The essential component that converts ultrasound waves into electrical signals is:

The transducer is the critical component in ultrasound systems that converts ultrasound waves into electrical signals. During ultrasound imaging, the transducer emits sound waves into the body and receives the echoes produced when these sound waves encounter different tissues and interfaces. The ultrasound waves are then transformed into electrical signals through a process known as piezoelectricity. Specifically, the piezoelectric crystals within the transducer vibrate in response to the returning echoes, generating electrical signals proportional to the intensity and frequency of the received sound waves. These electrical signals are then processed to create the images displayed on the monitor.

The other components like the display, scan converter, and CPU play supportive roles in the ultrasound system. The display presents the images produced by the processed signals, the scan converter translates the received electrical signals into a format suitable for display, and the CPU manages the overall operation of the ultrasound machine, including data processing and user interface functions. They are essential for the functioning of the system but do not directly perform the conversion from ultrasound waves to electrical signals.