Automatic gain calibration for gamma camera system
US5449897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Oct 3, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01T1/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
An automatic gain calibration system for photomultipliers of a scintillation detector operable during periods when a collimator is installed to the scintillation detector. The system provides for calibration of the photomultipliers (PMTs) that are located along the periphery of the detector whose surfaces that are partially or totally obscured by the solid lead edge regions of the installed collimator (e.g., obscured PMTs). In such a manner, the entire scintillation detector may be calibrated effectively without removal of the heavy and awkwardly handled collimator. The automatic calibration system adjusts the preamplification gain associated with each channel of the PMT array to maintain the effective gain of each PMT in response to long term variations in the characteristic gain of each PMT. For calibration, the system measures the response of an obscured PMT to gamma events occurring within a thin strip area that extends into the central portion of the collimator. There is a separate strip area for each obscured tube. The preamplification gain of an obscured tube is then calibrated, when the collimator is installed, based on a recorded value of an originally calibrated response …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.