The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Temperature elevations due to NIR exposure in the brain tissue
Author:	Ersen, Ali
View Online:	njit-etd2012-028 (xii, 55 pages ~ 1.1 MB pdf)
Department:	Department of Biomedical Engineering
Degree:	Master of Science
Program:	Biomedical Engineering
Document Type:	Thesis
Advisory Committee:	Sahin, Mesut (Committee chair) Pfister, Bryan J. (Committee member) Al-Smadi, Yahia M. (Committee member)
Date:	2012-01
Keywords:	Near infrared lasers Low power NIR laser irradiation Temperature distribution
Availability:	Unrestricted
Abstract:	Near infrared (NIR) lasers have been used in medical applications both for diagnostic and therapeutic purposes. Temperature elevation profile inside the tissue is a critical factor that needs to be better understood in these applications. The purpose of this study is to determine the temperature distribution due to a low power N I R laser irradiation in living neural tissue. Temperature measurements were made directly using a thermocouple probe inside the rat brain cortex within the sagittal plane. The spatial map indicates that N I R light penetrates more readily in the vertical directions than the spreading in the horizontal axis. The decrease in the vertical direction can be approximated with a single order exponentially decaying function. The results also suggest that the temperature elevation can be kept below 0.5 °C anywhere in the tissue if the incident laser beam power density is less than 27 mW/cm2. These experiments should be repeated in other types of neural tissue such as the white matter of the brain and the spinal cord to obtain more complete results.