The basics structures of this project are shown bellow,

The first part of my work will be in the current source block. That block is important because it will inject the current in the patient to create the voltage that will be later measured by the rest of the circuit.

For the current source i have selected a topology called " Howland Current Pump". Its basically a OPAMP and a bunch of resistors/capacitors. I will be designing and testing this part of the circuit and as soon as i have some results, i will be posting them online.