Patent US3555438A successfully refreshed from Google Patents.
US3555438A
Expired / Lapsed
US
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Digital filter and pulse width discriminator
Assignee: United States Department of the Army
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Filing: 1969-08-29
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Granted: 1971-01-12
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Expires: 1989-08-29
Abstract
Abstract DISCLOSED IS A DIGITAL FILTER FOR USE IN THE RATE MONITORING PORTION OF AN ELECTRICAL HEART MONITOR. THE FILTER COMPRISES A PULSE WIDTH DISCRIMINATOR COUPLED TO RECEIVE THE OUTPUTS OF A PAIR OF SCHMITT TRIGGERS AD INCLUDES A FIRST TIMER FOR REJECTING SHORT DURATION PULSES. THE TIMER OUTPUT IS ONLY ACTIVATED WHEN SIGNALS ARE RECEIVED FROM BOTH TRIGGERS. A SECOND AND THIRD TIMER COMBINE TO REJECT SUBSEQUENT LONG DURATION PULSES FOR A PREDETERMINED TIME AFTER AN ORIGINAL PULSE OF INTERMEDIATE DURATION.
Inventors
- 👤 Charles W Ragsdale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:46
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/024; A61B5/0245; A61B5/24; A61B5/316; A61B5/318; A61B5/346; G; G01; G01R; G01R29/00; G01R29/02; G01R29/027; G01R29/0273
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |