Nd:YAG LASER
Wavelengths and emissions
1
Nd:YAG (λ = 1064 nm) WAVELENGTH
Absorption coefficient
Nd:YAG
CO₂
808
980
Therapeutic
window
Source with a very low absorption coefficient in the tissue
2
Nd:YAG (λ = 1064 nm) EFFECTS
Biological effects
Emitted energy
Tissue heating
The energy density or fluence (J/cm2) is the energy per unit area
I (W/cm2) x t (s)
3
Nd:YAG (λ = 1064 nm) EMISSION MODALITY
Power
 Continuous emission
 Chopped emission
Time
Power
 Pulsed emission
Time
Power
Continuous: the average power is equal to the peak power.
Chopped: pulse duration ton is comparable to the period T.
Pulsed: the average power is far lower than the peak power.
Time
4
Nd:YAG (λ = 1064 nm) EMISSION MODALITY
 Continuous emission
 Chopped emission
 Pulsed emission
Fluence (J/cm2): I (W/cm2) x t (s)
In order to avoid thermal damage, emissions are
characterized by low intensities for long times:
Low Efficiency!
5
Nd:YAG (λ = 1064 nm) EMISSION MODALITY
 Countinuous emission
 Chopped emission
 Pulsed emission
(Hilterapia only)
Fluence (J/cm2): I (W/cm2) x t (s)
Excessive thermal increase is avoided thanks to pulses
with very high intensity and very short duration:
High Efficiency!
6
Comparison between
continuous and pulsed systems
CW:
• Pm = 1,5 W
• Spot = 0,3 cm2
• Fluence in 10 s = 50 J/cm2
• Incident Intensity = 1,5 W / 0,3 cm2 = 5 W/cm2
PW:
The Intensity of incident radiation is 1000
• Pm = 1,5 W
times higher in pulsed system respect to
continuous system!!
• Spot = 0,3 cm2
• Fluence in 10 s = 50 J/cm2
• Pp = 1500 W
• τ-on = 100 μs
• Freq.= 10 Hz
• Pulse Incident Intensity = 1500 W / 0,3 cm2 = 5000 W/cm2
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Power
ton
PW Emissione
Pp
CW Emission
Power
Pm=Pp
Power
Tempo
CW-I Emission
Pp
Pm
Pm
Time
• Diode Laser 632,780, 810, 980, 1064 nm
toff
Time
•Pulsed Nd:YAG 1064nm (only Hilterapia®)
8
Comparison CW/CW-I emission and Hilt®
CW:
HILT® PULSE SH1 :
•
•
•
•
•
•
•
•
•
•
•
•
•
Pm = 10 W
Spot = 0,2 cm2
Time = 10 sec
Energy = 100 J
Intensity= 10W/0,2 cm2 = 50 W/cm2
CW- I:
•
•
•
•
•
•
•
•
Pm = 10 W
Spot = 0,2 cm2
Time = 10 sec
Energy = 100 J
Pp = 20 W
τ-on = 10 ms
Freq = 50 Hz
Intensity =20 W/0,2cm2 = 100 W/cm2
Pm = 6 W
Spot = 0,2 cm2
Time = 10 sec
Energy = 60 J
Pp = 1000 W
τ-on = 150 μs
Freq = 40 Hz
Intensity=1000 W/0,2 cm2 =5000 W/cm2
HILT® PULSE HIRO 3.0:
•
•
•
•
•
•
•
Pm = 10 W
Spot = 0,2 cm2
Time = 10 sec
Energy = 100 J
Pp = 3000 W
τ-on = 120 μs
Freq = 28 Hz
•
Intensity=3000 W/0,2 cm2 =15000 W/cm2
9
®
Hilterapia
Technical characteristics
10
Hilterapia®
 Patented in USA (U.S. Patent n°6,527,797 B1)
 Approved by FDA-USA 510 (k) n. K051537
11
Unicity of Hilterapia®
INTENSE
DEEP
SAFE
12
Hilterapia®: why?
