Explain how an ECG electrode is made indifferent and what the significance of an indifferent electrode is in ECG.

Here's the explanation:

• Closed Circuit Principle: In a closed electrical circuit, the algebraic sum of potentials neutralizes each other, resulting in a net sum of zero.
• Common Terminal: When the three limb electrodes are connected to a single common terminal, they form such a closed circuit. Consequently, the electrical potential at this common terminal becomes zero.
• Wilson's Electrode: This common terminal, now at zero potential, is then connected to the negative pole of the electrocardiograph. This setup creates an indifferent electrode, also known as Wilson's electrode.
• Absolute Potential Measurement: With one electrode fixed at zero potential, any "exploring electrode" (connected to the positive pole of the electrocardiograph) placed elsewhere on the body (limbs or chest) will then record the absolute electrical potential at that specific point, rather than a potential difference between two active points.