Dr. Hrebien's research is focused on dynamics and controls of biological systems in the context of aerospace medicine, as well as detection and estimation in large scale databases of biological data. Of special note is his work on G-suits for aircraft pilots (worn by pilots who are subject to high levels of acceleration), improvements to other areas of aerospace medicine, and, most recently, new work on pattern recognition with applications to proteomics and cytometry and uses in predictive toxicology and drug development. These lines of work have been supported consistently by US Federal agencies and by the pharmaceutical industry (Glaxo Smithkline; Centocor). They are continually recognized by the Aerospace Medical Association. Dr. Hrebien's scholarly work has been recognized by peers and professional societies. His recognitions include nomination for the Alan T. Waterman Young Investigator Award, acceptance into the ASEE Summer Faculty Fellows program for three consecutive years, election to Senior Member of IEEE, election to Associate Fellow and then Fellow of the Aerospace Medical Association, and the Best Navy Paper at the Air Force/Navy Science and Engineering Symposium. He received the 2003 Professional Excellence Award and the 2007 Research and Development Award which were given by the Life Sciences and Biomedical Engineering Branch of the Aerospace Medical Association. Dr. Hrebien served as Guest Editor of IEEE Engineering in Medicine and Biology Magazine special issue on High-G Environments and the Editor of the "Science and Technology Watch" Column of the journal Aviation, Space and Environmental Medicine.