Event
Special BioE Seminar: Christian Puttlitz
Monday, March 5, 2012
2:00 p.m.
Pepco Room, Jeong H. Kim Engineering Building
Professor Adam Hsieh
hsieh@umd.edu
Adventures in Orthopaedic Biomechanics: Ligament Viscoelasticity and In Vivo Sensing of Fracture Healing
Christian Puttlitz
Monfort Professor
Director, Orthopaedic Bioengineering Research Laboratory
Associate Professor, Department of Mechanical Engineering
Associate Professor, School of Biomedical Engineering
Associate Professor, Department of Clinical Sciences
Colorado State University
At the Orthopaedic Bioengineering Research Laboratory at Colorado State University we seek to perform both basic science and clinically translatable research projects whose underpinnings are related to orthopaedic biomechanics. In this talk we present two such topics non-linear viscoelasticity and in vivo fracture healing sensing that currently dominate our labs efforts.
Our interest in viscoelasticity stems from the unavailability of a non-linear viscoelastic formulation that is computationally tractable and capable of describing/predicting the dynamic behavior of ligaments. Therefore, we have developed a comprehensive viscoelastic characterization (CVC) experimental method and associated analysis technique that results in dramatically increased dynamic accuracy predictions.
The course of aberrant bone fracture healing is not easily diagnosed in the early time period when standard radiographic information of the fracture site is not capable of discriminating the healing pathway. We have hypothesized that healing in the critically important early time period can be determined by monitoring of the implanted hardware mechanics. This postulation leverages the previously demonstrated phenomena whereby the soft tissue callus and newly formed bone progressively assume part of the load as healing proceeds, thus reducing the burden (and associated strain) on the implanted hardware. Thus, to address the critical need of identifying aberrant fracture healing during the early time period, our team (a collaboration between researchers at Bilkent University in Ankara, Turkey and Colorado State University) has developed a wireless, inductively-powered (no implantable power source), biocompatible micro-electromechanical sensor (BIOMEMS) that is capable of monitoring the surface strain on implanted bone fracture hardware and reports these data using radio frequency (RF) technology. In this talk we will present the most recent animal model results that demonstrate the ability of this sensor to discriminate between normal and delayed fracture healing. In addition, we will discuss some new embodiments of the technology that has opened the application space of our technology platform.
