Nev2lkit enhanced: An enhanced version of nev2lkit

Nev2lkit enhanced can sort successfully larger amount of spikes and adapt to low SNRs.

See Nev2lkit enhanced in action here: Live Demo

Nev2lkit is a preprocessor for the analysis of intra- or extracellular neuronal recordings. It can plot the data of a ‘format-supported’ opened file and automatically sort the units, a procedure that is reffered to as Spike Sorting.

Nev2lkit was developed by Daniel Micol for the Unit of Neuroprosthesis and Visual Rehabilitation, Institute of Bioengineering, University Miguel Hernandez of Elche under Cortivis project.

New features have been added to Nev2lkit’s source code, in order to provide enhanced functionality to the spike sorting process. In summary, the following features were added:

1. Variable Length Data Window
The ability of applying Principal Component Analysis on a variable-length data window was implemented, following 0.1 ms accuracy. The data window defines the spike waveform length that is taken into account in the spike extraction process and afterwards inserted into PCA. With this feature, the software can adopt in variable-length spiking activity and avoid the insertion of artifacts.

2. Variability of Principal Components
The ability to select the number of principal components used to perform spike waveform representation by PCA, was also added. The number of engaging principal components (between 2 & 7) can now be selected.

3. Calculation and Display of Variance
In spike waveform representation by the principal components, the percentage variance captured by that subspace is computed and displayed in the program’s graphical interface.

4. Spike Count in Each Cluster
Besides the total count of the detected spikes by the extraction process, the ability of displaying the number of spikes assigned to each cluster (as an additional output of the clustering process), was added.

These additional features are demonstrated in action below:

In order to exploit the above changes building the patched version of nev2lkit, we have issued a patch which is available for download here. (Please do note that nev2lkit requires Qt 3.* and Qwt 4.* to compile properly)

NEW! Precompiled binaries

o Mac OS X version 10.5 “Leopard” (Packed with Qt & Qwt libraries)
o Linux Ubuntu (x86) version 8.10 (Information about Qt & Qwt libraries are available here as well).

The development of this work was made by Dimitrios A. Adamos in the Laboratory of Animal Physiology, School of Biology, Faculty of Science, Aristotle University, Thessaloniki 54124, Greece.

This work was implemented in the context of PYTHAGORAS II (EPEAEK) project, a research program funded by the Greek Ministry of National Education and Religious Affairs.

For citation use:

1. Adamos D.A., Kosmidis E.K and Theophilidis G., ”Performance evaluation of PCA-based spike sorting algorithms“, Computer methods and programs in biomedicine (September 2008), vol. 91 (3) pp. 232-44.

An enhanced version of nev2lkit by Dimitrios A. Adamos is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Greece License.
Based on a work at http://nev2lkit.sourceforge.net.