Spatial effect of conical angle on optical-thermal distribution for circumferential photocoagulation.

Van Gia Truong,Hyun Wook Kang,Van Nam Tran,Suhyun Park

doi:10.1364/boe.8.005663

Abstract

A uniformly diffusing applicator can be advantageous for laser treatment of tubular tissue. The current study investigated various conical angles for diffuser tips as a critical factor for achieving radially uniform light emission. A customized goniometer was employed to characterize the spatial uniformity of the light propagation. An ex vivo model was developed to quantitatively compare the temperature development and irreversible tissue coagulation. The 10-mm diffuser tip with angle at 25° achieved a uniform longitudinal intensity profile (i.e., 0.90 ± 0.07) as well as a consistent thermal denaturation on the tissue. The proposed conical angle can be instrumental in determining the uniformity of light distribution for the photothermal treatment of tubular tissue.

Highlights

Laser systems have widely been developed for medical applications such as tumor ablation, blood coagulation, cancer treatment, surgical resection, and optical imaging [1,2,3]
The current study investigated various conical angles for diffuser tips as a critical factor for achieving radially uniform light emission
A customized goniometer was employed to characterize the spatial uniformity of the light propagation

Summary

Introduction

Laser systems have widely been developed for medical applications such as tumor ablation, blood coagulation, cancer treatment, surgical resection, and optical imaging [1,2,3]. A number of fabrication techniques have been developed, including acid-etching [9, 10], melt-drawing [9, 11], scattering media [12, 13], CO2 laser polishing [14], long period gating (LPG) [15, 16], and UV micro-drilling [10, 17]. The use of TiO2 usually limits the input power and wavelength (i.e., 600–1064 nm) [16] Another feasible method was developed to directly modify the end of the optical fiber by implementing laser processing [17, 18]. The diffusing fibers with various conical angle tips were quantitatively compared in terms of temperature distribution and irreversible tissue coagulation

Objectives

Methods

Results

Conclusion