|
What is laser therapy?
How does it work?
How deep into the tissue can laser light penetrate?
Lasers vs. LED
Pulsed vs. continuous wave lasers
Is laser therapy safe?
Is laser therapy scientifically well documented?
What is pulsed electromagnetic therapy?
What is the InSight system?
The InSight 40/ICL 15
The InSight 100/ICL 60
The Maxi pulsed EMF system
Does laser therapy cause heat damage or cancer in the
tissue?
Trends in laser therapy

What is laser therapy?
For a long time now L.A.S.E.R. (Light
Amplification by Stimulated Emission of Radiation) was an acronym
and today a word of common use. The word LASER is the name of a
device that projects intense radiation of the light spectrum. It
produces a beam of light in which high energies can be concentrated.
Laser light has unique physical properties, which no ordinary light
has. The unique properties of coherence and monochromaticity are
the key to why laser light is so effective compared to other kinds
of light in pain reduction and healing. Laser therapy, also known
as phototherapy and low level laser therapy, involves the application
of low power coherent light to injuries and lesions to stimulate
healing and reduce pain. It is used to increase the speed, quality
and strength of tissue repair, resolve inflammation and give pain
relief. Laser therapy has been found to offer superior healing and
pain relieving effects compared to other electrotherapeutic modalities
such as ultrasound, especially in chronic problems and in the early
stages of acute injuries. Laser therapy is a complete system of
treating muscle, tendon, ligament, connective tissue, bone, nerve,
and dermal tissues in a non-invasive, drug-free modality.

How does
it work?
The effects of laser therapy are photochemical
in general and with super-pulsed lasers such as the InSight Series
also photomechanical. Photons enter the tissue and are absorbed
in the cell’s mitochondria and at the cell membrane by chromophores.
These chromophores are photosensitizers that generate reactive oxygen
species following irradiation thereby influencing cellular redox
states and the mitochondrial respiratory chain. Within the mitochondria,
the photonic energy is converted to electromagnetic energy in the
form of molecular bonds in ATP. It is obvious that, in order to
interact with the living cell, laser light has to be absorbed by
intracellular chromophores.
Cell membrane permeability increases, which promotes physiological
changes to occur. These physiological changes affect macrophages,
fibroblasts, endothelial cells, mast cells, bradykinin, and nerve
conduction rates.
The clinical and physiological effects are obtained by the way in
which the tissues absorb laser radiation. This tissue absorption
depends on the wavelength of the beam itself and the power to ensure
that the laser energy reaches the target tissue at the necessary
clinical levels. The use of an improper wavelength laser would not
penetrate into the tissue to reach the target area. Furthermore,
even if one has a laser with the proper wavelength, if the device
does not have enough power to drive the energy into the tissue,
the target area may not realize the potential benefits.
Each type of laser emits light at a very specific wavelength which
interacts with the irradiated tissue. It also acts in particular
with the chromophores present in the tissue, but in a different
way. A chromophore, intrinsic or extrinsic, is any substance, colored
or clear, which is able to absorb radiation. Among the endogenous
chromophores, water and hemoglobin, nucleic acid and proteins can
be listed. Among the exogenic chromophores we can instead find porphyrins
and hematoporphyrins, which are injected into the organism. These
are described as photosensitizers because they fix themselves to
the tissue making it photosensitive at specific wavelengths.

