The root cause of this shortcoming is as follows: the CGH is not placed at an image conjugate of the asphere due to limitations imposed by the geometry of the test and the allowable size of the CGH. Existing CGH technology suffers from a reduced capacity to calibrate middle and high spatial frequencies. A typical scenario is the testing of aspheric surfaces with an interferometer placed near the paraxial center of curvature. 8 refsĬomputer Generated Hologram System for Wavefront Measurement System CalibrationĬomputer Generated Holograms (CGHs) have been used for some time to calibrate interferometers that require nulling optics. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers.
#SONY VEGAS PRO 80 SERIAL 1FW CODE#
The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system.
Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems.
Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. International Nuclear Information System (INIS)
Absolute calibration in vivo measurement systems