Feasibility test of an electromagnetically driven valve actuator for glaucoma treatment

Abstract

Though the conventional glaucoma implants have a capability of pressure regulation, they cannot maintain the intraocular pressure (IOP) desired for different patients. To solve these problems, it is needed to develop a new implant which is capable of controlling the IOP actively and coping with personal difference among patients. In this paper, we make an analysis of the operation of the conventional implant using a bond graph and showing its defects and limitations of the conventional valve analytically. On the basis of the analysis, design and fabrication of an active valve actuator is performed considering actuation principles, resistance elements, and control methods. An electromagnetic actuator is used for realizing the active resistance element. A passive resistance element is also included in addition to the active resistance in order to save the power consumption. A pulsewidth modulation (PWM) control method is used for enhancing the power consumption saving. Finally, we make experiments and simulations with the fabricated valve actuator in vitro environment, and estimate the in vivo experimental results using the in vitro experimental results.