Our research group focuses in the development of innovative biomedical devices and the study of human dynamics and neuromuscular control. Research projects are slanted toward commercial applications with most projects having elements of designing, building, and testing. Some projects are focused on developing new medical devices, while others are focused on optimizing engineering designs for improved manufacturability. A few of our current projects are shown below.
Design for Manufacturing
Optimizing product designs is an essential element when developing successful commercial products. Design for manufacturing (DFM) utilizes a set of principles that enable design engineers to optimize products designs improve product quality while simultaneously reducing cost. This is accomplished by considering the manufacturing process that will be used to produce the product during the design phase of product development. The design of each component is are optimized for the manufacturing process that will be used to produce it by minimizing of eliminating difficult to manufacture features. DFM may also be used to optimizes the assembly process (a.k.a. Design for Assembly or DFA).
Topology Optimization was used to optimize the design of a 3D Metal Printed part. He also employed Design for Metal additive manufacturing guidelines to improve the manufacturability of the design prior to printing. Overall, he achieved a 41% weight reduction and associated cost savings with the new design while maintaining the components ability to carry a load.
When designing a product the most fundamental component is the material from which the part is made. Some products are made from a single material while other consist of multiple parts made from different materials, each with different properties.
Controlling Material Properties using Mesostructures: Terail Conts is designing “materials” in which the elastic modulus can be adjusted. This is being achieved by 3D printing mesostructures within the material. These meso structures are smaller that the overall size of the part so overall part shapes can be achieved. However, they are larger than the microstructure, material grains visible using a microscope. Mesostructures are typically on the order of 0.1 mm to 1.5 mm in size. Unlike foam metal that has a random mesostructure, the mesostructure created by 3D printing can be designed enabling more control of material properties. One application of this research is to enable the ability to create an orthopaedic implant with an elastic modulus that matches that of bone to avoid stress shielding. Moreover, because the material stiffness can be adjusted throughout the structure, areas of higher stress can be stiffened and other areas can be made more compliant.
Medical Device Design
Neural Prosthesis: The latest generation of prosthesis include intelligent artificial controllers that enhance the performance of the prosthesis. We are working with the department of physical therapy to developing an experimental medical device to improve gait in people with muscle weakness associated with spinal cord injury, multiple sclerosis, muscular dystrophy, etc. The device under development by Premkumar Subbukutti uses artificial electrical stimulation to induce contractions in the muscles of the lower leg increasing the push off force while walking. Data from foot pressure sensors, accelerometers, and gyroscopes attached to the body are used by the onboard computer within the device to properly time muscle stimulations. We are developing neural networks to manage the large amount of data collected during the decision process.
Biofeedback Device for Stroke Rehabilitation: We are also developing another device to provide positive biofeedback to people during stroke rehabilitation gait retraining. The device is being developed by undergraduate student Jazz Click. The third generation of the device includes a Arduino Nano microcontroller, foot pressure sensor, microphone, and lithium batteries. During gait retraining, when the patient’s heel strikes the ground (as desired) a positive tone is emitted from the device providing biofeedback to reinforce the motion.