[Eeglablist] heplab processing

[Pandelis Perakakis]

Hi Meha,

Regarding the use of filters, I would recommend to first try the peak
detection algorithms on your raw signal and use filters only if necessary.
The filter options by default work well on most signals but feel free to
experiment based on the characteristics of your own ECG signal. The purpose
is to make the R and/or T peaks as distinguishable as possible so that they
can be better identified by the algorithms.

Again, regarding the 3 available R detection algorithms, feel free to
choose the one that best performs on your particular signal. Some details
about these algorithms are provided in the "articles" folder.

Following peak detection you can save the detected events to the eeglab EEG
structure (using the "save events" button). After that you can run any ERP
analysis you would normally run with eeglab (e.g., extract epochs, remove
baseline, average epochs, etc). If you want to work directly on the timing
of R (or T) events you can export the HEP structure (Menu/edit/save HEP
structure) on your matlab workspace. You can then access the timing of the
detected events through the HEP.qrs variable and plot it as a function of
event number, or run other types of analysis (e.g., HRV). Please note that
the amplitude of the events is not saved because it is not relevant for HEP
research.

For questions specific to HEP analysis and interpretation I recommend
starting from the following paper:
Park, H.-D., & Blanke, O. (08/2019). Heartbeat-evoked cortical responses:
Underlying mechanisms, functional roles, and methodological considerations.
NeuroImage, 197, 502–511.

Hope I have been able to help. If you have further questions please let me
know through the list or a private email.

All best,
Pandelis


*–What you do is not important. It's why you do it that matters*

Pandelis Perakakis, PhD
Research Associate
Mind, Brain & Behaviour Research Centre (CIMCYC)
University of Granada

e-mail: peraka at ugr.es | perakakis at gmail.com
url: pandelisperakakis.info


On Sat, Mar 21, 2020 at 7:57 AM Meha Fatima <mehafatima1 at gmail.com> wrote:

> Hello.
>
>  I have 2-3 questions regarding heplab. I am just a beginner in heplab and
> seek answers following questions:
>
> What is the best band-pass filter length for R peak detection? I am using 3
> and 30 as indicated here https://github.com/perakakis/HEPLAB . Also, when
> do we use ecglab fast and ecglab slow?
>
> After processing data on heplab, how can I draw graphs showing amplitude
> versus time and p and r values)? (Is there any tutorial for that?)
>
> What are the possible ways to interpret heplab data?
>
> Is there a particular frequency at which HEP appear (for e.g at 5-10 Hz or
> 15-20Hz) more pronounced?
>
>
>
> Thanking you in anticipation.
> Regards.
>
> Meha.
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