|
Light therapy can include everything from standing in
the sun to using full spectrum lighting to utilization of complex medical
light therapy units. For this conversation we will limit our discussion to
the common medical light therapy units available on the market today.
There are several different properties that
determine the effect of light on living tissue. These are the wavelength
of the light used, the power density or mW of power, the light
source that is used, and if that light source is continuous or pulsed and
it if is pulsed, at what frequency.
Surgical lasers are not considered therapeutic
because they are not designed to heal tissue but to burn and cut tissue
during surgical procedures. Even RK surgery on the eyes uses a burning
procedure to scar the surface of the eye to change the way it
focuses.
Ultraviolet light devices are also not designed to be
therapeutic. They are promoted to kill bacteria. It is often used for acne
therapy to kill bacteria that causes acne and you can even purchase a
tooth brush holder that utilizes ultraviolet radiation to sanitize your
tooth brush.
There are two basic concepts currently utilized
for Therapeutic light instruments. The first is higher power infrared
light devices and the second is low power visible red lasers that are
pulsed. We will discuss each of these in detail.
Infrared light therapy
devices:
Infrared lamps, LEDs and LASERS are
intended to emit energy in the infrared spectrum to provide topical and
deep heating for the purpose of elevating tissue temperature. This heating
is promoted to relieve pain, increase joint mobility and relax muscles.
The mechanism of action for infrared lasers and light units is thermal and
mechanical, and healing comes about as a byproduct of the stimulation not
as a direct mechanism of the therapy.
If the infrared therapy contains infrared lasers
they are seldom collimated because collimation will cause
heat to focus on a small area and burning may occur.
Many devices will only use LEDs or SLDs as their light source because the
properties of the laser light are not required for thermal actions and
LEDs are less expensive than lasers.
The
infrared light devices are very effective at killing pain. Pain
relief is so consistent and predictable that it is obviously a
pharmacological
dose of therapy.
As described in the glossary, this means that the patient’s body has
little to do with the response. The therapy is mechanically and/or
thermally killing the pain. This is usually accomplished by thermally
damaging the fine sensory nerve endings to stop the sensation of pain.
When used properly, this damage is not permanent and the nervous system
heals in two or three weeks. This factor is also why the therapy requires
another dose at or about the two to three week timeframe to keep the pain
away. This is certainly safer, more effective, and lower in cost than
using narcotics and other pain killing drugs, but the operator needs to
understand that they have not corrected the cause of the pain, they have only stopped the pain. When utilized on
athletes, caution must be advised or the athlete - without having the pain
sensation - may push an injured area to the point of severely injuring
himself or herself.
There is a suggested mechanism of healing with
infrared therapy which states that the stimulation of the infrared
wavelengths stresses the local tissue and stimulates the body to mobilize
resources to that area of the body to increase the healing of that tissue.
This is quite sound and emphasizes the fact that infrared is more of an
irritant than a healing stimulation to the body but can stimulate the healing
process.
Other
therapeutic effects of infrared lasers appear to be present but are not
understood or defined. Further research may discover other mechanisms of
action that are not understood today.
Infrared devices can
be recognized by the following characteristics:
- In the product
description the wavelength of the light will be in the infrared range,
greater than 760nm, usually in the 800nm and 900nm wavelengths.
- In the product
description the total power
output will be 100mW or higher. It can be much higher even up to 100,000
mW. The greater power density is needed to produce the
heat required to create the desired thermal effect on the tissue.
- If the unit contains laser diodes the unit will be classified
as a class IIIb or class IV
laser.
- They require that the wand that contains the
lasers be in direct contact with the skin. This is confusing since the
FDA states that you should avoid direct exposure to the radiation from
Class IIIb and Class IV lasers.
- Eye protection is mandatory for both operator
and patient.
- The proper treatment will be based on the Irradiation dose or the Joules of energy
delivered. This is an equation of the amount of optical energy or heat
that is delivered to the area of tissue.
- They will advertise greater penetration of energy into the body.
However, penetration is related to physical and thermal actions, not
healing actions.
- Infrared devices
frequently claim that the higher the mW, the faster the therapy.
