Title :
Toward an Ultralow-Power Onboard Processor for Tongue Drive System
Author :
Viseh, Sina ; Ghovanloo, Maysam ; Mohsenin, Tinoosh
Author_Institution :
Univ. of Maryland, Baltimore County, Baltimore, MD, USA
Abstract :
The Tongue Drive System (TDS) is a new unobtrusive, wireless, and wearable assistive device that allows for real-time tracking of the voluntary tongue motion in the oral space for communication, control, and navigation applications. The latest TDS prototype appears as a wireless headphone and has been tested in human subject trials. However, the robustness of the external TDS (eTDS) in real-life outdoor conditions may not meet safety regulations because of the limited mechanical stability of the headset. The intraoral TDS (iTDS), which is in the shape of a dental retainer, firmly clasps to the upper teeth and resists sensor misplacement. However, the iTDS has more restrictions on its dimensions, limiting the battery size and consequently requiring a considerable reduction in its power consumption to operate over an extended period of two days on a single charge. In this brief, we propose an ultralow-power local processor for the TDS that performs all signal processing on the transmitter side, following the sensors. Assuming the TDS user on average issuing one command/s, implementing the computational engine reduces the data volume that needs to be wirelessly transmitted to a PC or smartphone by a factor of 1500×, from 12 kb/s to ~8 b/s. The proposed design is implemented on an ultralow-power IGLOO nano field-programmable gate array (FPGA) and is tested on AGLN250 prototype board. According to our post-place-and-route results, implementing the engine on the FPGA significantly drops the required data transmission, while an application-specific integrated circuit (ASIC) implementation in a 65-nm CMOS results in a 15× power saving compared to the FPGA solution and occupies a 0.02-mm2 footprint. As a result, the power consumption and size of the iTDS will be significantly reduced through the use of a much smaller rechargeable battery. Moreover, the system can operate longer following every recharge, improving the iTDS usability.
Keywords :
CMOS logic circuits; application specific integrated circuits; field programmable gate arrays; interactive devices; low-power electronics; nanoelectronics; object tracking; signal processing; wearable computers; AGLN250 prototype board; ASIC; CMOS process; FPGA; TDS prototype; application-specific integrated circuit; battery size; data transmission; dental retainer; eTDS; external TDS; iTDS; intraoral TDS; mechanical stability; post-place-and-route; power consumption; power saving; real-life outdoor conditions; real-time tracking; rechargeable battery; sensors; signal processing; size 65 nm; tongue drive system; transmitter side; ultralow-power IGLOO nanofield-programmable gate array; ultralow-power onboard processor; unobtrusive wireless-wearable assistive device; voluntary tongue motion; wireless headphone; Accuracy; Application specific integrated circuits; Field programmable gate arrays; Power demand; Tongue; Training; Wireless communication; Application-specific integrated circuit (ASIC); field-programmable gate array (FPGA); low power; machine learning; onboard processor; personalized assistive device; wearable biomedical device;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2014.2387683