Analog signal conditioning circuit

[shaikss]

Hi,

For any biomedical applications, the sensor output has to be amplified and digitized.
For amplification, we use Instrumentation amplifier. But the output of IA has some dc voltage. So, how to suppress the dc voltage. At the same time, all biomedical signals are low frequency signals in the order of 0 to 20Hz. Which filter technique is better to use?
Is it good to go for Low pass/High pass/Band pass filter? Can you pls throw some light on this?

 

[Jim_A]

Personally I would remove the dc offset digitally after a/d conversion. Depending on how the data looks you could have a digital high-pass or you could have a calibration procedure where you record the offset.

 

[skeptic2]

You have specified an impossible condition. If your signal has the range of 0 to 20 Hz then you can't remove the DC without removing some of the signal. You must first define a lower frequency limit and an attenuation rate before you can talk about removing the DC.