How deep
into the tissue can laser light penetrate?
The level of tissue penetration by the laser beam depends on its
optical characteristics, as well as on the concentration and depth
of the chromophores, which according to the wavelength are absorbed
at different percentages. For instance, water absorbs almost 100
percent of the laser irradiation at the 10,600 nanometer wavelength,
the wavelength of the CO2 gas laser. That is the reason why this
type of laser wavelength is used in surgical applications.
Other factors affecting the depth of penetration are the technical
design of the laser device and the treatment technique used. There
is no exact limit with respect to the penetration of the light.
The laser light gets weaker the further from the surface it penetrates
with a limit at which the light intensity is so low that no biological
effect of the light can be measured. In addition to the factors
mentioned above, the depth of penetration is also contingent on
tissue type, pigmentation and foreign substances on the skin surface.
Bone, muscles and other soft tissues are transparent to certain
laser lights, which means that laser light can safely penetrate
these tissues.
The radiation in the visible spectrum, that between 400 and 600
nanometers, is absorbed by the melanin, while the whole extension
of the visible which goes from 420 to 750 nanometers is absorbed
by composite tetrapyrrolics. In the infrared, which covers about
10,000 nanometers of the light spectrum, water is the main chromophore.
Fortunately, there exists a narrow band in the light spectrum where
water is not a highly efficient chromophore, thereby allowing light
energy to penetrate tissue that is rich in water content. This narrow
band, which extends approximately from 600 to 1,200 nanometers,
is the so-called therapeutic window. That is the reason why the
therapeutic lasers in the market today have wavelengths within this
therapeutic window. The penetration index is not the same level
throughout the therapeutic window. In fact, lasers in the 600 to
730 nanometers have less penetration and are suitable for superficial
applications such as in acupuncture.

Lasers vs.
LED
Light emitting diodes (LED) are just tiny light bulbs that fit easily
into an electrical circuit. But unlike ordinary incandescent bulbs,
they do not have a filament that will burn out. They are illuminated
solely by the movement of electrons in a semiconductor material.
LED’s produce incoherent light just like an ordinary light
bulb does. Light from LED’s have very little tissue penetration
compared to laser light.
By applying the first law of photochemistry (Grotthus-Draper Law),
which states that light must be absorbed by a molecule before photochemistry
can occur, one can immediately conclude that light from LED’s
would work only on skin level conditions, if at all. For conditions
deeper than skin layers one must choose light from a laser source.

Pulsed vs.
continuous wave lasers
In general, lasers diodes are either continuous wave or pulsed.
The continuous wave (CW) diodes emit laser energy for the entire
time it is electrically driven, hence its name. Pulsed diodes emit
a radiation impulse with a high amplitude or intensity and duration
of which is typically extremely short such as 100 to 200 nanoseconds.
Continuous wave lasers produce a fixed level of power during the
emission. Although lacking the high peak power of a "true"
or "super" pulsed laser, most continuous wave lasers can
be made to flash a number of times per second to simulate pulse-like
rhythms by interrupting the flow of light rapidly as in turning
“off” and “on” a light switch.
Pulsed lasers, as the name implies, produce a high power level impulse
of light for a very brief duration for each pulse. It is the high
power level during each pulse that drives the light energy to the
target tissue. Even though the pulse peaks at a high power level
there are no thermal effects in the tissue because the pulses are
of extremely short duration. Therefore, the peak power of a pulsed
laser is high compared to its average pulse power. By using pulsed
lasers, one is able to more effectively drive light energy into
the tissue.
The laser and electronic technologies required to use pulsed diodes
are more advanced and the diodes themselves are more expensive than
the CW diodes. These are probably the main reasons why over 90%
of the therapeutic lasers in the North American market are low power
CW lasers. Some of these CW lasers provide power on the order of
inexpensive laser pointers costing around $30 USD.

Is laser
therapy safe?
Yes. Laser therapy is a drug-free, non invasive therapy with superior
healing ability. However, since lasers produce a high intensity
light, one should never shine the laser directly into the eye. Further
it is recommended that the laser device not be used directly on
any neoplasmic tissue. Pregnant patients should refrain from laser
therapy applied directly on the abdomen.

Is laser
therapy scientifically well documented?
There are more than 120 double-blind positive studies confirming
the clinical effects of laser therapy. More than 300 research reports
have been published. Looking at the laser therapy dental literature
alone there are over 300 studies. More than 90% of these studies
do verify the clinical value of laser therapy.
A review of the research literature of studies that produce negative
results one finds that low dose was the single most significant
factor. By dose is meant the energy of the light delivered to a
given unit area during a treatment session. The energy is measured
in joules and the area in cm2. Assuming that the power of the laser
remains constant during the treatment, the energy of the light will
be equal to the power in watts multiplied by the time in seconds
during which the light is emitted. Therefore, a laser with more
power (watts) can deliver the same amount of energy (joules) in
less time. If we use a pulsed laser we can extend the above statement
by saying that a pulsed laser with more average power (watts) can
deliver the same amount of energy (joules) in less time and at deeper
target tissues than continuous wave lasers.

