Duty cycle in electrical stimulation is defined as the ratio of what to what?

Duty cycle in electrical stimulation is defined as the ratio of what to what?

• A. On time to off time
• B. Off time to on time
• C. On time to total time
• D. Frequency to amplitude

Answer: (A)

Duty cycle describes how much of a stimulation cycle is spent delivering current versus resting. Expressing that pattern as the comparison of active time to inactive time—on time to off time—directly shows how long the stimulus is on relative to how long it is off. If the on time is long compared to the off time, the pulses are dense and the cycle has a high duty. In practice, some definitions use on time divided by the total cycle time (on plus off) to get the percentage of time the stimulus is on, but the fundamental idea captured by this ratio is the balance between active and rest phases. The other ratios don’t reflect that balance: off time to on time reverses the relationship; on time to total time mixes in the full cycle rather than comparing the active versus resting parts; frequency to amplitude concerns different parameters entirely.

Duty cycle describes how much of a stimulation cycle is spent delivering current versus resting. Expressing that pattern as the comparison of active time to inactive time—on time to off time—directly shows how long the stimulus is on relative to how long it is off. If the on time is long compared to the off time, the pulses are dense and the cycle has a high duty. In practice, some definitions use on time divided by the total cycle time (on plus off) to get the percentage of time the stimulus is on, but the fundamental idea captured by this ratio is the balance between active and rest phases. The other ratios don’t reflect that balance: off time to on time reverses the relationship; on time to total time mixes in the full cycle rather than comparing the active versus resting parts; frequency to amplitude concerns different parameters entirely.