portable and mobile equipment

1. Portable and mobile
radiographic equipment's
PRESENTED BY
SARITA GAIRE
BSC.MIT 1ST YEAR
ROLL NO.160
MAHARAJGUNG MEDICAL CAMPUS

2. Content
Introduction
Portable radiographic equipment's
Components of portable equipment
Advantages and disadvantages of portable radiographic equipment’s
Mobile equipment's
Components of mobile equipment
Capacitor discharge unit
Battery powered unit
Advantages and disadvantages of mobile radiographic equipment.
Mobile image intensifier
High tension generator.
Advancements
Machine used in our department

3. INTRODUCTION
 Machines that are used for
severely ill and unable patients,
who cannot be brought in the
radiology department.
 Used when surgeons requires x-
ray guidance during their work in
the operation theater.
 These machines can be divided
into two types:
 Portable and
 Mobile equipment.

4. Portable
 Portable x-ray unit were discovered in
1912.
 Portable units are small and light in
weight.
 Can be dismantled and carried
usually by one person around the
hospital or even at patients home.
 Have relatively low radiation output.
unit in 1912.

5. Figure: Fujifilm FDR Xair portable machine
Figure: old portable machine
THEN NOW

6. Components of
Portable unit.
Tube head.
Tube stand.
Control unit.(control
panel).

7. 1.Tube head.
A.X-ray tube.
- the tube is small stationary anode
- self rectified tube.
- single small focal spot of 1.0mm.
- has limit of exposure less than mobile x-ray equipment.
B. High tension generator.
-Tube and generator are enclosed in one oil tank , described
as tank construction and the whole enclosure called the tube head.
High tension generator
Xray tube
Oil filled tank
Tube head

8. 2.Tube stand
- it supports for the tube head.
3. Control unit(control panel)
- on off switch.
- kv and mAs selection.
- exposure switches.

9. Control unit

10. Advantages of portable.
 Simple and handy which can be folded into small package
whenever needed for transportation.
 It is very useful and advantages in during sports and military.
 Allows radiographic examination in locations limited by the
availability of a standard electrical supply.
 Used in remote areas where electricity is also not available.

11. Disadvantages of portable.
 Have relatively low radiation output.
 it is difficult to maintain in aspects of radiation
protection.
 Can be damaged by external source.

12. Mobile
 Mobile means capable of being moved.
 Mobile X-ray equipment's are Bigger and
heavier than portable and needs to be pushed
or motorized by human power.
 Is movable, but because of its heavy weight
and size it can only be wheeled along flat
surfaces with motion brakes.
 Have higher radiation output than portable.

13. Mobile units in 1940-1955 and now.

14. Components of mobile equipment
 Tube
 Tube stand
 High tension generator.
 Control unit(control panel)

15. 1.Tube
- Rotating anode x-ray tube.
- dual filament with dual focal spot.
- focal spot = about 1.0mm for fine focus.
= 2.0 mm for broad focus.
2.Tube stand
• a strong vertical column mounted on the base that
supports the cross arm which carries the x-ray tube.
• To prevent damage to cables movements.

16. Tube stand can be divided into 5 major movements.
1.Rotation movement.
-around the center of the column(R).
2.Cross arm movement
- the extension of the tube head away from
center of the column (A).
3.Rotation around the axis of the crossarm(D).
4.Angulation movement.
- across the long axis of the tube head(B).
5.Vertical movement up and down main column(H).

17. High tension generator
 Provides a maximum output of 125kvp and 300mA.
 Includes full wave rectification provided by means of
selenium rectifiers.
 The mobile x-ray unit consists of an earthed steel tank
filled with oil, which house the high-tension generator
rectifier and filament transformer.
 Connected to the x-ray tube by mean of high-tension
cable.

18. Control unit (control panel)
 Located behind the generator tank on the base unit.
It consist of
1. main on and off switch.
2. mA selector.
3. kv selector.
4. focal spot selector.
5. body parts selector.
6. exposure indicator .(ready and exposure).

19. Hand switch
A hand switch is a switch used for the x-
ray exposure process.
Transport handle
The rudder grip is the handle used
when moving in the mobile x-ray unit.
Cassette box holder
Place to put cassette when the plane
is moved.

20. Mobile classification can classified in two
ways
1. By power supply
a.Capacitor discharge unit.
• it does not operate on batteries.
• It can produce x-ray by store energy in capacitor then discharge through
it.
• Contains two metal plates that hold electrical charge.
b. Battery powered unit.
• Uses two sets of lead acid or nickel-cadmium batteries.
• One set powers driving of the machine.
• One set provides power to the x-ray tube.

