On lightmyography based muscle-machine interfaces for the efficient decoding of human gestures and forces.

Journal: Scientific reports
Published Date:

Abstract

Conventional muscle-machine interfaces like Electromyography (EMG), have significant drawbacks, such as crosstalk, a non-linear relationship between the signal and the corresponding motion, and increased signal processing requirements. In this work, we introduce a new muscle-machine interfacing technique called lightmyography (LMG), that can be used to efficiently decode human hand gestures, motion, and forces from the detected contractions of the human muscles. LMG utilizes light propagation through elastic media and human tissue, measuring changes in light luminosity to detect muscle movement. Similar to forcemyography, LMG infers muscular contractions through tissue deformation and skin displacements. In this study, we look at how different characteristics of the light source and silicone medium affect the performance of LMG and we compare LMG and EMG based gesture decoding using various machine learning techniques. To do that, we design an armband equipped with five LMG modules, and we use it to collect the required LMG data. Three different machine learning methods are employed: Random Forests, Convolutional Neural Networks, and Temporal Multi-Channel Vision Transformers. The system has also been efficiently used in decoding the forces exerted during power grasping. The results demonstrate that LMG outperforms EMG for most methods and subjects.

Authors

  • Mojtaba Shahmohammadi
    New Dexterity Research Group, Department of Mechanical and Mechatronics Engineering, University of Auckland, Auckland, 1010, New Zealand.
  • Bonnie Guan
    New Dexterity Research Group, Department of Mechanical and Mechatronics Engineering, University of Auckland, Auckland, 1010, New Zealand.
  • Ricardo V Godoy
    New Dexterity Research Group, Department of Mechanical and Mechatronics Engineering, University of Auckland, Auckland, 1010, New Zealand.
  • Anany Dwivedi
    Chair of Autonomous Systems and Mechatronics, Department of Electrical Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, Germany.
  • Poul Nielsen
    Auckland Bioengineering Institute, The University of Auckland, Auckland, 1010, New Zealand.
  • Minas Liarokapis
    New Dexterity Research Group, Department of Mechanical and Mechatronics Engineering, University of Auckland, Auckland, 1010, New Zealand. minas.liarokapis@auckland.ac.nz.