WELL COME TOOUR

PRESENTETIONX-RAY MACHINE

CHAPTER ONE INTRODUCTION An x ray machine is a complex device used in variety

of circumstances around the world. With the ability to penetrate hard objects, they are used for purposes such as air port security check points to see into backs, or in the medical community to look for broken bones or problems within the body.

BACKGROUND AND SCOPE OF STUDY Background A German physicist William

Rontgen is usually credited as the discoverer of x- rays because he was the first to systematically study them, though he is not the first to have observed their effects. He is also the one who got them the name “x-ray” .though many referred to this as “Rontgen rays” (x-ray radiographs or Rontgen grams).After their discovery and to this day in some language including Rontgen native Germany though x-ray overtook popular usage.

SCOPE OF STUDY The scope is to provide

information for common procedures involved in diagnosis or repairing the problems. Most of these procedures are applicable to all of fault diagnosis and repairs of medical device.

OBJECTIVE GENERAL OBJECTIVES To demonstrate understanding, knowledge and skills in

applying maintenance methodology strategies and quantitative techniques to medical device to increase its availability, reliability and maintainability.

SPECIFIC OBJECTIVES Get equipment back into operation as quickly as possible. Control cost of repairs. Control cost of the operation of repair shops. Control the investment in replacement spare parts. Control the investment in standby or backup machines. Perform the appropriate amount of repairs at each

malfunction

PROBLEM STATEMENT

During our work some of the problems we face were: unavailability of internet connection in our lab, transport problem and sometimes x-ray technician in Jimma university specialized hospital is busy to give us information. So it was difficult for us to collect a lot of information.

 

CHAPTER TWOX-RAY MACHINE

PRINCIPLES OF OPERATIONS An x-ray machine is essentially a camera. Instead of

visible light, however, it uses X-rays to expose the film. X-rays are like light in that they are electromagnetic waves, but they are more energetic so they can penetrate many materials to varying degrees. When the X-rays hit the film, they expose it just as light would. Since bone, fat, muscle, tumors and other masses all absorb X-rays at different levels, the image on the film lets you see different (distinct) structures inside the body because of the different levels of exposure on the film.

PARTS OF X-RAY MACHINE X-Ray Generator: High voltage generator: modifies

incoming voltage and current to provide an x-ray tube with the power needed to produce an x-ray beam of the desired peak-kilo-voltage (k V p) and current (mA) and duration (Time).

Control panel: Permits the selection of technique factors and initiation of radiographic exposures mA, kV, Time

Transformer: Transformers modify the voltage of incoming alternating-current (AC) electrical signals to increase or decrease the voltage in a circuit.

…CONT Step-up transformer: Supplies the high voltage to

the x-ray tube (voltage increases and current decreases)

Step-down transformer: Supplies power to heat the filament of the x-ray tube (voltage decreases and current increases)

Autotransformer: Supplies the voltage for the two circuits and provide a location for the K v p meter (indicates the voltage applied across the x-ray tube)

Rectifiers: Convert AC into the direct current (DC) required by the x-ray tube. A rectifier restricts current flow in an x-ray tube to one direction (from cathode to anode), thereby preventing damage to the x-ray tube filament. Two types: Half wave and Full wave.

…CONT X-RAY TUBE: It is an expensive wearing element in

medical radiological equipment. It consists of Anode, Expansion bellows (provide space for oil to expand), Cathode (and heating-coil), Tube envelope (evacuated) , Tube housing, Cooling dielectric oil, Rotor,

…CONT High Tension Cable: Special highly insulated cables

Considered are the cable capacitance (130-230 pF/m) because it affects the average value of the voltage and current across the x-ray tube (increases the power delivered to the tube.

Collimators and Grids: They are used to increase the image contrast and to reduce the dose to the patient by mean limiting the x-ray beam to the area of interest.

Collimator: It is placed between the x-ray tube and the patient and Usually provided with an optical device, by which the x-ray filed can be exactly simulated by a light filed.