Because pulsed technology is able to increase the intensity of incident radiation without
increase the total quantity of energy delivered to the tissue, with consequently:
 Deeper action, high peak power promote penetration inside the tissues
 Elevated efficacy, due to the ability of producing biological effects even in deep tissues.
 Higher safety of treatment (to minimize risk of thermal damage during laser treatment).
13
TECHNICAL CHARACTERISTICS of HILTERAPIA®
• Nd:YAG source (λ = 1064 nm)
• Pulsed emission
• Very high peak power (1-3 KW)
• Veru high intensity (5000-15000 W/cm2)
• High energy content (150-350 mJ)
• Short duration (120-150 µs)
• Low repetition frequency (10-40 Hz)
• Duty cycle 0,1 % - 0,6 %
14
Power
Vertical delivery of
energy!
Time
 High peak power pulse, up to 3 kW
 Short duration (120-150 µs) and long pulse interval (ms)
15
Power
Low frequency: 10-40 Hz
Time
 Low frequencies minimize damaging thermal effects
 It is known that many cell types are more responsive to low frequency
stimulations
16
LASER
PULSATO
High energy contents delivered in deph
respecting thermal relaxation time of tissues
17
HILTERAPIA®
Laser-Tissue Interaction
18
HILT PULSE
PHOTOTHERMAL INTERACTION:
•Increase of kinetic energy
•Localized increase of temperature
•Formation of temperature gradients
PHOTOMECHANICAL INTERACTION
(resulting from photothermal effect):
•Temporary deformation of ECM (extracellular matrix)
•Reorganization of cellular cytoskeleton
•Induction of specific intracellular signals
19
ACTION ON CELLS OF CONNECTIVE TISSUES:
• Induction of cell differentiation (maturation process in which cells
specialized themselves to perform the characteristic function of the tissue
they belong to) observed in chondrocytes and stem mesenchymal cells.
• Exaltation of inflammatory cytokines signaling pathway, promoting
reparative, regenerative and remodeling processes in tissue
• Increase of ECM production by fibroblasts and chondrocytes
• Induction of formation of very ordered arrays of fibronectin fibrils.
Fibronectin is a protein that connects ECM components each other and with
cell surface and constitutes a template for collagen fibres assembling.
20
ACTION ON ENDOTHELIAL CELLS :
• Promotion of ordered cell monolayers formation, with important
consequences on angiogenesis (formation of new vessels) and on endothelial
function (in particular, blood-tissue exchange)
21
ACTION ON NERVE FIBERS :
• Action on conduction mechanism of peripheral nerve fibers, inducing a
dose-dependent reduction of action potential.
• In soft tissue can decrease sensitivity to pain
22
HILT PULSE
PHOTOTHERMAL INTERACTION
PHOTOMECHANICAL INTERACTION
ACTION ON CELLS OF
CONNECTIVE TISSUES
ACTION ON ENDOTHELIAL
CELLS
ACTION ON NERVE
FIBRES
THERAPEUTIC EFFECT
•REPARATIVE, REGENERATIVE, REMODELING EFFECT
• ANTI-INFLAMMATORY EFFECT
• ANTI-OEDEMA EFFECT
• ANTALGIC EFFECT
23
HILTERAPIA®
Indications, contraindications
and warnings
24
THERAPEUTIC INDICATIONS

Acute pathologies
•
Tendinopathies
• Muscle lesions
•
Distortions and dislocations
•
Post-traumatic edemas
•
Synovitis and bursitis
•
Osteochondral lesions
 Degenerative and chronic pathologies
•
Osteoarthrosis
•
Degenerative chondropathies
• Fibromyalgia syndrome
25
CONTRAINDICATIONS
Therapy using the system is contraindicated for those patients who:
• have known sensitivity to the device
• take anticoagulants
• take medication that is known to increase sensitivity to sunlight
• have seizure disorders triggered by light
• are pregnant
