Development of a Soft Robotic Wearable Device to Assist Infant Reaching

Abstract

Existing devices to assist upper extremity (UE) movement in infants with or at risk for motor impairments remain limited and are mainly passive devices. The aim of this project was to develop and assess the validity and reliability of the first-actuated wearable device for this population. A wearable device consisting of four pneumatic actuators (two per arm) was developed and tested on a custom-built physical model with articulated joints (four degrees-of-freedom (DOFs) per arm) based on an average 12-month-old infant's upper body. The device actively controls 2DOFs per arm (one at the elbow and one at the shoulder) and does not prohibit motion about the remaining non-actuated DOFs. Three distinct device actuator synergies, that resemble muscle recruitment strategies, were evaluated in a vertical reaching task using one arm and both arms. The device was assessed for its performance, wearability, and safety. Performance was assessed via the average duration, smoothness, and repeatability of reaching movements, and maximum range of motion per actuated joint. Wearability was assessed via kinematic compatibility to infant reaching trajectories. Safety was assessed via actuator durability. Results demonstrate the efficacy of the device and reveal key insights for further improvements.

A Vacuum-Powered Artificial Muscle Designed for Infant Rehabilitation

“…In the current literature, utilization of soft robotic exoskeletons include gait assistance via ankle [ 3 ] and hip [ 2 ] support, as well as hand motion support and rehabilitation via pneumatic actuators designed to match finger motions [ 22 , 23 ]. For children above the age of three, active suits have been proposed that are powered by soft actuators at the shoulder [ 24 ] and both shoulder and elbow [ 25 ]. An active ankle exoskeleton powered by pneumatic actuators has also been proposed for pediatric use [ 10 ], and previous work has developed cable-driven robots to provide external forces to children with CP as a method to improve gait [ 26 ].…”

A pneumatic random-access memory for controlling soft robots

“…For some applications, dramatically reducing the amount of electromechanical control hardware may not be enough-completely eliminating it would be the ultimate goal. For example, soft robotic wearable devices can help infants with motor impairments lead normal lives [6], but the computers, microcontrollers, solenoid valves, batteries, and other hardware used to control these devices are difficult to safely use in close proximity to small children. Could pneumatic logic chips replace all this hardware?…”

“…Their ability to yield increases their safety in close proximity to humans [4]. Soft robots are also suitable for use in contact with humans, as wearable exoskeletons for assisting laborers, warfighters, the elderly, or patients with musculoskeletal or neurological conditions [5,6]. Additionally, soft robots resemble living organisms more closely, which makes them suitable for use in biomimetics [7][8][9][10][11][12][13].…”

Current Trends and Challenges in Pediatric Access to Sensorless and Sensor-Based Upper Limb Exoskeletons

“…This exoskeleton [69] is a soft robotic wearable for assisting and training upper extremity movements in infants. The exoskeleton has 4 active DOF: 1 at each shoulder (AA) and 1 at each elbow (FE).…”

“…Nonetheless, the sensors used in upper limb exoskeletons should allow the measurement and processing of upper limb movement data [87] to adapt to the user's needs during ADL [88] or to follow closely the rehabilitation progress [41]. Furthermore, sensors should also allow for device sensing, which can improve both the performance and safety of the exoskeletons [69]. For example, EMG and strain gauges can be used to predict the user's motion intention [89], which could allow the actuation of the exoskeleton at the correct timing.…”