17 May 2018 Relationship between NIR laser power and the human forehead tissue backscattering image features
Author Affiliations +
Abstract
A novel markerless near infrared (NIR) laser-based head tracking system was recently proposed to resolve patient's head motion problem during cranial radiotherapy. Although previous research showed that we could track the patient's head position with the sub-millimetre range accuracy, the tracking performance strongly relied on the accuracy of the tissue thickness estimation. We noticed the factors that inuence the ROI features extracted from the backscattering images were the NIR laser power fluctuation and inconsistency. Therefore, the propose of this paper was to investigate the relationship between these parameters and determine a laser power independent feature transformation. We set up our head tracking system to project the pulsed NIR laser beam onto a single point on subject's forehead and observed the changes of the 5-ROI feature values on the different laser power level. The scatter plots between each ROI feature values and the laser power showed distinctive straight lines with similar slopes while applying linear regression to each scatter plot indicated that the slope of each ROI feature was also in the same range. According to the results, we could transform the data by subtracting the feature value of each ROI from their average slope value and the laser power. This new feature is laser power noise tolerance and could be used to enhance the tissue thickness estimation accuracy.
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jirapong Manit, Jirapong Manit, Floris Ernst, Floris Ernst, Achim Schweikard, Achim Schweikard, } "Relationship between NIR laser power and the human forehead tissue backscattering image features", Proc. SPIE 10685, Biophotonics: Photonic Solutions for Better Health Care VI, 106853R (17 May 2018); doi: 10.1117/12.2306827; https://doi.org/10.1117/12.2306827
PROCEEDINGS
8 PAGES


SHARE
RELATED CONTENT

Two-Beam Optical Head
Proceedings of SPIE (January 13 1987)
Phase Conjugation In BaTiO3 At 830 Nanometers
Proceedings of SPIE (January 03 1990)
Digital Disk Optics
Proceedings of SPIE (November 09 1983)
A High-Resolution Laser Scale Interferometer
Proceedings of SPIE (December 11 1984)
Studies in optimal configuration of the LTP
Proceedings of SPIE (September 01 2010)

Back to Top