890 likes | 1.07k Views
PORTABLE / MOBILE EQUIP & APPLICATIONS. RTEC 124 – WEEK 9 Rev: SPRING 2010 Ref: Merrills Ch 13 & 29 Bushong – “ selected paragraphs” in text *Carlton- Rad Principles Ch 39 for mobile equipment (in library).
E N D
PORTABLE / MOBILE EQUIP & APPLICATIONS RTEC 124 – WEEK 9 Rev: SPRING 2010 Ref: Merrills Ch 13 & 29 Bushong – “ selected paragraphs” in text *Carlton- Rad Principles Ch 39 for mobile equipment (in library)
PORTABLE MOBILE RADIOGRAPHY& Intro to TRAUMAMerrills – Vol.3 – Ch. 29 Ports/Mobile Vol 2 - Ch 13 Trauma • Objectives • Recommend methods for accomplishing acceptable variations of standard radiographic projections, especially chest examinations for air-fluid levels • Assess the radiation protection rules for mobile radiography
Objectives • Identify factors contributing to the difficulty of mobile radiography • Explain appropriate communications methods for mobile examinations • Describe items that must be considered when arranging a patient room for a mobile examination
THREE BASIC types of UNITS RADIOGRAHIC: PORTABLE - refers to a small hand held unit, first designed by Picker for WW I • 15 ma generator = Chest & extremities MOBILE - Full powered institutional units much heavier - motor or muscle driven FLUOROSCOPIC: • C-arm and “Mini C-arm” or Fluoroscan • PORTABLE is accepted terminology
PORTABLE RADIOGRAPHY BASIC TYPES OF MOBILE RADIOGRAPHY • Battery Powered Unit • Capacitor-discharge Unit • High Frequency Units • Mobile Fluoroscopic ( C-ARM)
Portable Units - Special Features • Battery Powered uses Ni-Cd rechargeable batteries, DC high frequency pulsed power* • Capacitor-Discharged - uses 110 outlet. High voltage transformer - Capacitor discharges at time of exposure -voltage drops 1kv/mas during exposure • High Frequency- converts hf AC to DC - resulting in high voltage ripple 60hz-500 hz (square vs sine wave) • *Techniques are equivalent to 3Ø 12 p (like in a standard Radiographic room)
12 VOLT BATTERIES CAR BATTERY Silver or Nickel Cadmium
Power Drive • Self-propulsion for mobile unit • Dead-man switch • Must use caution when piloting equipment • Types of Batteries Used? • Weight of Equipment • Areas: safe and not safe to use
“PLUG –IN” : CAPACATOR DISCHARE UNIT
Power supplies Generators Power drive Power Supplies: Portable light duty units 220V or 110V outlet Full power mobile institutional units Capacitor discharge Battery operated Types of Equipment
Capacitor discharge Constant potential output Battery operated 3 phase output THEREFORE – TECHNIQUE IS CONSISTANT WITH X-RAY ROOM (GRID DIFFERENT) Generators
Milliampere-Seconds • Low power units not capable of high mAs techniques needed for grid radiography (300 mA) • Double or triple exposure • Be careful not to overload tube • EX: X-table L5 S1 SPOT (in surgery)
PORTABLE W/ AEC Some portable units have an AEC device attached This paddle with one or two cells is placed behind the patient and cassette Selection of density, back up time and cells are done at the control panel Positioning of cells –criticalsee photo pg 560 Carltons
Battery Powered Uses 9 - 10 12V batteries - (heavy) Battery supplies power for all inst. operations Motor Driven Wt - +1,000 lbs ? Constant potential Some have AEC Needs recharging - holds 8 hr charge 3Ø 12pulse techniques Can double expose + 110 V Capacitor DC Uses 110 outlet Capacitors stores up charge - then exposure discharges “Muscle Driven” Wt - + 450 lbs ? Constant potential Some have programmed memory Must be plugged in to store up charge ? Not for large parts COMPARISONS
HIGH FREQUENCY UNITS • Very Expensive - not many in use • Smaller - more compact units • High voltage transformer 1/10 the size • Minimal voltage ripple = higher efficiency
