| 摘要 |
<p>The invention concerns an electronic stethoscope comprising a transducer (12) for transforming sound energy of cardiac and pulmonary noises of a body to be examined into an analog signal representing said noises and a signal processing circuit (13), in particular, for amplifying said signal in output, and comprising selective filtering means (25, 26) for selectively separating the signals representing physiological cardiac noises from signals representing physiological and pathological pulmonary noises, the selective filtering means comprising in parallel a low-pass filter (26) whereof the cutoff frequency is predetermined for cutting off the physiological and pathological pulmonary noises and a high-pass filter (25) whereof the cutoff frequency is predetermined for cutting off the physiological cardiac frequencies, said low-pass and high-pass filters having each a cutoff frequency ranging between 145 and 160 Hz, preferably of the order of 150 Hertz.</p> |
