Comparative study of HD-EMG electrode setups for Smart Mechatronic Ankle-Foot Orthoses development

Smart mechanized ankle-foot orthoses aim to enhance rehabilitation and mobility assistance by integrating advanced human-machine interfaces. This study evaluates different high-density electromyography (HD-EMG) electrode configurations to investigate signal quality for future designs, addressing challenges in sensor variability and noise. By analyzing dorsiflexion and plantarflexion movements with HD-EMG arrays placed over the tibialis anterior and gastrocnemius medial muscles of 4 healthy participants, the research identifies configurations that improve signal quality and enable better integration into future ankle-foot orthoses. The results demonstrate that the electrodes with smaller surface area of sensors provide higher signal-to-noise ratio and more stable signals compared to the larger electrodes with a higher interelectrode distance. Additionally, while printed electrodes tend to offer greater comfort, due to their flexible design, they performed worse in comparison to their conventional counterparts. The study highlights the need for further investigation of alternative printed interfaces and materials, which will allow for smaller and more densely placed electrode pads while retaining the overall malleability.Clinical relevance - The results of this study provide guidance for future HD-EMG system designs for integration into advanced ankle-foot orthoses, which are used in the rehabilitation of mobility problems.