Publications - DO NOT EDIT
http://hdl.handle.net/10106/26489
2024-03-29T10:07:10ZInterplay between up-regulation of cytochrome-c-oxidase and hemoglobin oxygenation induced by near-infrared laser
http://hdl.handle.net/10106/26294
Interplay between up-regulation of cytochrome-c-oxidase and hemoglobin oxygenation induced by near-infrared laser
Wang, Xinlong; Tian, Fenghua; Soni, Sagar S.; Gonzalez-Lima, F.; Liu, Hanli
Photobiomodulation, also known as low-level laser/light therapy (LLLT), refers to the use of red-tonear-infrared light to stimulate cellular functions for physiological or clinical benefits. The mechanism
of LLLT is assumed to rely on photon absorption by cytochrome c oxidase (CCO), the terminal enzyme
in the mitochondrial respiratory chain that catalyzes the reduction of oxygen for energy metabolism. In
this study, we used broadband near-infrared spectroscopy (NIRS) to measure the LLLT-induced changes
in CCO and hemoglobin concentrations in human forearms in vivo. Eleven healthy participants were
administered with 1064-nm laser and placebo treatments on their right forearms. The spectroscopic
data were analyzed and fitted with wavelength-dependent, modified Beer-Lambert Law. We found
that LLLT induced significant increases of CCO concentration (Δ[CCO]) and oxygenated hemoglobin
concentration (Δ[HbO]) on the treated site as the laser energy dose accumulated over time. A strong
linear interplay between Δ[CCO] and Δ[HbO] was observed for the first time during LLLT, indicating a
hemodynamic response of oxygen supply and blood volume closely coupled to the up-regulation of CCO
induced by photobiomodulation. These results demonstrate the tremendous potential of broadband
NIRS as a non-invasive, in vivo means to study mechanisms of photobiomodulation and perform
treatment evaluations of LLLT
2016-08-03T00:00:00ZDiffused Correlation Spectroscopy for Measurement of Blood Perfusion During Low Level Laser Therapy (LLLT)
http://hdl.handle.net/10106/25936
Diffused Correlation Spectroscopy for Measurement of Blood Perfusion During Low Level Laser Therapy (LLLT)
Near infrared stimulation or Low Level Laser Therapy (LLLT) is an innovative technique shown to effect the microvasculature hemodynamics. The aim of this study is to use Diffused Correlation Spectroscopy (DCS) to evaluate the physiological effects of LLLT on blood perfusion. This study is divided into two parts: the fist part is the development of DCS system and the second part is investigating the effects of LLLT on biological tissue.
DCS is an emerging non-invasive technique to probe deep tissue hemodynamics. DCS uses time-averaged intensity autocorrelation function for the fluctuations caused due to the moving scatterers (RBCs) in biological tissue. We present a software based autocorrelator system to complete the acquisition and processing parts. We conducted validation studies on an intralipid phantom and human forearm. Both the studies proved smooth decay curves which help in getting a better curve fitting and as a result more accurate blood flow index (BFI). We show that the software based autocorrelation system can be an alternative to the conventional hardware based correlators in DCS systems with benefits such as flexibility in raw photon count data processing and low cost.
The objective of the second part of this study is evaluating how a single session of LLLT alters the hemodynamics in the microvasculature. We performed an experiment where the subjects forearm was stimulated with LLLT and the corresponding changes were recorded using DCS system. The results obtained shows significant hemodynamic changes in response to LLLT with a 95%confidence interval. The results in this study indicate that LLLT could lead to the development of non-invasive technique to help in rehabilitation and performance-enhancing of healthy humans.
2016-05-27T00:00:00Z