Professor of physics at UCSB Paul Hansma has coauthored a study of a new medical diagnostic tool for testing the quality of bone. The study, published in the Journal of Bone and Mineral Research, is called “Microindentation for in vivo Measurement of Bone Tissue Mechanical Properties in Humans,” and it validates a technique called Reference Point Indentation (RPI).
According to a press release from the university, RPI uses a mechanically driven test probe enclosed in a microscopically small cylinder which is driven like a tiny piston into the bone of the test subject, making microscopic indentations. The microfractures are then measured to determine the bone’s strength and quality.
According to Hansma, as quoted in the press release, RPI has been tested on live subjects in Barcelona, Spain under the supervision of him and Dr. Adolfo Diez-Perez, physician at Hospital del Mar. The FDA has not approved RPI tests on live subjects in the United States, and conventional measurement for bone mineral density is done with x-rays called dual energy x-ray absorptiometry (DEXA) which measures how much bone people have. “All they’re doing is dealing with bone quantity,” Hansma was quoted as saying. “They’re dealing with half the problem.”
According to Hansma, “several million dollars for clinical studies in the U.S.” are needed to convince the FDA to approve the RPI for tests in the United States. In order to promote the RPI, a Santa Barbara company, Active Life Scientific, is selling instruments to researchers for lab studies, hoping to raise the necessary funds. Hansma is the chief scientific officer for Active Life.
Hansma said RPI would help with the problems associated with bones’ becoming brittle with age. The press release noted that a woman is more likely to die in the next year after a hip fracture than if she’s had a heart attack.