Solid-State TechnologyBasics. 6 Marcel Kirsch 28.09.05. 7 Marcel Kirsch 28.09.05 By now Excimer...
Transcript of Solid-State TechnologyBasics. 6 Marcel Kirsch 28.09.05. 7 Marcel Kirsch 28.09.05 By now Excimer...
Solid-State Technology
The future in refractive surgery
OptecBB workshopPhotonics for medical Technologies
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Marcel Kirsch28.09.05
Outline
• Company
• Basics
• Why solid-state laser approach?
• Certified and available Product LASERSOFT
• Advantages for patients and surgeons
• Clinical data
• Conclusions
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Marcel Kirsch28.09.05
Company
•Located in Kleinmachnow, SW of Berlin
•Development and production of Systems for Laser-Vision-Correction utilizing a Solid State Laser Platform
•Based on developed and developing proprietarytechnology to deliver best in class products
•Katana owns exclusive, innovative, patentedtechnologies in the solid state laser field and applicationto refractive surgery
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Basics
link
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Refractive surgerychanging the shape of the corneaby removing tissue to correct-nearsightedness (myopia)-farsightedness (hyperopia)-astigmatism
•More myopia than hyperopia
Basics
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By now Excimer lasers are used:
UV pulse generation in an Excimer laser
high voltagepulse
UV pulses
@ 193 nm
Ar
F
Ar F*
Gas discharge tends to InstabilitiesDepends on the gas mixture
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Why solid-state laser approach?
Solid State Laser Crystals used as Laser medium§ Inexpensive to operate - no toxic gas (Excimer) anymore
Diode pumping provides long lifetime and high efficiency§ cw pumping, high shot to shot and long term stability§ stable energy and beam pointing (precise ablation rate).§ no high voltage gas discharge involved (Excimer)
High repetition rates up to 2kHz (Katana)§ less energy per pulse (heating)§ less shock waves (collateral distructions)§ treatment in a silent, patient-reassuring environment
Laser characteristics
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UV pulse generation in the all solid statediode pumped laser (highly stable)
Lasercrystal
Conversion 2Conversion 1
Modu-
lator
UV pulses
@ 210 nm
cw-pump
diodes
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Excellent (intrinsic Gaussian) beam spot distribution§ high quality of the ablated surface
Why solid-state laser approach?Beam characteristics
Small spot size§ important for fine-structured ablation
Highly collimated beam§ fast scanning, no strong focussing
DSSL are excellent candidates for true scanning small spot lasers for LVC
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Lasersoft(CE-certified)
CompactMobile200 kgFlying spot
Solid State LaserTechnology
for LVC
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Specifications
0.7-1mm
Repetition Rateup to 400Hz
Speed of Eye Tracking
few 250Hz(video based)
Spot Size
multimodeadditional opticsfor Gaussian profil
single mode (gauss.)smooth surface
Excimer (193 nm) LaserSoft (210 nm)
Beam Quality0,20 mm
Up to 2kHz !!
>1 kHz
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The advantages of the LaserSoft system can be differentiated into:
•Technical Advantages
•Clinical Advantages
•Economical Advantages
All of those are linked together in certain ways
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Technical advantages:
•Small spot size allows complex ablation profiles
•Low sensitivity to environmetal influences
•Fast and easy-to-use Eyetracker
•Intuitive and straightforward software
•Easy to setup
•Low weight, small dimensions
•Optics with high life expectancy
•No noise
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This shows the relation of spot sizes
Broad beam laser (7mm)
Scanning (flying) spot laser
Lasersoft Solid State Laser
The volume ablated is to thesquare of the diameter
Example: a spot with 0,5 mm diameterAblates 4 times less volume than a spot with 1 mm
Lasersoft ablates 16 times less tissue per spot than a Scanning (flying) spot excimer laser.Hence 16 times more resolution
Comparison of spot sizes
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•Small spot size creates very detailed contours
•210 nm Wavelength passes through water and BSS
•Soft ablation creates a very smooth surface with
fast healing
•Fast and accurate eyetracker
•Aspheric ablation profile
Clinical advantages
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210 nm Wavelength passes through water and BSS
•Water and BSS (Balancedsaline solution) absorbs thewavelength of 210nm ca. 40times less than the 193nmused by excimer lasers.
•fluid on the corneal stromahas little or no effect on theablationrate
•Changes of the ambienthumidity do not affect theablationrate.
210 nm Relative Ablation Rate
0
25
50
75
100
0 2 4 6 8 10
Fluid path length [ mm ]
Re
l. A
bla
tio
n r
ate
[
% ]
H2OBSS
193nmin water
0,25mm (not to scale)
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Economical advantages
•No laser gas, no filters
•Long optics lifetime for SSL, less maintenance costs
•Easy to service and little downtime
•No special „Excimer grade“ room requirements neccessary
•System is mobile within the location and completely mobile on request
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Cinical data
myopia and myopic astigmatism
244 eyes
mean refractive error sf.eq. -3,08D +/- 2
max sf.eq. -11D
hyperopia and hyperopic astigmatism
58 eyes
mean refractive error sf.eq. +1,9D +/- 1,13
max sf.eq. +6,13D
mixed astigmatism19 eyes
mean refractive error sf.eq. -0,31D +/- 0,66max sf.eq. +2 D; min sf.eq. -4,50D
TOTAL TREATMENT185 patients - 322 eyes
mean age 37+/- 13 mean refractive error sf.eq. -2,03D +/- 2,66
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Solid-State laser system LASERSOFT
Incorporates the big advantages made over thelast years in the laser and photonic technology
Refractive surgery without gas
Next generation laser
Conclusions
Future for frequency-shifted DSSL inRefractive Laser Surgery
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Enjoy theFreedom of Vision!
Katana International AGEuroparc Dreilinden, Albert-Einstein-Ring 7D-14532 Kleinmachnow, GERMANY
Thank You