What is the term to describe the polarity switch on a biphasic waveform?

• A. Tilt
• B. Phase shift
• C. Reversal
• D. Inversion

Answer: (A)

The polarity switch in a biphasic stimulus is described as tilt. In a biphasic waveform, the current begins in one direction and then reverses to the opposite direction, creating two opposite phases. Tilt is the term used to describe how the waveform transitions between those two phases—the way the amplitude “tips” from the first phase into the second and how the two phases are balanced in time and shape. This concept matters because the tilt of the waveform affects how effectively and safely the stimulation delivers energy. By contrast, phase shift implies a timing offset without necessarily capturing the two-phase shape, while reversal or inversion simply implies flipping polarity without describing the structured two-phase transition.