Title :
An Implantable Versatile Electrode-Driving ASIC for Chronic Epidural Stimulation in Rats
Author :
Giagka, Vasiliki ; Eder, Clemens ; Donaldson, Nick ; Demosthenous, Andreas
Author_Institution :
Dept. of Electron. & Electr. Eng., Univ. Coll. London, London, UK
Abstract :
This paper presents the design and testing of an electrode driving application specific integrated circuit (ASIC) intended for epidural spinal cord electrical stimulation in rats. The ASIC can deliver up to 1 mA fully programmable monophasic or biphasic stimulus current pulses, to 13 electrodes selected in any possible configuration. It also supports interleaved stimulation. Communication is achieved via only 3 wires. The current source and the control of the stimulation timing were kept off-chip to reduce the heat dissipation close to the spinal cord. The ASIC was designed in a 0.18- μm high voltage CMOS process. Its output voltage compliance can be up to 25 V. It features a small core area (<;0.36 mm2) and consumes a maximum of 114 μW during a full stimulation cycle. The layout of the ASIC was developed to be suitable for integration on the epidural electrode array, and two different versions were fabricated and electrically tested. Results from both versions were almost indistinguishable. The performance of the system was verified for different loads and stimulation parameters. Its suitability to drive a passive epidural 12-electrode array in saline has also been demonstrated.
Keywords :
CMOS integrated circuits; application specific integrated circuits; arrays; bioelectric phenomena; biomedical electrodes; biomedical electronics; low-power electronics; neurophysiology; patient treatment; prosthetics; ASIC electrical testing; ASIC fabrication; ASIC layout; electrode configuration; electrode driving application specific integrated circuit; electrode selection; electrode-driving ASIC design; electrode-driving ASIC testing; epidural electrode array; epidural spinal cord electrical stimulation; full stimulation cycle; fully programmable biphasic stimulus current pulse delivery; fully programmable monophasic stimulus current pulse delivery; heat dissipation reduction; high voltage CMOS process; implantable versatile electrode-driving ASIC; interleaved stimulation; load parameter variation; off-chip current source; off-chip stimulation timing control; output voltage compliance; passive epidural 12-electrode array; power 114 muW; rat chronic epidural stimulation; saline; size 0.18 mum; size 0.36 mm; small core area; stimulation parameter variation; system performance verification; wire communication; Application specific integrated circuits; Arrays; Clocks; Demodulation; Electrodes; Timing; Wires; Application specific integrated circuit (ASIC); electrode array; electrode driver; epidural stimulation; implantable electronics; low power; rats;
Journal_Title :
Biomedical Circuits and Systems, IEEE Transactions on
DOI :
10.1109/TBCAS.2014.2330859
