Hello Peter Gooding

The likely answer to your question, I think, is no. UNLESS it is an absolutely critical part of your methodology and it is inherently linked to your hypothesis - for example, if you are showing why that electrode is better. If it is only that you need to acquire an ECG (or multiple electrocardiographs) for the study for data collection purpose, then your methodology has not really changed.

You would have to note it in your write-up but I would not think it stops you from your research.

For a number of years, I was involved in seeing results from EKG, and Ambulatory EKG hook-up data. I can say from that experience all electrodes are not created equally especially when high fidelity signal and high resolution signal is required. Later for several years I worked with a portable telemedicine device were we demonstrated this in sweaty environments often with military simulation events. And further for another period of a few years, worked directly with Microvolt T Wave Alternans and Stress Tests. We did not have good experiences with the replacement you mentioned. We did in several settings have good experiences with Nissha Medical Vermed Sensors. They had a variety of levels of sensors for different levels of time attached to body or humidity etc and EMS needs. I would for sure not recommend what you mentioned as your potential replacement as we did not get good results with those, we saw much artifact in the trace obscuring things like ST segment, P moving through T, or even delta waves in WPW. Poor skin prep can also add to the problem of artifact, would discourage against using NuPrep or any gel skin prep. Nissha was so good at the electrodes they manufactured under the Vermed label, they were even private labelled for a variety of MCT, and other ambulatory monitoring manufacturer branding, and also manufactured an ICG Impedance eletrocardiography electrode.

I have no disclosures and do not sell or market electrodes for anyone.

Yes, as long as you prepare the skin properly. Skin resistance is around 10K ohms and is the primary reason for noise, artifact, etc.

"Is it ok to change ECG Electrodes mid research?" / Maybe....

Electrodes vary in contact type, chemistry, adhesive used and output. For example: Older electrodes may show output differences when compared to newer ones of the same exact type (higher noise and loss of signal as they age). Variation over time is normal. We have observed many differences in the output of commercially available new electrodes (different brands and models) so it is best to use the same exact type for any study that relies on the raw data collected. If your study only reviews general ECG findings and NOT measured voltages, and you obtain clean signals with no noise issues, then you may be OK substituting electrodes. Same may be true of the ECG instrument (ideally, use the same one). Documentation is of course critical in any situation.

That's great thank you !