An Arch-Shaped Intraoral Tongue Drive System with Built-in Tongue-Computer Interfacing SoC

• Main Authors: Hangue Park, Maysam Ghovanloo
• Format: Article
• Language: English
• Published: MDPI AG 2014-11-01
• Series: Sensors
• Subjects: Intraoral Tongue Drive System (iTDS); assistive technology; brain-tongue-computer interface; system-on-a-chip; magnetic sensors; buccal shelf
• Online Access: http://www.mdpi.com/1424-8220/14/11/21565

We present a new arch-shaped intraoral Tongue Drive System (iTDS) designed to occupy the buccal shelf in the user’s mouth. The new arch-shaped iTDS, which will be referred to as the iTDS-2, incorporates a system-on-a-chip (SoC) that amplifies and digitizes the raw magnetic sensor data and sends it wirelessly to an external TDS universal interface (TDS-UI) via an inductive coil or a planar inverted-F antenna. A built-in transmitter (Tx) employs a dual-band radio that operates at either 27 MHz or 432 MHz band, according to the wireless link quality. A built-in super-regenerative receiver (SR-Rx) monitors the wireless link quality and switches the band if the link quality is below a predetermined threshold. An accompanying ultra-low power FPGA generates data packets for the Tx and handles digital control functions. The custom-designed TDS-UI receives raw magnetic sensor data from the iTDS-2, recognizes the intended user commands by the sensor signal processing (SSP) algorithm running in a smartphone, and delivers the classified commands to the target devices, such as a personal computer or a powered wheelchair. We evaluated the iTDS-2 prototype using center-out and maze navigation tasks on two human subjects, which proved its functionality. The subjects’ performance with the iTDS-2 was improved by 22% over its predecessor, reported in our earlier publication.