US4015595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoplethysmographs
Assignee: Individual
•
Filing: 1975-09-15
•
Granted: 1977-04-05
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Expires: 1995-09-15
Abstract
Abstract A photoplethysmograph probe including a light source, a photo-sensitive cell and a light control film positioned in front of the light source and photo-sensitive cell for collimating the light emitted from the light source and reflected back to the photo-sensitive cell.
Inventors
- 👤 J. Malvern Benjamin, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:25
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/024; A61B5/02416; A61B5/02427
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
120 words
A probe for use with a photoplethysmograph for the measurement of peripheral pulsatile blood flow comprising: a casing having a window therein, a light source and a photo-sensitive cell mounted in said casing to overlie said window, said light source being arranged to direct light through said window, said photo-sensitive cell being arranged adjacent said light source to respond to light passing through said window as it is reflected from a field in line with said light source, and a light control film mounted to extend across said window for collimating the light emitted from said light source to direct the same toward said field and for collimating the light reflected to said photo-sensitive cell and passing through said window.
Claim 2
Dependent Claim
120 words
A probe for use with a photoplethysmograph for the measurement of peripheral pulsatile blood flow comprising: a casing having a window therein, a light source and a photo-sensitive cell mounted in said casing to overlie said window, said light source being arranged to direct light through said window, said photo-sensitive cell being arranged adjacent said light source to respond to light passing through said window as it is reflected from a field in line with said light source, and a light control film mounted to extend across said window for collimating the light emitted from said light source to direct the same toward said field and for collimating the light reflected to said photo-sensitive cell and passing through said window.
Claim 3
Dependent Claim
20 words
A probe according to claim 1 wherein said light control film is made of a clear cellulose acetate butyrate film.
Claim 4
Dependent Claim
14 words
A probe according to claim 2 wherein said light source comprises an incandescent lamp.
Claim 5
Dependent Claim
14 words
A probe according to claim 1 wherein said light source comprises an incandescent lamp.
Claim 6
Dependent Claim
23 words
A probe according to claim 1 wherein said light source is constructed to emit light in a narrow band of green wave lengths.
Claim 7
Dependent Claim
23 words
A probe according to claim 2 wherein said light source is constructed to emit light in a narrow band of green wave lengths.
Claim 8
Dependent Claim
123 words
A probe for use with a photoplethysmograph for the measurement of peripheral pulsatile blood flow by application to the surface of the patient's skin comprising: a casing having a window therein, a light source and a photo-sensitive cell mounted in said casing to overlie said window, said light source being arranged to direct light through said window to a field of blood, said photo-sensitive cell being arranged adjacent said light source to respond to light reflected from a field of blood in line with said light source, and said light source being constructed to emit light in a narrow band of green wave lengths so that substantially all of said light is absorbed by the blood so as to minimize the motion artifact.
Claim 9
Dependent Claim
123 words
A probe for use with a photoplethysmograph for the measurement of peripheral pulsatile blood flow by application to the surface of the patient's skin comprising: a casing having a window therein, a light source and a photo-sensitive cell mounted in said casing to overlie said window, said light source being arranged to direct light through said window to a field of blood, said photo-sensitive cell being arranged adjacent said light source to respond to light reflected from a field of blood in line with said light source, and said light source being constructed to emit light in a narrow band of green wave lengths so that substantially all of said light is absorbed by the blood so as to minimize the motion artifact.
References Cited (Backward Citations)
US3167658A
Cited
US3103214A
Cited
US3359975A
Cited
US3638640A
Cited
US3698382A
Cited
US3787119A
Cited
US3916205A
Cited
US3910701A
Cited
US3923397A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |