Artificial heart valve was later changed to use silicone-coated material. The first implantation of mechanical heart valve to human was performed by Dr. Hufnagel on 11 September 1952, using the valve that he developed. This event accelerated the development of other artificial heart valves. Artificial heart valve An artificial heart valve is a device implanted in the heart of a patient with valvular heart disease. When one of the four heart valves malfunctions, the medical choice may be to replace the natural valve with an artificial valve. This requires open-heart surgery. Valves are integral to the normal physiological functioning of the human heart.
Comparison of MD and DO in the United States schools opening at a rate faster than MD schools, and an increase in applicants for medical schools as a whole. A 2012 survey of students applying to both U.S. MD and DO schools found that 9% of applicants were admitted only to an MD school, 46% were admitted only to a DO school, 26% were admitted to both, and 19% were not admitted to any medical schools. Geographic location was the top reason given by both DO and MD students for choosing the school in which they enrolled. Of first-year medical students matriculating in 2016, 25.9% (7,369 students) entered DO