US3766413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rate discrimination circuit
Assignee: American Optical Corp
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Filing: 1972-01-03
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Granted: 1973-10-16
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Expires: 1992-01-03
Abstract
Abstract A rate discrimination circuit. A circuit is disclosed which discriminates between pulses occurring at a high rate and pulses occurring at a low rate on a pulse-by-pulse basis. The interval between successive pulses is used to control the extent of charging and discharging of a capacitor which in turn controls a switch. The circuitry can be used to discriminate against noise occurring at a 60 hertz rate. The circuitry is particularly useful in a demand cardiacpacer where the EKG signals contain near 60 hertz harmonics but occur at about a 1 hertz rate. Thus, the circuitry of the present invention is described in connection with its use in an atrial and ventricular demand pacer.
Inventors
- 👤 B Berkovits
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:34
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61N1/368
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
323 words
A rate discrimination circuit capable of use with a demand heart pacemaker consisting of means responsive to both positive and negative signals for detecting the occurrence of an event, a capacitor, charging resistance means connected in series with said capacitor, means for applying a current pulse to said charging resistance means for charging said capacitor responsive to each operation of said detecting means, discharging resistance means connected to said capacitor for discharging said capacitor between applications of said current pulses, output means capacitively coupled to said capacitor and operative in response to each rise in potential across said capacitor greater than a predetermined value, said charging and discharging resistance means including a common resistance path, a diode connected across said common resistance path poled in the direction of flow of discharge current from said capacitor conducting during the operation of said discharging means for decreasing the impedance of said common resistance path when said capacitor is charged to a voltage greater than the forward voltage drop of said diode and when said capacitor is discharging, first means for establishing the width of each applied current pulse equal to the duration of the detected event, second means for establishing the impedance of said common resistance path large enough to prevent a rise in potential across said capacitor equal to said predetermined value if an applied current pulse has a width shorter than the duration of a predetermined event, and wherein said discharging resistance means has a magnitude, when the impedance of said common resistance path is reduced, sufficiently small to permit the discharge of said capacitor to a level low enough such that the next applied current pulse causes the voltage rise across said capacitor to equal said predetermined value if said next current pulse occurs at a time after the preceding current pulse which exceeds a predetermined time interval, said predetermined time interval being the reciprocal of the rate to be discriminated against.
Claim 2
Dependent Claim
323 words
A rate discrimination circuit capable of use with a demand heart pacemaker consisting of means responsive to both positive and negative signals for detecting the occurrence of an event, a capacitor, charging resistance means connected in series with said capacitor, means for applying a current pulse to said charging resistance means for charging said capacitor responsive to each operation of said detecting means, discharging resistance means connected to said capacitor for discharging said capacitor between applications of said current pulses, output means capacitively coupled to said capacitor and operative in response to each rise in potential across said capacitor greater than a predetermined value, said charging and discharging resistance means including a common resistance path, a diode connected across said common resistance path poled in the direction of flow of discharge current from said capacitor conducting during the operation of said discharging means for decreasing the impedance of said common resistance path when said capacitor is charged to a voltage greater than the forward voltage drop of said diode and when said capacitor is discharging, first means for establishing the width of each applied current pulse equal to the duration of the detected event, second means for establishing the impedance of said common resistance path large enough to prevent a rise in potential across said capacitor equal to said predetermined value if an applied current pulse has a width shorter than the duration of a predetermined event, and wherein said discharging resistance means has a magnitude, when the impedance of said common resistance path is reduced, sufficiently small to permit the discharge of said capacitor to a level low enough such that the next applied current pulse causes the voltage rise across said capacitor to equal said predetermined value if said next current pulse occurs at a time after the preceding current pulse which exceeds a predetermined time interval, said predetermined time interval being the reciprocal of the rate to be discriminated against.
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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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |