position different from the position in which the first light irradiation means and the first light detection means are arranged; and

a first straight line linking a first irradiation position of the first light irradiation means with first detection position of the first light detection means and a second straight line linking a second irradiation position of the second light irradiating means with second detection position of the second light detection means are nonparallel lines, and

wherein the optical measurement instrument further comprises means for multiplication or addition of a first signal and a second signal in a calculator in which the first signal is based on the signal of a first transmitted light of the light irradiated from the first light irradiation means detected by the first detection means and the second signal is based on the signal of a second transmitted light of the light irradiated from the second light irradiation means detected by the second detection means.

3. The optical measurement instrument for a living body according to claim 2, wherein a detection sensitivity in at least one of the first and second light detection means for detecting a change of concentration of absorbed substances inside of the head under the center of the circle is higher than a detection sensitivity in at least one of the first and second light detection means for detecting a change of concentration of absorbed substances in each area inside of the head.

4. An optical measurement instrument for a living body comprising:

first and second light irradiation means and first and second light detection means arranged in equidistance on a circle having a diameter of a certain size in on the surface region as considered as a plan on the surface of a head of a subject;

a first straight line which link the first light irradiation means with the first light detection means passes through the center of the circle; and

a second straight line which links the second light irradiation means with the second light detection means passes through the center of the circle;

wherein first straight line and the second straight line are nonparallel lines;

wherein the optical measurement instrument further comprises means for multiplication or addition of a first signal and a second signal in a calculator in which the first signal is based on a signal of a first transmitted light of light irradiated from the first light irradiation means detected by the first detection means and the second signal is based on a signal of a second transmitted light of light irradiated from the second light irradiation means detected by the second detection means; and

wherein first and second irradiation positions and first and second detection positions of the first and second detection means are positioned such that a first transmitted light path and a second transmitted light path are overlapped in a certain region in the head, the first transmitted light path being from the first irradiation position to the first detection position, the second transmitted light path being from the second irradiation position to the second detection position.

5. The optical measurement instrument for a living body according to claim 4, wherein a detection sensitivity in light detection means for detecting a change of concentration of absorbed substances inside of the head under the center of the circle is higher than a detection sensitivity in light detection means for detecting a change of the concentration of absorbed substances in each area inside of the head.

6. An optical measurement instrument for a living body comprising:

first and second light irradiation means and first and second light detection means arranged in equidistance on a first circle having a diameter of a certain size in on a planar region as considered as a plan on a surface of a head of a subject;

a first straight line linking the first light irradiation means with the second light detection means passes through a center of the first circle;

a second straight line linking the second light irradiation means with the first light detection means passes through the center of the first circle;

the first straight line and the second straight line are nonparallel lines;

third and fourth light irradiation means and the first and second detection means are arranged in equidistance on a second circle on the planar surface region;

a third straight line linking the third light irradiation means with the second light detection means passes through a center of the second circle;

a fourth straight line linking the fourth light irradiation means with the first light detection means passes through the center of the second circle; and

the third straight line and the fourth straight line are nonparallel lines;

wherein multiplication or addition of a first signal and a second signal is carried out in a calculator in which the first signal is based on a signal of a first transmitted light of the light irradiated from the second light irradiation means detected by the first light detection means and the second signal is based on a signal of a second transmitted light of the light irradiated from the first light irradiation means detected by the second light detection means; and

wherein multiplication or addition of a third signal and a fourth signal is carried out in a calculator wherein the third signal is based on a signal of a third transmitted light of the light irradiated from the third light irradiation means detected by the second light detection means and the fourth signal is based on a signal of a fourth transmitted light of the light irradiated from the fourth light irradiation means detected by the first light detection means.

7. The optical measurement instrument for a living body according to claim 6 wherein a detection sensitivity in light detection means for detecting a change of concentration of the absorbed substances inside of the head under the first and second centers of the circles is higher than a detection sensitivity in light detection means for detecting a change of concentration of absorbed substances in each area inside of the head.

8. An optical measurement instrument for a living body comprising:

first, second and third light irradiation means, and first, second and third light detection means arranged in equidistance on a first circle having a diameter of a certain size in on a certain small planar region as considered as a plan on the surface of a head of a subject;

each of a first straight line linking the first light irradiation means with the second light detection means, a second straight line linking the second light irradiation means with the first light detection means and the third straight line linking the third light irradiation means with the third light detection means passes through a center of the first circle;

the first straight line, the second straight line and the third straight are nonparallel lines;

fourth light irradiating means, sixth light irradiating means and the second light irradiation means, and fifth light detection means, sixth light detection means and the first light detection means arranged in equidistance on a second circle having a diameter of the same size as that of the first circle in the planar region;

each of a fourth straight line linking the second light irradiation means with the fifth light detection means, a fifth straight line linking the fourth light irradiation means with the first light detection means and a sixth straight line linking the sixth light irradiation means with the sixth light detection means passes through the center of the second circle; and

the fourth straight line, the fifth straight line and the sixth straight are nonparallel lines;

wherein multiplication or addition of a first, a second, a third, a fourth, a fifth and a sixth signal is carried out in a calculator wherein the first signal is based on a signal of a first transmitted light of light irradiated from the first light irradiation means detected by the first light detection means, the second signal is based on a signal of a second transmitted light of light irradiated from the second light irradiation means detected by the second light detection means, the third signal is based on a signal of third transmitted light of light irradiated from the third light irradiation means detected by the third light detection means, the fourth signal is based on a signal of fourth transmitted light of light irradiated from the fourth light irradiation means detected by the first light detection means, the fifth signal is based on a signal of fifth transmitted light of light irradiated from the second light irradiation means detected by the fifth light detection means, and the sixth signal is based on a signal of the sixth transmitted light of light irradiated from the sixth light irradiation means detected by the sixth light detection means.

9. The optical measurement instrument for a living body according to claim 8, wherein a detection sensitivity in light detection means for detecting a change of concentration of absorbed substances inside of the head under the first and the second centers of the circles is higher than a detection sensitivity in light detection means for detecting a change of concentration of absorbed substances in each area inside of the head.

10. An optical measurement instrument for a living body comprising:

first and second light irradiation means and first and second light detection means arranged in equidistance on a first circle having a diameter of a first size on a planar region as considered as a plan on a surface of a head of a subject;

a first straight line linking the first light irradiation means with the first light detection means passes through a center of the first circle;

a second straight line linking the second light irradiation means with the second light detection means passes through the center of the first circle;

the first straight line and the second straight line are nonparallel lines;

third and fourth irradiation means and third and fourth detection means are arranged in equidistance on a second circle having a diameter of the same size as that of the first circle and arranged concentrically with the first circle on the planar surface region;

a third straight line linking the third light irradiation means with the third light detection means passes through a center of the second circle;

a fourth straight line linking the fourth light irradiation means with the fourth light detection means passes through the center of the second circle; and

the third straight line and the fourth straight line are nonparallel lines;

wherein multiplication or addition of a first signal and a second signal is carried out in a calculator wherein the first signal is based on a signal of a first transmitted light of light irradiated from the first light irradiation means detected by the first light detection means and the second signal is based on a signal of a second transmitted light of light irradiated from the second light irradiation means detected by the second light detection means; and

wherein multiplication or addition of a third signal and a fourth signal is carried out in a calculator wherein the third signal is based on a signal of a third transmitted light of light irradiated from the third light irradiation means detected by the third light detection means and the fourth signal is based on the signal of a fourth transmitted light of light irradiated from the fourth light irradiation means detected by the fourth light detection means.

11. The optical measurement instrument for a living body according to claim 10, wherein a detection sensitivity in light detection means for detecting a change of concentration of absorbed substances inside of the head under the first and the second centers of the circles is higher than a detection sensitivity in light detection means for detecting a change of concentration of the absorbed substances in each area inside of the head.

12. The optical measurement instrument for a living body according to claim 11, wherein an area having high detection sensitivity is under the first and the second circles and in two positions in the direction of depth.

13. An optical measurement instrument for a living body comprising:

a first light irradiation means for irradiating a first irradiated light having one intensity-modulated from light of wavelength λ

1 of a visible-infrared region with frequency f1 and one intensity-modulated from light of wavelength λ

2 other than λ

1 with frequency f2 other than f1 from a first irradiation position on a surface of a subject into an inside of a subject;

a second light irradiation means for irradiating a second irradiated light having one intensity-modulated from light of wavelength k1 with frequency f3 other than f1 and f2 and one intensity-modulated from the light of wavelength λ

2 other than λ

1 with frequency f4 other than f1˜

f3 from a second irradiation position different from the first irradiation position on the surface of a subject into the inside of the subject;

a first light detection means for selecting and detecting individually one intensity-modulated with frequency f1 and one intensity-modulated with frequency f2 among transmitted light to pass through the inside of the subject of first transmitted lights in the first detection position on the surface of the subject corresponding to the first irradiation position; and

a second light detection means for selecting and detecting individually one intensity-modulated with frequency f3 and one intensity-modulated with frequency f4 among transmitted light to pass through the inside of the subject of second transmitted lights in the second detection position other than the first detection position on the surface of the subject corresponding to the second irradiation position;

wherein multiplication or addition of a first signal and a second signal is carried out in a calculator wherein the first signal is based on the intensity of the first transmitted light of a signal having frequency f1 detected by the first light detection means and the second signal is based on the intensity of the second transmitted light of a signal having frequency f3 detected by the second light detection means;

wherein multiplication or addition of a third signal and a fourth signal is carried out in a calculator wherein the third signal is based on the intensity of a third transmitted light of a signal having frequency f2 detected by the first light detection means and the fourth signal is based on the intensity of a fourth transmitted light of a signal having frequency f4 detected by the second light detection means;

wherein the first and the second irradiation positions and the first and the second detection positions are predetermined such that a first transmitted light path and a second transmitted light path are overlapped in a certain measurement region in the subject, the first transmitted light path being from the first irradiation position to the first detection position, the second transmitted light path being from the second irradiation position to the second detection position; and

wherein a first straight line linking the first irradiation position with the first detection position and a second straight line linking the second irradiation position with the second detection position are nonparallel lines.