Question

Which of the following reason is responsible for the Welsh cup electrodes to record the electrical signal of the heart?

(a) low contact impedance

(b) zero contact impedance

(c) high contact impedance

(d) negligible contact impedance

I got this question in semester exam.

Question is taken from Biotelemetry Application on Wimax Networks topic in section Biomedical Telemetry of Biomedical Instrumentation

Answer 1

Right answer is (c) high contact impedance

Easy explanation: It has a high contact impedance as only the rim of the electrode is in contact with the skin. Welsh cup electrodes or suction electrodes is a metallic cup shaped electrode which is used for recording ECG from various positions from the chest.  It is commonly used to record the unipolar chest leads.