David Gaddes has been promoted to president...

David Gaddes has been promoted to president of Neuro Diagnostics Inc., a subsidiary of Luther Medical Products Inc. in Tustin. Gaddes, who joined Neuro Diagnostics in 1979, has been vice president of marketing for the past three years. In addition, D. Ross Hamilton has joined the board of directors of Luther Medical. He is the president of two New York companies: Hamilton Research Inc., a financial consulting firm, and Leads Securities Inc., a NASD brokerage and dealer.