Which term refers to the heated device that records the heart's activity on heat-sensitive graph paper?

• A. Standard limb lead
• B. Standardization mark
• C. Stylus
• D. Tracing

Answer: (C)

The term refers to the heated device that records the heart’s activity on heat-sensitive graph paper is the stylus. In ECG equipment, the stylus is the heated pen that traces the electrical signal from the heart onto the chart as the paper moves. The heat makes a mark on the paper, creating the visible tracing of the ECG waveform.

The other terms describe something else: a standard limb lead is a type of ECG electrode configuration, a standardization mark is a calibration mark on the strip, and a tracing is the final recorded waveform itself, not the writing instrument.