Computationally efficient, configurable, causal, real-time phase detection applied to local field potential oscillations

Neurological implantable devices with electrophysiological sensing capabilities may enable new medical therapies and diagnostics. Of specific interest is phase-dependent delivery of therapy-such as electrical stimulation-as a potential method to enhance therapy effectiveness in improving diseased or damaged physiological processes with respect to rhythmic biomarkers, while minimizing the average energy required to deliver the therapy. To address this need for phase-detection, within the constraints of device power limits, we have developed a computationally efficient, causal, real-time Fourier transform (RTFT) for use as a phase detection method that is both general and highly configurable. The application of this method to theta-band local field potentials recorded from the brains of sheep is demonstrated.