Gordon E S, Lagerwerff J M
Aviat Space Environ Med. 1976 Mar;47(3):312-6.
A small electronic stethoscope with variable frequency response characteristics has been developed for aerospace and research applications. The system includes a specially designed piezoelectric pickup and amplifier with an overall frequency response from 0.7 to 5,000 HZ (-3 dB points) and selective bass and treble boost or cut of up to 15 dB. A steep slope, high pass filter can be switched in for ordinary clinical auscultation without overload distortion from strong infrasonic signal inputs. A commercial stethoscope-type headset, selected for best overall response, is used which can adequately handle up to 100 mW of audio power delivered from the amplifier. The active components of the amplifier consist of only four opamp-type integrated circuits.
一种具有可变频率响应特性的小型电子听诊器已被开发用于航空航天和研究应用。该系统包括一个专门设计的压电传感器和放大器，其整体频率响应范围为0.7至5000赫兹（-3分贝点），并且选择性的低音和高音提升或衰减可达15分贝。在普通临床听诊时，可接入一个陡峭斜率的高通滤波器，以防止强次声信号输入产生过载失真。使用了一款经过挑选以获得最佳整体响应的商用听诊器式头戴耳机，它能够充分处理放大器输出的高达100毫瓦的音频功率。该放大器的有源元件仅由四个运算放大器型集成电路组成。
