Duty cycle in therapeutic ultrasound is defined as what?

Duty cycle in therapeutic ultrasound is defined as what?

• A. The percentage of time that ultrasound is being generated during one pulse period.
• B. The total duration of a treatment session.
• C. The ratio of heating to cooling time.
• D. The frequency of the ultrasound waves.

Answer: (A)

Duty cycle is the fraction of each ultrasound pulse period when the transducer is actually emitting. It’s calculated as on-time divided by the total cycle time, usually expressed as a percentage. This matters because it controls how much energy is delivered: higher duty cycles deliver more energy and heat, while lower ones deliver less energy and emphasize non-thermal effects. Continuous ultrasound effectively has a duty cycle of about 100% because it’s on the entire time. The total duration of a treatment session and the operating frequency are different concepts—treatment time is how long the session lasts, while frequency is how many cycles occur per second. The heating-to-cooling ratio isn’t the standard way we describe the output. So, the definition described—percentage of time the ultrasound is on during one pulse period—is the correct concept.

Duty cycle is the fraction of each ultrasound pulse period when the transducer is actually emitting. It’s calculated as on-time divided by the total cycle time, usually expressed as a percentage. This matters because it controls how much energy is delivered: higher duty cycles deliver more energy and heat, while lower ones deliver less energy and emphasize non-thermal effects. Continuous ultrasound effectively has a duty cycle of about 100% because it’s on the entire time. The total duration of a treatment session and the operating frequency are different concepts—treatment time is how long the session lasts, while frequency is how many cycles occur per second. The heating-to-cooling ratio isn’t the standard way we describe the output. So, the definition described—percentage of time the ultrasound is on during one pulse period—is the correct concept.