Detector signal readout channel multiplexing method

Abstract

A detector signal readout channel multiplexing method comprises the steps as follows: grouping L detectors to form a first source signal and a second source signal; respectively introducing L detector signals into a first signal transmission line including two readout channels A and B and a second signal transmission line including two readout channels C and D, and simultaneously introducing first signal delay units and second signal delay units to the first signal transmission line and the second signal transmission line; and marking source detectors for signal forming according to the four readout channels A, B, C and D and obtaining final pulse information. According to the invention, only four readout channels are needed for one flat plane detector, and the problem that the number of one-to-one readout channels is too large is solved effectively. Time division multiplexing design of the transmission lines ensures that the waveform of signals output by detectors in different positions is similar to the mode of one-to-one readout, and the requirement on the dynamic range of a backend readout circuit is lowered. Moreover, the delay units are added, which greatly lowers the requirement on the time resolution of the backend readout circuit.

Description

technical field [0001] The invention relates to the fields of nuclear detection technology and nuclear medical imaging technology, in particular to a channel multiplexing method for detector signal readout. Background technique [0002] In a clinical positron emission tomography (Positron Emission Tomography, hereinafter referred to as PET) equipment, the number of detectors is as many as 30,000. Direct readout of the electrical signal produced by each detector requires 30,000 channels of electronic processing. The large number of electronic channels makes the entire PET electronic system expensive and difficult to implement. [0003] In response to the above situation, researchers focused on the research and development of channel multiplexing technology for detector signal readout. The current mainstream readout channel multiplexing method is to weight the output signal of the detector signal by row and column with a resistor network and then read it out. [0004] The u...

AI Technical Summary

Problems solved by technology

However, when the resistance network is used, due to the different signal access points, the equivalent resistance of the resistance network for different detectors is also different, which eventually causes a large difference in the output signal amplitude of different detectors, requiring the back-end readout The circuit has a high dynamic range

However, the current conventional processing circuit has a limited dynamic range, and the signal-to-noise ratio is poor when the input signal is small, and there will be saturation problems when the input and output signals are too large.

[0005] Therefore, in view of the above technical problems, it is necessary to provide a channel multiplexing method for detector signal readout with an improved structure, to overcome the above defects, and effectively solve the problem that the dynamic range of the output signal after the multiplexing of the detector channels is too large

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