Low pass filter for electroencephalograph appts. - has attenuation above 60 dB for frequencies above 50 Hz.

摘要

The low-pass filter is inserted in at least one selection path of an electroencephalograph appts. It has an attenuation of below 1 decibel for signals having a frequency up to 40 Hertz and an attenuation above 60 decibel for signals having a frequency above 50 Hertz. It may be a Tchebyscheff filter circuit of the 7th order or three low-pass filters of the 2nd order may be coupled in cascade with an RC network. Pref, a low-pass filter is inserted in each selection path for the electroencephalograph appts., each filter having a given transfer function.