Question

The main design feature of pregelled disposable electrodes which helps to reduce the possibility of artefacts, drift and baseline wandering is _____________

(a) low absorbency buffer layer with isotonic electrolyte

(b) high absorbency buffer layer with isotonic electrolyte

(c) high absorbency buffer layer without  isotonic electrolyte

(d) low absorbency buffer layer without isotonic electrolyte

I got this question by my school principal while I was bunking the class.

Question is taken from Electrodes for ECG topic in chapter Bioelectric Signal and Electrodes of Biomedical Instrumentation

Answer 1

Right option is (b) high absorbency buffer layer with isotonic electrolyte

The explanation is: The main design feature of pregelled disposable electrode that helps in reducing the possibility of artefacts, drift and baseline wandering is the provision of high absorbency buffer layers with isotonic electrolyte. This layer absorbs the effects of movement of the electrode in relationship to the skin and attempts to maintain the polarization associated with the half-cell potential constant.