Final answer:
The percentage of time that a pulsed ultrasound unit is actually on is known as the duty cycle. It is crucial for both diagnostic imaging and therapeutic applications like ultrasound diathermy to ensure effectiveness and patient safety.
Step-by-step explanation:
The percentage of time that a pulsed ultrasound unit is actually on is referred to as the duty cycle. The duty cycle is an essential parameter in medical ultrasound procedures as it determines the duration of ultrasound pulses emitted by the ultrasound machine. It plays a significant role in the imaging process as well as in therapeutic applications like ultrasound diathermy, where controlling the thermal energy delivered to tissues is crucial.
For example, in ultrasound diathermy, commonly used for deep-heat treatments, the skill of the therapist in managing the duty cycle is critical to prevent tissue damage due to overheating. With typical frequencies of between 0.8 to 1 MHz for these treatments, the duty cycle becomes a critical component to ensure patient safety and therapeutic efficacy.