title: A Novel Fisheye-Lens-Based Photoacoustic System.
abstract: This paper presents a novel fisheye-lens-based photoacoustic (PA) system. In conventional PA systems, mechanical motors are utilized to obtain the target information due to the small fields of view of such systems. The use of such motors introduces mechanical noise, which is difficult to remove when processing the echo signals. A fisheye lens system offering a wide field of view would effectively reduce the motor effects (i.e., the noise) and enable the system to have a wide field of view. Therefore, in this work, we propose a novel fisheye lens scheme and describe a PA system based on the developed lens scheme. In addition, to confirm the feasibility of the fisheye-lens-based PA system, we present the typical pulse-echo responses obtained using a 20 MHz single element immersion transducer and the echo signals measured from bull's eye tissue samples separated by approximately 4, 6, 8, and 10 cm diagonally and 2 cm vertically from the fisheye lens. The experimental results demonstrate that the echo signal amplitudes, their center frequencies, and the -6 dB bandwidths obtained using red, green, and blue lights and a fisheye lens are acceptable when the fisheye lens is separated from a sample both diagonally and vertically. Therefore, fisheye-lens-based PA systems could be a potential method of achieving wide fields of view while reducing the mechanical motor effects.
authors.affiliation: Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39253, Korea. hojongch@kumoh.ac.kr.
authors.forename: Hojong
authors.initials: H
authors.lastname: Choi
authors.affiliation: Department of Optical System Engineering, Kumoh National Institute of Technology, Gumi 39253, Korea. jmryu@kumoh.ac.kr.
authors.forename: Jaemyung
authors.initials: J
authors.lastname: Ryu
authors.affiliation: Department of Biomedical Engineering, Gachon University, In-cheon 21936, Korea. jungsuk@gachon.ac.kr.
authors.forename: Jungsuk
authors.initials: J
authors.lastname: Kim
keywords: fisheye lens; photoacoustic; transducers; ultrasound