Total power in ultrasound therapy is measured in which unit?

Total power in ultrasound therapy is measured in which unit?

• A. Watts
• B. Volts
• C. Amperes
• D. Joules

Answer: (A)

Power is the rate at which energy is delivered. In ultrasound therapy, the transducer converts electrical energy into acoustic energy, and the total acoustic energy delivered per second—the power—is described in watts. Volts indicate electrical potential, and amperes indicate current, neither of which measures how quickly energy is transferred. Joules measure energy itself, not the rate. Often you’ll also see intensity expressed as watts per square centimeter, which shows how much power is delivered per area.

Power is the rate at which energy is delivered. In ultrasound therapy, the transducer converts electrical energy into acoustic energy, and the total acoustic energy delivered per second—the power—is described in watts. Volts indicate electrical potential, and amperes indicate current, neither of which measures how quickly energy is transferred. Joules measure energy itself, not the rate. Often you’ll also see intensity expressed as watts per square centimeter, which shows how much power is delivered per area.