THE SCIENCE OF PHOTOMEDICINE

INTRODUCTION TO PHOTOMEDICINE  

Photomedicine includes diagnostic and therapeutic applications of light for detecting and curing disease.  Light is composed of packets of energy called photons.  Therapeutic Light is defined as non-ionizing electromagnetic radiation between the wavelengths of about 200 nm to about 1200 nm.  Light energy is capable of causing heating, mechanical effects and chemical reactions. The transfer of light energy through photon absorption can lead to many different beneficial consequences in photomedicine. Moreover, there are many new approaches for using light to see inside the body to detect and diagnose disease. 

PHOTOTHERAPY

Phototherapy involves the transformation of light energy to chemical, kinetic or heat energy in order to achieve a desired physiological result. As stated by the First Law of Photobiology, light energy must be absorbed by an atom or molecule in order to initiate a physical or chemical process. Therefore, light that is used for therapeutic applications must be absorbed by a specific chromophore in the biological tissue.

THE STARK-EINSTEIN LAW

http://www.newworldencyclopedia.org/entry/Photochemistry  Stark–Einstein Law  “Number of activated molecules = number of quanta of radiation absorbed.” The Stark–Einstein law is named after German-born physicists Johannes Stark and Albert Einstein, who independently formulated the law between 1908 and 1913, and is also known as the Photochemical Equivalence Law. It says that every photon that is absorbed will cause a (primary) chemical or physical reaction; the photon = one unit of radiation; therefore, this is a single unit of EM radiation that is equal to Planck's constant (h) times the frequency of light. This quantity is symbolized by γ, hν, or ħω. 

THE RECIPROCITY RULE IN PHOTOMEDICINE 

The Reciprocity Rule in Photomedicine, Bunsen Roscoe Law The Reciprocity Rule states that specific biochemical and energy field interactions that occur in the body are directly proportional to the total energy dose received and governed by specific tissue variability factors; in this document, we define those factors and identify appropriate energy dosages required to effectively stimulate the desired tissue interactions. 

THE GROTTHUSS-DRAPER LAW

http://www.photobiology.com/reviews/bunsen/index.htm  Grotthuss–Draper Law  “Only radiation absorbed in a system can produce a chemical change.” The Grotthuss–Draper Law (also called the Principle of Photochemical Activation) states that only that light which is absorbed by a system can bring about a photochemical change. This law provides a basis for fluorescence and phosphorescence; the law was first proposed in 1817 by Theodor Grotthuss and in 1842, independently, by John William Draper. 

Further consideration of established values in biological (patient) factors needs to be considered for satisfactory results in photomedicine; we call these values Primary Tissue Variability Factors or (PTVF) We list these values here.

PTVF - Primary Tissue Variability Factors™ 

The following Primary Tissue Variability Factors™ have been established for setting and adjusting optimal laser therapy treatment dosages.

1. Tissue Type: blood, fat, nerve, muscle, skin, tendon, cartilage, bone 

2. Tissue Structure: Simple, stratified, pseudostratified, transitional   

3. Tissue Density: adiposity index or BMI (Body Mass Index) 

4. Tissue Permeability (ability of wave energy to pass through, or be absorbed by tissue structures)  

5. Tissue Proximity: (depth of tissue (shallow vs. deep)

6. Tissue Pigmentation: six levels, from white to black (Fitzpatrick Scale) 

7. Tissue Hydration: hydrated or dehydrated (typical = Min. 54.8% to Max. 78.1%) 

8. Tissue Stress: bio-behavioral factors that can induce cell damage (cortisol levels, etc.) 

9. Tissue Age: from atrophic to neoplastic 

10. Tissue Function/malfunction: Equilibrium, Entropy, & Homeostasis 

Why is it important to consider Primary Tissue Variability Factors when applying laser therapy?

PHOTOMEDICINE AND DOSE EFFECTIVENESS 

Laser therapy dose effectiveness is dependent on a variety of patient tissue factors, all other variables being equal - i.e. wavelength(s), output power, etc.; for example, degenerative disc disease usually requires a large volume of high-output energy for effective tissue interactions, while oral cavity sores require only a small volume of low-output energy to successfully treat; effective treatment application for most other conditions lie somewhere in between. The reason for this is oral cavity sores exist in shallow, pigmented, moist, warm tissues with a plentiful blood supply, while injured discs are non-pigmented and protected by layers of densely complicated structural tissues and do not have an independent blood supply.  

For more information on Primary Tissue Variability Factors (PTVF) please click on the FIND OUT MORE button below.