Example: If it takes 10 minutes to produce ‘x’ amount of
Jules of energy at 100 mW, then you could
perform the same therapy in 1 minute if you had a unit that produced
1,000mW of energy. If this example were accurate, it would also mean
that if you needed to bake a cake for 30 minutes at 300 degrees, if you
had a better oven you could bake the same cake for 3 minutes at 3,000
degrees and have the same outcome. Obviously, even though the math is
the same the results will be different in people and cakes. So just
because it sounds logical does not mean that it is.
- Infrared energy is not visible so most units
will contain a visible red laser for the purpose of aiming and knowing
when the laser in turned on. These are not considered part of the
therapy.
- The infrared units will have a pulse duration
setting. This setting is not for the pulse frequency but for the duty
cycle of the light. By varying the duty
cycles you can change the amount of energy delivered during the
treatment.
Low Level visible red Laser therapy
devices: (LazrPulsr
4X)
Unlike the
infrared devices that are only concerned about the heat that is delivered,
these lasers are very complex in their actions because they are designed
to stimulate the physiology of the body through a mechanism
called biomodulation or
photobiomodulation. These
principles of light or energy medicine originated in the quantum physics
of Einstein himself. He first introduced the concept of the LASER
“light amplification by stimulated emission
radiation”. He also stated that every living cell emits
radiation called the “photon emission of living cells”, or
what we commonly refer to as the aura. Albert Einstein, in 1917,
proposed all living and nonliving matter represented dynamic
electromagnetic fields, which exist in an electromagnetic environment –
the universe! It took nearly 60 years for fellow physicists to begin
to comprehend Einstein’s holistic worldview of quantum mechanics, and the
relationship between matter, energy and health.
Due to the low power density and the properties of
the wavelength used, the true low level therapy lasers are only capable of
delivering a physiological dose of therapy. Some
consider this limited because it is dependent on the ability of the
patient to respond to care which creates less consistent and predictable
outcomes. However, when you consider that this therapy actually gives the
body a greater ability to respond you can see that it has expanded the
limits of what can be accomplish.
One
of the most important aspects of a physiological dose of therapy is
that it is safe. It is safe no mater what the condition or pathology is,
no matter what medications the patient is on, no matter what the patient
may be allergic to, no matter what, a true LLLT unit will
“…DO NO
HARM!”
One of the most profound physiological effects of
low level therapeutic lasers is the effect of Neuroplasticity. Neuroplasticity
represents the brain’s ability to reorganize itself by forming new neural
connections throughout life. Neuroplasticity provides a way for nerve
cells (neurons) in the brain to respond and compensate for injury and
disease and adjust neuronal activity in response to a new situation or to
changes in the environment.
Reorganizing the
brain occurs by the mechanism of “axonal sprouting” where damaged axons
grow new nerve endings to reconnect neurons whose links were injured or
severed. Undamaged axons can also contribute new nerve endings and connect
with other undamaged nerve cells, forming new neural pathways to
accomplish a needed function. In order for neurons to reconnect or form
new connections, the neurons need active stimulation. LLLT provides one of
the most powerful stimulants for Neuroplasticity known today and it
provides that stimulation in a safe, therapeutically correct, organized
manner.
Neuroplasticity, represents unlimited
potential to retrain the brain after injury. However, Neuroplasticity can
also contribute to impairment. For example, deaf individuals may suffer
from continual ringing in the ears (tinnitus), which results from faulty
rewiring of the brain cells starved for sound. For beneficial neural
connections to form, neurons must be stimulated correctly.
Neuroplasticity
represents a new rapidly evolving approach to healing. Given any trauma, realizing all
traumas involve the central nervous system recognizing the trauma
(consciously or subconsciously), quick response with active neuronal
stimulation, could theoretically maintain, repair, retain most CNS
functions (learning, memory, speech, emotional distress, movement, balance
etc.). In simpler terms,
theoretically the proper immediate use of LLLT therapy post trauma,
especially brain trauma, could eliminate much of the neurological
disabilities common in head trauma today.
Even the simplest
memory stimulates complex neural networks at several different sites in
the brain. The content (what happened) and meaning (how it felt) of an
event are laid down in separate parts of the brain. The goal of
neuroplastic therapy is to connect these sites to resolve the damaged,
disjointed, dysfunctional nervous systems.
