A decade-long collaboration between a Peoria neurosurgeon and a Bradley mechanical engineering professor has been fueled by innovative ideas and a desire to improve patient care. They have worked on a wide variety of projects, such as understanding why hydrocephalic shunts fail, designing surgical tools to remove tumors from the brain more efficiently, researching the design of bicycle safety helmets, and reducing the cost of molding helmets for babies born with misshapen skulls.
The creative energy between Dr. Julian Lin of OSF Saint Francis Medical Center and Dr. Martin Morris, professor of mechanical engineering at Bradley, can be measured in the numerous successful senior projects for mechanical engineering students they have overseen. Most recently, one of these projects culminated in a patent disclosure for a valve technology that could greatly improve the quality of life for people living with hydrocephalus.
“He called me out of the blue one day,” Morris says, recalling his first contact with Lin. “He wanted help solving a problem directly affecting his patients with hydrocephalus.” This condition, in which excess cerebrospinal fluid (CSF) collects around the brain, is often treated with a shunt system that drains the fluid into a tube in the patient’s abdomen. “He wanted help understanding why these systems fail, and we began looking at ways to change the design to lower the failure rate. Each time the shunt has to be replaced or repaired,” Morris says, “the patient’s brain can be adversely affected, including the lowering of a person’s IQ.”
A senior design team in 2000 developed a shunt testing apparatus that allowed them to look at the reasons why the shunts failed and how this failure rate could be improved. As a result of this project, Lin and Morris were members of a team that received a Peoria NEXT grant in 2005 to develop an electro-mechanical shunt system that would overcome many of the causes of shunt system failure.
This type of system would provide more diverse strategies for controlling the intracranial pressure and might provide alternatives to replacing entire components, as is done with
the current passively controlled systems. “I still believe such a system has a lot of potential, and I hope we can continue to pursue it,” Morris says. Lin adds that “it has been wonderful working with Bradley and Dr. Morris. We have learned much about fluid dynamics in CSF shunts.”
The team’s most recent work stems from Lin’s idea for a new approach to controlling the flow of CSF through the shunt system. Current systems, designed to reduce the intracranial pressure by draining the CSF surrounding the brain, are regulated by controlling the fluid flow based on the pressure inside the skull.
This control design can allow too much fluid to drain as the hydrostatic pressure at the end of the tubing creates a siphoning effect. This happens most frequently when a person stands up from a prone position and the valve responds to both the intracranial pressure and the change in pressure across the distal tubing created by the change in position. As too much fluid drains, ventricles within the brain can collapse. The collapse of these fluid-filled cavities can cause the patient to experience severe headaches and vomiting.
Lin and Morris challenged a 2008–2009 senior design team to develop a valve that would change this system. The valve design would control the flow of CSF independent of pressure changes across the distal catheter. The student team, comprised of Kathleen Nowak, Daniel Smith, Jeremy Yee, and Anne Zborowski, came up with numerous designs. Once they selected one to test, they faced the creative challenge of choosing materials for the model and determining how to machine it.
“The students took the design from paper and then created a real piece of hardware that they could test,” Morris says. “They created a super-sized model to test and prove the concept. At this point, we’ve built the model and we’ve made it work.”
While the design and concept can most likely be patented at this point, Morris says they still have a lot of work to do. “The physics of the fluid flow change with the scale of the model. When we begin working on a human-sized model, we need to develop a mechanism driven by viscous forces.” Developing the actual human-scale model is equally challenging, as this requires incredible precision and special equipment.
While they explore how to develop this technology into a device that can actually benefit patients, Dr. Lin and Bradley’s Mechanical Engineering Department continue to move forward with new ideas. A 2009–2010 senior design team will create a prototype of a device that is capable of measuring, recording, and controlling the amount of fluid that passes through the shunt each day, providing information that will tell doctors if the shunt is functioning properly. Dr. Kalyani Nair, assistant professor of mechanical engineering, will advise this team, whose members are Charlie Corrie, Brian Del Bene, and Michelle Eastburn.
Lin says he is looking forward to continuing this collaboration. “I hope the students have learned as much as I have learned from them.”
“Dr. Lin is extremely creative and has many ideas for improving patient care,” says Morris. “This collaboration has been very beneficial to Bradley and to our students. Our hope is that some of them will move on to careers in biomedical engineering—and indeed that has happened.”