Optical measurement apparatus for living body

• US 7,353,054 B2
• Filed: 09/09/2004
• Issued: 04/01/2008
• Est. Priority Date: 09/11/2003
• Status: Expired due to Fees

• Current Assignee: Gunma University, National University Corporation
• Original Assignee: Gunma University, National University Corporation, Hitachi, Ltd., Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Fukuda, Masato, Mikuni, Masahiko, Kawasaki, Shingo, Tanaka, Naoki, Kawaguchi, Fumio, Ichikawa, Noriyoshi, Kawaguchi, Hideo
• Primary Examiner(s): Winakur; Eric
• Assistant Examiner(s): Berhanu; Etsub D
• Application Number:
  US10/571,430
• Publication Number:
  US 20070055118A1
• Time in Patent Office: 1,300 Days
• Field of Search: 600/300, 600/322, 600/323, 600/328, 128/923
• US Class Current: 600/310
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety

Abstract

An apparatus which can objectively assess and display to what extent and to which disease the subject belongs based on the signals of changes in hemoglobin amount measured by the optical measurement apparatus is provided. The disease assessment apparatus comprises the feature extraction unit 15 for extracting features of the hemoglobin waveform, the feature analysis unit 16 and the storage unit 12 for storing features by each disease as database. The disease is assessed by extracting various kinds of feature amounts from the hemoglobin signals of the subject measured by the optical measurement apparatus in the feature extraction unit 15 and by applying multivariate analysis of similarities between feature amounts extracted and feature amounts stored by disease in the storage unit 12. Results of assessment are shown as scores expressing similarity with each disease group in a bar graph.

Claims

1. An optical measurement apparatus for a living body comprising a light source for generating a light to be irradiated onto an object to be examined, a light measurement means that detects a light transmitted inside the object and generates hemoglobin signals corresponding to hemoglobin changes in the object, an assessing means that analyzes feature amounts of the hemoglobin signals and assesses a disease of the object from the analyzed feature amount, and a display means for displaying disease information of the object,

wherein said assessing means comprises:

an extracting means for extracting various kinds of feature amounts from the hemoglobin signals,

a storing means for storing feature amounts of hemoglobin variation signals of multiple diseases in a database;

analyzing means for calculating a similarity of extracted feature amounts of an acquired hemoglobin variation signal with stored feature amounts of hemoglobin variation signals characterizing the multiple stored diseases in order to diagnose a disease of a subject; and

a guantifying means for guantifying the similarity estimated by the analyzing means.

2. The optical measurement apparatus for a living body according to claim 1, wherein said display means displays said similarity in a graph.

3. The optical measurement apparatus for a living body according to claim 1, which further comprises a storing means that stores the assessed results for each subject together with its optical measurement data and image data as a combined data.

4. An optical measurement apparatus for a living body comprising a light source for generating a light to be irradiated onto an object to be examined, a light measurement means that detects a light transmitted inside the object and generates hemoglobin signals corresponding to hemoglobin changes in the object, an assessing means that analyzes feature amounts of the hemoglobin signals and assesses a disease of the object from the analyzed feature amount, and a display means for displaying disease information of the object,

wherein said assessing means comprises:

an extracting means for extracting various kinds of feature amounts from the hemoglobin signals,

a storing means for storing feature amounts of each of different disease types in a database,

an analyzing means for analyzing feature amounts extracted by the extracting means and for estimating their similarity with the feature amounts of each disease stored in said storing means; and

a quantifying means for quantifying the similarity estimated by the analyzing means.

5. The optical measurement apparatus for a living body according to claim 4,

wherein said analyzing means calculates, by means of multivariate analysis, a similarity between various kinds of feature amounts extracted by said extracting means and the feature amounts of each disease stored as data in the storing means.

6. The optical measurement apparatus form living body according to claim 4, wherein said analyzing means calculates said similarity by calculating Mahalanobis distances between the feature amounts of the subject and the gravity center of the feature amount data of each disease.

7. The optical measurement apparatus for a living body according to claim 4, wherein said extracting means extracts the various kinds of feature amounts from a pattern (graph) of changes in the hemoglobin amount when a specified task is loaded onto the object.

8. The optical measurement apparatus for a living body according to claim 7, wherein said extracting means extracts, as said feature amounts, at least one of a gradient of the graph immediately after the initiation of a task, a gradient of the graph after the completion of the task, an integral value A during the task, an integral value B after the completion of the task, a ratio of the integral values (NB), a maximum value of the graph and a correlation value with square waveform after the completion of the task.

9. The optical measurement apparatus for a living body according to claim 4, wherein said extracting means uses an average of values obtained by multiple measurements as the hemoglobin signals.

10. The optical measurement apparatus for a living body according to claim 4, wherein said storing means includes a database of feature amounts for, at least, normal subject group, schizophrenia group and depression group.

11. The optical measurement apparatus for a living body of claim 4, wherein said analyzing means stores a data of a subject whose similarity with a particular disease is within a predetermined threshold, as a data of the particular disease.

12. The optical measurement apparatus for a living body according to claim 4, which further comprises an input means for inputting direction of assessment by the assessing means, preparation of reports, update of the database and displaying by the display means.

13. A method of assessing a disease of an object to be examined using hemoglobin signals of the object measured by optical measurement comprising the steps of:

measuring hemoglobin signals by optical measurement for a plurality of subjects whose diagnosis of disease among a plurality of disease groups has been established,

extracting a plurality of feature amounts from the hemoglobin signal of each subject,

storing the feature amounts as data in a database,

assessing disease of the object to be examined by extracting a plurality of feature amounts from a hemoglobin signal measured by optical measurement for the object to be examined, calculating a similarity of the extracted feature amounts with data for each disease, and

determining a disease having a highest similarity as a disease of the object to be examined.

14. A method of assessing a disease according to claim 13, which further comprises the steps of extracting principal component waveform by performing principal component analysis for hemoglobin signals of a plurality of subjects each whose diagnosis of disease has been established, extracting feature amounts from the principal component waveform of each object, and storing the extracted feature amount as data of the disease of the object.