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The increased use of Virtual and Augmented Reality based systems necessitates the development of more intuitive and unobtrusive means of interfacing. Over the last years, Electromyography (EMG) based interfaces have been employed for interaction with robotic and computer applications, but no studies have been carried out to investigate the continuous decoding of the effects of human motion (e.g., manipulated object behavior) in simulated and virtual environments. In this work, we compare the object motion decoding accuracy of an EMG based learning framework for two different dexterous manipulation scenarios: i) for simulated objects handled by a teleoperated model of a hand within a virtual environment and ii) for real, everyday life objects manipulated by the human hand. To do that, we utilize EMG activations from 16 muscle sites (9 on the hand and 7 on the forearm). The object motion decoding is formulated as a regression problem using the Random Forests methodology. A 5-fold cross validation procedure is used for model assessment purposes and the feature variable importance values are calculated for each model. The decoding accuracy for the real world is considerably higher than the virtual world. Each of the objects examined had a single manipulation motion that offered the highest estimation accuracy across both worlds. This study also shows that it is feasible to decode the object motions using just the myoelectric activations of the muscles of the forearm and the hand. This is particularly surprising since simulations lacked haptic feedback and the ability to account for other dynamic phenomena like friction and contact rolling.

Electromyography (EMG) is a wearable, noninvasive, commonly used method for measuring the human muscular activations from the surface of the skin. In this work, we present a pilot study that focuses on the formulation of a shared control framework to facilitate the simplified execution of Electromyography (EMG) based telemanipulation tasks with a robotic platform. The framework combines a Random Forests (RF) regression method with a compliance controller that relies on the force measurements collected with a force-torque sensor. The RF regression efficiently maps the myoelectric activations of the human muscles to corresponding human wrist positions. Then, a teleoperation process is used to control the robot arm end-effector’s position, utilizing the human wrist position estimations. The examined application involves semi-autonomous cleaning of a whiteboard surface with the proposed framework. The compliance controller guarantees that a desired contact force will always be maintained on the whiteboard surface during task execution. This ensures that any EMG based decoding inaccuracies will not drive the robot away from the cleaning plane. Essentially, the system projects the EMG based estimation on the cleaning plane. The shared control framework offers robust performance, with minimal training and calibration required.

Teleoperation and telemanipulation have since the early years of robotics found use in a wide range of applications, including exploration, maintenance, and response in remote or hazardous environments, healthcare, and education settings. As the capabilities of robot manipulators grow, so does the control complexity and the remote execution of intricate manipulation tasks still remains challenging for the user. This paper proposes an intuitive telemanipulation framework based on electromyography (EMG) and fiducial marker based tracking that can be used with a dexterous robot arm hand system. The EMG subsystem captures the myoelectric activations of the user during the execution of specific hand postures and gestures and translates them into the desired grasp type for the robot hand. The pose of the tracked fiducial marker is used as a taskspace goal for the robot end-effector. The system performance is experimentally validated in a remote operation setting, where the system successfully performs a telemanipulation task.

Electromyography (EMG) based interfaces are the most common solutions for the control of robotic, orthotic, prosthetic, assistive, and rehabilitation devices, translating myoelectric activations into meaningful actions. Over the last years, a lot of emphasis has been put into the EMG based decoding of human intention, but very few studies have been carried out focusing on the continuous decoding of human motion. In this work, we present a learning scheme for the EMG based decoding of object motions in dexterous, in-hand manipulation tasks. We also study the contribution of different muscles while performing these tasks and the effect of the gender and hand size in the overall decoding accuracy. To do that, we use EMG signals derived from 16 muscle sites (8 on the hand and 8 on the forearm) from 11 different subjects and an optical motion capture system that records the object motion. The object motion decoding is formulated as a regression problem using the Random Forests methodology. Regarding feature selection, we use the following time-domain features: root mean square, waveform length and zero crossings. A 10-fold cross validation procedure is used for model assessment purposes and the feature variable importance values are calculated for each feature. This study shows that subject specific, hand specific, and object specific decoding models offer better decoding accuracy that the generic models.

The field of Brain Machine Interfaces (BMI) has attracted an increased interest due to its multiple applications in the health and entertainment domains. A BMI enables a direct interface between the brain and machines and is capable of translating neuronal information into meaningful actions (e.g., Electromyography based control of a prosthetic hand). One of the biggest challenges in developing a surface Electromyography (sEMG) based interface is the selection of the right muscles for the execution of a desired task. In this work, we investigate optimal muscle selections for sEMG based decoding of dexterous in-hand manipulation motions. To do that, we use EMG signals derived from 14 muscle sites of interest (7 on the hand and 7 on the forearm) and an optical motion capture system that records the object motion. The regression problem is formulated using the Random Forests methodology that is based on decision trees. Regarding features selection, we use the following time-domain features: root mean square, waveform length and zero crossings. A 5-fold cross validation procedure is used for model assessment purposes and the importance values are calculated for each feature. This pilot study shows that the muscles of the hand contribute more than the muscles of the forearm to the execution of inhand manipulation tasks and that the myoelectric activations of the hand muscles provide better estimation accuracies for the decoding of manipulation motions. These outcomes suggest that the loss of the hand muscles in certain amputations limits the amputees’ ability to perform a dexterous, EMG based control of a prosthesis in manipulation tasks. The results discussed can also be used for improving the efficiency and intuitiveness of EMG based interfaces for healthy subjects.