Aims and objectives
Several studies have been conducted using ultrasonography to characterise how peripheral nerves respond and adapt to body movement (nerve biomechanics),
both in terms of quantity and direction as well as which factors affect nerve movement.
A systematic review showed that body movement might induce up to 12.
5 mm of nerve gliding,
which seem to vary according to range of motion for the moving joint,
position of adjacent joints,
number of moving joints and whether joint movement stretches or shortens nerve bed .
Methods and materials
We developed different algorithms based on the Lucas-Kanade optical flow methods .
Using a C++ implementation and the OpenCV library,
three different methods were created to quantify the movement of the median nerve in response to wrist flexion and extension based on Optical Flow algorithms: i) ROI tracking,
ii) Point-wise Tracking and iii) Contour Tracking.
Longitudinal and axial acquisitions were taken at approximately the mid-forearm.
ROI Tracking: Consists of a selection of an arbitrary number of points used to calculate the optical flow.
It was possible to observe the median nerve displacement in axial and longitudinal acquisitions using ROI Tracking,
Point-wise Tracking and Contour Tracking methods.
structure dimensions and histogram representative of the frequency and direction of movement in each direction were achieved.
The histogram descriptors enable compact assessment of principal motion properties.
Longitudinal acquisition during wrist extension
According to the ROI Tracking method the median nerve travelled space was 3,1mm on the distal direction.
It was noticeable that there was no significant movement on the...
This work proposes a strategy to characterize and quantify peripheral nerve movement in different anatomical planes.
The histogram descriptor enables compact assessment of principal motion properties.
It is clear that both the axial plane and longitudinal plane may be mapped to rather different motion histogram signatures.
some limitations must be considered,
such as the speckle pattern,
which is an intensity pattern produced by the interference of random aggregates of tiny echogenic structures.
This phenomenon can create interference between the points being tracked because of...
Master in Electronics and Telecommunications Engineering - Department of Electronics,
Telecommunications and Informatics.
University of Aveiro,
Master dissertation in Neuromuscular Tracking by Ultrasound Imaging.
Silva is an Assistant Professor at the School of Health Sciences,
University of Aveiro,
She was trained as a Physiotherapist and gained her PhD at the Center for Pain Research,
Leeds Metropolitan University,
She has published more than one hundred publications distributed by articles in international peer-reviewed journals,...
“Quantitative in vivo longitudinal nerve excursion and strain in response to joint movement: A systematic literature review,” Clinical Biomechanics,
“Reference values for nerve ultrasonography in the upper extremity,” Muscle and Nerve,