Analog to digital conversion shift error correction
AssigneeKoninklijke Philips Electronics N.V.
InventorDonald R. Wellnitz
Life of this patent
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Abstract
A method for correcting energy values of pulses from a nuclear medicine camera for errors due to Analog to Digital conversion shift includes determining a relationship between a subset of samples selected from a set of samples from the pulse, the relationship being expressed in the form of a code. A conversion table is accessed which provides a list of codes and corresponding conversion factors. The conversion factor for the closest code to that of the subset of samples is selected from the table and applied to an integration of the set of samples to correct the energy value of the pulse.
Claims21
A method of reducing errors resulting from a temporal shift between an analog pulse and digital sampling intervals, the method comprising:
- digitally sampling the analog pulse at a plurality of spaced sampling intervals to generate a set of digital samples;
- determining an integral from the samples in the set;
- selecting a subset of the samples;
- determining a correction factor corresponding to the subset of samples;
- and
- applying the correction factor to the integral to generate a corrected integral value.
(canceled)
A nuclear camera comprising:
- at least one detector head which generates energy pulses in response to received radiation;
- and
- a processor for integrating the pulses wherein the processor carries out the actions of:
- digitally sampling an analog pulse at a plurality of spaced sampling intervals to generate a set of digital samples;
- determining an integral from the samples in the set;
- determining a correction factor corresponding to at least a portion of the samples in the set;
- and
- applying the correction factor to the integral to generate a corrected integral value.
A system for reducing temporal shift errors between an analog pulse and a digital sampling interval comprising:
- a means for digitally sampling the analog pulse at sampling intervals to generate a set of digital samples;
- a means for determining an integral of the analog pulse from the set of digital samples;
- a means for selecting a subset of the digital values;
- a means for determining a correction factor from the subset of digital samples;
- and
- a means for applying the correction to the integral.
A system for reducing temporal shift errors between an analog pulse and a digital sampling interval comprising:
- an analog to digital converter for sampling the pulse at intervals of time to generate a set of digital samples;
- a correction table which assigns a correction factor to each of a plurality of codes, each of the codes corresponding to a relationship amongst samples in a subset of calibration samples, each of the subsets of calibration samples being selected from a different set of calibration samples, wherein each of the sets of calibration samples are shifted in time relative to a sampling interval;
- and
- a processor for calculating an integral of the pulse from the digital values and the correction factor.
Dependencies are inferred from the claim text.