CMOS-MEMS capacitive sensors for intra-cranial pressure monitoring : sensor fabrication & system design

• Main Authors: George, Arup K., Chan, Wai Pan, Narducci, Margarita Sofia, Kong, Zhi Hui, Je, Minkyu
• Other Authors: School of Electrical and Electronic Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/100181; http://hdl.handle.net/10220/13608
• Institution: Nanyang Technological University

Low-frequency variation of intracranial pressure (ICP) is a key indicator determining the successful outcome of a patient, subjected to traumatic brain injury (TBI). Post-trauma ICP increase can lead to fatal secondary injuries and hence continuous ICP monitoring would be an essential modality required in a neuro-monitoring system. This paper discusses the system design considerations of an integrated CMOS-MEMS sensor system for monitoring ICP in patients subjected to TBI. Design and fabrication steps of the on-chip CMOS-MEMS sensor are presented first. Interface circuit design challenges introduced by the low, not-well-controlled MEMS sensitivity and large offset due to the fabrication tolerance are discussed next. A review and comparison of the reported capacitive sensors and their interface circuits follows. The paper concludes discussing the biocompatible packaging of the system for in-vivo testing.