mobile x-ray units Flashcards
where do we use mobile radiography?
- A&E
- ITU (intensive therapy unit)
- CCU (coronary care unit)
- SCBU/NNU (special baby care unit/ neonatal)
what are the limitations of imaging patients outside main x-ray dept?
- equipment may differ
- wheeled base machine
- patient condition - may not be able to cooperate
- cramped examination areas
- need for consistent + optimum performance of equipment
- safety for staff and patients
how long does exposure handswitch cable have to be in hospital ward
2 metres long or have infrared remote control
what is the power supply of mobile x ray units
- mains dependent - HIGH freq
- only some battery operated
- dual powered
name some characteristics of high frequency mobile units
- short exposure times
- near constant potential output
- light + relatively inexpensive unit
what do capacitors do?
a device for storing electrical charge
what are the capacitors supplying
supply constant DC to freq converter (inverter)
cordless battery operated unit
- dont need to plug into mains for exposure
- lead acid batteries supply power to x-ray tube
- batteries supply DC
how long does battery last in cordless battery operated unit
18 months
what is cordless battery operated unit suitable for
chest radiography or paed intensive care unit
what is output of cordless battery operated unit
20/30/40/50kW
what is a dual powered hybrid
- mains to charge batteries
- battery/ mains for exposure
- exposure can be made if batteries not FULLY charged
what is a exposure factor selection
- touch screen digital console
AED
automatic exposure device
APR
anatomical programmed radiography
siemens exposure point system
changing exposure without having to manipulate numbers
remote control exposure switch
- exposures from any angle to up to 10m
- radiation protection
- long battery life
- can locate transmitter unit out of cradle
what are some technical features of mobile units
- electrically earthed to prevent electrocution
- tubes similar to x ray rooms + equip
- Dual focal spot size of 0.8mm2 and 1.3mm2
physical features - wheel base plate
- wide and heavy for stability
- wheels fitted with antistatic rubber tyres for safety
vertical column and cross arm design (RADBH)
R - rotation around centre of column
A - extension tube head away from centre of column
D - rotation around axis of cross arm
B - angulation across long axis of tube head
H - vertical movement up and down main column
4 digital imaging features
- instantaneous viewing
- remote from department
- image manipulation
- improved image detail
maintanence
- serviced regularly
- charged in well ventilated atmosphere
- kept clean to prevent cross contamination
safety
- tube head parked properly during transport
- brakes should be applied when stationary or using lift
- security key unusable - only authorised personnel (IRMER 2017)
when in use
- brakes on in correct position
- manual present
- tube head locked for exposure
- check for loose cables
- report any malfunction
- do not use sign when necessary
give an example of a high frequency mobile unit
siemens MULTIMOBIL
how do high frequency units work?
fully rectify AC current and supply x-ray generator with DC current for a constant stream of radiation at high frequency up to 100kHz
what do high frequency mobile units use to supply constant DC
capacitors
what type of current supply is needed for x-rays
AC supply (4.5kHz) for a constant unidirectional flow of electrons
example of cordless battery operated unit
philips practix convenio
