Deep brain drug-delivery control using vagus nerve communications
Vagus nerve, Compound action potential, Neural transmission, Forward error correction
Vagus nerve stimulation (VNS) uses electrical impulses applied at the neck in order to mitigate the effects of, for example, epileptic seizures. We propose using VNS to provide data pulses to communicate with a drug-delivery system embedded near the brainstem. We model the generation of a vagus nerve compound action potential (CAP), calculating the signal attenuation and the resulting transmission range. The metabolic cost of CAP transmission in terms of the use of adenosine triphosphate (ATP) is also calculated. The channel capacity for on-off keying (OOK) is computed from the CAP characteristics, the neural refractory period and the level of background neural noise. The resulting low bit-rate, unidirectional asynchronous transmission system is analysed for the use of different methods of forward error correction (FEC) to improve bit-error rate (BER). We show a proposed data packet structure that could deliver instructions to an embedded drug-delivery system with multiple addressable drug reservoirs. We also analyse the scope for powering the drug-delivery system with energy harvested from cerebrospinal glucose.