The Study Of Radiation Dose And Protection Tactic For Doctor And Nurse For Exposing In C-arm Machine In Orthopaedics Operating Room

Objective:n order to safeguarding health and safety of doctors and nurses when they are operating under C-arm x rays machine, we study radiation dose distributiong of C-arm x rays machine, reduce probability of radiation causing cancer for doctors and nurses during orthopaedics operating, provide clinic radiation dose datas, and bring forward idiographic radiation protection tactic, ensureing radiation safety of orthopaedics doctor and nurses.Methods:According as standard WS /T 189-1999 , we monitor equipment quality of C-arm x rays machine, and measure radiation dose distribution of C- arm x rays machine of two conditions, which are x-rays tube above the diagnosis bed and x-rays tube under the diagnosis bed.We bring forward protection tactics utilize in three principle belong to outer exposure protection, this three principle include time protection, distance protection and shield protection, analyze the fatalness of causing cancer make use of correlation datum.Result:The measuring result of performance and quality for C-arm machine is that, incidence kerma rate of body surface is 9.0mGy/min, interspaces differentiate is 1.4LP/cm, low contrast resolution of image intensifier system is 1.5mm, the voltage direction warp of x-rays tube is 0.6%, exposure time direction warp is 0.4%, half value layer of useful radial is 3.4mmAl in 80kV, the incidence kerma in front of image intensifier screen is 17.8μGy/min, the automatic luminance control system of image intensifier is 3.7%; The dose rates of 200cm height in cylinder which are apart from shoot bundle center line 20cm and 50cm are 14.3% and 17.2% of the most dose rate at the same of cylinder when x-rays tube above the diagnosis bed, the dose rates of 10cm height are 4.8% and 8.6%. The dose rates of 200cm height in cylinder which are apart from shoot bundle center line 20cm and 50cm are 5.8% and 3.0% of the most dose rate at the same of cylinder when x-rays tube under the diagnosis bed, the dose rates of 10cm height are 21.4% and 23.5%; When x-rays tube above the diagnosis bed and doctors and nurses wearing 0.5mmPb protection appliance, the dose rates in cylinder which are apart from shoot bundle center line 20cm and 50cm are 8.6% and 8.2% compare to the same site without protection, When x-rays tube under the diagnosis bed the values change into 7.5% and 6.7%. When x-rays tube above the diagnosis bed without any protection, the most annual exposure dose of sensitivity organ belong to doctor in charge of a case is 5.76mSv, the value is 7.06mSv when x-rays tube under the diagnosis bed, moreover this two values of the other assistants are 1.13 mSv and 1.17 mSv. When x-rays tube above the diagnosis bed and doctors and nurses wearing 0.5mmPb protection appliance, the most annual exposure dose of sensitivity organ belong to doctor in charge of a case is 0.49mSv, the value is 0.53mSv when x-rays tube under the diagnosis bed, moreover this two values of the other assistants are 0.10 mSv and 0.08 mSv; The causing cancer probabilities of doctor in charge of a case are 1/3300 and 1/3000 when tube above and under bed, the probabilities of other assistants are 1/15000. When doctors and nurses wear protection appliance, the causing cancer probabilities reduce to 1/40000 and 1/200000.Conclusion:The quality of c- arm machine reach to correlative nation standard, no matter that x-rays tube above or under bed, the dose rates reduce gradually from the horizontal of the most dose rates to high or low site. When tube above the diagnosis bed, the most dose rates site is near the galactophore/breast; When tube under the bed, the most rates site is near abdomen. When tube above the bed, the dose rates of thyroid gland, eye crystalloid, galactophore/breast are high obviously than that tube under the bed, but the dose rates of sex gland and abdomen are reverse. The causing cancer risk of doctors and nurses without protection is twelve and thirteen times to wearing 0.5mmPb protection appliance; The radiation protection tactic of doctors and nurses:(1)Worker wearing lead clothes, lead apron and lead round neck etc., reduce the occurrence probability of stochastic effects; (2) Doctors and the other assistants grasp operating skills expertly, reduce operating time, so reduce the exposure doses of doctors and nurses accordingly. (3) When operation going along, someone of standby is waiting for behind lead screen, we make use of time protection, shield protection and distance protection correctly. (4) The workers adorn individual dose meter when C-arm machine exposuring, monitoring radiation dose of doctors and nurses termly. It is obvious that this study provide significant clinic radiation dose data and material radiation protection tactic for doctors and nurses of clinic orthopaedics operating room.