MinXray high frequency portable medical x-ray units These models are designed for use in nursing homes, private homes, correctional facilities, field clinics, hospitals, or anywhere an x-ray machine must be brought to a patient. maximum of 80 mAs 70 lbs
SUMMARY • Battery Powered Uses batteries 3Ǿ 12p (4%ripple) • Capacitor Discharge Needs wall outlet Constant Potential (1 % ripple) • C-Arm Fluoroscopic Digital, Subtraction, Last Image Hold
“PREP”GETTING READY FOR EXAMS YOUR PATIENT THE ROOM YOURSELF
POSITIONING APPLICATIONStypes of exams • CHEST - AP ( & DECUBS) • ABD – AP and/or LLD • PELVIS WITH X TABLE LAT OF HIP • EXTREMITIES – 2 VIEWS - 90° • SPINE – USUALLY C.SP (LAT) • IN OR or POST OP • (will cover OR later in semester)
Special Patient Considerations • Communication • Manipulating equipment • Positioning and pathology • Intro to MOBILE/ PORT EQUIPMENT • More on this in RT 244
THE TECHNOLOGIST • Portables can be the “ultimate test” of skill, competency and resourcefulness • Compounded with the urgency and tension of the Emergency Room , Intensive Care Unit and/or Operating Room • Patient’s inability to cooperate for positioning • Technical Considerations - varying SID, grid alignment, patient positioning
THE PATIENT • More acutely ill and/or unable to transport • Cardiac Monitoring • Lines, tubes, ventilators and traction • Pt may be conscious or unconscious cooperative or uncooperative • Show courtesy to the patient - even the one who may not appear to be able to hear or understand* *remember Phil Ballingers’ Story
Patient Considerations • Before entering, park machine outside of room and go in and talk to the patient (establish rapport, check for correct patient) • Rearrange equipment/furniture if necessary - remember to put it back when done! • Radiographer’s responsibility to return all items to their original locations • Locks on bars, bed rails, etc
Communication • Get patient’s permission to do the exam • Explain the procedure • Move items that will be in the way • Overhanging TV’s and the X-ray tube can be hazardous to your head! • Don’t bump the bed or your head • Place cassette in a pillowcase when possible • Unconscious patients • Surgery/Emergency Room/ICU
Manipulating Equipment • Watch out for: • Equipment power supplies • Oxygen tubing • Intravenous lines • Catheters, etc. EKG wires
Caution with blocker - Side up of cassette Proper labeling of cassettes
POSITIONING APPLICATIONS • CHEST – PLACE C/R ± TO STERNUM – • or ANGLE 5° CAUDAL FROM ± TO CASSETTE • C/R TOO CEPHALIC = APICAL LORDOTIC • C/R TOO CAUDAL = CLAVICLES IN MIDDLE OF THE CHEST • CONSIDER YOUR PATIENT’S BODY HABIUTS
Positioning and Pathology • Maintain typical positioning for examinations • Perform chest radiography in semi-erect position whenever possible • Check with the nurse for Critically ill patients
Positioning of patientas upright as possible = when possiblecheck with nursing if unsure!!!Why???
Positioning Applications • When checking for air-fluid levels : 2 exposures may be necessary • 1 - horizontal beam to see level • 1 - C/R ± to sternum “anatomically correct” • CHECK FOR ARTIFACTS • Grid alignment - low ratio grids used • (see coconut for fluid levels pg 525 Carltons)
Special Technical Factor Selection Considerations • Kilovoltage • Milliampere-seconds • Distance • Grids • Film/screen combinations • Other factors
TECHNIQUE CONSIDERATIONS • SAME RULES APPLY AS IN RAD ROOM • AP CHEST – SCREEN OR GRID * • (REMEMBER: 4x LESS FOR SCREENS*) • BODY PARTS OVER 12 CM = GRID • SID – VERY IMPORTANT TO MEASURE • CHEST USUALLY DONE AT 62 – 72” • ALL OTHER DONE AT 40” * • SEE MERRILLS BEGINNING AT PG 212