2018/07/30 by Billy Woods, Woods, Billy, Mahendran Subramanian +5
Engineering · Neuroscience · #Advanced Sensor and Energy Harvesting Materials #FOS: Computer and information sciences #Muscle activation and electromyography studies #Neuroscience and Neural Engineering #Robotics (cs.RO)
paper · pdf · doi:10.48550/arxiv.1807.11241
openalex publication_date 2018/07/30 · openalex created_date 2022/08/04 · openalex updated_date 2026/07/28
Functional Electrical Stimulation (FES) systems are successful in restoring\nmotor function and supporting paralyzed users. Commercially available FES\nproducts are open loop, meaning that the system is unable to adapt to changing\nconditions with the user and their muscles which results in muscle fatigue and\npoor stimulation protocols. This is because it is difficult to close the loop\nbetween stimulation and monitoring of muscle contraction using adaptive\nstimulation. FES causes electrical artefacts which make it challenging to\nmonitor muscle contractions with traditional methods such as electromyography\n(EMG). We look to overcome this limitation by combining FES with novel\nmechanomyographic (MMG) sensors to be able to monitor muscle activity during\nstimulation in real time. To provide a meaningful task we built an FES cycling\nrig with a software interface that enabled us to perform adaptive recording and\nstimulation, and then combine this with sensors to record forces applied to the\npedals using force sensitive resistors (FSRs), crank angle position using a\nmagnetic incremental encoder and inputs from the user using switches and a\npotentiometer. We illustrated this with a closed-loop stimulation algorithm\nthat used the inputs from the sensors to control the output of a programmable\nRehaStim 1 FES stimulator (Hasomed) in real-time. This recumbent bicycle rig\nwas used as a testing platform for FES cycling. The algorithm was designed to\nrespond to a change in requested speed (RPM) from the user and change the\nstimulation power (% of maximum current mA) until this speed was achieved and\nthen maintain it.\n