Implantable neural interfaces have evolved in the
past decades from stimulation-only devices to closed-loop record-
ing and stimulation systems, allowing both for more targeted
therapeutic techniques and more advanced prosthetic implants.
Emerging applications require multi-module active implantable
devices with intrabody power and data transmission. This
distributed approach poses a new set of challenges related
to inter-module connectivity, functional reliability and patient
safety. This paper addresses the ground referencing challenge in
active multi-implant systems, with a particular focus on neural
recording devices. Three different grounding schemes (passive,
drive, and sense) are presented and evaluated in terms of both
recording reliability and patient safety. Considerations on the
practical implementation of body potential referencing circuitry
are finally discussed, with a detailed analysis of their impact on
the recording performance.