“…The effect of LLLT
on the brain is not magic, it’s malleable”
As
with the infrared lasers, the wavelength and power density selected for an
LLLT laser is very important, but for very different reasons. There are
also a third and fourth component that is critically important for the
LLLT laser use. One is the light source and the properties of the light
itself and the other is frequency. It is not only important for the light
to be pulsed but the frequency it is pulsed is specific to the therapeutic
response desired.
Following is a
close look at the four separate therapeutic properties of the LazrPulsr 4X
unit.
The mechanism of action for 635nm
light:
Biological
light receptors in living tissue, termed chromophores, have peak
activation at wavelengths between 600nm and 720nm. The most commonly used
wavelengths to activate these chromophores are from 630nm to 635nm. This
is because even though different chromophores have peak activation
somewhere between 600nm and 720nm, each chromophore can still be activated
within a wider wavelength spectrum. 635nm falls within the wavelength
spectrum of all biological chromophores in man and animals. This means
there is no need to utilize multiple colors of lasers to activate the
different chromophores in the body. One wavelength – 63nm – has the
potential to activate every biological photo-sensitive receptor in the
body. For this reason, the LazrPulsr System have selected only 635nm lasers for the therapy lasers.
There
are three specific and unique methods the 635nm wavelength lasers of the
LazrPulsr 4X modulates tissues:
1. Within the cell, the signal is transduced and amplified by a photon acceptor
(chromophore). When a
chromophore first absorbs light, electronically excited states are
stimulated, primary molecular processes are initiated which lead to
measurable biological effects. These photobiological effects are mediated through a
secondary biochemical reaction, photosignal
transduction cascade, or intracellular signaling which amplifies the
biological response.
2. The ionizing effects
of LLLT allow photon acceptors to accept an electron. This turns on the
oxidation-reduction cycle of the stimulated chromophores such as Cytochrome oxidase,
hemoglobin, melanin, and serotonin.
Changing the re-dox state of the
chromophore changes the biological activity of that chromophore e.g.,
hemoglobin changes its oxygen carrying capacity. This has the potential to
triple the oxygen carrying capacity of blood
instantly.
3. When photon energy breaks a chemical bond,
changes occur in the allosteric proteins in cell
membranes (cell, mitochondrial, nuclear) and monovalent and divalent fluxes activate cell
metabolism and intracellular enzymes directly. Direct activation of cell
membranes alters ion fluxes, particularly calcium, across that
membrane. Changes in
intracellular calcium alter the concentrations of cyclic nucleotides,
causing an increase in DNA, RNA, and protein synthesis, which stimulate
mitosis and cellular proliferation.
When
any of the above occurs, the initial biological reaction rapidly catalyzes
thousands of other chemicals similar to the calcium regulated,
2nd messenger cAMP cascade. This biological
amplification process
produces systemic effects – which means that as
you are treating a wound on the left hand, the wound on your right hand
and the injury to your liver and kidney are also being treated equally as
well. So while the infrared manufactures brag about a 2 inch penetration
of their energy, true therapeutic lasers are profoundly more advanced,
producing systemic therapeutic results.
These
three actions produce four separate and distinct functions that are
clearly understood in the body.
1.
Growth factor production
occurs within cells and tissue in
response to increased ATP and protein synthesis. This initiates mitosis and cell
proliferation by changing the cell, mitochondrial, or nuclear membranes
permeability to monovalent (Na+, K+) and
divalent (Ca++, Mg++) ions (Karu 1987, 1998,
2002).
2.
Pain relief
results from suppression of the nociceptor
response mediated by increased serotonin and endorphin release (Sumano et al., 1987a, 1987b).
3.
Immune-modulation
and mitigation of the inflammatory response occur
because the mononuclear phagocytic cells, mast
cells, and leukocytes are stabilized preventing the release of harmful
inflammatory mediators (Amano 1994).
In addition, vasodilatation and increased microcirculation allows a
rapid return to homeostasis and promotes first intention healing (Sumano 1987a, 1987b; Fiszerman and Rozenbom
1995).
4. Direct trigger
point stimulation allows
direct release of endorphins and other endogenous pain mediators such as
serotonin, VIP, substance P, prostaglandins, etc. (Kaada, B and Eielson O, 1983, Kaada, Olsen and Eielson,1985).
