Hybrid robotic and electrical stimulation assistance can enhance performance and reduce mental demand

Combining functional electrical stimulation (FES) and robotics may enhance recovery after stroke, by providing neural feedback with the former while improv- ing quality of motion and minimizing muscular fatigue with the latter. Here, we explored whether and how FES, robot assistance and their combination, affect users’ per- formance, effort, fatigue and user experience. 15 healthy participants performed a wrist flexion/extension tracking task with FES and/or robotic assistance. Tracking per- formance improved during the hybrid FES-robot and the robot-only assistance conditions in comparison to no assistance, but no improvement is observed when only FES is used. Fatigue, muscular and voluntary effort are estimated from electromyographic recording. Total muscle contraction and volitional activity are lowest with robotic assistance, whereas fatigue level do not change between the conditions. The NASA-Task Load Index answers indi- cate that participants found the task less mentally demand- ing during the hybrid and robot conditions than the FES condition. The addition of robotic assistance to FES train- ing might thus facilitate an increased user engagement compared to robot training and allow longer motor training session than with FES assistance

Dr. Martin Hillenbrand to Receive University of Dayton Distinguished Alumnus Award

News release announcing the University of Dayton will Award Assistant Secretary of State for European Affairs, Dr. Martin Hillenbrand, with the Distinguished Alumnus Award

Nonlinearity Compensation in a Multi-DoF Shoulder Sensing Exosuit for Real-Time Teleoperation

The compliant nature of soft wearable robots makes them ideal for complex multiple degrees of freedom (DoF) joints, but also introduce additional structural nonlinearities. Intuitive control of these wearable robots requires robust sensing to overcome the inherent nonlinearities. This paper presents a joint kinematics estimator for a bio-inspired multi-DoF shoulder exosuit capable of compensating the encountered nonlinearities. To overcome the nonlinearities and hysteresis inherent to the soft and compliant nature of the suit, we developed a deep learning-based method to map the sensor data to the joint space. The experimental results show that the new learning-based framework outperforms recent state-of-the-art methods by a large margin while achieving 12ms inference time using only a GPU-based edge-computing device. The effectiveness of our combined exosuit and learning framework is demonstrated through real-time teleoperation with a simulated NAO humanoid robot.Comment: 8 pages, 7 figures, 3 tables. Accepted to be published in IEEE RoboSoft 202

Exploring user motor behaviour in bimanual interactive video games

Video games have proved very valuable in rehabilitation technologies. They guide therapy and keep patients engaged and motivated. However, in order to realize their full potential, a good understanding is required of the players' motor control. In particular, little is known regarding player behaviour in tasks demanding bimanual interaction. In this work, an experiment was designed to improve the understanding of such tasks. A driving game was developed in which players were asked to guide a differential wheeled robot (depicted as a rocket) along a trajectory. The rocket could be manipulated by using an Xbox controller's triggers, each supplying torque to the corresponding side of the robot. Such a task is redundant, i.e. there exists an infinite number of input combinations to yield a given outcome. This allows the player to strategize according to their own preference. 10 participants were recruited to play this game and their input data was logged for subsequent analysis. Two different motor strategies were identified: an "intermittent" input pattern versus a "continuous" one. It is hypothesized that the choice of behaviour depends on motor skill and minimization of effort and error. Further testing is necessary to determine the exact relationship between these aspects

A Simple fMRI Compatible Robotic Stimulator to Study the Neural Mechanisms of Touch and Pain.

This paper presents a simple device for the investigation of the human somatosensory system with functional magnetic imaging (fMRI). PC-controlled pneumatic actuation is employed to produce innocuous or noxious mechanical stimulation of the skin. Stimulation patterns are synchronized with fMRI and other relevant physiological measurements like electroencephalographic activity and vital physiological parameters. The system allows adjustable regulation of stimulation parameters and provides consistent patterns of stimulation. A validation experiment demonstrates that the system safely and reliably identifies clusters of functional activity in brain regions involved in the processing of pain. This new device is inexpensive, portable, easy-to-assemble and customizable to suit different experimental requirements. It provides robust and consistent somatosensory stimulation, which is of crucial importance to investigating the mechanisms of pain and its strong connection with the sense of touch

Vortex solutions in axial or chiral coupled non-relativistic spinor- Chern-Simons theory

The interaction of a spin 1/2 particle (described by the non-relativistic "Dirac" equation of L\'evy-Leblond) with Chern-Simons gauge fields is studied. It is shown, that similarly to the four dimensional spinor models, there is a consistent possibility of coupling them also by axial or chiral type currents. Static self dual vortex solutions together with a vortex-lattice are found with the new couplings.Comment: Plain TEX, 10 page

Thick-Film Radial Position Sensor for High Temperature Active Magnetic Bearings

This paper presents the development of radial eddy-current position sensors for high temperature active magnetic bearing (AMB) applications. Thick-film technology was used to realize silver coils printed on ceramic substrates. Long term measurements showed a good stability of this technology at high temperature. However, silver migration was observed between the wire connections and countered with the use of dielectric pastes. An AC current source at 900 kHz and high impedance amplifiers enabled the sensor temperature compensation. The sensor response was measured from room temperature up to 600°C