US3811429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arterial pulse wave pressure transducer
Assignee: National Aeronautics and Space Administration
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Filing: 1972-09-25
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Granted: 1974-05-21
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Expires: 1992-09-25
Abstract
Abstract A novel arterial pulse wave pressure transducer is disclosed, the transducer comprising a fluid-filled cavity having a flexible membrane member disposed over the cavity and adapted to be placed on the skin over an artery. An arterial pulse wave creates pressure pulses in the fluid which are transduced by a pressuresensitive transistor disposed in direct contact with the fluid into an electric signal. The electrical signal is representative of the pulse waves and can be recorded so as to monitor changes in the elasticity of the arterial walls, and the like.
Inventors
- 👤 J Fletcher
- 👤 Chen Wayne
- 👤 Kim Chung
- 👤 D Gorelick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:31
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0098; A; A61; A61B; A61B5/00; A61B5/02; A61B5/021
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
179 words
An arterial pulse wave pressure transducer comprising, in combination, a housing having a fluid-filled cavity therein; a flexible membrane disposed over said cavity for closing same, said membrane being adapted to be placed in contact with the skin of a patient at a location over an artery, said membrane defining means for converting displacements effected by naturally occurring arterial pressure pulsations into corresponding pressure pulses in the fluid within said cavity; semiconductor pressure-sensing means disposed through a wall of said cavity in direct communication with the fluid therein for effectinG changes of the electrical characteristics thereof in response to pressure pulses applied thereto; said semiconductor pressure-sensing means comprising a transistor having a pressure-sensitive casing mechanically coupled to a pn junction therein so as to vary the current gain, said casing being disposed through said cavity wall into contact with the fluid therein; and electrical conductors coupled to said semiconductor pressure-sensing means and leading outside said housing to define a means for monitoring changes in said electrical characteristics as representative of arterial pulsations and displacements applied to said flexible membrane.
Claim 2
Dependent Claim
179 words
An arterial pulse wave pressure transducer comprising, in combination, a housing having a fluid-filled cavity therein; a flexible membrane disposed over said cavity for closing same, said membrane being adapted to be placed in contact with the skin of a patient at a location over an artery, said membrane defining means for converting displacements effected by naturally occurring arterial pressure pulsations into corresponding pressure pulses in the fluid within said cavity; semiconductor pressure-sensing means disposed through a wall of said cavity in direct communication with the fluid therein for effectinG changes of the electrical characteristics thereof in response to pressure pulses applied thereto; said semiconductor pressure-sensing means comprising a transistor having a pressure-sensitive casing mechanically coupled to a pn junction therein so as to vary the current gain, said casing being disposed through said cavity wall into contact with the fluid therein; and electrical conductors coupled to said semiconductor pressure-sensing means and leading outside said housing to define a means for monitoring changes in said electrical characteristics as representative of arterial pulsations and displacements applied to said flexible membrane.
Claim 3
Dependent Claim
38 words
An arterial pulse wave pressure transducer as defined in claim 1, wherein said cavity is disposed in one end of said housing, said flexible membrane being placed over said one end of said housing to seal said cavity.
Claim 4
Dependent Claim
34 words
An arterial pulse wave pressure transducer as defined in claim 2, wherein said membrane is removably maintained in place about said one housing end by an O-ring, whereby replacement of said membrane is facilitated.
Claim 5
Dependent Claim
78 words
An arterial pulse wave pressure transducer as defined in claim 2, wherein said cavity is defined by an axial bore in said one end of said housing, said housing incorporating a further axial bore in the other end thereof of a predetermined depth whereby a wall of predetermined thickness is formed between both said axial bores, said transistor being disposed in said further axial bore with the casing thereof extending through said wall into contact with said cavity.
Claim 6
Dependent Claim
36 words
An arterial pulse wave pressure transducer as defined in claim 4, further including a channel through said housing communicating with said cavity, said channel defining a filling port, and means to selectively close said filling port.
Claim 7
Dependent Claim
60 words
An arterial pulse wave pressure transducer as defined in claim 5, further including an elongated end section member attached to said other end of said housing, said elongated end section member having an axial bore therein adapted to receive a holder, and channel means therethrough communicating with said further axial bore of said housing and defining an atmospheric pressure vent.
Claim 8
Dependent Claim
24 words
An arterial pulse wave pressure transducer as defined in claim 6, wherein said housing and said elongated end section member are constructed of plastic.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |