Method to improve the time resolution of digital silicon photomultipliers
AssigneeKoninklijke Philips Electronics N.V.
InventorsThomas Frach, Gordian Prescher
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Abstract
A radiation detector module (10) for use in a time-of-flight positron emission tomography (TOF-PET) scanner (8) generates a trigger signal indicative of a detected radiation event. A timing circuit (22) including a first time-to-digital converter (TDC) (30) and a second TDC (31) is configured to output a corrected timestamp for the detected radiation event based on a first timestamp determined by the first TDC (30) and a second timestamp determined by the second TDC (31). The first TDC is synchronized to a first reference clock signal (40, 53) and the second TDC is synchronized to a second reference clock signal (42, 54), the first and second reference clock signals being asynchronous.
Claims21
A timing circuit, comprising:
- a first time-to-digital converter (TDC) configured to output a first timestamp in response to a detected event based on a first reference clock signal;
- at least a second TDC configured to output a second timestamp in response to said detected event based on a second reference clock signal, the at least first and second reference clock signals being temporarily offset;
- and
- a circuit operatively connected to each TDC configured to output a corrected timestamp based on the at least first and second timestamps.
A method for assigning a timestamp to a detected event, including:
- generating a first reference clock signal;
- generating at least a second reference clock signal, the at least first reference clock signal and the second reference clock signal being non-synchronous;
- receiving a trigger signal in response to a detected event;
- determining a first timestamp based on a temporal relationship between the trigger signal and the first reference clock;
- determining at least a second timestamp based on a temporal relationship between the trigger signal and at least the second reference clock;
- and
- outputting a corrected timestamp based on at least the first timestamp and the second timestamp.
A method for associating a time index to a detected event, including:
- using a first TDC to associate time indices to detected events;
- if a detected event occurs during a metastable phase of the first TDC, using at least a second TDC to associate a time index to the detected event;
- and
- providing the time indices to detector circuitry.
Dependencies are inferred from the claim text.