Analysis of electromagnetic fields induced in operation of a wireless fully passive backscattering neurorecording microsystem in emulated human head tissue

Helen N. Schwerdt, Felix A. Miranda, Junseok Chae

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

This paper reports on a fully passive microsystem that wirelessly records and transmits neuropotentials exclusively by means of electromagnetic backscattering techniques, affording substantially simpler circuitry and potentially safer and more reliable approach for implantable wireless neurorecording. A fundamental practical barrier for wireless brain-implantable microsystems includes heat dissipation by on-chip circuitry, which may cause permanent brain damage. Hence, measurement of thermal profiles of surrounding tissue induced by operation of wireless implants is imperative in assessing the safety of these devices. Evaluation of specific absorption rate (SAR) is especially relevant for wireless electromagnetic transmission schemes operating at microwave frequencies and directly relates to the heat generated within biological tissue media. In this study, computational and empirical methods are used to measure SAR within a human-head-equivalent phantom during operation of the embedded fully passive wireless neurorecording microsystem. The maximum average SAR, coinciding with the worst case scenario, measured within 1 g of brain tissue is < 0.45 ± 0.11 W/kg, complying with the U.S. FCC threshold (1.6 W/kg).

Original languageEnglish (US)
Article number6493470
Pages (from-to)2170-2176
Number of pages7
JournalIEEE Transactions on Microwave Theory and Techniques
Volume61
Issue number5
DOIs
StatePublished - Apr 5 2013

Keywords

  • Backscattering
  • brain-machine interfaces
  • implantable electronics
  • microelectromechanical systems (MEMS)
  • passive devices
  • specific absorption rate (SAR)

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Analysis of electromagnetic fields induced in operation of a wireless fully passive backscattering neurorecording microsystem in emulated human head tissue'. Together they form a unique fingerprint.

  • Cite this