• Inflammatory Conditions

• Bursitis

• Carpal Tunnel Syndrome

• Edema

• Effusion

• Epicondylitis

• Inflammation

• Muscle Spasms

• Myofasciitis

• Paresthesia

• Plantar Fasciitis

• Primary Diagnosis Pain

• Radicular Pain

• Restricted Rom / Stiffness

• Rheumatoid Arthritis

PAIN MANAGEMENT

• Bursitis

• Cervical/Neck Pain

• Edema

• Effusion

• Fasciitis

• Fibromyalgia

• Inflammation

• Low Back Pain

• Muscle Spasms

• Myofascial Pain

• Myofasciitis

• Primary Diagnosis Pain

• Restricted ROM / Stiffness

CONNECTIVE TISSUE DISORDERS

• Edema

• Effusion

• Inflammation

• Muscle Spasms

• Myofasciitis

• Primary Diagnosis Pain

• Radicular Pain

• Restricted Rom / Stiffness

• Sprains

• Strains

• Tendon Ruptures

• Tendonitis

MUSCLE DISORDERS

• Edema

• Inflammation

• Muscle Bruises, Contusions

• Muscle Contractures

• Muscle Ruptures

• Muscle Spasms

• Myofasciitis

• Myositis

• Primary Diagnosis Pain In Joint

• Restricted ROM / Stiffness

JOINT DISORDERS

• Dislocations

• Edema

• Effusion Of Joint

• Inflammation

• Ligament Injury

• Osteoarthritis

• Primary Diagnosis Pain in Joint

• Restricted Rom Stiffness

• TM Disorders

NEUROLOGICAL DISORDERS

• Crush Injuries

• Decreased Rom / Stiffness

• Edema

• Effusion

• Inflammation

• Muscle Spasms

• Myofasciitis

• Neuritis

• Paresthesia

• Primary Diagnosis

• Prolapsed Disk

• Radicular Pain

• Ruptured Disk

SKIN CONDITIONS

• Burns

• Edema

• Inflammation

• Joint Pain as Primary Diagnosis

• Scars, Restricted Range of Motion

• Skin Grafts

• Skin Ulcers

• Surgical Incisions

CHROMOPHORES ABSORB QUANTUM LIGHT ENERGY 

Chromophores are substances present in living tissues that absorb quantum light energy (all energy from the sun is quantum energy, or energy in its purest and smallest particle form). Examples of endogenous (existing inside the body) chromophores that absorb NIR, or near infrared quantum energy are hemoglobin, oxyhemoglobin, de-oxyhemoglobin and methemoglobin (absorbed by 810nm energy), water, protein, peptide bonds (absorbed by 980nm energy), aromatic amino acids, nucleic acid, urocanic acid and bilirubin (absorbed by UV energy (10nm to 400nm). Melanin in the skin also absorbs quantum UV energy at different rates according to skin pigmentation; then acts as an ‘umbrella’ to protect underlying tissue substances from destructive UV rays. Exogenous (existing outside the body) compounds, like colors of tattoo ink also act as chromophores.  

Water as a Chromophore The liquid component (water) of the human body is contained in the tissues, the blood, the bones, and elsewhere; this water makes up a significant portion of the human body, both by weight and by volume, and ranges from maximum 78.1% to minimum 54.8%. It is made up of primarily plasma; fatty tissues contain less water content than lean tissues. Ensuring the right amount of body fluids is an important aspect of homeostasis; proper hydration is also very important for successful photomedicine treatments. The 980nm wavelength is primarily absorbed by tissue fluids, as well as nerve tissues, ligamentous and bony (structural tissues), white adipose tissues fatty tissues, other connective and lymphatic tissues that are lightly pigmented. 

Hemoglobin as a Chromophore Red blood cells (Erythrocytes), white blood cells (Leukocytes), and platelets (thrombocytes), make up 45% of blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid component of blood. The 808nm wavelength is primarily absorbed by hemoglobin, vascular tissues, endothelial tissues muscle tissues. There are three types of muscle tissue: striated muscles, such as those that move the skeleton (also called voluntary muscle), smooth muscles (involuntary muscle), such as the muscles contained in the stomach and other internal organs, and cardiac muscle, which makes up most of the heart wall (also an involuntary muscle). 

Melanin as a Chromophore Epithelial tissue covers the body surface and forms the lining for most internal cavities – melanin is found primarily in epithelial tissues, and in the skin presents a barrier to NIR energy absorption and penetration, and is readily absorbed by 1064nm as well as lower wavelengths in the UV range (10nm to 400nm). More than 60% of directed quantum energy from a therapy laser is attenuated by melanin in the skin.  

DNA as A Chromophore DNA contains molecules that absorb and transfer quantum energy via the F.R.E.T. (Fluorescent Resonance Energy Transfer) process. Substances in DNA (receptor chromophores) are excited by quantum energy to a higher vibrational, or energy state - they then resonate, or transfer the higher energy state to acceptor chromophores (targeted substances in DNA). This process is enhanced by high volumes of excited quantum particles to direct higher energy states where it is most needed; in addition, laser energy represents a control of photochemical reactions that mimics and greatly enhances the mitochondrial functional response to natural light, much like photosynthesis in plants, algae, and many types of bacteria except at a more highly accelerated rate.