Brain wave data processing device and storage medium

• US 6,339,721 B1
• Filed: 10/20/1999
• Issued: 01/15/2002
• Est. Priority Date: 10/28/1998
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kenmochi, Akihisa, Yamazaki, Toshimasa
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/421,271
• Time in Patent Office: 818 Days
• Field of Search: 600/300, 600/544, 600/545
• US Class Current: 600/544
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/417 the bone marrow
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

A wavelet conversion means (13) for subjecting brain wave data in a single trial to wavelet conversion, a wavelet coefficient window means (15) for extracting a predetermined area by a wavelet coefficient window from a wavelet coefficient surface obtained by the wavelet conversion, and a brain wave data discriminating means (17) for discriminating brain wave data by judging whether or not the predetermined area is extracted are provided to automate the work to extract distinguishing patterns from individual (in a single trial) brain wave data and to obtain averaging of the brain wave data. By considering whole of wavelet conversion coefficients, averaging and extraction of a vertex latency of distinguishing patterns can be executed without significantly losing the information of original waveform data.

Claims

1. A brain wave data processing device detecting distinguishing patterns from individual brain wave data obtained in a single trial, said brain wave data processing device comprising:

a brain wave data storage means for storing digital brain wave data;

a wavelet conversion means for subjecting said digital brain wave data read out from said brain wave data storage means to wavelet conversion to determine a wavelet coefficient;

a wavelet coefficient surface output means for outputting said wavelet coefficient as function values of a scale parameter and a shift parameter in said wavelet conversion;

a wavelet coefficient window parameter setting means for setting a wavelet coefficient window;

a wavelet coefficient window means for extracting a predetermined area based on said wavelet coefficient window from a wavelet coefficient surface defined by said scale parameter, said shift parameter, and said wavelet coefficient; and

a brain wave data discriminating means for discriminating whether or not said predetermined area has been extracted from said wavelet coefficient surface by said wavelet coefficient window means for individual digital brain wave data.

2. The brain wave data processing device according to claim 1, further comprising electrodes for brain wave, an amplifier for amplifying feeble signals measured by said electrodes for brain wave, and an analog-digital converter for converting analog brain wave data outputted from said amplifier to digital brain wave data.

3. The brain wave data processing device according to claim 1, wherein said wavelet coefficient window is set based on a wavelet coefficient surface corresponding to brain wave data from which distinguishing patterns are detected.

4. The brain wave data processing device according to claim 1, wherein Mexican Hat is used as a mother wavelet in said wavelet conversion.

5. The brain wave data processing device according to claim 1, further comprising a brain wave data averaging means for averaging only digital brain wave data from which said predetermined area is extracted in said wavelet coefficient surface.

6. The brain wave data processing device according to claim 1, further comprising a pattern latency extraction means for determining a vertex latency of distinguishing patterns included only in digital brain wave data from which said predetermined area is extracted in said wavelet coefficient surface.

7. A storage medium in which individual digital brain wave data due to a single trial is inputted and which can be read out by a computer, said storage medium comprising a computer program, the computer program comprising instructions which, when executed, perform:

a function for subjecting said digital brain wave data to wavelet conversion to determine a wavelet coefficient;

a function for determining said wavelet coefficient as function values of a scale parameter and a shift parameter in said wavelet conversion;

a function for setting a wavelet coefficient window;

a function for extracting a predetermined area based on said wavelet coefficient window from a wavelet coefficient surface defined by said scale parameter, said shift parameter, and said wavelet coefficient; and

a function for discriminating whether said predetermined area is extracted from said wavelet coefficient surface for each individual brain wave data.

8. The storage medium according to claim 7, wherein said instructions of said program further perform a function for adding and averaging only digital brain wave data from which said predetermined area is extracted.

9. The storage medium according to claim 7, wherein said instructions of said program further perform a function for determining a vertex latency of distinguishing patterns included only in digital brain wave data from which said predetermined area is extracted.