Open AccessStethoscope with digital frequency translation for improved audibility
Author(s) -
Aumann Herbert M.,
Emanetoglu Nuri W.
Publication year - 2019
Publication title -
healthcare technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.45
H-Index - 19
ISSN - 2053-3713
DOI - 10.1049/htl.2019.0011
Subject(s) - stethoscope , computer science , frequency shift keying , high fidelity , frequency modulation , speech recognition , acoustics , radio frequency , telecommunications , physics , demodulation , channel (broadcasting)
The performance of an acoustic stethoscope is improved by translating, without loss of fidelity, heart sounds, chest sounds, and intestinal sounds below 50 Hz into a frequency range of 200 Hz, which is easily detectable by the human ear. Such a frequency translation will be of significant benefit to hearing impaired physicians and it will improve the stethoscope performance in a noisy environment. The technique is based on a single sideband suppressed carrier modulation. Stability and bias problems commonly associated with an analog frequency translator are avoided by an all‐digital implementation. Real‐time audio processing is made possible by approximating a Hilbert transformer with a time delay. The performance of the digital frequency translator was verified with a 16‐bit 44.1 Ks/s audio coder/decoder and a 32‐bit 72 MHz microcontroller.