1. U.S. Food and Drug Administration, Silver Spring, MD, USA
2. Onda Corporation, Sunnyvale, CA, USA
3. Precision Acoustics Ltd., Dorchester, U.K
4. School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
5. Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
6. National Physical Laboratory, Teddington, U.K.