About us D. A. Surgical is continually focused on developing and marketing innovative patient positioning devices as well as other patient and staff safety related products. Dan ​Allen is best known as being the inventor of the Allen Stirrup*. The retired founder of Allen Medical Systems* and founder of MEDICUS Surgical, Nursing CE Portal and D. A. Surgical, he is a respected pioneer and product designer of patient positioning and pressure management devices that continue to be used every day in operating rooms around the globe.