Tongue-Drive System (TDS) is a wireless and wearable assistive technology that enables people with severe disabilities to control their computers, wheelchairs, and smartphones using voluntary tongue motion. To evaluate the efficacy of the TDS, several experiments were conducted, in which the performance of nine able-bodied (AB) participants using a mouse, a keypad, and the TDS, as well as a cohort of 11 participants with tetraplegia (TP) using the TDS, were observed and compared. Experiments included the Fitts' law tapping, wheelchair driving, phone-dialing, and weight-shifting tasks over five to six consecutive sessions. All participants received a tongue piercing, wore a magnetic tongue stud, and completed the trials as evaluable participants. Although AB participants were already familiar with the keypad, throughputs of their tapping tasks using the keypad were only 1.4 times better than those using the TDS. The completion times of wheelchair driving task using the TDS for AB and TP participants were between 157 s and 180 s with three different control strategies. Participants with TP completed phone-dialing and weight-shifting tasks in 81.9 s and 71.5 s, respectively, using tongue motions. Results showed statistically significant improvement or trending to improvement in performance status over the sessions. Most of the learning occurred between the first and second sessions, but trends did suggest that more practice would lead to increased improvement in performance using the TDS.

Currently available treatments for kinetic tremor can cause intolerable side effects or be highly invasive and expensive. Even though several studies have shown the positive effects of external feedback (i.e., electrical stimulation) for suppressing tremor, such approaches have not been fully integrated into wearable real-time feedback systems. Method:We have developed a wireless wearable stimulation system that analyzes upper limb tremor using a three-axis accelerometer and that modulates/attenuates tremor using peripheral-nerve electrical stimulation with adjustable stimulation parameters and a real-time tremor detection algorithm. We outfitted nine subjects with tremor with a wearable system and a set of surface electrodes placed on the skin overlying the radial nerve and tested the effects of stimulation with nine combinations of parameters for open- and closed-loop stimulation on tremor. To quantify the effects of the stimulation, we measured tremor movements, and analyzed the dominant tremor frequency and tremor power. Results: Baseline tremor power gradually decreased over the course of 18 stimulation trials. During the last trial, compared with the control trial, the reduction rate of tremor power was 42.17 ± 3.09%. The dominant tremor frequency could be modulated more efficiently by phase-locked closed-loop stimulation. The tremor power was equally reduced by open- and closed-loop stimulation. Conclusion: Peripheral nerve stimulation significantly affects tremor, and stimulation parameters need to be optimized to modulate tremor metrics. Clinical Impact: This preliminary study lays the foundation for future studies that will evaluate the efficacy of the proposed closed-loop peripheral nerve stimulation method in a larger group of patients with kinetic tremor.

To minimize the excavation damage of underground pipelines, in this article, we propose to provide real-time feedback to operators by monitoring the distance information from the underground pipeline. Despite multiple efforts to locate underground ferromagnetic pipelines using the magnetic anomaly detection, it has not been implemented in real-time excavation operations due to low signal-to-noise ratios, unknown external magnetic interference (EMI), and high computational power. To address these limitations, we propose an approach to locating a custom-designed wireless sensor system on the excavator bucket to increase accuracy of real-time distance estimation with efficient EMI cancelation. We present the system using a 14:1 lab-scaled excavator and six sizes of ferromagnetic pipes. To create a distance estimation model of each pipe, we measure the magnetic anomaly caused by ferromagnetic pipes from eight distances (from 5 to 75 mm, spaced 10 mm apart). The wireless system with the localization algorithm successfully estimates the distance between the sensor and the pipe with a less than 4.38 ± 1.62 mm error overall. This pilot study shows that the proposed system with the localization algorithm is able to accurately locate pipes. This will lay the foundation for providing accurate spatial information, and ultimately prevent critical excavation/drilling damage at construction sites.

Tongue Drive System (TDS) is a noninvasive, wireless and wearable assistive technology that helps people with severe disabilities control their environments using their tongue motion. TDS translates specific tongue gestures to commands by detecting a small permanent magnetic tracer on the users' tongue. We have linked the TDS to a smartphone (iPhone/iPod Touch) with a customized wireless module, added to the iPhone. We also migrated and ran the TDS sensor signal processing algorithm and graphical user interface on the iPhone in real time. The TDS-iPhone interface was evaluated by four able- bodied subjects for dialing 10-digit phone numbers using the standard telephone keypad and three methods of prompting the numbers: visual, auditory, and cognitive. Preliminary results showed that the interface worked quite reliably at a rate of 15.4 digits per minute, on average, with negligible errors.

(1) Background: Non-invasive neuromodulation is a promising alternative to medication or deep-brain stimulation treatment for Parkinson’s Disease or essential tremor. In previous work, we developed and tested a wearable system that modulates tremor via the non-invasive, electrical stimulation of peripheral nerves. In this article, we examine the proper range and the effects of various stimulation parameters for phase-locked stimulation. (2) Methods: We recruited nine participants with essential tremor. The subjects performed a bean-transfer task that mimics an eating activity to elicit kinetic tremor while using the wearable stimulation system. We examined the effects of stimulation with a fixed duty cycle, at different stimulation amplitudes and frequencies. The epochs of stimulation were locked to one of four phase positions of ongoing tremor, as measured with an accelerometer. We analyzed stimulation-evoked changes of the frequency and amplitude of tremor. (3) Results: We found that the higher tremor amplitude group experienced a higher rate of tremor power reduction (up to 65%) with a higher amplitude of stimulation when the stimulation was applied at the ±peak of tremor phase. (4) Conclusions: The stimulation parameter can be adjusted to optimize tremor reduction, and this study lays the foundation for future large-scale parameter optimization experiments for personalized peripheral nerve stimulation.

Current methods of evaluating essential tremor (ET) either rely on subjective ratings or use limited tremor metrics (i.e., severity/amplitude and frequency). In this study, we explored performance metrics from Fitts law tasks that replicate and expand existing tremor metrics, to enable low-cost, home-based tremor quantification and analyze the cursor movements of individuals using a 3D mouse while performing a collection of drawing tasks. We analyzed the 3D mouse cursor movements of 11 patients with ET and three controls, on three computer-based tasksa spiral navigation (SPN) task, a rectangular track navigation (RTN) task, and multi-directional tapping/clicking (MDT)with several performance metrics (i.e., outside area (OA), throughput (TP in Fitts law), path efficiency (PE), and completion time (CT)). Using an accelerometer and scores from the Essential Tremor Rating Assessment Scale (TETRAS), we correlated the proposed performance metrics with the baseline tremor metrics and found that the OA of the SPN and RTN tasks were strongly correlated with baseline tremor severity (R²=0.57 and R²=0.83). We also found that the TP in the MDT tasks were strongly correlated with tremor frequency (R²=0.70). In addition, as the OA of the SPN and RTN tasks was correlated with tremor severity and frequency, it may represent an independent metric that increases the dimensionality of the characterization of an individuals tremor. Thus, this pilot study of the analysis of those with ET-associated tremor performing Fitts law tasks demonstrates the feasibility of introducing a new tremor metric that can be expanded for repeatable multi-dimensional data analyses.