Image Quality Assurance - KaVo FS Ergo User And Installation Manual

6 Maintenance
• Always place holders in autoclave bags. The sterilization bag must be large enough
for the holder to fit without stretching the bag. Seal each holder individually in a
sterilization item package.
• Run the appropriate autoclave cycle according to ANSI/AAMI ST79 & A1 & A2 & A3:
275°F (135°C) for 10 minutes, drying time minimum 30 minutes.
• Always avoid direct contact of the holders with metal trays, instruments, and heating
elements.
• Always situate bagged holders into the autoclave so that they are furthest from the
heat source.
• Do not use a chemical autoclave. The holder material may deteriorate when using
unapproved chemicals.
Exposing the holders to hot metal and placing them close to heating elements will reduce
the lifetime of the holders.
Process the sensor holders before first use.
If the infection control guidelines of your country permit, the holders can disinfected with
a cleaning agent. Follow the cleaning agent manufacturer´s instructions.
The microbiological efficacy of the disinfectant must be ensured by the disinfectant
manufacturer and proven by an expert opinion.

6.3 Image quality assurance

Image quality of the sensor depends on several factors:
• the quality of the X-ray source (kV, focal spot size, distance)
• the alignment of the X-ray source to the anatomic region
• the applied X-ray dose/exposure time
• the patient remaining still during exposure period
• the settings of the computer monitor.
It is recommended to check the image quality monthly. If image quality is not
satisfactory, or if it is degrading, check the contributing system parts as instructed
below:
X-ray dose/ Exposure time settings
• The sensor has been designed to be used with a wide range of dose settings, to allow
adjustments of the dose to the specific diagnostic task, and to compensate for both
under and overexposure. Start by using dose/exposure time settings recommended
by your X-ray source manufacturer for digital X-ray sensors.
• The sensor can be used with low dose/exposure time settings. Nevertheless, low dose
operation of a digital sensor can result in grainy images. If the image of the sensor
appears grainy, increase the dose settings. If you obtain good results with a particular
setting, you might try a lower dose setting to see if you still gain good results.
• The sensor can be used at higher dose/exposure time settings if needed for a
particular diagnostic task. At high dose/exposure time settings, it might not be
possible to distinguish air from soft tissue. Such regions may appear overexposed. If
air and soft tissue regions in the image appear overexposed, reduce the dose settings.
• You may need to adjust the duration setting to compensate for tooth type (central
incisor to molar) and the patient´s body size (larger adult to small child). The settings
you choose should be what you consider to be suitable for your diagnostic needs.
X-ray sharpness/contrast
Many parts of the X-ray imaging system contribute to the sharpness and contrast of
the image. It is recommended to use a dental phantom for a periodic (at least annual)
assessment of the image quality by performing a side-by-side comparison of an initial
dental phantom image to a current dental phantom image to ensure that the images
have sufficient quality for diagnostic purposes in your application.
28 FS Ergo Sensor