Patent US3881481A successfully refreshed from Google Patents.
US3881481A
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US
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Left ventricular ejection meter
Assignee: AUDRONICS Inc
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Filing: 1973-02-08
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Granted: 1975-05-06
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Expires: 1993-02-08
Abstract
Abstract A meter for measuring the heart left ventricular ejection characteristic. The meter includes a circuit for emphasizing the left ventricular ejection phase preferentially to the other heart beat phases. According to a preferred embodiment, a circuit is provided which emphasizes signals of a blood volume waveform sensed by a pulsed light, source, photoelectric probe in a range of about 3.75 to 6.75 hertz.
Inventors
- 👤 James E Heule
- 👤 Richard C Gaard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:22
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/024; A61B5/02416
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
An apparatus for measuring and indicating the left ventricular output of the heart by monitoring light reflective characteristics of blood flow in blood vessels and capillaries, comprising: a. a pulsating light source placed in proximity to said blood vessels and capillaries; b. a light responsive element placed in reflective relationship to said light source and said blood vessels and capillaries, and having means for converting received light into electrical signals; c. circuit means, connected to said light responsive element, for receiving said electrical signals and attenuating frequency components of said signals below about 0.6 Hz. and above about 40 Hz.; and d. indicator means, connected to said circuit means, for providing an observable indication of said nonattenuated electrical signals.
Claim 2
Independent Claim
119 words
An apparatus for measuring and indicating the left ventricular output of the heart by monitoring light reflective characteristics of blood flow in blood vessels and capillaries, comprising: a. a pulsating light source placed in proximity to said blood vessels and capillaries; b. a light responsive element placed in reflective relationship to said light source and said blood vessels and capillaries, and having means for converting received light into electrical signals; c. circuit means, connected to said light responsive element, for receiving said electrical signals and attenuating frequency components of said signals below about 0.6 Hz. and above about 40 Hz.; and d. indicator means, connected to said circuit means, for providing an observable indication of said nonattenuated electrical signals.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 wherein said circuit means further comprises a band pass circuit portion for emphasizing signal frequencies in the range of 3.75 Hz. to 6.75 Hz.
Claim 4
Dependent Claim
35 words
The apparatus of claim 2 wherein said band pass circuit further comprises a first capacitor in series connection with said light responsive element and a second capacitor in shunt connection with said light responsive element.
Claim 5
Dependent Claim
29 words
The apparatus of claim 2 wherein said band pass circuit portion further comprises means for attenuating signals outside the frequency range about 0.6-40 Hz. by at least 3 decibels.
Claim 6
Dependent Claim
14 words
The apparatus of claim 1 wherein said indicator means further comprises a current mEter.
Claim 7
Dependent Claim
29 words
The apparatus of claim 1 wherein said pulsating light source is pulsated at a frequency of about 1000 Hz. and having a light pulse duration of about 100 micro-seconds.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |