Optical network-based PET DAQ system: One fiber optical connection

We are developing a DAQ system for an MRI compatible PET brain scanner using an optical transceiver to interconnect boards in a daisy-chained structure. For processing 576 differential detector signals, 18 DAQ boards are interconnected with only 18 optical patch cables. Using this optical connection, the system can globally synchronize all the analog-to-digital converters (ADCs) and time-to-digital converters (TDCs) in the system and process coincidence detection with singles rate above 100Mevent/sec. By replacing the signal lines used for parallel data buses, serial buses, control signals and clock signals with a single optical fiber channel, we minimized the number of interconnections between each DAQ unit, which greatly simplifies the scaling process. Proposed “asymmetric coincidence processing” method has higher coincidence-processing throughput in a given network bandwidth compared to the conventional coincidence processing methods thereby achieving only one fiber connection between DAQ units and higher throughput.