FPGA-based pulse pileup correction

Abstract

Modern Field Programmable Gate Arrays (FPGAs) are capable of performing complex discrete signal processing algorithms with clock rates above 100MHz. This combined with FPGA’s low expense, ease of use, and selected dedicated hardware make them an ideal technology for a data acquisition system for a positron emission tomography (PET) scanner. The University of Washington is producing a high-resolution, small-animal PET scanner that utilizes FPGAs as the core of the front-end electronics. For this next generation scanner, functions that are typically performed in dedicated circuits, or offline, are being migrated to the FPGA. This will not only simplify the electronics, but the features of modern FPGAs can be utilizes to add significant signal processing power to produce higher resolution images. In this paper we report on an all-digital pulse pileup correction algorithm that is being developed for the FPGA. The pileup mitigation algorithm will allow the scanner to run at higher count rates without incurring large data losses due to the overlapping of scintillation signals. This correction technique utilizes a reference pulse to extract timing and energy information for most pileup events. Using pulses were acquired from a Zecotech Photonics MAPDN with an LFS-3 scintillator, we show that good timing and energy information can be achieved in the presence of pileup.

A Building Block for Nuclear Medicine Imaging Systems Data Acquisition

“…The board also has one high speed (> 300 MHz) ADC channel for those detectors that provide a fast timing pickoff signal. The Phase II board is designed around a family of high performance FPGAs from Altera, and we have developed a wide range of pulse integration, timing, and processing algorithms for the device [4][5][6][7]. Figure 2 is a diagram of the basic FPGA logic structure that supports our cMiCE detectorsand represents the most demanding use of the Phase II board resources we have implemented to date.…”

Pile-up discrimination method applied to novel gamma-ray detectors based on SiPMs arrays

“…The addition of the pile-up information to the acquired data will permit us to investigate experiments with higher count rates [2]. It is the current practice to increase the injection doses to mice in order to improve the signal to noise ratio, or to reduce the scanning time and, thus, improving the workflow.…”