Recent%20Progress%20in%20Medical%20Laser%20Technologies%20____________________________

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
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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
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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),

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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 !!