Data converter for CT data acquisition system

摘要

A data acquisition system employs data conversion circuitry well suited to large multisensor systems such as computerized tomography systems utilizing X-ray detectors. The data conversion system consists of a number of detectors or similar signal sources and a corresponding number of data registers and accumulation registers. Each data register contains a previous sample output of a signal source. Differential data conversion is employed such that the difference between the previous output and the current signal source output is added to the data register in order to update it to the current signal source output. Each signal source is repeatedly sampled and the samples accumulated in an accumulation register. The data conversion system thus provides increased system linearity, accuracy, and dynamic range, and yields improved measurement simultaneity of a large number of signal sources. These factors combine to result in substantial improvement in image resolution after suitable processing by a computer. Increased resolution and dynamic range is achieved through oversampling and a differential data conversion technique, which may be implemented at relatively low cost with largely conventional components.