High stability voltage controlled current source for cervical cancer detection using electrical impedance spectroscopy

作者：Amaya Palacio Jose Alejandro; Van Noije Wilhelmus Adrianus

来源：Analog Integrated Circuits and Signal Processing, 2016, 89(3): 541-547.

DOI：10.1007/s10470-016-0828-8

• Current source
• Cervical cancer detection
• Electrical bioimpedance
• CMOS
• Howland current source

The design of a high stability voltage controlled current source (VCCS) for cervical cancer detection (CCD) applying electrical bio-impedance spectroscopy (EBS) is presented. The circuit was designed, simulated and fabricated in TSMC 130 nm CMOS technology at 1.3 V power supply. The proposed Howland current source is based on self-biased complementary folded cascode (SB-CFC) operational amplifier (OA). Complying with the requirements for medical electrical equipment of international standard ABNT-NBR-IEC-60601-1 the sinusoidal current peak amplitude was settled at 10 mu A. In accordance with the requirements of the EBS for CCD, the specifications for the SB-CFC-OA were calculated to meet the 100 Hz-1 MHz frequency range for the sinusoidal output current and the output impedance higher than 1 Ma"broken vertical bar at 1 MHz frequency. Post-layout simulations were run and the main results were: 10 +/- 0.0335 mu A for the output current peak amplitude over the specified frequency range and with 5 ka"broken vertical bar load impedance; values above 1.6 Ma"broken vertical bar output impedance at 1 MHz; nominal current amplitude variations lower than 0.4 % for load impedances in the range of 10 a"broken vertical bar up to 5 ka"broken vertical bar. And the experimental result for maximum non-linearity was 2.19 % of full scale. From these results, the performance of the VCCS is adequate for EBS-CCD applications.

• 出版日期2016-12