Endoscopic optical coherence tomography (OCT) catheters comprise a transparent tube to separate the imaging instrument from tissues. This tube acts as a cylindrical lens, introducing astigmatism into the beam. In this report, we quantified this negative effect using optical simulations of OCT catheter devices, and discuss possible compensation strategies. For esophageal imaging, the astigmatism is aggravated by the long working distance. For intracoronary imaging, the beam quality is degraded due to the liquid imaging environment. A nearly circular beam profile can be achieved by a curved focusing optics. We also consider the method of matching refractive indices, and it is shown to successfully restore a round beam.
© 2012 Optical Society of America
Medical Optics and Biotechnology
Original Manuscript: April 25, 2012
Manuscript Accepted: May 27, 2012
Published: July 18, 2012
Vol. 7, Iss. 9 Virtual Journal for Biomedical Optics
Tianshi Wang, Antonius F. W. van der Steen, and Gijs van Soest, "Numerical analysis of astigmatism correction in gradient refractive index lens based optical coherence tomography catheters," Appl. Opt. 51, 5244-5252 (2012)