LASER SAFETY

Principle of Laser Application in Medicine & LASER SAFETYPeter Hasan H.W., MD.Laser Clinic, Dept. of Surgery,Pluit Hospital, Jakarta, Indonesia.

1APA LASER ITU ?Singkatan dari : L ight A mplification by the S timulated E mission of R adiation.2Laser =/= X-ray=/= Gamma-ray =Usual light with unique characterWavelength from far infra-red to visible light and near ultra violet 3

44SINAR LASERSama seperti sinar biasaCiri Unik : Monokromatik Kolimasi Koheren55

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21Thermal Injury to cells < 43 C : the skin remain unharmed 43 - 50 C : tissue necrosis (after several minutes) 45 C : fibroblast die after about 20 minutes 70 - 100 C : irreversible thermal damage22Laser Effect on TissueCollagen Reaction to Temperature Elevation - Less than 40o C : no effect - 40o 53o C : Protein Denaturation - 55o 60o C : Protein Degradation - 63o 90o C : Protein Coagulation. - 90 = 100 C : Evaporization - > 200 C : Carbonization23Coagulation Maybe reversible or irreversible 61 63 C : reversible non-lethal thermal damage = collagen shrinkage 61- 71 C : The goal of laser resurfacing Achieve the desired shrinkage of collagen without completely denaturating collagen24Vaporization 70 - 100 C : irreversible thermal damage and denaturation tissue necrosis 100 C : vaporization 100 - 120 C : fluctuation between vaporization and charring 120 - 200 C : charring occurs25Thermal Injury to cells < 43 C : the skin remain unharmed 43 - 50 C : tissue necrosis (after several minutes) 45 C : fibroblast die after about 20 minutes 70 - 100 C : irreversible thermal damage26LASERSYSTEM INTENSECOHERENT LIGHTPOTENTIAL HAZARDSSKIN EYEOTHERS27Comparison : Sunlight, Light Bulb, and Laser source DISTANCE IRRADIANCELight Bulb D = 1.0 m. ------------------------- 100 w light bulb 0.2 mwatt / cm2

( 0.002 ) Sunlight

D = 150,607,200 km -------------------------------

The Sun

0.1 watt / cm2

(1.0 )LaserBeam

D = ??? ------------------------- 1.0 Watt Laser 130 watt / cm2

( 1,300 ) 28 LASER Hazards Recordedin USA (1964 -1982) 53 cases of Laser incidents.15 cases were Medical Laser Incidents involving : - patients - medical personnel - laser representative - observer29MEDICAL LASER HAZARDSBurns : Skin, eye, drapes, etc.Blindness : - Total - Partial - Temporary - PermanentExplosion : - Airway - Digestive tract - intra-cavity - Endoscopic, flammable anesthetics.30Laser is Hazardous to EyeEye function : to seeCornea/oculi/retina unprotected by overlying skin, living organ exposed to environment The Eye = highest risk to be injuredSelf protection by build in blinking reflex/aversion response = 0,25 secNot enough to prevent macular burn if>MPEHazards are depending on Wavelength used. 31Hazards correspond -Wavelength Type of LASER Wavelength

DamageExcimer/UV

200-315315-400nmPhotokeratitisCataract formation

Argon, KTP, Pulse Dye,HeNe, Krypton, Ruby, dsb.IR, Diode400-700 nm. (Visible)700-780 nm.Retinal (Macular) burn injuryAlexandrite, Nd.YAG, Er.Glass780-1400 nm.Retinal burn, CataractHo.YAG, Er.YAG1400-3000 nm.Corneal burn, Aqueous flare, Cataract formation Carbondioxide

3000-80000 nm.Corneal burn32A.N.S.I.(American National Standards Institute)N.C.D.R.H.(National Center for Devices and Radiological Health)

ANSI/NCDRH Standard : Laser Classification : 4 Major Hazard Categories / Class33Class I LaserLow energy laserCannot emit radiation of known hazard (eye)Less than MPE (= Maximum Permissible Exposure)No need for control, no safety requirement. Example : - Completely enclosed diagnostic laboratory equipment. - Video laser disc player - etc. 34

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36Class II LaserLow power laser, visible, up to 1-2 mW.Incapable to cause injury within aversion reflex/response of the eye (0,25sec.)Hazard can exist only if stares directly into the laser beam or point directly to the eye.Need to have a CAUTION label and indicator light.Example : laser pointer/alignment

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42Class III LaserMedium Power laserCapable to cause injury to the eye within 0,25 sec.Divided into 2 subgroups: - Class IIIA laser - Class IIIB laser43Class IIIA LaserOutput in the range 1-5 mWNot hazardous if exposed in short period. Low laser beam density (irradiance) less than 2.5 mW/cm2Usually large beam diameter/expanded diameter (with diffusing/diverging lens)Need a CAUTION label

44Class IIIB LaserPower range 1-500 mW.Can be hazardous if eye expose to direct laser beam.Need a DANGER & Laser Aperture labelExamples : - Laser pain attenuator - Laser acupuncture apparatus - Ophthalmic laser photo-coagulator45Class IV LaserHigh Power laserAre Hazardous to view either directly or indirectlyMost surgical lasers are Class IV laserCan cause serious damage to skin and eye within less than 0.25 sec.Need a DANGER & Laser Aperture" label46MEDICAL LASER PROTECTIONOrgan prone to laser injury : - Skin - Eye

Protection toward : Skin = wet gauge, inflammable drape, etc. avoid direct or indirect exposure to laser Eye : CO2 laser = Ordinary Goggles Argon, KTP, Nd.YAG, Ruby lasers = Goggles for specific wavelength.Avoid using flammable material. Use black coated /non reflecting instrument

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57LASER DANGERSNo comprehensive listEach procedure have : - different situations - different conditions - different hazardsTo achieve successful laser applications : Mastering Laser Physics, Laser Tissue Interactions, Laser Safety, Laser Operating Principles/Technique is a MUST

58Qualification and TrainingStaff / Personnel involve in Laser Treatment should have laser safety training.Only Qualified and Authorized Operators are permitted to operate the laser.Every Safety precaution provided by the manufacturer of each individual laser equipment should be followed routinely, particularly Class III & IV Lasers.59ConclusionLaser Applications/treatment are beneficial and superior to conventional treatment when done in Good Hands and Correct indications.In the Contrary Laser Treatment have the potential to harm the Patient, the Operator as well as the Personnel assisting the Laser Treatment.

60Pedoman bagi PemulaPahami Fisika Laser dan Interaksi JaringanGunakan jenis laser yang sesuaiGunakan tehnik dan asesori yang sesuaiSet daya seuai kebutuhan, mulai dengan daya yang paling rendah yang masih berkhasiatTingkatkan daya secara bertahap setelah mendapat pengalaman/perasaan(feeling)

61 Thank You Terima Kasih62