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US3555438A Expired / Lapsed US ⏱️ 0.0 years remaining

Digital filter and pulse width discriminator

Assignee: United States Department of the Army
•
Filing: 1969-08-29
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Granted: 1971-01-12
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Expires: 1989-08-29
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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 2026-10-25 05:58
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)

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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) 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

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