Development of a MEMS device to monitor glaucoma

Abstract

Glaucoma is one of the leading causes of blindness affecting millions of people worldwide. Regular monitoring of intra ocular pressure (IOP) in the eyes is an important component in the treatment of this affliction. Current manual measurements do not give room for continuous indication of the progression of the disease. Microelectromechanical System (MEMS) technology lends itself to the development of devices capable of in-situ monitoring of the phenomenon that occur at the micro and nano scales, inside the human body. The paper reports on the complex flow and pressure relationships in the eye and the current methods of monitoring Glaucoma. The comparison highlights the requirements of an implantable miniature device that can indicate the changes leading to an increase of IOP inside the eye. An analysis of the pressures in the anterior chamber of the eye was undertaken to estimate the out put voltages that could be obtained from a micro structure implanted in the eye.

MEMS glaucoma monitoring device

“…A MEMS-based piezo resistive pressure sensor was previously characterised for IOP measurement by the author and output voltages were estimated [10]. It has been found upon further investigation that the stresses along the length and width of piezo resistors in a bridge configuration could vary greatly and this could cause the fractional change in resistance (dR 1 /R 1 , dR 2 /R 2 ) to be unequal and lead to a reduction in sensor output voltage.…”