DEGENERATION OF SILICONE RUBBER HEART VALVE POPPETS.

Experimental study is reported in which unused silicone rubber poppets (some of them with BaSO//4 filler) were examined by using various chemical and physical techniques and then immersed in a 1% solution of cholesterol in chloroform to study their in-vitro autoxidation. Results are discussed in terms of practical recommendation. On the basis of these findings the author has dismissed the hypothesis that ball variance is due to the absorption of an abnormal component of blood.