US5566673A
Expired / Lapsed
US
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Apparatus for measuring brain activity
Assignee: Mitsubishi Electric Corp
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Filing: 1995-06-01
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Granted: 1996-10-22
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Expires: 2015-06-01
Abstract
Abstract In a brain activity measuring apparatus, the reflected light from the brain surface is conducted by way of an objective lens and focusing lens and split into two beams by a beam splitter. The light beams are conducted through respective band-pass filters having different transmission wavelengths, and received by CCD cameras in which images are formed from the filtered light beams. The CCD cameras produce signals of the images, and a differential amplifier subtracts one image signal from the other thereby to remove a background noise component. The apparatus is free from noises caused by mechanical vibration, and the resulting differential signal exhibits the brain activity accurately.
Inventors
- 👤 Satoru Shiono
- 👤 Manabu Tanifuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:20
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/14551; A61B5/14553; A61B5/40; A61B5/4058; A61B5/4064
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
126 words
A brain activity measuring apparatus comprising: light projection means for projecting a ray of light on to a surface of a brain; light reception means for receiving a reflected light, which is derived from the projected light, from the brain surface; light path dividing means for splitting and directing a light beam provided by said light reception means to a plurality of light paths; light transmission means disposed on said light paths and adapted to transmit light beams having light components of different wavelengths; image signal producing means for producing image signals from the light beams transmitted by said light transmission means; and differential amplifier means for producing a differential signal based on a difference of the image signals produced by said image signal producing means.
Claim 2
Dependent Claim
126 words
A brain activity measuring apparatus comprising: light projection means for projecting a ray of light on to a surface of a brain; light reception means for receiving a reflected light, which is derived from the projected light, from the brain surface; light path dividing means for splitting and directing a light beam provided by said light reception means to a plurality of light paths; light transmission means disposed on said light paths and adapted to transmit light beams having light components of different wavelengths; image signal producing means for producing image signals from the light beams transmitted by said light transmission means; and differential amplifier means for producing a differential signal based on a difference of the image signals produced by said image signal producing means.
Claim 3
Dependent Claim
25 words
A brain activity measuring apparatus according to claim 1, wherein said light path dividing means splits and directs the light beam to two light paths.
Claim 4
Dependent Claim
51 words
A brain activity measuring apparatus according to claim 2 further including intensity adjustment means for equalizing the intensity of a background section of the image signal produced by one image signal producing means and the intensity of the background section of another image signal produced by another image signal producing means.
Claim 5
Dependent Claim
29 words
A brain activity measuring apparatus according to claim 2 further including contrast adjustment means for equalizing the contrast of the image signals produced by said image signal producing means.
Claim 6
Dependent Claim
54 words
A brain activity measuring apparatus according to claim 2, wherein said light reception means comprises an objective lens which forms the reflected light into a parallel light beam, and wherein said apparatus further includes focusing lenses for focusing the light beams, which have passed said light transmission means, on said image signal producing means.
Claim 7
Dependent Claim
43 words
A brain activity measuring apparatus according to claim 2 further including correction means for correcting the light beams, transmitted by said light transmission means, so as to equalize a focal point of each of the light beams on the image signal producing means.
Claim 8
Dependent Claim
20 words
A brain activity measuring apparatus according to claim 2, wherein said light transmission means comprises band-pass filters of thin film.
Claim 9
Dependent Claim
53 words
A brain activity measuring apparatus according to claim 2, wherein at least one of said light transmission means is a band-pass filter which transmits only a light component of emission wavelength and at least one of other light transmission means is a band-pass filter which transmits only a light component of excitation wavelength.
Claim 10
Dependent Claim
50 words
A brain activity measuring apparatus according to claim 2 including a beam splitter which directs based on reflection the light produced by said light projection means to the brain surface and directs based on transmission the reflected light received by said light reception means to said light path dividing means..
Claim 11
Dependent Claim
45 words
A brain activity measuring apparatus according to claim 2, wherein said light path dividing means includes a beam splitter which reflects a light component of one particular wavelength in the reflected light and transmits another light component of another particular wavelength in the reflected light.
Claim 12
Dependent Claim
62 words
A brain activity measuring apparatus according to claim 2, wherein the light transmission means includes first and second light transmission means each respectively receiving one of the two light paths wherein said first light transmission means transmits a light component having wavelengths of approximately 570 nm and said second light transmission means transmits a light component having wavelengths of approximately 630 nm.
Claim 13
Dependent Claim
51 words
A brain activity measuring apparatus according to claim 1 further including intensity adjustment means for equalizing the intensity of a background section of the image signal produced by one image signal producing means and the intensity of the background section of other image signals produced by another image signal producing means.
Claim 14
Dependent Claim
54 words
A brain activity measuring apparatus according to claim 12, wherein said light reception means comprises an objective lens which forms the reflected light into a parallel light beam, and wherein said apparatus further includes focusing lenses for focusing the light beams, which have passed said light transmission means, on said image signal producing means.
Claim 15
Dependent Claim
43 words
A brain activity measuring apparatus according to claim 12 further including correction means for correcting the light beams, transmitted by said light transmission means, so as to equalize a focal point of each of the light beams on the image signal producing means.
Claim 16
Dependent Claim
20 words
A brain activity measuring apparatus according to claim 12, wherein said light transmission means comprises band-pass filters of thin film.
Claim 17
Dependent Claim
53 words
A brain activity measuring apparatus according to claim 12, wherein at least one of said light transmission means is a band-pass filter which transmits only a light component of emission wavelength and at least one of other light transmission means is a band-pass filter which transmits only a light component of excitation wavelength.
