US3842844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromedical pulse generator with continuous pulse width adjustment circuitry
Assignee: Medtronic Inc
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Filing: 1972-06-30
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Granted: 1974-10-22
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Expires: 1992-06-30
Abstract
Abstract A pulse generator for providing timed pulses, such as in a cardiac pacemaker, having a timing circuit comprising a capacitor which determines pulse width, and having a reference voltage node and a substantially constant voltage feedback node, apparatus for substantially increasing pulse width in response to decreases in the reference voltage comprising a first resistance connecting the capacitor to the reference node and a second resistance connecting the capacitor to the feedback node. This voltage divider provided in the RC circuit will increase the time constant of the circuit to a new fixed value and make it respond to each decrease in reference voltage in a manner to keep the energy of the pulses from the pulse generator above a predetermined energy level over a wide range of voltage decreases.
Inventors
- 👤 C Alferness
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:52
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
In electrical medical apparatus including pulse generator means adapted to provide stimulation pulses to means adapted to be connected to a body, and including power supply means for providing voltage to the pulse generator means, the improvement comprising: pulse width timing circuit means connected to the pulse generator means; the pulse width timing circuit means including fixed time constant means; and means connected to the timing circuit means for substantially increasing the pulse width of the stimulation pulses in response to decreases in voltage from the power supply means, to maintain the total energy of the stimulation pulses above a predetermined level over a range of decreasing voltage levels.
Claim 2
Dependent Claim
109 words
In electrical medical apparatus including pulse generator means adapted to provide stimulation pulses to means adapted to be connected to a body, and including power supply means for providing voltage to the pulse generator means, the improvement comprising: pulse width timing circuit means connected to the pulse generator means; the pulse width timing circuit means including fixed time constant means; and means connected to the timing circuit means for substantially increasing the pulse width of the stimulation pulses in response to decreases in voltage from the power supply means, to maintain the total energy of the stimulation pulses above a predetermined level over a range of decreasing voltage levels.
Claim 3
Dependent Claim
105 words
The apparatus of claim 1 in which the means for substantially increasing the pulse width includes: a reference voltage node means in the pulse generator and means connecting the reference voltage node means to the power supply means; a feedback voltage node means in the pulse generator and means connected to the feedback voltage node means for maintaining it at a substantially constant level; and the fixed time constant means including capacitance means having first and second plates, first impedance measn connecting the first plate to the reference voltage node means and second impedance means connecting the second plate to the feedback voltage node means.
Claim 4
Dependent Claim
15 words
The apparatus of claim 2 in which the first and second impedance means comprise resistors.
Claim 5
Dependent Claim
118 words
In electrical medical apparatus with pulse generator means for providing output pulses, the generator means comprising an RC timing circuit means for determining output pulse width, the generator means having a power supply and including means for producing a voltage reference junction and a substantially constant voltage feedback junction, the improvement for substantially increasing output pulse wideth in response to decreasing power supply voltage in which the timing circuit means comprises: a capacitor, first and second resistor means; means connecting the first resistor means between the capacitor and the reference junction; means connecting the second resistor means between the capacitor and the feedback junction; and the capacitor and the first resistor means comprising a fixed time constant means.
Claim 6
Dependent Claim
118 words
In electrical medical apparatus with pulse generator means for providing output pulses, the generator means comprising an RC timing circuit means for determining output pulse width, the generator means having a power supply and including means for producing a voltage reference junction and a substantially constant voltage feedback junction, the improvement for substantially increasing output pulse wideth in response to decreasing power supply voltage in which the timing circuit means comprises: a capacitor, first and second resistor means; means connecting the first resistor means between the capacitor and the reference junction; means connecting the second resistor means between the capacitor and the feedback junction; and the capacitor and the first resistor means comprising a fixed time constant means.
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) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |