The Exploration of Biasing Voltage Range on Implantable Microscale Electrochemical Sensors for Post-Surgery Cancer Recurrence Monitoring

摘要

Cancer surgery prognosis currently relies heavily on expensive diagnostics devices that have limited availability to patients. Minute-to-minute cancer recurrence monitoring device is needed. This paper investigates a novel design and simulation of Implantable micro-scale, minute-to-minute sensors of low manufacture cost. In Cadence simulation software, electrochemical sensor array circuit in 0.35 micron complementary metal oxide semiconductor (CMOS) process was designed. The simulated circuit supported both pH ISFET sensor and soluble oxygen level O2-FET sensor. The simulation result showed that the circuit’s output voltage has optimal sensitivity when ISFET Vsubgate/sub was biased at range of 2.29-2.49 volts. The output voltage in this biasing scheme varies linearly with the input voltage Vsubgate/sub making it ideal region for monitoring of cancer. The appropriate biasing of ISFET Vsubgate/sub voltage found by simulation is within 2.29-2.49 volts. In the case of pH measurements, the sensitivity can be up to 0.02 pH in a minute-to-minute pH probing device for cancer prognosis tracking. Other chemical probes such as O2-FET and Oct4 sensors are also supported by the device architecture.