1 / 12

Medical L-A-S-E-R

Dr. Ali Saad/ biomedical technology KSU. 2. ? 1961 Ruby laser invented (Maiman)??1965 Argon laser applied to eye surgery? Surgical applications??Opthalmology??General surgery??Ob-gyn??Cardiac??Orthopaedic??Plastic/dermatology. Medical L-A-S-E-R. Dr. Ali Saad/ biomedical technology KSU. 3. T

shelby
Télécharger la présentation

Medical L-A-S-E-R

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


    1. Dr. Ali Saad/ biomedical technology KSU 1 Medical L-A-S-E-R

    2. Dr. Ali Saad/ biomedical technology KSU 2

    3. Dr. Ali Saad/ biomedical technology KSU 3

    4. Dr. Ali Saad/ biomedical technology KSU 4

    5. Dr. Ali Saad/ biomedical technology KSU 5

    6. Dr. Ali Saad/ biomedical technology KSU 6 Laser Tissue Interaction • Energy is reflected, transmitted, absorbed and scattered • Lambert Beer law I = Io 10-aX a= absorption coefficient X = thickness of material Io = incident intensity I = transmitted intensity • Extinction length = 1/a = L; where 90% of the intensity is absorbed.

    7. Dr. Ali Saad/ biomedical technology KSU 7 Laser Tissue Interaction

    8. Dr. Ali Saad/ biomedical technology KSU 8 Laser Tissue Interaction Power density important for tissue vaporization Spot size minimum proportional to wavelength Shorter wavelength ~ Smaller spot size

    9. Dr. Ali Saad/ biomedical technology KSU 9 Carbon Dioxide Laser 10.6 um - Far infra-red - need visible aiming Gas mix - 5CO2 + 10N2 + 85He Electrical pumping - DC or RF ??100+ watts may be used ??10-20% efficient • Absorbed by all tissue/H2O • Extinction length is .03mm - vaporization • Fiberoptic losses significant - use lens

    10. Dr. Ali Saad/ biomedical technology KSU 10 ND:Yag Laser • 1.06 um - Infra-red • ND doped YAG crystal • Optical pumping • 1% efficiency • Two types Continuous/pulsed for general surgery Excellent for coagulation, deep heating Weakly absorbed by H2O - transmit through H2O Can go thru fiberoptics easily Q-switched for opthalmology

    11. Dr. Ali Saad/ biomedical technology KSU 11 Argon and argon dye laser • 488 nanometers - blue light • Argon gas • Electrical pumping • Low efficiency .1% • Little absorption by H2O - high absorption by red objects (e.g. retina) • Small spot size • Argon dye provides multiple wavelengths ??Photoradiation therapy @ 630 nm Eximer

    12. Dr. Ali Saad/ biomedical technology KSU 12 Diode and Holmium Laser - 193 nm - UV, Exciter fluoride gas, electrical pumping, very precise, ophthalmic use (corneal sculpting) ??Diode - aluminum gallium arsenide (AlGaAs) @ 810 nm or indium gallium arsenide (InGaAs) @ 980 nm, fiber optic transmission, long life Holmium:yttrium-aluminum-garnet (Ho:YAG), similar to ND:YAG; 2100 nm; orthopaedic,general and other procedures

More Related