Rush's tranquiliser chair. Illustration of a man in Benjamin Rush's 'tranquiliser chair'. Rush (1746-1813) was a physician and one of the Founding Fathers of the United States. He is considered the 'Father of American Psychiatry' and believed that many mental illnesses were caused by sensory overload. As such he treated them with devices designed to provide sensory deprivation, such as the 'tranquiliser chair' - a restraining chair with a sensory-deprivation head enclosure.