At a duty cycle of 20%, what is the ultrasound machine's active time per 10 ms?

To determine the active time of the ultrasound machine at a 20% duty cycle over a period of 10 ms, you need to apply the definition of duty cycle. The duty cycle represents the proportion of time that the ultrasound is actively emitting sound waves compared to the total time of the cycle.

In this case, a 20% duty cycle means that the ultrasound is actively sending out waves for 20% of the total time. To calculate the active time, you multiply the total time (10 ms) by the duty cycle (expressed as a decimal):

Active time = Total time × Duty cycle

Active time = 10 ms × 0.20

Active time = 2 ms

Thus, the ultrasound machine is actively emitting sound for 2 ms during a 10 ms period when operating at a 20% duty cycle. This calculation shows how duty cycle directly impacts the duration of active ultrasound application, reflecting the balance between active and rest periods to ensure effective treatment while minimizing potential overheating or tissue damage.