TY - JOUR
T1 - An inductively powered implantable blood flow sensor microsystem for vascular grafts
AU - Cheong, Jia Hao
AU - Ng, Simon Sheung Yan
AU - Liu, Xin
AU - Xue, Rui Feng
AU - Lim, Huey Jen
AU - Khannur, Pradeep Basappa
AU - Chan, Kok Lim
AU - Lee, Andreas Astuti
AU - Kang, Kai
AU - Lim, Li Shiah
AU - He, Cairan
AU - Singh, Pushpapraj
AU - Park, Woo Tae
AU - Je, Minkyu
PY - 2012
Y1 - 2012
N2 - Monitoring blood flow rate inside prosthetic vascular grafts enables an early detection of the graft degradation, followed by the timely intervention and prevention of the graft failure. This paper presents an inductively powered implantable blood flow sensor microsystem with bidirectional telemetry. The microsystem integrates silicon nanowire (SiNW) sensors with tunable piezoresistivity, an ultralow-power application-specific integrated circuit (ASIC), and two miniature coils that are coupled with a larger coil in an external monitoring unit to form a passive wireless link. Operating at 13.56-MHz carrier frequency, the implantable microsystem receives power and command from the external unit and backscatters digitized sensor readout through the coupling coils. The ASIC fabricated in 0.18-μm CMOS process occupies an active area of 1.5 × 1.78mm2 and consumes 21.6 μW only. The sensors based on the SiNW and diaphragm structure provide a gauge factor higher than 300 when a small negative tuning voltage (-0.5-0V) is applied. The measured performance of the pressure sensor and ASIC has demonstrated 0.176 mmHg/√Hz sensing resolution.
AB - Monitoring blood flow rate inside prosthetic vascular grafts enables an early detection of the graft degradation, followed by the timely intervention and prevention of the graft failure. This paper presents an inductively powered implantable blood flow sensor microsystem with bidirectional telemetry. The microsystem integrates silicon nanowire (SiNW) sensors with tunable piezoresistivity, an ultralow-power application-specific integrated circuit (ASIC), and two miniature coils that are coupled with a larger coil in an external monitoring unit to form a passive wireless link. Operating at 13.56-MHz carrier frequency, the implantable microsystem receives power and command from the external unit and backscatters digitized sensor readout through the coupling coils. The ASIC fabricated in 0.18-μm CMOS process occupies an active area of 1.5 × 1.78mm2 and consumes 21.6 μW only. The sensors based on the SiNW and diaphragm structure provide a gauge factor higher than 300 when a small negative tuning voltage (-0.5-0V) is applied. The measured performance of the pressure sensor and ASIC has demonstrated 0.176 mmHg/√Hz sensing resolution.
KW - Blood flow monitoring
KW - implantable biomedical IC
KW - inductively powered
KW - passive telemetry
KW - piezoresistive sensor
KW - sensor interface IC
KW - silicon nanowire (SiNW)
KW - successive approximation register analog-to-digital converters (SAR ADC)
UR - http://www.scopus.com/inward/record.url?scp=84865468063&partnerID=8YFLogxK
U2 - 10.1109/TBME.2012.2203131
DO - 10.1109/TBME.2012.2203131
M3 - Article
C2 - 22692871
AN - SCOPUS:84865468063
SN - 0018-9294
VL - 59
SP - 2466
EP - 2475
JO - IEEE Transactions on Biomedical Engineering
JF - IEEE Transactions on Biomedical Engineering
IS - 9
M1 - 6213087
ER -