What is
pulsed electromagnetic therapy?
Magnetic fields play a key role in biological life. A magnetic field
is created when a conductor is crossed by an electrical current.
Magnetic fields arranged around single conductors are summed in
a coil producing a density of magnetic force lines. If current produced
in this way flows in pulses, then a pulsed magnetic field is created.
In the bioenergetic and chemical terms of the organism, the essential
concept of magnetism is not the magnetic load, but the energy-rich
dipole which is surrounded by a magnetic field and whose transformation
and exploitation for the production of energy in the organism is
highly significant.
The most important effect from pulsed electromagnetic fields (EMF)
therapy is found on the cellular transmembrane potential (TMP).
It is known that damaged or diseased cells present an abnormally
low TMP, up to 80% lower than healthy cells. This signifies a reduced
metabolism, impairment of the electrogenic sodium-potassium (Na-K)
pump activity, and therefore, reduced ATP production. In a nutshell,
the TMP is proportional to the activity of the Na-K pump and thus
to the rate of healing.
Healthy cells have TMP voltages of 70 to 100 millivolts. Due to
constant stresses of modern life and a toxic environment, cell voltages
tend to drop as we age or due to illness. As the voltage drops,
the cell is unable to maintain a healthy environment for itself.
If the electrical charge of a cell drops to 50, the patient may
experience chronic fatigue. Electromagnetic therapy with the Maxi
provides one effective way to affect healing rates by increasing
cellular TMP

What are
the InSight systems?
The
InSight 40/ICL 15
The InSight 40 is a desktop laser instrument with a pulsed diode
that provides peak powers of up to 40,000 mW for very effective
photonic tissue penetration. The power is modulated so that it is
adjustable from 10% to 100%. This allows matching the average power
to the specific patients’ needs. The peak pulse power is of
up to 40,000 mW and the average power is of 250 mW. This achieves
high depth of tissue penetration while providing gentle average
power levels. The laser beam is transmitted through fiberoptic cables
and is guided by a blue LED light at the treatment probe aperture
to ensure patient comfort and treatment accuracy.
The
InSight 100/ICL 60
The InSight 100 is a laser instrument with pulsed diodes that provides
peak powers of up to 100,000 mW for the most effective photonic
tissue penetration. The power is modulated so that it is adjustable
from 10% to 100%. This allows matching the average power to the
specific patient’s needs. With a peak pulse power is up to
100,000 mW and an average power of 850 mW, the InSight 100 achieves
high depth of tissue penetration while providing gentle average
power levels. The laser beam is transmitted through fiberoptic cables
and is guided by a blue LED light at the treatment probe aperture
to ensure patient comfort and treatment accuracy.

The Maxi
pulsed EMF system
The Maxi pulsed electromagnetic field (PEMF) generator is an innovative
equipment for magnetotherapy that generates low and medium frequency
pulsating magnetic fields. In addition to the well-known use in
the orthopedic and traumatology fields, it can also be usefully
applied for conditions in the vascular, dermatological and internal
medicine arenas, as well as in sports and aesthetic medicine. In
the United States, these devices can be used for wellness purposes
only.

Does laser
therapy cause heat damage or cancer in the tissue?
No. The average powers and the type of light source (non-ionizing)
do not permit heat-damage or carcinogenic (cancer-causing) effects.
Due to increased blood circulation there is sometimes a minimal
sensation of warmth locally.

Trends
in laser therapy
Therapeutic lasers are getting better every year. New lasers have
entered the North American markets that provide deeper tissue penetration,
higher power densities and reliable electronics to achieve better
clinical outcomes. The trend has been to increase power density
and dose, since these have been shown to produce better clinical
outcomes. In the case of superficial target tissues, clinicians
have several laser options to consider. For tissue just beyond a
few millimetres from the skin surface, underpowered lasers currently
available in North America do not deliver the needed light energy
to the treated tissues that present in patients in a typical healthcare
office.

|