i am building a project that deals with the extraction of EOG signals (which are biological signals caused due to eye movements)....
These are extremely small signals with an amplitude range between 0.3mV to 1mV and frequency range of 0 to 25 hz....
so i took these signals (with electrodes), fed them to an instrumentation amplifier (AD620 set to a gain of 1000) and subsequenctly filtered the resulting signal using 4th order active low pass filters.... but still couldnt get appraciable outputs....
i used OP177 type op-amps for building the filters.... wat could be the problem??? can anyone pls help me..... wat type of op-amps can give good results???
thanks in advance...
These are extremely small signals with an amplitude range between 0.3mV to 1mV and frequency range of 0 to 25 hz....
so i took these signals (with electrodes), fed them to an instrumentation amplifier (AD620 set to a gain of 1000) and subsequenctly filtered the resulting signal using 4th order active low pass filters.... but still couldnt get appraciable outputs....
i used OP177 type op-amps for building the filters.... wat could be the problem??? can anyone pls help me..... wat type of op-amps can give good results???
thanks in advance...