Similar to any medication, the effectiveness of PBM therapy is reliant upon the proper dosing. Decades ago, in the early days of PBM, many studies found the therapy to be ineffective. It was only later discovered that these findings were the result of inaccurate dosing. Based on a combination of Power Intensity and duration used, one can determine the amount of Joules (Joules = power * time) delivered in order to provide the most beneficial therapy session possible.
PBM: Photobiomodulation – the biological effect of light on living tissue.
Power Intensity: The amount of energy going thru an area perpendicular to the beam. Typically in mw/cm2 (milliwatts per centimeter squared).
Irradiance: The amount of energy that arrives on a certain surface with a given orientation. Also noted as mw/cm2.
Joules: Power (mw) * Time (seconds)
Dose: The amount of light applied to a site. Stated in Joules (J) or Joules per centimeter squared J/cm2.
Biphasic Dose Response: describes the magnitude of the response of an organism, as a function of exposure (or doses) to a stimulus or stressor after a certain exposure time. A very low dose of light has little to no effect where a slightly higher dose generates a positive effect. This is based Arndt-Schulz rule that states “For every substance, small doses stimulate, moderate doses inhibit, large doses kill.”
Do not, under any circumstance, let someone tell you that because their light is “stronger” it is better. We have been conditioned to think that more is better, but that isn’t the case here. It’s been shown thru research that the body can only absorb so many photons, and the rest goes to waste. Read here to learn more about Power Intensity, as too much is too much.
The following Red, Blue, NIR and Green Light Therapy Dosing Table provides a guideline for Dosing with the Visum Light. You’re able to select the combination of time (T) and Power Intensity in mW/cm2 (I) to determine the Joules delivered. We encourage you to use the default output of 33.3 mw/cm2 unless there is a specific reason you need a stronger output.
This Dosing Table is not intended to confuse you and most people will never need to use it. This table is intended for those that are tracking the joules delivered for each session and it is the operator’s choice to go low and slow or fast and furious. Our suggestion is to go low and slow as our bodies can only absorb so many photons at one time. We have a blog on that, read it here.
As the industry becomes more standardized with LED testing, we’re offering the below videos to show how the Visum Light is tested at the manufacturer. The Visum Red, Nir and Blue have 4 output settings, whereas the Green only has two or three settings at this time (depending on if you have received the software update to add the 33.3 mw/cm2 to the green*).
Testing results can be very different depending on the test equipment and the data collected. For instance, do you test total output or average output? Do you test per LED or per the unit? Do you test on an integrated sphere or can you use a power meter, such as the one from Thor?
There are a lot of questions still to be answered, and one method is not necessarily better than another. It is important to know how the test was performed, and on what equipment and what data they are reporting.
We’ve tested the lights through two different sources, each taking a very different approach. One tested total radiant flux and total radiant power per the unit, where the other tested the output per LED.
*If you are interested in having your light updated (this only pertains to the very early lights), please contact us for instructions. You will be responsible for shipping costs both ways.
Henderson, T. A., & Morries, L. D. (2017). Multi-Watt Near-Infrared Phototherapy for the Treatment of Comorbid Depression: An Open-Label Single-Arm Study. Frontiers in Psychiatry / Frontiers Research Foundation, 8, 187. https://doi.org/10.3389/fpsyt.2017.00187
Wikipedia contributors. (2021, October 23). Arndt–Schulz rule. Wikipedia, The Free Encyclopedia. https://en.wikipedia.org/w/index.php?title=Arndt%E2%80%93Schulz_rule&oldid=1051428222