Artificial heart valve 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. Natural heart valves are evolved to forms that perform the functional requirement of inducing unidirectional blood flow through the valve structure from one chamber of the heart to another. Natural heart valves become dysfunctional for a variety of pathological causes. Some
Rayner (company) London, Ridley performed the first IOL operation on the eye of a 45-year-old female patient. The operation was conducted in secret, done in two stages with the artificial lens permanently implanted three months later. In 1952 the first IOL implant was performed in the United States: a Ridley-Rayner lens was implanted at the Wills Eye Hospital in Philadelphia. Surgeons Turgut Hamdi MD and Warren Reese MD implanted a series of these lenses – some with good visual function results (reported in a review by Dr Charles Letocha in the "Journal of Cataract and Refractive Surgery" in 1999). A lens designed