Digital event detection in a nuclear imaging system
AssigneeSiemens Medical Solutions USA, Inc.
InventorRoger E. Arseneau
Life of this patent
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Abstract
Digital detection of the occurrence of nuclear medicine radiation interaction events in a detector utilizes a digital energy signal sample to trigger signal processing of event signals from the detector by performing mathematical operations on the energy signal sample to determine the existence of a set of predetermined conditions that indicate the beginning of an interaction event in the detector.
Claims21
A method of determining the start time of a gamma interaction in a nuclear imaging detector, comprising the steps of:
- obtaining a digital sample of an energy signal from said nuclear imaging detector;
- calculating a second derivative of said digital sample;
- determining when said second derivative has returned to zero after first reaching a maximum value;
- and
- upon determination that said second derivative has returned to zero, triggering an event start signal that initiates signal processing of signals from said nuclear imaging detector.
A method of determining the start time of a gamma interaction in a nuclear imaging detector, comprising the steps of:
- obtaining a digital sample of an energy signal from said nuclear imaging detector;
- calculating a second derivative of said digital sample;
- determining when said second derivative has returned to zero after first reaching a maximum value;
- upon determination that said second derivative has returned to zero, triggering an event start signal that initiates signal processing of signals from said nuclear imaging detector, determining whether a value of said sample is greater than a first preselected value, determining whether an event signal was previously generated when a value of said sample was greater than a second preselected value, and triggering output of a pulse pile-up detection signal when results of said last two determining steps are affirmative.
A computer program product comprising a computer-readable storage medium containing computer-executable instructions stored thereon, including computer-executable instructions for:
- obtaining a digital sample of an energy signal from a nuclear imaging detector;
- calculating a second derivative of said digital sample;
- determining when said second derivative has returned to zero after first reaching a maximum value;
- and
- upon determination that said second derivative has returned to zero, triggering an event start signal that initiates signal processing of signals from said nuclear imaging detector.
A circuit for determining the start time of a gamma interaction in a nuclear imaging detector, comprising:
- means for obtaining a digital sample of an energy signal from a nuclear imaging detector;
- means for calculating a second derivative of said digital sample;
- means for determining when said second derivative has returned to zero after first reaching a maximum value;
- and
- means for triggering an event start signal that initiates signal processing of signals from said nuclear imaging detector, upon determination that said second derivative has returned to zero.
A method of determining the start time of a gamma interaction in a nuclear imaging detector, comprising the steps of:
- obtaining a digital sample of an energy signal from said nuclear imaging detector;
- performing a sequence of predetermined mathematical operations on said digital sample;
- and
- upon determination that results of said sequence of operations meet a set of one or more preselected conditions, triggering an event start signal that indicates the start time of said gamma interaction and initiates signal processing of signals from said nuclear imaging detector.
A method of determining the start time of a gamma interaction in a nuclear imaging detector, comprising the steps of:
- obtaining a digital sample of an energy signal from said nuclear imaging detector;
- comparing said digital sample with a predetermined threshold value;
- if said digital sample exceeds said predetermined threshold value, performing a sequence of predetermined mathematical operations on said digital sample;
- and
- upon determination that results of said sequence of operations meet a set of one or more preselected conditions, triggering an event start signal that initiates signal processing of signals from said nuclear imaging detector.
Dependencies are inferred from the claim text.