The mechanism of action for
LASER:
There
are different properties of light. Most light that we are exposed to is
reflected off our
bodies. This is a natural in vivo protection mechanism. If we
absorbed all photon energy that struck our skin, we would explode in a few
minutes of standing in the sun. So the first requirement is understanding how to achieve the proper penetration
through the skin. This includes all the skin layers – not only our outer
skin but the skin of the cell, the skin of the nucleus of the cell, the
skin of the mitochondria and so on. All tissues have optical windows and
guards to let only specific forms of light penetrate and activate the
chromophores and other light sensitive properties of the tissue. This
requires the properties that only LASER
light
possesses.
Collimated light is essential for penetrating the outer surface of the
skin. Coherent light and polarized light is required to pass through the
optical windows of different tissues. The monochromatic property of laser
light is the ability to activate only the chromophores desired. Many
assertions have been made claiming that LEDs – which do not have coherent,
polarized, or collimated properties – work as well as LASER light does. If
one reviews the scientific papers, one quickly will find that these
studies were performed on tissue cells in vitro, or in a
test tissue sample. When the test is run on living animals and people,
in vivo, LED light is not nearly as effective as the LASER
light source due the above mentioned properties of the LASER.
The different mechanisms of power
density:
Power
density or mW of power of the light source is every important. As
identified earlier, the power density of the infrared radiation needs to
be high to quickly produce the heat desired. However, in the low-level
therapeutic lasers, heat is the enemy. Heating tissue is not
conducive to healing. Chromophores are very sensitive to the power
density. For example, the easiest way to understand the action of the
chromophore is to think about your vision. The cones on the retina of the
eye contain three different chromophores. Each is sensitive to different
wavelengths of light, allowing us to see in colors. But it is not just the
wavelength; it is also the power density of the light. If it is too dark,
you cannot see because the power density is too low to activate the
chromophore. However, if the light is too bright, it over stimulates the
chromophore into a sedated state and you still can’t see. The chromophore
has to be stimulated not only by the right wavelength but also with the
correct power density. This is one more reason why a fully collimated
laser light source is needed for LLLT. To get the correct penetration of
the outer skin with very low power density, you must use a fully
collimated laser light source
The different mechanisms of
frequency:
Frequency addresses the very fundamental properties of your
life and the world we live in. Each atom, element, molecule, cell,
organism, or substance has its own ideal electrical wavelength and
resonance frequency of vibration that coordinates its
activities (Lakovsky,
1970). At the resonance frequency, energy is maximized and
harmonious. The further a substance deviates from its resonance
frequency, the more dissonance and disease occurs (Pauling, Wilson 1963; Vithoulkas,
1980)
The
body itself uses frequency to alter its functions and control its
physiology. Using brainwave entrainment (specific frequency stimulation),
it is possible to coax the brainwaves to a certain frequency and achieve
the mental state associated with that frequency. This is the basis of
the much accepted Biofeedback modulation used to treat Post Traumatic
Stress patients.
Brainwave
Frequencies
are frequencies associated with different mental states. A familiar
example is the five brain wave ranges recorded by the EEG;
Delta
Range
0.5
to 4 HZ - associated with deep sleep.
Theta
Range 4
to 8 HZ - associated with dreaming sleep and other mental states where the
mind is wandering, daydreaming, or imaging.
Alpha
Range
8
to 13 HZ – associated with a relaxed but awake
state.
Beta
Range
13 to 30 HZ – associated with the normal awake/aware state and speech.
Gamma
Range
30 to 60 HZ -associated with higher mental activity including perception
and consciousness. General anesthesia
eliminates gamma waves.
Just
as the brain can be stimulated to change function by introducing and
changing resonant frequencies, frequency stimulation can alter all
functions of the body by altering the frequency of the tissue. When you
consider that frequency pollution from EMFs,
florescent lights, cell phones, all the other radio waves and
telecommunication transmissions etc. are devastating to your health,
frequency therapy becomes mandatory to just correct these pollutants in
our environment.
Low Level
Therapeutic Lasers (LLLT) can be
recognized by the following characteristics:
- In the product
description the wavelength of the light will be in the visible red
range, 630nm (for HeNe tube lasers) and 635nm
(for semiconductor laser diodes).
- In the product
description the total power
output will be less than 5mW per laser.
- It will always have fully collimated true lasers
and the unit will be classified as a class IIIa laser.
- The housing that contains the lasers can be held
at a comfortable distance from the wound or tissue being
treated.
