terial, electrically induced forces on cells, and other such phenomena.

Schwan was also deeply concerned about the possible health effects of nonionizing electromagnetic fields. In 1953, he sent a letter to the U.S. Navy proposing a safe limit for human exposure to microwave energy of 100 W/m² (based on thermal analysis). This letter became the basis for exposure standards in the United States and elsewhere. In 1965, Schwan chaired the committee that established the first U.S. exposure limit for radio-frequency energy for the American National Standards Institute, which evolved into the present IEEE C95.1 standard. The U.S. standard was influential in the development of exposure limits around the world.

Schwan also played an important role in the development of the fields of biomedical engineering and biophysics. In the early 1950s, he served on numerous national and international committees helping to organize and promote professional societies. He was chair (1960) of the Institute of Radio Engineers Professional Group on Medical Electronics, the largest biomedical engineering society of its time, and helped guide the evolution of this and other groups into the present IEEE Society on Engineering in Medicine and Biology. Schwan held many leadership positions in the biomedical engineering sections of the American Institute of Electrical Engineering and Institute for Radio Engineering, the two engineering societies that eventually merged to form the IEEE. He was a founding member of the Biophysical Society, Bioelectromagnetics Society, and Biomedical Engineering Society and chairman of the American National Standards Institute committee that developed the first limit for human exposure to radio-frequency energy in the United States.

Schwan is survived by his wife (since 1949), Anne Marie Del Borrello, of Philadelphia, five children, and six grandchildren. He was a mentor to all of them, teaching them first and foremost to think for themselves and never to simply follow the crowd. A man of integrity, Schwan influenced not only his wife and children, but also his many students and colleagues.