title: Penetration of laser light at 808 and 980 nm in bovine tissue samples.
abstract: OBJECTIVE
  The purpose of this study was to compare the penetration of 808 and 980 nm laser light through bovine tissue samples 18-95 mm thick.
  
  
  BACKGROUND
  Low-level laser therapy (LLLT) is frequently used to treat musculoskeletal pathologies. Some of the therapeutic targets are several centimeters deep.
  
  
  METHODS
  Laser light at 808 and 980 nm (1 W/cm(2)) was projected through bovine tissue samples ranging in thickness from 18 to 95 mm. Power density measurements were taken for each wavelength at the various depths.
  
  
  RESULTS
  For 808 nm, 1 mW/cm(2) was achieved at 3.4 cm, but for 980 nm, 1 mW/cm(2) was achieved at only 2.2 cm depth of tissue.
  
  
  CONCLUSIONS
  It was determined that 808 nm of light penetrates as much as 54% deeper than 980 nm light in bovine tissue.
authors: Respond Systems, Inc., Branford, CT 06405, USA. don@respondsystems.com
authors: Donald E
authors: DE
authors: Hudson
authors: Doreen O
authors: DO
authors: Hudson
authors: James M
authors: JM
authors: Wininger
authors: Brian D
authors: BD
authors: Richardson
mesh_terms: D000818:Animals; D002417:Cattle; D007834:Lasers; D008460:Meat / Q000528:radiation effects*; D012984:Software