- The therapy can be administered through natural
fiber cloths so that the patient seldom has to disrobe.
- Eye protection is
not necessary for the patient or the doctor; although directing any LLLT
unit at the eyes can be dangerous.
- The proper treatment will be based on the
frequency utilized and the Jules of energy are never mentioned.
- Photobiomodulation and biological amplification
is promoted, the word “penetration” will never be found.
- Low power and no
heat will be promoted, High power of any kind should not be seen.
- 635nm energy is visible so you always know if
the unit is on and where it is pointed.
- The laser will have pulse frequency settings and
they will be documented as accurate and with a broad range.
The LazrPulsr 4X not only possesses all the
qualities of a true Low Level Therapeutic Laser it is also designed to be
the most user friendly LLLT unit on the market with easy to use controls,
lightweight, one hand operation, fully portable and the most accurate and
broad range of frequency therapy in any LLLT unit on the market.
|
Light:
Light is a small spectrum of electromagnetic energy with wavelengths
between 380nm and 760nm in length. This spectrum of energy is visible to
the naked eye.
Wavelength: The property that differentiates different
spectrums of energy within the electromagnetic spectrum of energy is
wavelength. Each photon contains energy and just as energy of the ocean
comes to shore in waves of high and low energy the same is true of
photons. Only with photons the energy is not measured by the height of the
wave but the number of waves the photon carries. These waves are measured
in two ways, the number of waves that will pass a given point in one
second, or wavelength, the distance between one wave and the next.
Ultraviolet: Ultraviolet is electromagnetic energy with a
wavelength shorter than 380nm. It is not truly light because it is not
visible to the eye but it is still commonly called light therapy.
Ultraviolet rays are damaging to all organic material. It is the
ultraviolet (UV) protection that we look for in sunscreens and sun glasses
to prevent us from being burned by the sun There are no known healing
effects of UV radiation that this author knows of. UV burns tissue with
energy but produces no heat in the process.
Infrared:
Wavelengths above 760
nm have fewer waves per second than red and termed infrared
wavelengths. They carry or transfer heat from one object to another. They
have been utilized for thermal applications for many years in the medical
field as infrared lamps.
Collimation: A property of light commonly associated with
lasers and accomplished with focusing lenses where all the photons are
traveling in the same direction.
LED: Light Emitting
Diode: There are thousands of different types of diodes
that can emit light ranging in power density and bandwidths of wavelength.
All semiconductor lasers produce light from a diode, however, LED’s are
Lasers. LEDs can not produce coherent or polarized
light.
SLD: Super
Luminescent Diode; is a specific type of LED that has a higher
emission of energy than typical LEDs. All other aspects are the same as
LEDs.
Pharmacological Dose:
A
pharmacological dose of any therapy is the dose necessary to produce and
maintain a desired effect. The goal is to have a drug or therapy to stay
above or at the threshold level for effective therapeutic action but below
the toxic level.
Therefore;
- A pharmacological dose always
contains risk and WILL DO
HARM.
- A pharmacological dose seldom
improves health on its own merit.
- A pharmacological dose will
generally be predictable and consistent for symptomatic response because
it is measuring a response to a concentration, exposure, etc. mostly
independent of the body – overriding the normal physiology of the
patient.
Nanometer
(nm): One nanometer is one
billionth of a meter. 10-9 meters or .000000001 meter = 1
nm. It is the unit of
measurement that is commonly used to measure the wavelength of energy
commonly used in light therapy.
Power
Density (mW): Power density is synonymous with the Watts of power produced by the light source. P =
mW
LASER:
Light
Amplification by Stimulated Emission of
Radiation; refers to the
specific qualities and methods by which lasers produce light. Originally
theorized and defined by Albert Einstein in 1917, it was not produced
until the 1950s. Laser light is Coherent, has a Monochromatic
wavelength, is Collimated, and Polarized. These four characteristics
differentiate Laser’s from LED & SLD light
sources.
Irradiation
Dose (J/cm2): Irradiation dose is defined by the
product of the power density (mW); exposure time divided by area
irradiated and is reported as Joules of energy per square centimeter
(J/cm2).
