Method and apparatus for coincidence imaging digital triggering

A trigger circuit for a coincidence imaging system, said trigger circuit comprising:

• an analog-to-digital converter coupled to a detector output;
• a set of N accumulators coupled in a circuit parallel to the output of the analog-to-digital converter wherein N is a predetermined value;
• and
• a shift register coupled to the output of said plurality of accumulators.

A trigger circuit for a coincidence imaging system, said trigger circuit comprising:

• an analog-to-digital converter coupled to a detector output;
• a plurality of N accumulators coupled to the output of the analog-to-digital converter wherein N is a predetermined value;
• a shift register coupled to the output of said plurality of accumulators, said shift register configured to output at least one of a Q1, a Q2, a Q3, and a Q4, where:
• Q1 represents a sum of N values sampled immediately prior in time to a predetermined y-axis,
• Q2 represents a sum of N values sampled substantially immediately subsequent in time to the y-axis,
• Q3 represents a sum of N values substantially centered on the y-axis, and
• Q4 represents a sum of N values sampled substantially prior in time to a start of a pulse rise of said detector output.

An imaging system comprising:

• a radiation detector positioned to receive radiation from an object under examination and generate a detector output relative to the received radiation;
• an analog-to-digital converter coupled to the detector output;
• a set of N accumulators coupled in a circuit parallel to the output of the analog-to-digital converter wherein N is a predetermined value;
• and
• a shift register coupled to the output of said plurality of accumulators.