TY - JOUR
T1 - Active Books
T2 - The design of an implantable stimulator that minimizes cable count using integrated circuits very close to electrodes
AU - Liu, Xiao
AU - Demosthenous, Andreas
AU - Vanhoestenberghe, Anne
AU - Jiang, Dai
AU - Donaldson, Nick
N1 - Funding Information:
Manuscript received July 06, 2011; revised September 02, 2011; accepted October 20, 2011. Date of publication January 09, 2012; date of current version May 22, 2012. This work was supported by the United Kingdom Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/F009593/1, and by the European Commission under project NEUWalk (Grant agreement 258654). This paper was recommended by Associate Editor A. Burdett.
PY - 2012
Y1 - 2012
N2 - This paper presents an integrated stimulator that can be embedded in implantable electrode books for interfacing with nerve roots at the cauda equina. The Active Book overcomes the limitation of conventional nerve root stimulators which can only support a small number of stimulating electrodes due to cable count restriction through the dura. Instead, a distributed stimulation system with many tripole electrodes can be configured using several Active Books which are addressed sequentially. The stimulator was fabricated in a 0.6-μm high-voltage CMOS process and occupies a silicon area of 4.2 × 6.5 mm 2. The circuit was designed to deliver up to 8 mA stimulus current to tripole electrodes from an 18 V power supply. Input pad count is limited to five (two power and three control lines) hence requiring a specific procedure for downloading stimulation commands to the chip and extracting information from it. Supported commands include adjusting the amplitude of stimulus current, varying the current ratio at the two anodes in each channel, and measuring relative humidity inside the chip package. In addition to stimulation mode, the chip supports quiescent mode, dissipating less than 100 nA current from the power supply. The performance of the stimulator chip was verified with bench tests including measurements using tripoles in saline.
AB - This paper presents an integrated stimulator that can be embedded in implantable electrode books for interfacing with nerve roots at the cauda equina. The Active Book overcomes the limitation of conventional nerve root stimulators which can only support a small number of stimulating electrodes due to cable count restriction through the dura. Instead, a distributed stimulation system with many tripole electrodes can be configured using several Active Books which are addressed sequentially. The stimulator was fabricated in a 0.6-μm high-voltage CMOS process and occupies a silicon area of 4.2 × 6.5 mm 2. The circuit was designed to deliver up to 8 mA stimulus current to tripole electrodes from an 18 V power supply. Input pad count is limited to five (two power and three control lines) hence requiring a specific procedure for downloading stimulation commands to the chip and extracting information from it. Supported commands include adjusting the amplitude of stimulus current, varying the current ratio at the two anodes in each channel, and measuring relative humidity inside the chip package. In addition to stimulation mode, the chip supports quiescent mode, dissipating less than 100 nA current from the power supply. The performance of the stimulator chip was verified with bench tests including measurements using tripoles in saline.
KW - Active Book
KW - crosstalk
KW - distributed stimulation system
KW - humidity measurement
KW - implanted device
KW - integrated circuit
KW - nerve root stimulator
KW - passive discharge
KW - spinal cord injury
KW - tripole
UR - http://www.scopus.com/inward/record.url?scp=84862810799&partnerID=8YFLogxK
U2 - 10.1109/TBCAS.2011.2174360
DO - 10.1109/TBCAS.2011.2174360
M3 - Article
C2 - 23853144
AN - SCOPUS:84862810799
SN - 1932-4545
VL - 6
SP - 216
EP - 227
JO - Ieee Transactions On Biomedical Circuits And Systems
JF - Ieee Transactions On Biomedical Circuits And Systems
IS - 3
M1 - 6126002
ER -