Patent ID: 6252531
Filing Date: 2001-06-26
Classification: H03M

Abstract:
A CT scanner comprising a source of X-rays, an array of detectors for detecting X-rays emitted by said source and received by said detectors, and a data acquisition system for processing signals generated by said detectors, said data acquisition system comprising a plurality of oversampling delta-sigma A/D converters, each of said delta-sigma A/D converters comprising:a delta-sigma modulator for providing an intermediate digital output signal as a function of said analog input signal; anda filtering arrangement for decimating the data rate of and for filtering said intermediate digital signal so as to generate a digital output signal at a view rate, f.sub.VR, said filtering arrangement including a filter providing gentle roll-off within a frequency band of interest between DC and f.sub.INF, and roll-off at 2*f.sub.VR exceeding -100 dB/octave, wherein f.sub.VR is at least twice f.sub.INF.