Recent Progress in Medical Laser Technologies ____________________________ - PowerPoint PPT Presentation

Loading...

PPT – Recent Progress in Medical Laser Technologies ____________________________ PowerPoint presentation | free to download - id: 594234-M2Y0Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Recent Progress in Medical Laser Technologies ____________________________

Description:

Title: Laser applications in Cosmetology and Ophthalmology ( ) Author: Yuchin Lin Last modified by – PowerPoint PPT presentation

Number of Views:256
Avg rating:3.0/5.0
Slides: 49
Provided by: Yuchi2
Learn more at: http://opt.zju.edu.cn
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Recent Progress in Medical Laser Technologies ____________________________


1
Recent Progress inMedical Laser
Technologies____________________________
? ? ? ? ? ? ? ? ? ? ?
J.T. Lin, Ph.D Chairman New Vision,
Inc. ????(???????) (????) ???(???)
???????? (??) ?? (????)?????? (??)
3-2008
2
Definitions
  • LASER Light
  • Amplification by
  • Stimulated
    Emission of
  • Radiation (??)
  • --------------------------------------------------
    ------------------------------
  • ?? (??) vs ?? (??)
  • --------------------------------------------------
    --------------------------------------
  • ?? (Photon) vs. ?? (Wave)
  • -----------------------------------------------
  • Diode vs. LED
  • (laser) . (light)

3
Historical
  • 1900 (Max Planck) quantum mechanics
  • 1917 (Einstein) A B Coefficients
  • 1954 (Townes)... MASER (microwave)
  • 1960 (Maiman) Ruby laser
  • 1961 (Javan, Johnson) . HeNe, NdYAG
  • 1962 (Bennett).. Argon laser
  • 1964 (Patel) . CO2 laser
  • The laser-patent war /Gordon Gould (1997).
  • ????
  • 1983.. (UV-193 on organic tissue IBM
    Patent, )
  • 1990 . PRK (vision correction, VisX
    patent)
  • 1992 . LASIK (Scanning) ( Lins patent)
  • 1998 . Presbyopia-I (Lins patent)
  • 2008 . Presbyopia-II , 3um didoe-laser
    (Lin)

4
Overall Laser Applications
  • ?,?,?,?,??
  • ??,???
  • ??????
  • ?????
  • ??,????,???
  • ??????????
  • ?????

5
SPECIAL Features of LASER
(1) ???? (low divergence)
??????????????????, ????????????????????
?? (2) ??? (high intensity) ?????????????
focused spot size (micron 0.001 mm) (3)
Pure-spectrum (narrow band-width)
spectroscope, chemistry.. (4) Tunable spectrum
(via non-linear processes) ?????, ????,
??(pulse width) (5) ???? (high Coherence)
??????????????????????? ??????????????????????
??
6
Non-medical applications
  • Military??
  • - laser range-finder (1064, 1554 nm)
  • - laser beam-weapon (STAR War)
  • Car industry
  • - speeding, counter-speeding
  • - collision-free
  • - auto-parking
  • - overhead screen, GPS
  • - auto-driven

7
Bio-PHOTONICS
Bio-medical
Bio-Medical
Photonics
? ? ? ?
Photon Electronics
Biology Medicine
  • Energy beams
  • Laser, LED, RF,
  • non-coherent- light,
  • Ultrasound
  • Optical materials
  • Fibers beam delivery
  • Optical diagnosis,
  • spectroscope
  • Electronic
  • System integration
  • Software hardware
  • Bio-imaging, Bio-sensor
  • Photo-therapy (PDT)
  • Photo-biology
  • Surgical, coagulation
  • Drug delivery, tracking, characterization
  • Nano-medicine, bio-materials, bio-chem
  • Tissue Engineering/welding
  • Bionic human (artificial organs)

NVI
8
to be an Innovator (? ? ?)
Innovation VS. Improving
Know known Un-know known Un-know
un-known Know un-known
Rumsfield (2006)
NVI
9
? ? ? ? ( Pioneer ) VS.
? ? ? ? ( Follower )
? ? ? (innovator) ? ? ? ? ? ? ! Know un-known
?? ?????
10
???(???) ???????? ITRI Projects ???(???)???
  • (1) ??(???????)
  • - ???????????????
  • - ???????
  • (2) ???,???,???(??????)
  • (3) ?????????
  • (4) ?? 2 3 ????????????
  • ??????? .
  • (5) ??,??,??,?????????????.