Grid: It is inserted between the patient and the film cassette in order to reduce the loss of contrast due to scattered radiation.

…CONT X-ray film: X-ray film is a sensitive material (sheet)

for the x-ray. A film that has been exposed to x-rays shows an image of the x-ray intensity.

SCHEMATIC DIAGRAM 11) cassette holder 12) Cable 13) Imaging hand switch 14) Control panel 15)

Generator 16) Display screen 17) Stretcher 18) X-ray tube 19) Collimator 20) Cassette 21) Interface cable 22) trolley 46) Hand grip 66)tube

TECHNICAL SPECIFICATIONS X-RAY MACHINE 300mA. 125 KVP Full Wave Rectified

X-ray Generator for Radiography suitable for single Tube.

TIMER The exposure timer should be digital & from 0.02to 5 sec.

CONTROL Consisting of On & Off Switches, with Voltmeter, Voltage Compensator, Tube overload indicator provided, Space charge compensator. etc

Static balancer 30 KVA capable of converting 3‑phase in range 365-400 VAC with 0.2 ohms resistance at 50-60Hz to single phase 230VAC/50Hz

HV TRANSFORMER Compact Heavy Duty Transformer comprising HV Silicon Rectifiers, Filament Transformer, bushings all immersed in oil.

…CONTACCESSORIES Hand Switch with Flexible long cord enables

the operator to keep away from the Radiation area during exposure.- Aluminum Filter.

POWER SUPPLY REQUIREMENT 440V + 10% V AC, 50 Hz, Three Phase

TUBE UNIT One No. 20/40 Rotating Anode Tube (BEL / TOSHIBA or equivalent) with Dual Focus (Large & Small).

HV CABLE One Pair of 10 meter High Voltage Cables Sleeping’s - Straight.

STAND Floor to Ceiling Stand & with Counter Balanced Tube Head (Rotatable+180 Degree), 360 Degree Rotatable;

TABLE 5 Position Table Hand tilt; 15 Degree trendelenburg to vertical

VERTICAL BUCKY Vertical Bucky Stand with moving Grid of Ratio 8:1, 103 lines/inch.

CHAPTER THREE USER MAINTENANCE TROUBLESHOOTING: Trouble shooting is a

procedure of observation then making suitable test to either to eliminate or confirm a suitable section of device

Trouble shooting tips for the X-ray equipment

No X-rays Check for warning lamps. FC: implies burnt filament,

CW: implies inadequate cooling water flow, OLL: implies an overload problem -- common during filament aging and usually can just be restarted,

…CONT Check the voltage and current meter, on the two older

generators (Denali and tick). If there is voltage but zero current, then it is likely that

the filament has blown, on the newest generator (flea), both meters will indicate 0 when the filament has burnt out.

If no voltage or current, check for X-ray ready lamp on front panel and on light pole (flea).

If ready lamp is not on , Try starting target rotation (TR or T-REV) , Check for burnt out X-ray warning lamps on the front panel and on the generator table top, or "Christmas tree" (light pole), Check for water flow problems.

CHAPTER FOUR MAINTENANCE ACTIVITIES MAITENANCE ACTIVITIES INCLUDE: Repairs

Repair activities are reactive.Breakdowns and malfunctions typically occur when

equipment is in use.Standby machines and parts can speed repairs.

Preventive Maintenance (PM)Regularly scheduled inspections are performed.PM activities are performed before equipment fails.PM is usually performed during idle periods.

4.2 FAILURE AND DIAGNOSIS Fault 1: no display after booting console (to send non

power) Diagnosis: check power (the console power switch on

the light is bright, if not check the light), Check the power outlet has power, Joints between the console and the columns is plugged in, Fuse box , fuse is good , Power switch is good , If the light is checked , Console within the control panel of the cable is loose, Circuit board component and welding has a problem

…CONT Fault 2: the boot that exposure Diagnosis: check of Exposure switch hands (hand

break) remove from the console, remote control battery removed, power is no longer than exposure, check the hand break switch,

Fault 3: exposure burning insurance Diagnosis: check of Column between console and

unplug the connector, turn the exposure, check the console is working properly, if not properly check the control panel whether the cable, short piece if not replace the console .

