A wireless magnetoresistive sensing system for an intraoral tongue-computer interface

Hangue Park, Mehdi Kiani, Hyung Min Lee, Jeonghee Kim, Jacob Block, Benoit Gosselin, Maysam Ghovanloo

Research output: Contribution to journalArticlepeer-review

69 Citations (Scopus)


Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, and wireless assistive technology (AT) that infers users' intentions by detecting their voluntary tongue motion and translating them into user-defined commands. Here we present the new intraoral version of the TDS (iTDS), which has been implemented in the form of a dental retainer. The iTDS system-on-a-chip (SoC) features a configurable analog front-end (AFE) that reads the magnetic field variations inside the mouth from four 3-axial magnetoresistive sensors located at four corners of the iTDS printed circuit board (PCB). A dual-band transmitter (Tx) on the same chip operates at 27 and 432 MHz in the Industrial/Scientific/Medical (ISM) band to allow users to switch in the presence of external interference. The Tx streams the digitized samples to a custom-designed TDS universal interface, built from commercial off-the-shelf (COTS) components, which delivers the iTDS data to other devices such as smartphones, personal computers (PC), and powered wheelchairs (PWC). Another key block on the iTDS SoC is the power management integrated circuit (PMIC), which provides individually regulated and duty-cycled 1.8 V supplies for sensors, AFE, Tx, and digital control blocks. The PMIC also charges a 50 mAh Li-ion battery with constant current up to 4.2 V, and recovers data and clock to update its configuration register through a 13.56 MHz inductive link. The iTDS SoC has been implemented in a 0.5-μm standard CMOS process and consumes 3.7 mW on average.

Original languageEnglish
Article number6392916
Pages (from-to)571-585
Number of pages15
JournalIEEE Transactions on Biomedical Circuits and Systems
Issue number6
Publication statusPublished - 2012
Externally publishedYes

Bibliographical note

Funding Information:
Manuscript received June 06, 2012; revised September 07, 2012; accepted October 19, 2012. Date of publication December 24, 2012; date of current version January 14, 2013. This work was supported in part by the National Institute of Biomedical Imaging and Bioengineering Grant 1RC1EB010915, and the National Science Foundation Award CBET-0828882 and IIS-0803184. This paper was recommended by Associate Editor A. Burdett.


  • Assistive technologies
  • Duty cycling
  • Industrial-scientific- medical (ISM) band
  • Intraoral Tongue Drive System (iTDS)
  • Magnetoresistive sensors
  • System-on-a-chip

ASJC Scopus subject areas

  • Biomedical Engineering
  • Electrical and Electronic Engineering


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