Comparing 905 & 1064nm Tissue Penetration

This is important to recognize since the prevailing understanding is that lower wavelength penetrate deeper and here we see that 1064 is penetrating slightly deeper than 905nm. I share this to help in our overall appreciation of how much variability there is in the impact of different wavelengths through skin and other tissues. I hope we can see more evidence in future in vivo human studies. The peak transmission through water is at this 1060-1070nm range and so our thinking is that given the brain is 70% water thereby conferring greater impact on cellular activity. 
 
Abstract: The choice of parameters for laser beams used in the treatment of musculoskeletal diseases
is of great importance. First, to reach high penetration depths into biological tissue and, secondly,
to achieve the required effects on a molecular level. The penetration depth depends on the wavelength
since there are multiple light-absorbing and scattering molecules in tissue with different
absorption spectra. The present study is the first comparing the penetration depth of 1064 nm laser
light with light of a smaller wavelength (905 nm) using high-fidelity laser measurement technology.
Penetration depths in two types of tissue ex vivo (porcine skin and bovine muscle) were investigated.
The transmittance of 1064 nm light through both tissue types was consistently higher than of
905 nm light. The largest differences (up to 5.9%) were seen in the upper 10 mm of tissue, while the
difference vanished with increasing tissue thickness. Overall, the differences in penetration depth
were comparably small. These results may be of relevance in the selection of a certain wavelength in
the treatment of musculoskeletal diseases with laser therapy.

Quietmind is working to better articulate the importance of the various wavelengths and studying how best to leverage their benefits in producing better clinical outcomes and a higher level of precision medical application of near-infrared photobiomodulation. 


​