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 SCOPE OF STUDY A German physicist William The scope is to provide Rontgen is usually credited as information for common the discoverer of x- rays procedures involved in because he was the first to diagnosis or repairing the systematically study them, problems. Most of these though he is not the first to procedures are applicable to have observed their effects. all of fault diagnosis and He is also the one who got repairs of medical device. 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.
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
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.
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.
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.
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.
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,
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.
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.
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. etcStatic 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/50HzHV TRANSFORMER Compact Heavy Duty Transformer comprising HV Silicon Rectifiers, Filament Transformer, bushings all immersed in oil.
ACCESSORIES 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 PhaseTUBE 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 verticalVERTICAL BUCKY Vertical Bucky Stand with moving Grid of Ratio 8:1, 103 lines/inch.
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,
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.
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.
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
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 .
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.
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.
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.
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.
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
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.
Some o f the spare parts provided for x-ray machine are: Cable Cassette Film X-ray tube Lead shield etc
The typical reconditioning process consists of assessment visual inspection EDDY current cleaning preparation chemical stripping sand blasting repair machine shopping service coating
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
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.
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.