…C0NT Console and the column will be inserted between the

joint the x-ray source component (head) removed after the push to the highest position, check console is working properly. If the above are normal check the console diode and 300 ohm variable resistor is damaged. If the above is normal replace the x-ray source component

Fault4: perspective image place is not suitable Diagnosis: disconnect switch and check 24v DC

voltage, then open switch and DC voltage decrease 14v and inspect bridge pile output load normal.

4.3 PREVENTIVE MAINTENANCE Preventive maintenance program are available and

include: X-ray room inspection and minor repairs (adjustment) check calibration., High voltage cables and electrical wiring inspection., Electrical and mechanical locks adjustment., Tube stand and table anchors inspection., Bearing and tracks lubrication., Handles and knobs inspection., Verify processor temperature., Cassette identification., Id printer operation., Check ID card quality., Certificate of completion.

4.4 RELIABILITY CENTERED MAINTENANCE It integrate preventive, predictive testing and

inspection, repair/reactive maintenance and proactive maintenance to increase the probability that the machine or component will function in required manner over its design life cycle with a minimum amount of maintenance and down times.

4.5 SCHEDULED MAINTENANCE Scheduled maintenance reduce incidence of failure

through inspection designs to detect potential problems before they become reality. It is performed on an annual or semiannual basis, according to device uses or history. Equipment required for scheduled maintenance: Cleaning supplies, Vacuum cleaners, Lubrication, Tools etc.

4.6 PLANNED MAINTENANCE Planned maintenance is maintenance organized and

carried out with for thought, control, and records, to a predetermined plan. In doing this, the following factors have to be kept in mind: The extent of utilization (is the machine working), Severity of utilization (is the machine work under normal load condition), Operating condition, Are there any other specific factors that may affect the instrument

4.7 RELIABILITY, MAINTAINABILITY AND AVAILABILITY  Reliability is the probability that an item will survive a

given period, under specified operating condition without failure.

Maintainability was defined as “the ability to maintain the least amount of time at the lowest cost”.

Availability is the probability that the device were used under stated condition in an ideal support environment, will operate satisfactorily at any point in time as required. It includes preventive or scheduled maintenance action and administrative delay time.

4.8 SPARE PARTS PROVISIONING

Some o f the spare parts provided for x-ray machine are: Cable Cassette Film X-ray tube Lead shield etc

4.9 RECONDITIONING PROCESS The typical reconditioning process consists of assessment

visual inspectionEDDY current

cleaning preparationchemical strippingsand blasting

repairmachine shopping servicecoating

CMMS A CMMS is a software package that contains a

computer database of information about an organization’s maintenance operations.

IT ASSISTS IN MANAGEMENT OF: Scheduling maintenance projects Maintenance cost reports by production department,

cost category, and other classifications Inventory status reports for maintenance parts and

supplies Parts failure data Operations analysis studies

CHAPTER FIVE CONCLUSION Information on the status of the equipment surveyed

has been collected and a data base to that effect has been prepared.

It is intended that the result in this survey help in establishing a maintenance program to protect investment in the x-ray machine, through regular and adequate maintenance.

It was also noted that most of the equipment had no maintenance records.

RECOMMENDATION Since maintenance activity and its element require

availability and the proper balance of various levels of skills, it is recommended that the integrated approach to the program should start with the users who have the basic knowledge of maintenance, quality control and fault detection.

There should be well trained technician that can recover malfunctioning x-ray machine to normal operating condition.

Since there is no enough spare parts the health institution should have provide additional spare parts to increase the life time of the equipment.

THANK YOU!!