ID
(J/cm2) = P (mW) X T (sec) / A
(cm2 /sec)
Penetration:
Propagation of light
though tissue is regulated by three properties, Reflection,
Penetration, and Absorption. Penetration refers to the distance an
energy wave travels into the tissue before it is absorbed and dissipated
as heat or molecular vibration. Penetration is a physical and thermal
phenomenon, not a therapeutic phenomenon.
Duty
Cycle: Duty cycle relates
to the amount of time the light source is active, usually from 10% to
100%. If the setting was a 10% duty cycle then out of every second the
light source would on 1/10 of a second and be off 9/10 of a second. This
cycle can be at various pulse intervals depending on the manufacture.
Biomodulation: Biomodulation is the
process of changing the natural biochemical response of a cell or tissue
within the normal range of its function, stimulating the cell’s innate
metabolic capacity to respond to a stimulus. A cell can heal itself
by this basis.
Photobiomodulation:
When
biomodulation occurs from a photon transferring its energy to a
chromophore it is referred to as photobiomodulation.
Physiological Dose of
therapy: A Physiological Dose
of any therapy is designed to stimulate production of, or provide to the
body what it needs to normalize and heal itself through biomodulation. The
symptomatic response to a physiological dose of therapy is dependent of
the capacity of the patient’s body to respond to the therapy. The
physiological dose of any treatment has specific advantages.
- A physiological
dose represents the body’s own response to a stimulus (e. g., adrenaline in response to a
“fight or flight” challenge) and is
generally safe and will DO NO
HARM.
- A physiological dose generally
improves the patient’s health.
- A physiological dose will always
be less predictable and consistent than a pharmacological dose for
symptomatic response because it depends upon an interaction with the
individual patient’s entire body system.
Chromophores:
Chromophore literally
means, “Color lover” (L. chromo = color; L. Phore = to seek out, to have an affinity for, to
love). Chromophores are generally pigmented molecules that accept
photons within living tissue. When the chromophore accepts a
photon, it causes a biochemical change within an atom, molecule,
cell or tissue. If this change increases cellular function, it is said to
have activated the tissue. If this change decrease cellular function it is
said to have inhibited the tissue. Biomodulation occurs in both cases.
Biological
Amplification: When
photobiomodulation occurs, the photon activates a chromophore, amino acid,
nucleic acid, or molecule. Activation of a single enzyme molecule
rapidly catalyzes thousands of other chemical reactions amplifying the
signal to the cell. This is similar to the, calcium regulated, 2nd
messenger cAMP cascade. Biological amplification
explains how systemic, cellular, and clinical effects can occur almost
instantaneously after exposure to light therapies.
Reflection:
Propagation of light
though tissue is regulated by three properties, Reflection, Penetration,
Absorption. When energy waves strike the skin of any tissue, they will
either pass through or reflect off the tissue. The energy’s ability to
pass through a surface tissue is dependent on the collimation, coherency,
wavelength and polarization of the light. Reflected energy has no
therapeutic effect to the internal tissue.
LASER:
Light
Amplification by Stimulated Emission of
Radiation; refers to the
specific qualities and methods by which lasers produce light. Laser light
is Coherent (having all
waves in phase), Monochromatic (having a very narrow band of
wavelength), Collimated (all photons traveling in the same
direction), and Polarized (all waves are in the same plane).
These four characteristic differentiate Laser’s form LED & SLD, light
sources.
Dose: The term
dose is an estimate of a therapy, traditionally a
drug, which produces a desired therapeutic action without harmful side
effects. The therapeutic dose (safe and effective) range is
defined by clinical evaluation of the response of a sufficient number of
patients, generally 50 percent who improve without toxicity.
Drugs are
evaluated at doses to which 20%, 70% or any percentage to which a subject
responds.
It is
customary to calculate:
Median
Effective Doses or
ED50, the dose that gives rise to a response in 50 % of the
subject
Median Toxic
Dose or
TD50 is the dose that manifests toxic side effects in 50 % of
the subjects
Median Lethal
Dose
or
LD50 is the dose that gives rise to the death of 50% of the
subjects
In
general, a therapy (traditionally a drug) is considered safe when the
harmful LDR region of the side effects is much greater than the
therapeutic dose range, expressed as: Therapeutic Index: TI
= TD 50/ED50 Medical Principles of Pharmacology,
1990
Frequency
Biomodulation: Biomodulation caused
by specific frequencies produced by therapeutic light devices is called
frequency biomodulation.
|