Hulda Regehr Clark (1928 - 2009) studied biology at the University of Saskatchewan in Canada. After graduation and another two years of study at McGill University, she began studying biophysics and cell physiology at the University of Minnesota. She received her doctorate in 1958. In 1979 she left government-funded research and began private practice. Six years later, she discovered an electronic technique for measuring the frequencies of pathogenic microorganisms. In the course of her research, she rediscovered the destruction of pathogenic microorganisms by high-frequency pulses and developed many procedures and methods for the non-traditional treatment of almost all diseases. Hulda Regehr Clark has given lectures and seminars all over the world, and with the help of her procedures, thousands of people have already regained what is most valuable - health. Dr. Hulda Regehr Clark brought to the modern age many new information for treatment using frequency generators. But her main contribution lies in the fact that she was not afraid of persecution and false personal accusations, and she published the practical results of her research in several of her books, which she published one after the other in a very short time.