Thermal drift and dynamic response of micro flow sensors for smart vp shunts

Eniko T Enikov, Gergó Édes, Rein Anton

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper describes the development of a highly sensitive microfluidics flow sensor using MTJ magnetic sensors to detect motion of slow-moving fluids. A motivating application for the proposed device is the development of an implantable flow sensor, capable of monitoring the amount of cerebral spinal fluid drained from the ventricles of the brain. Micro-fabricated ferromagnetic flaps are used to detect motion of the surrounding fluid. The deflection of the flaps is detected by an ultra-sensitive MTJ magnetic field sensor placed outside of the lumen of the catheter. Previous studies have presented a working device with a resolution of up to 1.4 mL/hr. This paper presents the improvements made to the device in terms of sensitivity, thermal noise rejection, and dynamic response. Upon investigation of possible noise sources, a thermally induced sensor drift was found to be the most significant factor affecting the sensors response. A static temperature compensation reduced this drift to less than 120 mL per 12-hr period. Further improvements to the design of the ferromagnetic transducers resulted in a 4.5-fold increase in sensitivity over the previous designs. Results from dynamic testing of the sensor revealed a time constant of 0.4 seconds, which was found adequate for the envisioned application.

Original languageEnglish (US)
Title of host publicationBiomedical and Biotechnology Engineering
PublisherAmerican Society of Mechanical Engineers (ASME)
Volume3
ISBN (Electronic)9780791850534
DOIs
StatePublished - 2016
EventASME 2016 International Mechanical Engineering Congress and Exposition, IMECE 2016 - Phoenix, United States
Duration: Nov 11 2016Nov 17 2016

Other

OtherASME 2016 International Mechanical Engineering Congress and Exposition, IMECE 2016
CountryUnited States
CityPhoenix
Period11/11/1611/17/16

ASJC Scopus subject areas

  • Mechanical Engineering

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  • Cite this

    Enikov, E. T., Édes, G., & Anton, R. (2016). Thermal drift and dynamic response of micro flow sensors for smart vp shunts. In Biomedical and Biotechnology Engineering (Vol. 3). [2602008] American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/IMECE2016-65401