Electronic stethoscope system and method
First Claim
1. A method for enhancing acoustic vibrations having frequency components that are not within the auditory range or the human ear comprising:
- detecting an input acoustic vibrational waveform within a first frequency range having frequency components that are not within the auditory range of the human ear, said frequency components having an intercomponent tonal relationship;
converting said detected input acoustic vibrational waveform into an input electrical signal;
performing a Fourier transform operation upon said input electrical signal, whereby an input frequency spectrum signal is obtained comprising frequency components, each frequency component comprising frequency, phase and amplitude elements, the frequencies of the frequency components comprising the a first inter-component frequency relationship and the phases of the frequency components comprising a first inter-component phase relationship;
translating said input frequency spectrum signal in the time scale from said first frequency range to a second frequency range by multiplying said frequencies of the input frequency spectrum signal by a time scale compression factor, said frequency components of the translated frequency spectrum signal having a second inter-component frequency relationship and second inter-component phase relationship equivalent to the first inter-component frequency relationship and first inter-component phase relationship;
performing an inverse Fourier transform operation on said translated frequency spectrum signal whereby an output electrical signal is obtained; and
converting said output electrical signal into an output vibrational waveform having frequency components that are within the auditory range or the human ear and in which the inter-component tonal relationship is maintained.
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Accused Products
Abstract
A microprocessor based sound enhancement system in which frequencies outside of the auditory range of the human ear are translated into sound within the auditory range by translating each frequency component of the entire frequency spectrum of the input signal by a time scale compression factor. Preferably, a microprocessor transforms an electrical signal corresponding to the input signal into a frequency spectrum signal comprising frequency components having frequency, phase, and amplitude elements by performing a fast Fourier transform (FFT) operation on the input signal. The frequency components of this transformed signal are translated and the resulting translated frequency spectrum signal is transformed into a time varying output signal by performing an inverse FFT operation on the translated frequency spectrum signal. When heart pulses or similar periodic waveforms are monitored, the pulse rate of the signal is maintained in the output signal. Alternatively, the time varying signal is compressed in the time scale and then transformed into audible sound, while maintaining the original pulse rate in the output signal, thereby resulting in the same output signal as that resulting from translating the entire frequency spectrum by the time scale compression factor.
114 Citations
18 Claims
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1. A method for enhancing acoustic vibrations having frequency components that are not within the auditory range or the human ear comprising:
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detecting an input acoustic vibrational waveform within a first frequency range having frequency components that are not within the auditory range of the human ear, said frequency components having an intercomponent tonal relationship; converting said detected input acoustic vibrational waveform into an input electrical signal; performing a Fourier transform operation upon said input electrical signal, whereby an input frequency spectrum signal is obtained comprising frequency components, each frequency component comprising frequency, phase and amplitude elements, the frequencies of the frequency components comprising the a first inter-component frequency relationship and the phases of the frequency components comprising a first inter-component phase relationship; translating said input frequency spectrum signal in the time scale from said first frequency range to a second frequency range by multiplying said frequencies of the input frequency spectrum signal by a time scale compression factor, said frequency components of the translated frequency spectrum signal having a second inter-component frequency relationship and second inter-component phase relationship equivalent to the first inter-component frequency relationship and first inter-component phase relationship; performing an inverse Fourier transform operation on said translated frequency spectrum signal whereby an output electrical signal is obtained; and converting said output electrical signal into an output vibrational waveform having frequency components that are within the auditory range or the human ear and in which the inter-component tonal relationship is maintained. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for enhancing acoustic vibrations having frequencies that are not within the auditory range of the human ear comprising:
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means for detecting an input acoustic vibrational waveform within a first frequency range having frequencies that are not within the auditory range of the human ear, said frequencies having an inter-component tonal relationship; means for converting said detected input acoustic vibrational waveform to an input electrical signal; means for performing a Fourier transform operation upon said input electrical signal whereby an input frequency spectrum is obtained having a plurality of frequency components, each frequency component having frequency, phase and amplitude elements, the frequencies of the frequency components comprising a first inter-component frequency relationship and the phases of the frequency components comprising a first inter-component phase relationship; means for translating said frequency components of the input frequency spectrum to a frequency range within the auditory range of the human ear by multiplying said frequencies by a time scale compression factor, said frequency components of the translated frequency spectrum having a second inter-component frequency relationship and second inter-component phase relationship equivalent to said first intercomponent frequency relationship and first inter-component phase relationship; means for performing an inverse Fourier transform operation upon the translated frequency spectrum whereby an output electrical signal is obtained; and means for converting said output electrical signal into an output acoustic vibrational waveform, said output acoustic vibrational waveform having frequencies that are within the auditory range of the human ear and in which the inter-component total relationship is maintained. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification