Luisada A A, Feigen L P, Bhat P K, Perez G L, Aravanis C
G Ital Cardiol. 1977;7(1):33-40.
A technical set up for recording high frequency components of the cardiac vibrations is described. This was based on the use of several amplifiers, taking the third derivative of the displacement tracing, and using a high pass filter with a sharp slope. The tape-recorded high frequency tracing, at 500 Hz, 1000 Hz, or higher, was replayed at slower speed for accurate recording of the high speed signals. A study of the first and second hearts sound at 500 Hz and 1000 Hz was made in 14 young, normal volunteers. The high frequency vibrations of these sounds are analyzed and discussed.
本文描述了一种用于记录心脏振动高频成分的技术装置。该装置基于使用多个放大器，对位移记录进行三阶导数运算，并使用具有陡峭斜率的高通滤波器。以500赫兹、1000赫兹或更高频率磁带记录的高频记录，以较慢速度重放，以便准确记录高速信号。对14名年轻健康志愿者在500赫兹和1000赫兹频率下的第一心音和第二心音进行了研究。对这些声音的高频振动进行了分析和讨论。
