1979 年 8 巻 1 号 p. 128-131
We have practiced transtelephone PCG monitoring for the management of the patients who have undergone the operation of the prosthetic heart valve. For this system we developed PCG amplifier which has two low cut filters, filter M and filter SH. Each of low cut frequency as following; filter M is 160Hz and filter SH is 2kHz. By using this filter SH, only metallic sound of the prosthetic valve was recorded. While we used this amplifier at O. P. D. to judge the function of prosthetic valve, we could find the malfunction of SAM valve in an early stage. We decided, this system is available for the diagnosis of the malfunction of the prosthetic valve.