Gantry position reference for tomographic scanners

US5175754A · kind A · utility

Assignee

• General Electric Company · US

Inventors

• Colin J. Casey · Fort Wayne, US
• Russell Wayne Hum · Waukesha, US
• Phil E. Pearson, Jr. · Pewaukee, US
• Judith A. Clifford · Temple Terrace, US
• Harold Dalman · Brookfield, US

Key dates

• Filing date: May 11, 1992
• Grant date: Dec 29, 1992
• Expiry date: May 11, 2012

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05G1/26
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A CT apparatus produces a trigger position signal having a programmable angular spacing, for triggering the acquisition of projections, from an encoder index pulse having a different fixed angular spacing. An estimation circuit estimates the time of occurrence of a next pulse in the trigger position signal by evaluating the timing of the encoder index pulses. The estimation circuit may be a phase-locked-loop or a set of lookup tables keyed to gantry position and speed.