11
Examples of innovation-IMPACT
  • Only lt 1 patents has major financial impacts !!!
  • (the METHODS patents)
  • IBM (1983 US patent)
  • UV laser (193 nm, ArF) for all organic
    tissue ablation
  • licensed to LaserSight for
    gt30M
  • Steve Troke (Columbia Univ.)
  • 1986 US PatArF for PRK/LASIK
  • value gt2.0 B
  • JT Lin (1991, 2000, 2004, 2006 US pat)
  • scanning-laser for Lasik
  • value gt 500M
  • Shue Lai (1993)
  • eye-tracking device, value gt200M
  • JT Lin (1998)..
  • laser for presbyopia value gt 200M
    (???)

12
Medical products development
Idea, concept, theory
Search, re-search Defining parameters
Lab test, RD
Proto-type (1-2 years)
Phase-I (Safety) Phase-II (Efficacy) Phase-III
(Commercial)
Clinical (Animal, human) (in Vitro, in
Vivo)
(1-8 years) FDA approval (510-K or PMA)
System Integration
Commercialization
(patents, improving)
NVI
Lin-7-2007
13
Bio-Physics Laser-tissue interaction
  • Mechanisms (Absorption, reflection, scattering)
  • 1) Thermal
  • 2) non-thermal
  • 3) combined effects
  • (Coagulation-ablation, cutting-incision)
  • Key parameters
  • Wavelength, Pulse width (Tp),
  • Energy (E), Intensity (I), Power
    (P), fluency (F)
  • Absorption coefficient (A),
    Reflection/scattering loss
  • concept F E/ laser spot-size
  • I E/ pulse-width

14
Thermal vs. Non-thermal
  • (1) Thermal ( most cosmetic lasers)
  • low-power, low intensity,
    long-pulse
  • weak-absorption (A) ,
  • CW visible
    lasers, LED (400-700 nm)
  • Diode (1.3-2.2 um)
  • HoYAG (2.1 um),
    CO/2(10.6 um)
  • (2) Non-thermal (Lasik, kidney-stone,
    dental/hard-tissue)
  • Short-pulse, high peak-power,
  • Strong absorption (Agt100 cm-1)
  • (in water, tissue, melanin, protein
    , etc)
  • short-pulsed (ps - fs) laser (independent
    to wavelength)
  • ErYAG (2.94 um), Excimer-laser
    (193, 248 , 308 nm)

15
Absorption (blood, skin)
melanin
A
HbO2
420
580
0.2 0.5 1.0
1.2
wavelength (um)
16
Absorption in Water/Tissue
Absorption (A)
2.94
1.93
CO2-laser
1.45
0 1.0 2.0 3.0
10 (microns)
17
Penetration-depth(d1/A) vs. wavelength
UV VISIBLE Near-IR
Mid-IR
(0.2-0.4) (04.-0.7) (0.8- 2.1)
(2.7-3.2) um
0.05 mm
(0.2-0.5)
(0.05-0.5) mm
(0.5-2.0)
(2.0-6.0)
Water 3 absorption peaks 1.45, 1.93, 2.94 um
18
Laser Ablation Theory
  • (1) Beers law
  • I(z) I(0) Exp -Az
  • (2) Ablation depth (H) is given by
  • H (1/A) ln (F/F)
  • where F threshold laser fluence
  • for ablation to occur.
  • optimal A given by dH/dA 0
  • A2.718 (F/F)
  • (3) Lins law (2005, for focused laser)
  • I B I(0) Exp(-Az)
  • Bfocusing factor for optimal depth.

Depth (H)
0 F F
Depth (H)
0 A A
19
Laser heating theory
  • Laser produced tissue temperature via heat
    conduction equation
  • dT/dz k (d2 T/dz2)
  • where ktemperature conductivity
  • Laplace transform or the Green function method
    to obtain
  • T(z,t) Integrate S G dz dt
  • S is the heat source and G is the Green
    function given by
  • G C exp -(z-z0)2 / 4k(t t0)
  • Thermal penetration depth
  • d square root of (4kt)
  • 0.75 square root laser pulse width
  • for d (in um)m and t (in usec).
  • Example
  • for 1 usec laser, the heat conduction
    distance is about 0.75 um.
  • The one-micron rule ( t1.0 usec)
  • short pulsed laser for non-thermal
    process.
  • example fiber laser (f.s.)

Temp.
time
20
System design consideration
(1) For soft-tissue
  • 1. Hemoglobin (blood)
  • 2. Melanei (skin-color)
  • 3. Water (Tissue)
  • 4. Others (protein etc)
  • (2) Hard tissue (bones, teeth)
  • shock-wave
  • plasma-assisted

Wrinkle-removal
Hair-removal
(invasive)
PDT
Non-invasive
21
  • Major medical procedures
  • 1. ??
  • 2. ??????
  • 3. ???
  • 4. ???, ???
  • 5. ??

