Active transducer probes and circuits

An active ultrasonic probe comprising:

• a housing;
• a multichannel transducer disposed within the housing;
• and
• a bidirectional multichannel circuit disposed within the housing and including,
• (a) a first plurality of channel ports;
• (b) a second plurality of channel ports which are coupled to the multichannel transducer;
• (c) channel circuitry coupling the first plurality of channel ports to the second plurality of channel ports to provide a plurality of active channels, where each active channel includes:
• i) an amplifier having an input coupled to one of the second plurality of channel ports and an output;
• ii) an amplifier output protector including a solid state switch coupling the output of the amplifier to a channel port of the first plurality of channel ports, the solid state switch having an open position and a closed position;
• and
• iii) a controller coupled to the channel port of the first plurality of channel ports and to the amplifier output protector.