Differential stethoscope
First Claim
1. A portable stethoscope for listening to internal sounds of a body comprising:
- first and second sensor means for selective application at two selectively and variably spaced portions of the external surface of said body and for detecting said internal sounds and outputting electrical signals in response to said sounds, said sound signals including a first signal desired for detection and a second undesired signal, said first signal being masked by said second signal;
comparison means for receiving said electrical signals from said first and second sensor means and outputting a comparison signal, said comparison signal being the difference between concurrently received electrical signals from said first and second sensor means;
output means receiving said comparison signal and outputting a sensible signal, said sensible signal corresponding to said difference comparison signal of said detected sound signals.
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Accused Products
Abstract
A portable differential stethoscope includes small microphone elements which are attached to the stethoscope heads to pick up acoustic signals from the body. The sounds picked up by the stethoscope heads include body noise signals as well as heartbeat signals. Each stethoscope head and microphone element provides an output which is amplified in an individual amplifier. The two amplified signals are inputted to separate terminals of a differential amplifier through a gain and balance control element. The differential amplifier outputs a difference signal which is amplified and inputted to an electrical headset or an electrical earphone element which is acoustically coupled to the conventional acoustic tube.
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Citations
16 Claims
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1. A portable stethoscope for listening to internal sounds of a body comprising:
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first and second sensor means for selective application at two selectively and variably spaced portions of the external surface of said body and for detecting said internal sounds and outputting electrical signals in response to said sounds, said sound signals including a first signal desired for detection and a second undesired signal, said first signal being masked by said second signal; comparison means for receiving said electrical signals from said first and second sensor means and outputting a comparison signal, said comparison signal being the difference between concurrently received electrical signals from said first and second sensor means; output means receiving said comparison signal and outputting a sensible signal, said sensible signal corresponding to said difference comparison signal of said detected sound signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of separating heartbeat sounds from a signal dominated by noise, comprising the steps:
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(a) simultaneously sensing combined heartbeat and internal noise signals at a first and a second selectively variable external body location, said heartbeat signals being of different amplitude at said first and second locations; (b) subtracting, one from the other, said combined signals from said first and second body locations; (c) outputting the difference signal produced in step b, said difference signal being dominated by the difference in said heartbeat signals from said first and second body locations. - View Dependent Claims (15, 16)
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Specification