Combining ultrafast ultrasound and high-density EMG to assess local electromechanical muscle dynamics: a feasibility study

Waasdorp, R.; Mugge, W.; Vos, H.J.; De Groot, Jurriaan H.; Verweij, M.D.; de Jong, N.; Schouten, A.C.; Daeichin, V.

doi:10.1109/ACCESS.2021.3067162

Combining ultrafast ultrasound and high-density EMG to assess local electromechanical muscle dynamics

Title

Combining ultrafast ultrasound and high-density EMG to assess local electromechanical muscle dynamics: a feasibility study

Author

Waasdorp, R. (TU Delft ImPhys/Medical Imaging)
Mugge, W. (TU Delft Biomechatronics & Human-Machine Control)
Vos, H.J. (TU Delft ImPhys/Medical Imaging; Erasmus MC)
De Groot, Jurriaan H. (Leiden University Medical Center)
Verweij, M.D. (TU Delft ImPhys/Medical Imaging; Erasmus MC)
de Jong, N. (TU Delft ImPhys/Medical Imaging; Erasmus MC)
Schouten, A.C. (TU Delft Biomechatronics & Human-Machine Control; University of Twente)
Daeichin, V. (TU Delft ImPhys/Medical Imaging; Kaminari Medical, Rotterdam)

Date

2021

Abstract

Skeletal muscles generate force, enabling movement through a series of fast electro-mechanical activations coordinated by the central nervous system. Understanding the underlying mechanism of such fast muscle dynamics is essential in neuromuscular diagnostics, rehabilitation medicine and sports biomechanics. The unique combination of electromyography (EMG) and ultrafast ultrasound imaging (UUI) provides valuable insights into both electrical and mechanical activity of muscle fibers simultaneously, the excitation-contraction (E-C) coupling. In this feasibility study we propose a novel non-invasive method to simultaneously track the propagation of both electrical and mechanical waves in muscles using high-density electromyography and ultrafast ultrasound imaging (5000 fps). Mechanical waves were extracted from the data through an axial tissue velocity estimator based on one-lag autocorrelation. The E-C coupling in electrically evoked twitch contractions of the Biceps Brachii in healthy participants could successfully be tracked. The excitation wave (i.e. action potential) had a velocity of 3.9±0.5ms-1 and the subsequent mechanical (i.e. contraction) wave had a velocity of 3.5±0.9ms-1. The experiment showed evidence that contracting sarcomeres that were already activated by the action potential (AP) pull on sarcomeres that were not yet reached by the AP, which was corroborated by simulated contractions of a newly developed multisegmental muscle fiber model, consisting of 500 sarcomeres in series. In conclusion, our method can track the electromechanical muscle dynamics with high spatio-temporal resolution. Ultimately, characterizing E-C coupling in patients with neuromuscular diseases (e.g. Duchenne or Becker muscular dystrophy) may assess contraction efficiency, monitor the progression of the disease, and determine the efficacy of new treatment options.

Subject

Action potentials
Couplings
Electromyography
electrostimulation
excitation-contraction coupling
Force
high-density electromyography
Hill model
latency relaxation
multisegmental modeling
muscle modeling
Muscles
speckle-tracking
Transducers
Ultrafast ultrasound
Ultrasonic imaging
wave tracking