22
??? (Prostate)
  • Technology endoscope laser fiber
  • Laserscope, Inc. (acq. by AMS for 1.9 B)
  • high-power (50-80 W)
  • cw, green (532 nm) laser
  • fiber-coupled
  • side
    firing
  • Other lasers
  • ErYAG (2.9 um) HoYAG(2.1 um), ThYAG(2.07
    um)
  • diode-laser (1.4 2.9 um)

45-angle
23
Dental lasers
  • (1) Hard tissue (dentin, carries)
  • a) Biolase water-laser (ErYSGG at
    2.78 um)
  • b) Lin/ITRI, mid-IR diode laser
    (2.7-3.0 um)
  • (2) Diode laser (soft tissue)
  • at 808, 940, 980 nm
  • (3) Teeth whitening
  • NdYAG (1064) dye
  • (4) Velcope
  • Blue-light (or LED) to detect cancer
    tissue

24
Photodynamic therapy (PDT)
  • Laser-activated process
  • a). Photo-sensitizers
  • Red-dye, ALA red-laser (630-660 nm),
  • IR-dye, HPPH,
    IR-laser (750 - 1200 nm)
  • b) UV-laser excitation ..
    visible-laser fluorecense
  • c). Nano-particle ..(ITRI-2008)
  • 780-850 nm ps-laser
  • ,
  • Applications
  • Cancer, tumor , antibody
    detection,
  • Psoriasis, acne,
  • Age-related macular degeneration
    (AMD)
  • hair-growth, wound-healing
    etc..

25
Optical Biopsy (breast cancer detection)
500 nm
  • Prof. Alfano at CCNY
  • SPIE (2006, 6091)
  • breast cancer detection
  • UV (282, 300 nm) as excitation,
  • compare fluorescence spectra
  • of normal and cancerous tissue
  • Ratio
  • I/345 I /500 3 to 5 times

UV
345 nm
cancer
26
Ultra-short-pulsed (USP) Lasers
  • USP laser (tplt 20 p.s.)non-thermal
  • Applications
  • (1) high speed spectroscopy
  • (2) 3-photon cancer diagnosis
  • (1.2 um, third-harmonic)
  • (3) corneal-flap for Lasik (NdYAG, 1064 nm)
  • (4) materials process
  • fiber-laser at 1030-1550 nm
  • - Raydiance, Inc.(USA)
  • - ITRI(???,???)
  • for medical, industrial uses.

27
Cosmetic Applications
  • 1). Hair removal
  • Diode lasers (808, 940, 1064 nm)
  • Alexandrite laser (at 760 nm,
    pulsed)
  • (damage of follicle, hair-root ..)
  • Hair-growth red LED (630-680 nm)
  • 2). Skin Rejuvenation
  • Invasive (ErYAG, CO2),
  • Non-invasive (1.32, 1.55 um)
  • LED (880,630,580,420 nm)
  • 3). lesions
  • Acne (blue-LED/420 nm, IR
    fiber-laser/1550 nm)
  • tatoo (ruby, NYAG),
  • spots (co2, ErYAG, alex, dye laser)
  • 4). Psoriasis (excimer-308, red-LED/630)
  • non-laser methods
  • Radio-Frequency (MHz),

28
Laser hair removal
29
  • Wrinkle removal
  • (2) pigmented lesion
  • (3) vascular lesions
  • (4) acne
  • (5) leg veins (6)
    tatoo

30
Home use hand-held LED
4- color LEDs IR (940 nm) Yellow (580
nm) Red (660 nm) Blue (470 nm)
31
Hair growth
Laser-comb Red-LED (630-695 nm)
32
????Combining-energy
  • (????)
  • Laser LED RF
  • Intense-Pulsed-light (IPL)
  • ?????
  • ?????
  • ?????
  • ???

(1) ???(Er YAG), (2) IR-diode laser
(1.34,1.54,1.9, 2.8 um) (3) fiber-laser
(FRACTOR)
33
Smart eye designs (learned from natures
evolution theory )
  • On the origin of species by means of
  • Natural Selection
  • (Charles Darwin,1859)
  • Functional adaptation is one of the
    important
  • built -in survival mechanisms
  • of all species.
  • Analysis of smart eyes with high power
    lens-accommodation
  • (Lin, JCRS, 2007, 35, 758-759)
  • Examples Diving birds, sharks, octopus,
    Stingrays

34
Low-field myopia theroy
???????? ?
V (cm)
LFM (diopter)
  • Frog (1994)
  • 2. Stingray (1942)
  • 3. Pigeon (1942)
  • 4. Crane
  • 5. Horse (1975)

