MSc thesis presentation Stefan van Waalwijk van Doorn

Date:
21 June
Time:
15:30 - 16:30
Location:
Matrix 1.60

A lot of research is done towards skin electrodes, a part of this research is focused on improving the quality of bio-electrical signals measured on the skin, in order to make it possible to measure even smaller amplitude signals. An example of an application that benefits greatly from this research is an electrode patch to measure fetal ECG (electrocardiogram) on a pregnant belly.

One of the biggest challenges on this topic is the noise that exists between the electrolyte gel and the human skin. This is a phenomenon that has been studies for a while but still it not well understood. A reason for this is that it is hard to isolate and measure only a part of the skin-electrode  interface. Another reason is the complexity of the skin which is still hard to understand all processes going on and model them correctly. Without a model the measurements are still done directly on the human skin meaning other unwanted events like EMG (Electromyogram) from the muscles is picked up as well and interferes with the results. All these challenges are to blame for the many inconsistencies found in literature about this topic. Some other effects like differences in the protocols used during measurements make it hard to find possible electrode solutions from research and compare their results.

This is the reason why Holst Centre wants one working protocol to compare different electrode solutions and will be able to use it to improve electrodes in the future for applications like the fECG patch. During my research I build a setup to execute some experiments to get further insight in the challenges for the protocol to benchmark the different electrode solutions for small biosignal sensing. Because skin prepping plays an important role in the electrolyte-skin noise source, a new improved method for skin preparation with a micro-needle roller was compared to the normally used abrasive method with sandpaper.