Using the Osteoprobe, the Hansma Lab's most recent development.

Clinical Trial Results of the Reference Point Indentation Instrument Published in JBMR [PDF]



The Paul Hansma Research Group has an extensive history developing Atomic Force Microscopes (AFMs) for almost twenty years. Our focus on creating AFMs especially suited for biophysical research has led to many discoveries in biomaterials. In addition to our research using AFMs, we have begun development of a mechanical Reference Point Indentation (RPI) instrument (formerly known as the Bone Diagnostic Instrument, BDI, and the Tissue Diagnostic Instrument, TDI) to measure bone fracture risk in living patients.

Using our AFM techniques we are able to explore the molecular origins of fracture resistance in mineralized tissues (primarily bone). Recently, we discovered that some noncollagenous bone proteins act as a molecular glue to resist bone fracture, using a fracture-resisting mechanism we have termed the sacrificial bond and hidden length mechanism. We are now working on characterizing this bone glue, among other research divisions on bone fracture resistance.

Our most current research involves development of medical diagnostic instruments such as the Reference Point Indentation instrument. The Reference Point Indentation instrument consists of a mechanically driven test probe enclosed in a reference probe (a hypodermic needle). The test probe is driven into the bone and creates microscopic indentations. After repeated cycling the indentation distance increase (the difference in indentation from the last and first cycle) is measured. This quantity has been shown to give the best representation of fracture risk. For more information please refer to the complete RPI webpage.