TY - JOUR T1 - Platform for Closed Loop Neuromodulation Based on Dual Mode Biosignals JF - bioRxiv DO - 10.1101/163329 SP - 163329 AU - Khalid B. Mirza AU - Nishanth Kulasekeram AU - Simon Cork AU - Stephen Bloom AU - Konstantin Nikolic AU - Christofer Toumazou Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/07/14/163329.abstract N2 - Closed loop neuromodulation, where the stimulation is controlled autonomously based on physiological events, has been more effective than open loop techniques. In the few existing closed loop implementations which have a feedback, indirect non-neurophysiological biomarkers have been typically used (e.g. heart rate, stomach distension). Although these biomarkers enable automatic initiation of neural stimulation, they do not enable intelligent control of stimulation dosage. In this paper, we present a novel closed loop neuromodulation platform based on a dual signal mode that is detecting electrical and chemical signatures of neural activity. We demonstrated it on a case of vagus nerve stimulation (VNS). Vagal chemical (pH) signal is detected and used for initiatisng VNS and vagal compound action potential (CAP) signals are used to determine the stimulation dosage and pattern. Although we used the paradigm of appetite control and neurometabolic therapies, the platform developed here can be utilised for prototyping closed loop neuromodulation systems before adapting the final System-on-Chip (SoC) design. ER -