Centennial Seminar Series

Ronald L dougherty

Associate Chair - University of Kansas Mechanical Engineering Department

From Power Plants to Eye Implants

“From an engineering point-of-view, what relationship could there be between power plants and eyes?”  

One answer is that both require complicated fluid flow systems which must function within specific, but very different, flow regimes.  For power plants, flow systems must handle hundreds of liters per minute at pressures ranging from 10 kPa to 20 MPa, depending upon location within that type of system.  The eye’s flow system must handle two to three microliters per minute at pressures ranging from 0.5 to 5.0 kPa.  At various points in both systems, flow rate and pressure must be maintained within relatively narrow ranges, else the systems fail; and the consequences can be dire.  In a power plant, those consequences could mean that injuries occur and/or extremely expensive components must be replaced.  In the eye, those consequences could mean limited, or loss of, sight. 

In today’s world, engineers work to make both types of systems function reliably.  This presentation will focus on research directed at maintaining the proper pressure and flow rate in/from the eye; but will also describe one viewpoint as to how power plant systems have ‘set the stage’ for applying engineering perspectives to eye-related research.  

Glaucoma is a result of the eye’s pressure becoming too high, with serious potential for optic nerve damage, thus having a direct and permanent impact on sight.  Once glaucoma causes optic nerve damaged, the effects cannot be reversed.  If eye (intraocular) pressure (IOP) becomes too high, initial drug treatment is performed, which lowers production of eye fluid (aqueous humor, AH) and thus IOP.  If the situation persists, laser therapy may follow.  When these steps fail to resolve the issue, drainage tubes are sometimes inserted in the eye in order to provide another means for AH to drain, forcing the IOP to reach acceptable levels.  The desired IOP range is roughly between 0.75 and 2.5 kPa (5 to 20 mm Hg).  However, care must be taken so that the drainage tubes still provide reasonable resistance to AH flow.  Otherwise, a different set of complications arises when IOP drops well below 5 mm Hg (hypotony).  Current research is aimed at optimizing the design of these drainage tube systems, through experimental measurements coupled with theoretical modeling.

Dr. Ronald L. Dougherty is the Associate Chair of KU’s Mechanical Engineering Department.  He earned his PhD from MS&T (then UMR) in 1978; and took a position with Pratt & Whitney Aircraft in East Hartford, CT, designing, modeling and testing jet engine burners.  In 1983, he took a position with Terra Tek, Inc. [an oil/gas consulting firm; now part of Schlumberger] in Salt Lake City, UT, working on computer modeling of oil recovery.  In 1985, he started as an associate professor in Oklahoma State’s School of Mechanical and Aerospace Engineering - - promoted to full professor in 1992, and then to Graduate Director in 1995.  In 1999, he became the Chair of KU’s Mechanical Engineering Department, stepped down from that position in 2012, and took on the Associate Chair position in 2015. 

Dr. Dougherty has researched in various areas:  dynamic light scattering, non-intrusive laser diagnostics, particle sizing and size distribution, power plant pumping systems, driving distractions, blood spatter, hypothermia, and glaucoma-related flow systems.  He is a member of AIAA, ASHRAE, and ASME; and is a licensed professional engineer in Oklahoma.  He has over 60 peer-reviewed and conference publications.  He has been funded by Bonavista Technologies, Dayco-Purolator, Grundfos Pump Company, Institute for Advancing Medical Innovation (KU Medical Center), National Science Foundation, Nuclear Regulatory Commission, Purolator Products, and University of Tulsa Joint Industry Project.