Georgia Tech brings fluid power into the world of healthcare
The Georgia Institute of Technology, a seven-year member of the Center for Compact and Efficient Fluid Power is involved in research spanning seals and fluid characteristics, medical applications of fluid power and controls and interfaces for human operators. Georgia Tech does not offer a degree in fluid power, but has added classes focusing on the subject.
Collaborating with Vanderbilt University, research into the use of fluid power in medical applications is leading to the development of a patient transfer device. This device would use hydraulics to lift patients with limited mobility from their beds to a wheelchair or from a wheelchair to a shower stool. The power density of the system would allow the device to lift up to 500 lbs, yet would be maneuverable enough and have enough degrees of freedom to be used in the patient’s home.
Wayne Book, professor emeritus and former HUSCO/Ramirez distinguished professor of fluid power and motion control, hopes the device will not only help the patient but their caregivers as well.
“Some of them are living more or less independently, but find themselves falling and their home care giver just can’t manage it,” Book said. “ As a consequence of attempting to help them, there is a high incidence of injury to the caregiver.”
The device occupies the power range from ~100W to ~1kW in the CCEFP’s efforts to apply to the full power range of applications. Intuitive controls are also on the agenda for the device, so only a single operator would be needed to aid a patient.
This work on controls and interfaces has also extended into work on making the controls of mobile hydraulic equipment, such as excavators and backhoes, more intuitive than the standard two-joystick control scheme. Operator effectiveness will be enhanced for existing and newly emerging devices through interfaces that take advantage of multiple sensing and display modalities and control technologies incorporating augmented reality, shared human/computer control and actuator control algorithms to enhance devices operational effectiveness. The work has dramatically reduced the amount of time needed to train someone to competently operate a device with multiple degrees of freedom.
Research into seals has been focused on modeling the seal behavior. This is done to develop numerical models, which would be capable of predicting key seal performance characteristics. The project has been able to develop several models: a steady-state model, an elastic transient model, and a visco-elastic transient model. These have been used to simulate various seals in an injection molding application and in a high pressure, high frequency actuator application. The results of these simulations have shown that mixed lubrication occurs in the seal-rod interface, where seal roughness and visco-elasticity both play a factor.
“That is an area that has been ignored,” Book said. “It’s also the area where there is the largest leakage problem leading to environmental concerns.”
Georgia Institute of Technology