Abstract: Spectrometer is a key control unit in magnetic resonance imaging (MRI) systems. Pulse programmer of the spectrometer outputs multi-channel instructions to control each hardware component separately, and to coordinate work, collect data, and reconstruct image. Relative time delay among the hardware components may disable the system, or affect the quality of the images acquired. This work designed a pulse programmer whose output channels all boasted adjustable time delay capability. The maximal time delay for each channel was 819 μs, and the step time delay was 50 ns. As such, accurate compensation to relative time delay could be achieved. By adding independent delay circuits on every output channel of the pulse programmer, adjustable time delay capability was achieved. The pulse programmer proposed has the advantages of simple structure and high flexibility.

Key words: pulse programmer, relative delay, independent delay capability, magnetic resonance imaging (MRI)