21. 2. By output:
 Low Power Mobiles: 10 to 30mA and 40 to 90 kVp.
 Average Power Mobiles:100 to 150 mA and 40-95 kVp.
 High power mobiles : up to 300 mA and 125 kVp.

22. Capacitor discharge unit.
 When charge circuit is activated, voltage
from HTT charges a capacitor up to the kilo
voltage required for the exposure.
 The capacitor becomes source of power for x
ray exposure. It is disconnected from the
charging circuit and connected to the x ray
tube for exposure.
 its discharge through tube constitutes the
mAs of the radiographic exposure factors.

24. • Rotating anode tube with single focal spot size of 1.2mm
and heat storage capacity of 80,000 HU.
Grid controlled:
• Uses a third electrode i.e., focusing cup to control flow
of electrons from filament to target.
• Voltage across filament-grid produces electric field along
path of electron beam that pushes electrons closer.
• Exposure start & stop controlled by voltage on grid.
• Large enough negative voltage on grid blocks tube
current from cathode to anode.
Xray tube:
+

25. • Automatic charging circuit for charging the capacitor.
• The kV range is from 30kv to 125kv. If preselected Kv is
altered after charging, the tube voltage is automatically
adjusted to the new value.
• A single mAs control, rather than mA and exposure
time being selected separately. The units are usually
designed to operate at a high, fixed mA value, so that
exposure time becomes the main variable by default.
control unit:

26. Advantages of capacitor discharge unit.
• Light weight ,smaller and easier to movement.
• Require much less time to charge than battery units.
• No battery usage.
Disadvantages of capacitor discharge unit.
• Can’t handle thick body parts due to voltage drop
during exposure.
• Must be charge prior to each use.

27. Battery powered mobile unit.
 Also called cord less mobile unit.
 Lithium/Ni-Cd batteries are used as a source of energy
for x ray exposure .
 The generator is referred to as constant potential
generator (CPG).
 Power supply is used to charge the batteries.
 The batteries produces low voltage DC charge.

28. Major components of battery powered x-ray
machine.

29. Advantages of battery powered unit.
• Stores considerable energy to generate x rays. It can
store 10,000 mAs.
• Make exposures independent of power supply mains.
• Supplies constant output of KV and mA through out
the exposure.
• Used in case of emergency power failure.

30. Disadvantages of battery powered unit.
• Needs special care and maintenance.
• Batteries must be charged
• Require regular batteries maintenance
• Heavy and hard to control .

31. Care and maintenance.
• The unit should be left connected to the
mains power supply of 220V.
• Naked flames or lighted cigarettes should
not be held near the batteries when they are
being charged.
• The acid level in the batteries should be
checked every 2 weeks.

32. Advantages and disadvantages of mobile unit.
 High radiation output than portable is the advantage
 And heavier than portable unit is the disadvantage.

33. Mobile image intensifiers unit.
 They are used in OT (operating theater) for fluoroscopic
examination.
 This reduces the number of radiographs taken and saves
the time of surgery.

34. Important features of mobile unit for
fluoroscopy.
 The x-ray tube.
 The image intensifier.
 High tension generator.
 Control console.

35. The x-ray tube and image intensifier.
• Mounted opposite to each other at the end of C-arm
• Xray tube head is at the lower end of C-arm and the
image intensifier is at the upper end with input phosphor
facing towards the x-ray tube.
• The tube head houses the x-ray tube.
• The x-ray tube is stationary anode and two focal spots.

36. • the c-arm is mounted on a cross arm which extend from a
carriage carried on a vertical support rising from the control
console.
• The x-ray tube and the image intensifier are held directly
opposite to each other with x-ray beam permanently
centered to the input phosphor.
• At the back of image intensifier is the television pickup tube
so that image can be viewed on monitor.
• The input phosphor of the image intensifier is cesium iodide
which gives good contrast.

39. Movements
• The vertical support can be raised and lowered, and the
cross arm can be extended through the carriage.
• The x-ray tube and image intensifier are attached to the
c-arm and move together.
• The c-arm can be moved in any direction, so the
equipment enables a good range of position and
projections to be used without wastage of time.

40. High tension generator
• The x-ray tube and high-tension generator are together
in the tube head.
• High tension generator are single phase with full wave
rectification provided by silicon rectifiers.

41. Fig: sequence of transference of signal

42. Control console.
• Kilovoltage for fluoroscopy or radiography range from 50kv
to 105kv.
• mA settings for fluoroscopy range from 0.1 to0.3mA .
• For radiography, the kv and mA are linked .i.e.
50mA at 55kv.
40mA at 80kv.
30mA at 105kv.
• The timer for radiographic exposure is electronic and gives
range from 0.1 to 0.3sec.