0
5(horse)
20
4 (Crane)
3 (Pigeon)
10
-10
2 (Stingray)
7
1 (Frog)
-20
5
0 10 100
Pupil height (cm)
Near vision distance V -100/ D (cm)
35
Stingray non-spherical eye-structure(to see
both far near)
Y
Retina surface
X'
y
LENS
See far
x
Optical
axis
?
V
H
Sin? H/V
?
See near D - 1000 H/ Sin? (long axis)
Object
Lin (2005, unpublished)
36
Scan-195 LASIK System (developed by JT Lin,
1995)
37
LASIK vs. PRK
LASIK (stroma) PRK
(surface) 2 steps
1-step microkeratom
38
Flying-spot scanning system
SCANNER
193 nm
EXCIMER (ArF)
Eye-tracking
  • Advantages of Scanning LASIK
  • Smooth surface
  • Smaller energy/pulse ( 1 vs. 36 mJ)
  • Customized ablation for
  • super-vision (lt 20/10)

CORNEA
Lin (US Patent, 1992)
39
Non-linear process
  • Harmonic generation
  • 1064 gtgt 532 gtgt355 gtgt213 nm (KTP, LBO,
    BBO)
  • 5-th harmonic (213 nm) for LASIK (Lin,
    1992 US patent)
  • Optical Parametric Oscillation (OPO)
  • for tunable lasers (0.6 -3.2 um)
  • 1064 gtgt (1.5 to 3.2 um) ... KTP (Lin
    Montgomery, 1989)
  • 355 gtgt (0.6 to 1.3 um) .... BBO
  • Raman shift (SRS, SBS)
  • (in methane, H2, D2 gas)
  • 1064 (in CH4)gtgt 1.54 um (eye-safe
    range finder/Litton)
  • 532 (in H2) gtgt 460(Stokes), 682
    (anti-stokes)

40
Diode-pumped solid-state LASIK
1064 532 532 266 213
NdYAG
1064
1064
KTP(II) BBO(I) BBO(II)
Diode-pumped 100Hz, 40mJ 10 ns
LBO(I) KDT(I)
UV-213 100Hz 5 mJ Overall eff. 12
UV-213 for LASIK (Lin, US patent, 1992)
41
PR-270 ?? ??-???
Laser for Presbyopia
??????
UV-laser
for patients age 45-68
True accommodation
??,????(??LASIK) ??????(??CK???)
??????? (JT Lin, JRS, 2005) J.T. Lin
2001?????????????(ESCRS) ?? LPT
??????????(accommodation amplitude) A LRAS,
LR ?????(lens relaxation) AS
?????(anterior shift), AS(1.0-1.5)
D/mm
New Vision, Inc.(2008)
42
SCIENCE (September 29, 2006)
43
The Bionic-human(2/2002, Science)
44
Bionic Technologies
  • 1. Robotic hand
  • 2. Tissue repairing
  • 3. Artificial organs
  • (heart, liver, blood)
  • 4. Bionic-eye
  • Combined efforts of
  • bio-engineers, cell-biologists, clinicians

45
Bionic-eyeRetina-simulation
Micro-chip (3x3x1 mm)
46
New Directions (The next 3-5 years trends)
  • - Innovative concepts for new methods
    treatments - - - LED for low-cost light source
    (replacing lasers).
  • - Diode lasers in Mid-IR (2- 3 microns),
  • replacing Ho, ErYAG
  • - Ultra-short pulsed (fiber) lasers
  • - Combined energy-beam LASER, IPL, LED, RF
  • - New optical fibers (materials structures)
  • - Real-time image monitoring (endoscope)
  • - More efficient, selective image detection
    devices
  • in optical biopsy
  • - Less-toxic agents, such as nanoparticles
    and new
  • IR dyes, in PDT procedures.

47
More New Directions
  • - Solid-state UV laser , replacing the toxic
    excimer laser
  • for LASIK.
  • - Femto-second lasers for
  • PDT, cancer diagnosis,
  • and blade-less LASIK
  • - Multiple wavelength, multi-applications
    systems
  • - Minimally invasive techniques for class
    II or II procedures.
  • REFERENCES
  • 1. J.T. Lin, Laser Applications in
    Ophthalmology, Jaypee Brothers (2008),
  • 2 J.T. Lin, US Patent No. 5144630 (1992).
  • 3. ????,Medical Applications of Lasers
    Tokyo, Japan page 186 (1985).

48
  • Conclusion
  • (1) ?????????
  • ??, ??????
  • ???, ???
  • ???, ??
  • (type II, III)market-driven
  • (2) ?,?.?,???????
  • ???????????????
  • ????? ?
  • (3) ??????,??
  • Thank you for your attention !!
About PowerShow.com