title: Fundamental study to develop a fiber-optic gap sensor for a rotary undulation pump.
abstract: The rotary undulation pump is believed to be a good candidate for the next-generation artificial heart. Due to its complex movement, it is desirable to magnetically levitate the rotor and dynamically control the gap. In this article, the applicability of a fiber-optic gap sensor to the dynamic position control of the rotor in the rotary undulation pump was investigated. The fiber-optic gap sensor consisted of two plastic-core fibers and a reflection plate. Two 1-mm-diameter optical fibers were aligned parallel: one for source light propagation and the other for reflected light transmission. The basic properties of gap sensors using four different light sources were explored in five media (air, physiologic saline, and blood samples with three different hematocrit levels). The influence of the oxygen saturation level in the blood on sensing was investigated with two types of light sources. It is desirable to use a light source the wavelength of which shows similar absorption coefficients for both oxygenated blood and deoxygenated blood. The effect of the distance between the two fibers on the sensing and range was also investigated. The results indicated that the fiber-optic gap sensor is quite promising for the active control of rotor positioning in the rotary undulation pump.
authors: Department of Artificial Biomechanism, Research Center for Advanced Science and Technology, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan. norihiko@bme.rcast.u-tokyo.ac.jp
authors: Norihiko
authors: N
authors: Mitsumune
authors: Itsuro
authors: I
authors: Saito
authors: Shuichi
authors: S
authors: Mochizuki
authors: Yusuke
authors: Y
authors: Abe
authors: Takashi
authors: T
authors: Isoyama
authors: Hidemoto
authors: H
authors: Nakagawa
authors: Toshiya
authors: T
authors: Ono
authors: Akimasa
authors: A
authors: Kouno
authors: Ayaka
authors: A
authors: Sugino
authors: Tsuneo
authors: T
authors: Chinzei
mesh_terms: D000818:Animals; D005336:Fiber Optic Technology; D006041:Goats; D006354:Heart, Artificial; D018056:Hemorheology; D008280:Magnetics; D055100:Optical Fibers; D011474:Prosthesis Design