43. • For the television chain, circuit includes controls which allow the
image to be transposed right to left and inverted top to bottom.
• There is control for memory circuit with two magnetic disc that
is image storage is possible.
• There is facility for pulsed fluoroscopy with electronic selector.
the rates provided vary from 1 flash per sec to 1 flash every 5
sec.
• This allows to monitor dynamic events without subjecting the
patient to continuous radiation.

44. Advancements.
High frequency generator mobile units.
Computed radiography mobile x-ray unit.
Direct digital radiography mobile x-ray unit.

45. High Frequency Generator
 Recently high frequency generators are more popular for
use in radiology for mammography and mobile units.
 One of significant advantages is its compact design.
 Converts low frequency (50 HZ) to high frequency (5KHZ)
pulsed DC, by altering waveform of incoming electrical
circuit which is subsequently increased to kilovolts,
rectified and sent to the x-ray tube.

46. Produces a nearly constant voltage wave form with extremely
low ripple(<1%).
Provides great x-ray quality(effective energy) and quantity.
More efficient.
 More expensive than previous mobile units.
Uses inverter circuit.
The DC power supply produces a constant voltage from either
a single phase or three phase input line source.
inverter circuit creates the high frequency AC waveform.

47. This AC current supplies the high voltage transformer and creates a
waveform of fixed high voltage and corresponding low current.
After rectification and smoothing two high voltage capacitor on the
secondary circuits accumulates electron charges. These capacitors
produce a voltage across the x-ray tube, that depends upon the
accumulated charges.

48. Fig: Block diagram of high frequency generator

49. Computed radiography mobile x-ray unit.
 It is a mobile imaging system used for capturing X-ray
images using a CR imaging plate.
 It allows for convenient on-site imaging in various
healthcare settings, such as hospitals, clinics, emergency
rooms, and nursing homes.

50. Computed radiography mobile x ray unit.

51. Direct digital radiography mobile x ray unit.
It is a mobile imaging system used for capturing X-
ray images using a digital detector. Unlike computed
radiography (CR), which uses an imaging plate, DR
directly captures the X-ray image in a digital format.
This technology offers several advantages.
These system represents an evolutionary move in mobile
diagnostic imaging equipment and includes unique
features in terms of operability, mobility and image
quality.

52. these system meets todays and future clinical demands
providing the premium solution for
• Immediate image processing
• An efficient clinical workflow
• A rapid display of high-quality clinical images
• Fast integration into the hospital network.

53. Digital portable unit.

54. Digital mobile unit.

55. Mobile equipment in our hospital.
 Used in ICU ONLY.
 Battery powered.
 Rotating anode.
 Mains supply 100-220v /50/60hz.
 Kvp ranges from 40 to 125Kvp.
 mAs ranges from 0.32-320mAs
 Body part selection mode.
 Size selection mode.
SIMADZU

56. SIEMENS
 used in pediatric ICU only.
 Capacitor discharge.
 Rotating anode.
 Mains supply 190-240v/50hz
 Kvp range 40-100
 mAs range 0.32-80 mAs
 There is no body part selection and
size selection in this one .

57. uDR(United Imaging)
 Used in all wards and intensive care
units.
Features
 battery powered(lithium)
 Rotating anode
 Dual focal spot of 1.2 and 0.6
 Tube Filtration of 1.5mm AL
 Collimator filtration of 1mm AL
 Mains supply:-230V /50hz/60hz.
 range upto 150kvp and 320mAs.

58.  19” LCD touchscreen with body part,
size selection which presents all data
clearly.
 With the help of a tablet pc, operators
can do imaging remotely, thus which
optimally protects them from
radiation damage.
 Electric driving system for easy
transport.
 Multi angle and flexible operation.
 Fine motion control for higher
mobility.
 Dual battery for longer power supply.

59. Cassette/detector used for DR and CR mobile machine
CR imaging plate(Cassette)
DR wireless imaging plate

60. REFERENCES
• Chesney's equipment for student radiographers
• Christensen's physics of diagnostic radiology
• www.slideshare.com
• Various websites and PowerPoint presentations.

61. Thank you

62. Questions
1. What are the features of portable unit?
2. What are the features of mobile unit?
3. What are the components of portable unit?
4. How does a capacitor discharge mobile unit work?
5. Why high frequency generator is used in portable unit?
6. What are the advantages and disadvantages of battery powered unit?
7. What are the features of mobile image intensifier unit?
8. Which type of x ray unit is used in our department for ward radiography?