US3918459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant current electrotherapy device with plug-in current control means
Assignee: MDT Corp
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Filing: 1974-01-16
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Granted: 1975-11-11
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Expires: 1994-01-16
Abstract
Abstract A low intensity direct current device for treating skin ulcers and the like by electrotherapy, the device having a simple tamper-proof arrangement to prevent the patient or other uninformed persons from changing the intensity of the prescribed current, and an alarm to indicate an improper patient connection, or defective battery.
Inventors
- 👤 Anton James Horn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:28
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/20; A61N1/02; A61N1/08; A61N2001/083
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
166 words
A low intensity direct current device for electrotherapy Uses comprising: a. an electrical circuit means for producing a constant direct current of a predetermined value within a range of currents which promotes healing when passed through tissue containing a skin lesion, said circuit means having a pair of output terminals; b. a cable for conducting the direct current produced by said circuit means to a patient, said cable having a socket at one end for connection to said terminals and a pair of electrodes at its other end for attachment to a patient; c. a battery connected to said circuit means for powering said circuit means; d. said circuit means having a sensor portion and electrically connected to at least one of said terminals and said battery, for comparing the voltage across said terminals to said battery voltage; and e. said circuit means having an alarm actuated by said sensor portion when the voltage across said terminals is within about one volt of said battery voltage.
Claim 2
Dependent Claim
166 words
A low intensity direct current device for electrotherapy Uses comprising: a. an electrical circuit means for producing a constant direct current of a predetermined value within a range of currents which promotes healing when passed through tissue containing a skin lesion, said circuit means having a pair of output terminals; b. a cable for conducting the direct current produced by said circuit means to a patient, said cable having a socket at one end for connection to said terminals and a pair of electrodes at its other end for attachment to a patient; c. a battery connected to said circuit means for powering said circuit means; d. said circuit means having a sensor portion and electrically connected to at least one of said terminals and said battery, for comparing the voltage across said terminals to said battery voltage; and e. said circuit means having an alarm actuated by said sensor portion when the voltage across said terminals is within about one volt of said battery voltage.
Claim 3
Dependent Claim
85 words
A device as set forth in claim 1 wherein said sensor portion includes a transistor having its emitter electrically connected to said battery, its base electrically connected to one of said terminals, and its collector electrically connected to said alarm, said alarm being electrically connected to said battery the flow of collector current of said transistor being initiated when the voltage on the base thereof is within one volt of the emitter voltage, the flow of collector current resulting in the sounding of said alarm.
Claim 4
Dependent Claim
110 words
A device as set forth in claim 1 in which said circuit means includes: a. a first transistor means functioning as a constant direct current source and connected to a first terminal of said two terminals and said battery for delivering a constant direct current through said first terminal and said cable to said patient, said direct current returning through said cable and the second terminal; b. a second transistor means functioning as a bias for said first transistor means; and c. a resistor electrically connected to said second tranistor means for determining the bias level of said first transistor means and thereby the level of said constant direct current.
Claim 5
Dependent Claim
17 words
A device as set forth in claim 3 wherein said resistor is incorporated into said cable socket.
References Cited (Backward Citations)
US3107672A
Cited
US3180338A
Cited
US3612041A
Cited
US3769986A
Cited
US3720199A
Cited
US3756245A
Cited
US3807411A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |