IEC 62494-1:2008 pdfダウンロード

IEC 62494-1:2008 pdfダウンロード。Medical electrical equipment – Exposure index of digital X-ray imaging systems – Part 1: Definitions and requirements for general radiography
1 Scope
This part of IEC 62494 specifies definitions and requirements for the EXPOSURE INDEX of images acquired with DIGITAL X – RAY IMAGING SYSTEMS .
This standard is applicable to DIGITAL X – RAY IMAGING SYSTEMS used in general radiography for producing PROJECTION X-ray images for general applications, such as,
but not exclusively:
• computed radiography (CR) systems based on stimulable phosphors;
• flat-panel detector based systems;
• charge-coupled device (CCD) based systems.
Image intensifier based systems and systems for mammographic or dental application are not covered in this first edition.
This standard defines the EXPOSURE INDEX
only for images generated with a single
IRRADIATION event. Images generated from multiple IRRADIATIONS (e.g., tomosynthetic or dualenergy images, multiple views on a single CR plate) are not covered.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC/TR 60788:2004, Medical electrical equipment – Glossary of defined terms
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC TR 60788 and the following apply.
3.1
CALIBRATION CONDITIONS
set of conditions under which EXPOSURE INDEX calibration is done
3.2
CALIBRATION FUNCTION
function expressing the VALUE OF INTEREST as a function of the IMAGE RECEPTOR AIR KERMA that is valid under CALIBRATION CONDITIONS
3.3
DETECTOR SURFACE
accessible area which is closest to the IMAGE RECEPTOR PLANE
NOTE After removal of all parts (including the ANTI – SCATTER GRID and components for AUTOMATIC EXPOSURE CONTROL , if applicable) that can be safely removed from the RADIATION BEAM without damaging the digital X-ray detector.
[IEC 62220-1 -2:2007, definition 3.3]
3.4
DEVIATION INDEX
DI
number quantifying the deviation of the actual EXPOSURE INDEX from a TARGET EXPOSURE INDEX
3.5
DIGITAL X-RAY IMAGING DEVICE
device consisting of a digital X-ray detector including the protective layers installed for use inpractice, the amplifying and digitizing electronics, and a computer providing the ORIGINAL DATA(DN) of the image
[IEC62220-1:2003，definition 3.5]
NOTE This may include protecting parts, such as anti-scatter grids or AEC components
3.6
DIGITAL X-RAY IMAGING SYSTEM
X-ray equipment using a DIGITAL X-RAY IMAGING DEVICE providing PROJECTION images in digitalformat, comprising subsystems allowing to process, display, print or store the images
3.7
EXPOSURE INDEX
EImeasure of the detector response to radiation in the RELEVANT IMAGE REGION of an imageacquired with a DIGITAL X-RAY IMAGING SYSTEM
NOTE For a fixed RADIATION QUALITY, the signal generated in the detector is proportional to the iMAGE RECEPTORAIR KERMA(or exposure).
3.8
IMAGE RECEPTOR AIR KERMA
AIR KERMA at the position of the DETECTOR SURFACE, free-in-air (excluding backscatter)
3.9
INVERSE CALIBRATION FUNCTIONfunction expressing the IMAGE RECEPTOR AIR KERMA as a function of the VALUE OF INTEREST thatis valid under CALIBRATION CONDITIONS
3.10
ORIGINAL DATA
DN
RAW DATA to which the corrections allowed in this standard have been applied