Functional Tasks Performed by People with Severe Muscular Atrophy Using an sEMG Controlled Robotic Manipulator

Abstract

For paralyzed people activities of daily living like eating or drinking are impossible without external assistance. Robotic assistance systems can give these people a part of their independence back. Especially if the operation with a joystick is not possible anymore due to a missing hand function, people need innovative interfaces to control assistive robots in 3D. Besides brain computer interfaces an approach based on surface electromyography (sEMG) can present an opportunity for people with a strong muscular atrophy. In this work we show that two people with proceeded spinal muscular atrophy can perform functional tasks using an sEMG controlled robotic manipulator. The interface provides a continuous control of three degrees of freedom of the endeffector of the robot. The performance was assessed with two clinical measures of upper limb functionality: the Box and Blocks Test and the Action Research Arm Test. Additionally, the participant could show that they can drink by themselves with the provided system.

In Search of a Cure: The Development of Therapeutics to Alter the Progression of Spinal Muscular Atrophy

“…Advances in biomedical devices have shown that some SMA-affected individuals may benefit from use of orthoses (externally applied devices designed to improve muscular function), such as robotic exoskeletons. These devices improve quality of life for people with muscular diseases [320][321][322][323][324], including SMA. One study demonstrated positive effects on range of motion and performance of daily living activities of SMA-affected individuals [322].…”

AMiCUS 2.0—System Presentation and Demonstration of Adaptability to Personal Needs by the Example of an Individual with Progressed Multiple Sclerosis

“…Interfaces, which use the remaining capabilities of tetraplegics to generate signals suitable for proportional real-time control, may be based on neural activity [8,9], electromyography (EMG) [10,11], gaze [12], tongue movement [13], or head motion [14,15]. While all these solutions are generally feasible to enable robotic arm control, they might not be accessible to a subset of tetraplegic MS patients, due to the presence of interfering symptoms.…”

Employing Whole-Body Control in Assistive Robotics

“…Currently, the system can be interfaced either by a conventional joystick or alternatively by an interface based on electromyography (EMG). This EMG-based interface allows people to operate robotic systems continuously in 3D, when the use of a joystick is not an option due to the users impairment [19]. Furthermore, the system is equipped with an Asus Xtion Pro Live RGB-D camera to perceive the environment as well as an integrated head switch for additional user input.…”

“…where the corresponding null space projector is denoted by N ∈ R 8×8 while J elbow ∈ R 6×8 and f elbow ∈ R 6 are the elbow Jacobian matrix and wrench, respectively. Similar to (19) the elbow wrench is calculated with a Cartesian stiffness and damping applied to the elbow frame. The forces that are applied to the mobile base are calculated by introducing end-effector-boundaries in which the platform motion should occur.…”

“…10. In this mode the whole-body motion is active including the impedance controller (19), and the platform commands are computed according to the mapping of the interaction forces (24). The noisy raw signal of the estimated external forces can be used thanks to the admit-tance interface (9), generating smooth commanded velocities due to the filtering effect.…”