ABSTRACT
Objective To investigate and design a coincidence detection system for an all-digital small animal PET scanner and evaluate its preliminary performance properties.Methods This coincidence module adopted a coincidence identification mode based on singles data in list-mode.Using digital signal processing technology,energy calibration,crystal identification,timing alignment and coincidence events extraction were performed on singles data in list-mode.The obtained data could be used for image reconstruction.Results The 13 × 13 crystal array was well recognized by the position histogram of one lutetium yttrium orthosilicate (LYSO) crystal block.In the coincidence timing histogram of the micro-Derenzo phantom,1.36 ns full width at half maximum was obtained.The rods with a diameter of 1.2 mm were clearly displayed in the reconstructed image of the micro-Derenzo phantom.Conclusion The coincidence module can provide satisfactory performance to meet the design needs of an all-digital small animal PET scanner.
ABSTRACT
This paper presents a new pulse oximeter used to low perfusion at 0.125% and wide oxygen saturation range from 35% to 100%. In order to acquire the best PPG signals, the variable gain amplifier(VGA) is adopted in hardware. The self-developed auto-correlation modeling method is adopted in software and it can extract pulse wave from low perfusion signals and remove motion artifacts partly.