Hardware-in-the-Loop Testing for closed-loop Brain Stimulators

Thorough testing procedures are generally a key step towards validation and successful certification of medical equipment. This has to be kept in mind even for academic prototype development. We present here a novel testing environment for a new embedded deep brain recording and signal analysis system, using real-time hardware communication in a strictly defined environment. Starting with an analysis of external requirements for our new closed-loop deep brain stimulator system, we construct test requirements that must be fulfilled by a standalone testing system. This hardware-in-the-loop (HIL) test system is based on a high-performance single-board DSP computer (SBC) to generate multiple analog signals resembling intracranial multi-electrode microrecordings. The stimulator system under scrutiny is required to analyse the presented signals and to reliably produce a trigger output to its connected stimulator. The trigger output and monitoring signals are recorded by the SBC and thus correlated to the desired stimulator output.