US3650264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for electro-medical investigation
Assignee: US Philips Corp
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Filing: 1969-12-02
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Granted: 1972-03-21
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Expires: 1989-12-02
Abstract
Abstract A medical diagnostic apparatus for producing an audible indication of the nature of electric signals produced in the human body by the action of the heart. An audio frequency carrier wave is modulated both in frequency and in amplitude in accordance with the aforesaid applied electric signals. The level of the fundamental tone normally remains below the limit of audibility. This limit is exceeded only when an electric heartbeat signal occurs.
Inventors
- 👤 Frits Jacques Janssen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:20
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/318; A61B5/332; A61B5/74; A61B5/7405; A61B5/7415; A61B7/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 words
An apparatus for providing an audible indication of the strength of electric signals produced in the human body by heart activity comprising, means for generating an audiofrequency carrier wave, means for modulating the frequency thereof in accordance with the strength of the electric signals, and means for amplitude modulating the frequency-modulated carrier wave so as to vary the tone strength of the carrier wave in accordance with the strength of the electric signals applied to the apparatus.
Claim 2
Independent Claim
77 words
An apparatus for providing an audible indication of the strength of electric signals produced in the human body by heart activity comprising, means for generating an audiofrequency carrier wave, means for modulating the frequency thereof in accordance with the strength of the electric signals, and means for amplitude modulating the frequency-modulated carrier wave so as to vary the tone strength of the carrier wave in accordance with the strength of the electric signals applied to the apparatus.
Claim 3
Independent Claim
132 words
A device for the audible observation of heart activity comprising, at least two electrodes adapted to derive electric signals from the body produced by the action of the heart, means for generating an audio frequency carrier wave, amplifier means having an input coupled to said electrodes, means for coupling the output of said amplifier means to an input of said audio frequency generating means whereby the carrier wave is frequency modulated in accordance with said electric signals, means coupled to the output of said amplifier means and to the output of said audio frequency generating means for amplitude modulating the frequency modulated carrier wave in accordance with said electric signals derived from the human body, and means responsive to the amplitude and frequency modulated carrier wave for producing an audible indication thereof.
Claim 4
Independent Claim
132 words
A device for the audible observation of heart activity comprising, at least two electrodes adapted to derive electric signals from the body produced by the action of the heart, means for generating an audio frequency carrier wave, amplifier means having an input coupled to said electrodes, means for coupling the output of said amplifier means to an input of said audio frequency generating means whereby the carrier wave is frequency modulated in accordance with said electric signals, means coupled to the output of said amplifier means and to the output of said audio frequency generating means for amplitude modulating the frequency modulated carrier wave in accordance with said electric signals derived from the human body, and means responsive to the amplitude and frequency modulated carrier wave for producing an audible indication thereof.
Claim 5
Dependent Claim
27 words
A device as claimed in claim 2 further comprising rectifier means connected between the output of said amplifier means and an input of said amplitude modulating means.
Claim 6
Dependent Claim
27 words
A device as claimed in claim 2 further comprising means for suppressing the audio frequency carrier wave whenever the electric signals are below a given threshold level.
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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |