Title :
A 4.9 mΩ-Sensitivity Mobile Electrical Impedance Tomography IC for Early Breast-Cancer Detection System
Author :
Sunjoo Hong ; Kwonjoon Lee ; Unsoo Ha ; Hyunki Kim ; Yongsu Lee ; Youchang Kim ; Hoi-Jun Yoo
Author_Institution :
Dept. of Electr. Eng., Korea Adv. Inst. of Sci. & Technol., Daejeon, South Korea
Abstract :
A mobile electrical impedance tomography (EIT) IC is proposed for early breast cancer detection personally at home. To assemble the entire system into a simple brassiere shape, EIT IC is integrated via a multi-layered fabric circuit board which includes 90 EIT electrodes and two reference electrodes for current stimulation and voltage sensing. The IC supports three operating modes; gain scanning, contact impedance monitoring, and EIT modes for the clear EIT image. A differential sinusoidal current stimulator (DSCS) is proposed for injection of low-distortion programmable current which has harmonics less than -59 dBc at a load impedance of 2 kΩ. To get high sensitivity, a 6-channel voltage sensing amplifier can adaptively control the gain up to a maximum of 60 dB, and has low input referred noise, 36 nV/ √Hz. The 2.5 × 5 mm chip is fabricated in a 0.18 μm 1P6M CMOS process and consumes 53.4 mW on average. As a result, a sensitivity of 4.9 mΩ is achieved which enables the detection of a 5 mm cancer mass within an agar test phantom.
Keywords :
CMOS integrated circuits; adaptive control; amplifiers; biological tissues; biomedical electrodes; biomedical electronics; cancer; electric impedance imaging; gain control; mammography; medical control systems; patient monitoring; phantoms; portable instruments; programmable circuits; textile technology; 1P6M CMOS; 6-channel voltage sensing amplifier; DSCS; EIT IC integration; EIT electrode; EIT mode; IC operating mode; adaptive gain control; agar test phantom; brassiere shape system; cancer mass detection; chip fabrication; clear EIT image; contact impedance monitoring; current stimulation; differential sinusoidal current stimulator; early breast-cancer detection system; gain scanning; load impedance; low input referred noise; low-distortion programmable current injection; mobile EIT IC; mobile electrical impedance tomography IC sensitivity; multi-layered fabric circuit board; power 53.4 mW; programmable current harmonics; reference electrode; resistance 2 kohm; resistance 4.9 mohm; size 0.18 mum; size 2.5 mm; size 5 mm; Breast cancer; Current measurement; Electrodes; Impedance; Integrated circuits; Tomography; Voltage measurement; Electrical impedance tomography (EIT); breast cancer detection; contact impedance sensing; mobile healthcare; planar-fashionable circuit board (P-FCB);
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2014.2355835
