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@article{Luan:2014:10.1016/j.jneumeth.2013.11.028,
author = {Luan, S and Constandinou, TG},
doi = {10.1016/j.jneumeth.2013.11.028},
journal = {Journal of Neuroscience Methods},
pages = {39--47},
title = {A Charge-Metering Method for Voltage-Mode Neural Stimulation},
url = {http://dx.doi.org/10.1016/j.jneumeth.2013.11.028},
volume = {224},
year = {2014}
}
TY - JOUR
AB - Electrical Neural Stimulation is the technique used to modulate neural activity by inducing an instantaneous charge imbalance. This is typically achieved by injecting a constant current and controlling the stimulation time. However, constant voltage stimulation is found to be more energy-efficient although it is challenging to control the amount of charge delivered. This paper presents a novel, fully-integrated circuit for facilitating charge-metering in constant voltage stimulation. It utilises two complementary stimulation paths. Each path includes a small capacitor, a comparator and a counter. They form a mixed-signal integrator that integrates the stimulation current onto the capacitor whilst monitoring its voltage against a threshold using the comparator. The pulses from the comparator are used to increment the counter and reset the capacitor. Therefore, by knowing the value of the capacitor, threshold voltage and output of the counter, the quantity of charge delivered can be calculated. The system has been fabricated in 0.18μm CMOS technology, occupying a total active area of 339μm×110μm. Experimental results were taken using: (1) a resistor-capacitor EEI model and (2) platinum electrodes with ringer solution. The viability of this method in recruiting action potentials has been demonstrated using a cuff electrode with Xenopus Sciatic nerve. For a 10nC target charge delivery, the results of (2) show a charge delivery error of 3.4% and a typical residual charge of 77.19pC without passive charge recycling. The total power consumption is 45μW. The performance is comparable with other publications. Therefore, the proposed stimulation method can be used as a new approach for neural stimulation.
AU - Luan,S
AU - Constandinou,TG
DO - 10.1016/j.jneumeth.2013.11.028
EP - 47
PY - 2014///
SN - 0165-0270
SP - 39
TI - A Charge-Metering Method for Voltage-Mode Neural Stimulation
T2 - Journal of Neuroscience Methods
UR - http://dx.doi.org/10.1016/j.jneumeth.2013.11.028
UR - http://hdl.handle.net/10044/1/13728
VL - 224
ER -