• suspected of carrying serious infectious disease and/or disease where
it is advisable to suppress heat or fever
• with hemorrhagic diatheses
• have HIV positive history
26
CONTRAINDICATIONS
The device should not be used:
• over areas of suspicious, potentially or known cancerous tissue
• over areas of active hemorrhage
• over areas injected with steroids in the past 2-3 weeks
• over the thoracic area if the patient is using a pacemaker
• over the sympathetic ganglia
• over the vagus nerve
• over the neck (thyroid or carotid sinus region)
• over or near bone growth centers until bone growth is complete
• over area where analgesia may mask progressive pathology
27
CONTRAINDICATIONS
The device should not be used:
• over anesthetic areas
• over an area of the spinal cord following a laminectomy, i.e., when major covering
tissue have been removed
• on ischemic tissue where the blood supply would be unable to follow the increase in
metabolic demand and tissue necrosis might result
• for symptomatic local pain relief unless a pain syndrome has been diagnosed or unless
etiology is established
28
WARNINGS
• No direct aim into the eyes of humans or animals
• Patients with an implanted neurostimulation device must not be treated with or
be in close proximity to any shortwave diathermy, microwave diathermy,
therapeutic laser diathermy or laser diathermy anywhere on their body.
Energy from diathermy can cause tissue damage and can result in severe injury or
death, even if neurostimulation system is turned off.
29
WARNINGS
•The application on wounds has to be performed at a certain distance to avoid the
spread of bacteria.
• Higher output levels have a greater potential for patient discomfort. Choose a
lower dosage to reduce output or select a frequenced output to decrease patient
discomfort.
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ELECTROTHERAPY
1-Chemical effect
2-Thermal effect
TRADITIONAL
LASER THERAPY
SHOCK WAVES
1-Photochemical effect
1-Mechanical effect
2-Photothermal effect
1- PHOTOCHEMICAL EFFECT
2- PHOTOTHERMAL EFFECT
DIATHERMY AND
HYPERTHERMIA
3- PHOTOMECHANICAL EFFECT
MAGNETOTHERAPY
1-Chemical effect
2-Magneto-mechanical
effect
1-Thermal effect
ULTRASOUND
1-Thermal effect
2-Mechanical effect
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CLINICAL EVIDENCES
32
Conservative treatment of low back pain caused
by intervertebral disk displacement:
Comparison among HILT ®, TENS e NSAID
(Zati et al. Medicina dello Sport, 2004, 57: 77-82)
33
Clinical protocol
60 low back pain patients, divided in 3 groups.
Treatment lasted 15 days.
1. HILT, n=20 pts: 10 Tx, 5 Tx/week
2. TENS, n=20 pts: 10 Tx, 5 Tx/week
3. NSAID, n=20 pts: Ketoprofene 200 mg/d. (15 days)
Clinical tests: Backill and VAS at:
•
T/0 : before treatment
•
T/1 : 15 days after T/0 (end of treatment)
•
T/2 : 45 days after T/0
•
T/3 : 180 days after T/0
34
Results
HILT
TENS
NSAID
Total Backill test scores
HILT
TENS
NSAID
Backill test – t scores
35
Results
HILT
TENS
NSAID
Total VAS test scores
HILT
HILT
TENS
NSAID
VAS test – t scores
36
score
score
Results
HILT
TENS
NSAID
HILT
TENS
NSAID
VAS score and Backill score
37
Conclusion
•
In low back pain Hilterapia® is safe and well-tolerated.
•
In short terms we obtained similar results using HILT ®, TENS and NSAIDs.
•
While, in mid and long terms HILT ® allows better and longer results than TENS
and NSAIDs.
Hilterapia® effects are more long-lasting
38
Hilterapia® for the treatment of calcifying
tendonitis of the rotator cuff
(Valent A., Benedetti E., Istituti Ortopedici Rizzoli, 2003)
39