Claim 18
Dependent Claim
50 words
A brain activity measuring apparatus according to claim 12 including a beam splitter which directs based on reflection the light produced by said light projection means to the brain surface and directs based on transmission the reflected light received by said light reception means to said light path dividing means.
Claim 19
Dependent Claim
45 words
A brain activity measuring apparatus according to claim 12, wherein said light path dividing means includes a beam splitter which reflects a light component of one particular wavelength in the reflected light and transmits another light component of another particular wavelength in the reflected light.
Claim 20
Dependent Claim
29 words
A brain activity measuring apparatus according to claim 1 further including contrast adjustment means for equalizing the contrast of the image signals produced by said image signal producing means.
Claim 21
Dependent Claim
54 words
A brain activity measuring apparatus according to claim 19, wherein said light reception means comprises an objective lens which forms the reflected light into a parallel light beam, and wherein said apparatus further includes focusing lenses for focusing the light beams, which have passed said light transmission means, on said image signal producing means.
Claim 22
Dependent Claim
43 words
A brain activity measuring apparatus according to claim 19 further including correction means for correcting the light beams, transmitted by said light transmission means, so as to equalize a focal point of each of the light beams on the image signal producing means.
Claim 23
Dependent Claim
20 words
A brain activity measuring apparatus according to claim 19, wherein said light transmission means comprises band-pass filters of thin film.
Claim 24
Dependent Claim
53 words
A brain activity measuring apparatus according to claim 19, wherein at least one of said light transmission means is a band-pass filter which transmits only a light component of emission wavelength and at least one of other light transmission means is a band-pass filter which transmits only a light component of excitation wavelength.
Claim 25
Dependent Claim
50 words
A brain activity measuring apparatus according to claim 19 including a beam splitter which directs based on reflection the light produced by said light projection means to the brain surface and directs based on transmission the reflected light received by said light reception means to said light path dividing means.
Claim 26
Dependent Claim
45 words
A brain activity measuring apparatus according to claim 19, wherein said light path dividing means includes a beam splitter which reflects a light component of one particular wavelength in the reflected light and transmits another light component of another particular wavelength in the reflected light.
Claim 27
Dependent Claim
52 words
A brain activity measuring apparatus according to claim 1, wherein said light reception means comprises an objective lens which forms the reflected light into a parallel light beam, said apparatus further includes focusing lenses for focusing the light beams, which have passed said light transmission means, on said image signal producing means.
Claim 28
Dependent Claim
43 words
A brain activity measuring apparatus according to claim 1 further including correction means for correcting the light beams, transmitted by said light transmission means, so as to equalize a focal point of each of the light beams on the image signal producing means.
Claim 29
Dependent Claim
20 words
A brain activity measuring apparatus according to claim 1, wherein said light transmission means comprises band-pass filters of thin film.
Claim 30
Dependent Claim
53 words
A brain activity measuring apparatus according to claim 1, wherein at least one of said light transmission means is a band-pass filter which transmits only a light component of emission wavelength and at least one of other light transmission means is a band-pass filter which transmits only a light component of excitation wavelength.
Claim 31
Dependent Claim
50 words
A brain activity measuring apparatus according to claim 1 including a beam splitter which directs based on reflection the light produced by said light projection means to the brain surface and directs based on transmission the reflected light received by said light reception means to said light path dividing means.
Claim 32
Dependent Claim
45 words
A brain activity measuring apparatus according to claim 1, wherein said light path dividing means includes a beam splitter which reflects a light component of one particular wavelength in the reflected light and transmits another light component of another particular wavelength in the reflected light.
Claim 33
Dependent Claim
103 words
A brain activity measuring apparatus comprising: a light source; a lens barrel which receives light reflected off of a surface of a brain from said light source and splits said received light into at least two beams of light; a plurality of filters each associated with a corresponding beam of light, each filter passing a different range of predetermined wavelengths; a plurality of image signal producers each associated with a corresponding filter; and a differential amplifier which receives image signals produced by each image signal producer, evaluates a difference of the image signals and produces a differential signal representative of relative brain activity.
Claim 34
Dependent Claim
103 words
A brain activity measuring apparatus comprising: a light source; a lens barrel which receives light reflected off of a surface of a brain from said light source and splits said received light into at least two beams of light; a plurality of filters each associated with a corresponding beam of light, each filter passing a different range of predetermined wavelengths; a plurality of image signal producers each associated with a corresponding filter; and a differential amplifier which receives image signals produced by each image signal producer, evaluates a difference of the image signals and produces a differential signal representative of relative brain activity.
Claim 35
Independent Claim
115 words
A method of measuring brain activity, comprising the steps of: projecting light towards a surface of a brain; splitting light reflected off the surface of the brain into a plurality of light beams; filtering each light beam of the plurality of light beams to generate a plurality of filtered light beams, each filtered light beam having different wavelength components than other filtered light beams of the plurality of filtered light beams; producing a plurality of image signals, each image signal of the plurality of image signals corresponding to one filtered light beam of the plurality of filtered light beams; and producing a differential signal representative of relative brain activity using the plurality of image signals.
Claim 36
Independent Claim
115 words
A method of measuring brain activity, comprising the steps of: projecting light towards a surface of a brain; splitting light reflected off the surface of the brain into a plurality of light beams; filtering each light beam of the plurality of light beams to generate a plurality of filtered light beams, each filtered light beam having different wavelength components than other filtered light beams of the plurality of filtered light beams; producing a plurality of image signals, each image signal of the plurality of image signals corresponding to one filtered light beam of the plurality of filtered light beams; and producing a differential signal representative of relative brain activity using the plurality of image signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-10-22 | 2000-04-22 | 2000-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-22 | 2004-04-22 | 2004-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-22 | 2008-04-22 | 2008-10-22 | $7700.00 | Window Closed / Lapsed |