Patent US4920972A successfully refreshed from Google Patents.
US4920972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gel-filled blood pressure transducer
Assignee: Smiths Medical ASD Inc
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Filing: 1988-12-12
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Granted: 1990-05-01
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Expires: 2008-12-12
Abstract
Abstract A reusable pressure transducer for use with a detachable dome. The pressure transducer includes a body having a recess with an opening covered by a flexible diaphragm. The body has a hole opposite the flexible diaphragm and a sensor placed over the hole. A dielectric gel fills the recess to transmit to the sensor variations in pressure imparted to the diaphragm.
Inventors
- 👤 Thomas P. Frank
- 👤 Warren B. Nicholson
- 👤 Mark D. Pfouts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:57
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/0215; G; G01; G01L; G01L19/00; G01L19/06; G01L19/0627; G01L19/0645; G01L19/14; G01L19/142; Y; Y02; Y02B; Y02B10/00; Y02B10/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
109 words
A reusable pressure transducer comprising: a body having a recess terminating in an opening surrounded by a rim, said body having an outer surface; a flexible diaphragm placed over said rim to enclose said recess; said body having a hole spaced from said diaphragm, said hole connecting the outer surface of said body to said recess; a pressure sensor mounted on said outer surface over said hole; and a dielectric gel completely filling said recess and hole and in contact with both said diaphragm and said pressure sensor whereby pressure on said diaphragm will be communicated through said gel to said sensor, said dielectric gel slightly distending said diaphragm.
Claim 2
Dependent Claim
109 words
A reusable pressure transducer comprising: a body having a recess terminating in an opening surrounded by a rim, said body having an outer surface; a flexible diaphragm placed over said rim to enclose said recess; said body having a hole spaced from said diaphragm, said hole connecting the outer surface of said body to said recess; a pressure sensor mounted on said outer surface over said hole; and a dielectric gel completely filling said recess and hole and in contact with both said diaphragm and said pressure sensor whereby pressure on said diaphragm will be communicated through said gel to said sensor, said dielectric gel slightly distending said diaphragm.
Claim 3
Dependent Claim
46 words
A reusable pressure transducer as in claim 1 in which said gel is cured in said recess from two parts that are mixed together: one of said parts is polydimethylsiloxane and a catalyst, and the other of said parts is polydimethylsiloxane with a hydrogen cross linker.
Claim 4
Independent Claim
95 words
The method of making a transducer comprising the steps of: forming a body with a cavity opening at one side and a first bore extending from said cavity to another side of said body; forming a filling bore to said cavity; enclosing said opening with a flexible diaphragm; mounting a sensor assembly over said first bore; filling said cavity with a curable liquid through said filling bore; plugging said filling bore, the quantity of liquid in said cavity distending said diaphragm upon plugging of said filling bore; and curing said liquid to form a gel.
Claim 5
Independent Claim
95 words
The method of making a transducer comprising the steps of: forming a body with a cavity opening at one side and a first bore extending from said cavity to another side of said body; forming a filling bore to said cavity; enclosing said opening with a flexible diaphragm; mounting a sensor assembly over said first bore; filling said cavity with a curable liquid through said filling bore; plugging said filling bore, the quantity of liquid in said cavity distending said diaphragm upon plugging of said filling bore; and curing said liquid to form a gel.
Claim 6
Dependent Claim
31 words
The method as in claim 3 further comprising the steps of: mixing said curable liquid in a vacuum; filling said cavity with said liquid while said cavity is in a vacuum.
Claim 7
Dependent Claim
30 words
The method as in claim 4 in which one part of said gel is polydimethylsiloxane and a platinum catalyst and the other part is polydimethylsiloxane with a hydrogen cross linker.
Claim 8
Dependent Claim
31 words
The method as in claim 3 in which said gel has a Universal Penetrometer penetration of about 3.0 -9.0 mm using a 19.5 gram shaft with a 1/4 inch diameter foot.
References Cited (Backward Citations)
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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) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |