What is the function of a transmit/receive switch and how does it protect the transducer during pulsed operation?

• A. It doubles as the power supply.
• B. It protects the transducer by isolating the receiver during transmission; enables timing.
• C. It increases the frequency of emitted waves.
• D. It measures tissue attenuation.

Answer: (B)

During pulsed ultrasound, the transducer both emits a high-voltage pulse and then listens for echoes. The transmit/receive switch isolates the receiver during transmission, routing the pulse to the transducer while preventing that powerful signal from reaching and potentially damaging the receiver electronics or the transducer elements themselves. Immediately after the pulse, the switch quickly reconnects the receiver so the returning echoes can be captured. This precise timing protects the hardware from overload and ensures the system is ready to detect echoes at the right moment, enabling clean, accurate signal reception. In short, it both shields the transducer/receiver during the transmit phase and coordinates the switch to the receive phase for pulsed operation.