Patent US2914854A successfully refreshed from Google Patents.
US3677092A
Expired / Lapsed
US
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Volume metering apparatus for circulatory assist pumps
Assignee: United States Department of Health and Human Services
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Filing: 1970-06-17
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Granted: 1972-07-18
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Expires: 1990-06-17
Abstract
Abstract An electronic transient pulse operated volume metering circuit is disclosed which produces a visually readable volume indication derived from signals representative of the stroke of a blood pump in a circulatory assist system. Provisions are made for correcting the volume indication as a function of instantaneous pressure samples such as encountered in the patients circulatory system, and for visually presenting the relationship between the volume and pressure.
Inventors
- 👤 Henry R Guarino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:05
CPC Classifications
G; G01; G01F; G01F15/00; G01F15/02; G01F15/022
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
164 words
Volume indicating apparatus for visually displaying from periodically recurring pulse signals of varying peak level indicative of volume such as provided from the stroke of a blood pump operating in a circulatory assist system comprising in combination, an operational amplifier providing an amplitude gain, means clamping said pulse signals, first resistor means applying the clamped pulse signals to one input terminal of said operational amplifier, rectification means coupled to the output terminal of said operational amplifier, a capacitor receiving the amplified pulse signals from said amplifier through said rectification means to store a peak value thereof, feedback resistor means of the same value as said first resistor means coupling said amplified signals from said capacitor back to said one input terminal of the operational amplifier, metering means indicating the peak level at said capacitor to produce a volume reading, and time constant resistive means coupled to said capacitor to retain said peak value reasonably constant over the repetition frequency of said recurring pulse signals.
Claim 2
Dependent Claim
164 words
Volume indicating apparatus for visually displaying from periodically recurring pulse signals of varying peak level indicative of volume such as provided from the stroke of a blood pump operating in a circulatory assist system comprising in combination, an operational amplifier providing an amplitude gain, means clamping said pulse signals, first resistor means applying the clamped pulse signals to one input terminal of said operational amplifier, rectification means coupled to the output terminal of said operational amplifier, a capacitor receiving the amplified pulse signals from said amplifier through said rectification means to store a peak value thereof, feedback resistor means of the same value as said first resistor means coupling said amplified signals from said capacitor back to said one input terminal of the operational amplifier, metering means indicating the peak level at said capacitor to produce a volume reading, and time constant resistive means coupled to said capacitor to retain said peak value reasonably constant over the repetition frequency of said recurring pulse signals.
Claim 3
Dependent Claim
33 words
Apparatus as defined in claim 1 including means responsive to periodic pressure pulses producing a corrective d-c signal, and means coupling the corrective d-c signal to adjust the indication on said metering means.
Claim 4
Dependent Claim
72 words
Apparatus as defined in claim 2 wherein the means responsive to periodic pressure pulses comprises an operational amplifier and means providing a pressure pulse waveform to one input terminal and a reference pulse waveform of lesser duration and greater amplitude than the pressure pulse waveform and of opposite phase to thereby produce at the output of the operational amplifier a corrective signal representative of a predetermined portion of the pressure pulse waveform.
Claim 5
Dependent Claim
43 words
Apparatus as defined in claim 1 including oscilloscope means having the stroke pulse signals coupled to one deflection axis, and means presenting periodically occurring pressure pulses to another deflection axis to thereby generate a visual trace showing the relationship between stroke and pressure.
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) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |