APPARATUS AND METHOD FOR PROCESSING BIOLOGICAL INFORMATION

• US 20100094561A1
• Filed: 10/02/2009
• Published: 04/15/2010
• Est. Priority Date: 10/03/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Masumura, Takahiro
• Granted Patent: US 8,364,414 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• 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 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/0097 by applying acoustic waves and detecting light, i.e. acoustooptic measurements
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 2291/02475 Tissue characterisation
• CPC Class Codes: G01N 29/0672 by acoustic tomography medical tomography A61B8/13
• CPC Class Codes: G01N 29/2418 using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046

Abstract

A biological information processing apparatus includes the following elements. A light source irradiates biological tissue with light. A transducer functions as an ultrasonic wave transmitting unit that applies an ultrasonic wave to a local region in the biological tissue. A photodetector detects modulated light obtained by modulating the light from the light source with the ultrasonic wave in the local region. The transducer also functions as an acoustic wave detecting unit that detects an acoustic wave emitted from the local region at a time when the local region absorbs the light from the light source. An absorption characteristic in the local region is calculated using an acoustic signal, serving as an output of the acoustic wave detecting unit, on the basis of a light intensity in the local region calculated based on a modulation signal, serving as an output of the photodetector.

Claims

1. A biological information processing apparatus comprising:

a light source configured to irradiate biological tissue with light;

an ultrasonic wave transmitting unit configured to apply an ultrasonic wave to a local region in the biological tissue;

a photodetecting unit configured to detect modulated light obtained by modulating the light from the light source with the ultrasonic wave in the local region;

an acoustic wave detecting unit configured to detect an acoustic wave emitted from the local region at a time when the local region absorbs the light from the light source; and

an arithmetic logical unit configured to calculate an absorption characteristic in the local region using an acoustic signal, serving as an output of the acoustic wave detecting unit, on the basis of a light intensity in the local region calculated based on a modulation signal, serving as an output of the photodetecting unit.

2. The apparatus according to claim 1, wherein the ultrasonic wave transmitting unit and the acoustic wave detecting unit are realized by an elastic wave transducer.

3. The apparatus according to claim 1, wherein an incidence optical fiber and a detection optical fiber are arranged so that an incident light propagation area, where the light emitted from the light source propagates to the local region through the biological tissue, overlaps a detection light propagation area where the modulated light propagates from the local region to the photodetecting unit through the biological tissue.

4. The apparatus according to claim 3, wherein the incidence optical fiber and the detection optical fiber are arranged so that the incident light propagation area and the detection light propagation area are regarded as identical to each other, and

the arithmetic logical unit calculates the light intensity in the local region using a relational expression obtained on the condition that the incident light propagation area is identical to the detection light propagation area.

5. A method for processing biological information, comprising the steps of:

when a local region in biological tissue is irradiated with light and is simultaneously irradiated with an ultrasonic wave, detecting modulated light obtained by modulating the light with the ultrasonic wave in the local region;

detecting an acoustic wave emitted from the local region at a time when the local region absorbs the light; and

calculating an absorption characteristic in the local region using an acoustic signal, obtained from the acoustic wave, on the basis of a light intensity in the local region calculated based on a modulation signal obtained from the modulated light.

6. The method according to claim 5, wherein the irradiation of the light and the detection thereof are performed so that an incident light propagation area, where the applied light propagates to the local region through the biological tissue, overlaps a detection light propagation area where the modulated light to be detected propagates from the local region through the biological tissue.

7. The method according to claim 6, wherein

the irradiation of the light and the detection thereof are performed so that the incident light propagation area and the detection light propagation area are regarded as identical to each other, and

the light intensity in the local region is calculated using a relational expression obtained on the condition that the incident light propagation area is identical to the detection light propagation area.

8. The method according to claim 5, wherein

in the step of detecting the acoustic wave, the acoustic wave is detected in any local region in the biological tissue,

the method further includes the step of specifying a section in which the acoustic signal is obtained with higher contrast than a predetermined threshold value in the biological tissue, and

the local region is set in the specified section and the modulated light is detected.

9. The method according to claim 5, wherein

the step of detecting the modulated light includes the substeps:

detecting modulated light from each of positions inside the biological tissue to calculate a spatial distribution of light attenuation coefficients inside the biological tissue; and

calculating the light intensity in the local region using the spatial distribution.

10. The method according to claim 9, further comprising the step of:

segmenting the biological tissue into a plurality of sections on the basis of ultrasonic echoes obtained by applying the ultrasonic wave to the biological tissue, wherein

the light intensity in the local region is calculated using the spatial distribution of light attenuation coefficients calculated in the respective sections.

11. The method according to claim 5, wherein the absorption characteristic obtained in the local region is associated with the coordinates of the position of the local region to form a three-dimensional tomogram relating to the absorption characteristics in the biological tissue.

12. A computer-readable recording medium that records a program allowing a computer to execute the method according to claim 5.