------ 1. TITLE
Peak-delay method for estimating the average motor unit action potential conduction velocity

------ 2. PROJECT DESCRIPTION
The method estimates the delay between highly correlating (R>0.9) high-density EMG peaks
which are matched between neighbouring channels (in cranial-caudal direction). Based on the 
delay and inter-electrode distance the conduction velocity is determined. Using all the
conduction velocity of individual high-density EMG peaks, the average conduction velocity
is computed per 10 seconds.

The set of code includes example data (ExampleData.mat):
ExampleData.mat contains 5 min of monopolar high-density EMG data from an 8x8 electrode 
grid (inter-electrode distance: 8.5mm) which was placed between T12 and L3 on the right 
side of the spine.
rows = time
columns = channels
   spatial location of colums (ie channels):
   [  ]    1  2  3  4  5  6  7  8
   [L1]    9 10 11 12 13 14 15 16
   [  ]   17 18 19 20 21 22 23 24
   [  ]   25 26 27 28 29 30 31 32
   [  ]   33 34 35 36 37 38 39 40
   [  ]   41 42 43 44 45 46 47 48
   [L2]   49 50 51 52 53 54 55 56
   [  ]   57 58 59 60 61 62 63 64

------ 3. Table of Contents
ExampleScript.m		general/main script
ddHDsEMG.m		function to compute double differential from monopolar channels
peakdelay.m		function which runs the peak delay method
winmean.m		function to compute windowed average/median
plotPeakMatches.m	function to plot the conduction velocity of matched peaks
plotCVtimeseries.m	function to plot the conduction velocity time series
ExampleData.mat		Example data file

------ 4. How to use
Run the main script ExampleScript.m
The code runs from MATLAB 2019a onwards. Earlier MATLAB versions are not tested.

------ 5. Credits:
Please cite:

Brouwer, N. P., Tabasi, A., Kingma, I., Stegeman, D. F., van Dijk, W., Moya-Esteban, A., 
Sartori, M., & van Dieën, J. H. (2022). Low back muscle action potential conduction 
velocity estimated using high-density electromyography. Journal of Electromyography and 
Kinesiology, 66, 102679. https://doi.org/10.1016/j.jelekin.2022.102679

and

Brouwer, N. P., Tabasi, A., Kingma, I., Stegeman, D. F., van Dijk, W., Moya-Esteban, A., 
Sartori, M., & van Dieën, J. H. (2023). Trunk extensor muscle endurance and its 
relationship to action potential conduction velocity and spectral parameters estimated 
using high-density electromyography. Journal of Electromyography and Kinesiology, 73, 
102830. https://doi.org/10.1016/j.jelekin.2023.102830

Code upload:
DOI: 10.5281/zenodo.11358225

------ 6. Contact:
Jaap van Dieën
E-mail address: j.van.dieen@vu.nl