The Body Synthetic
  Winter 2008

  Dr. D. Jaron
  Dr. P. Lelkes
  Dr. R. Seliktar

  Shuk-Man Charli Hon
  Richard Gerbino
  Natalie Gostola

The ball valve was the first mechanical heart valve used and designed by Charles Hufnagel.  The Starr-Edwards ball valve was first used clinically as a mitral valve replacement in 1960.  After the Starr-Edwards valve was established, several other design variations were created such as Magovern–Cromie, DeBakey–Surgitool, and Smeloff–Cutter ball valves.  These valves are shown in Figure 1.  A variation of the ball valve utilizes a metal cage to contain the ball which allows a smaller ball to be used.  A caged ball valve is shown in Figure 2. 

Ball valves operate on the simple principle that the ball will be forced to one side of the valve or the other depending on which way blood is flowing.  They were modeled after ball valves used in industrial applications to allow the flow of fluids on only one direction.  When the pressure exerted by the heart onto the blood (and the ball) exceeds the pressure in the aorta, the ball is pushed away from the heart.  This is the open position of the valve and blood can flow out of the heart into the aorta.  After the heart ejects blood, the pressure inside the heart is greatly reduced so blood will try to flow back inside the heart.  The negative pressure sucks the ball valve backwards.  It fits over the opening of the heart and prevents backflow of blood.  

In a natural heart valve, blood flows directly through the center of the valve (central flow.)  With a ball heart valve, the heart must work harder to push blood around the ball.  There is no central flow with a ball valve and although it works in principle, it is not a good solution.  Ball valves also are known to damage or kill blood cells due to colliding with the ball. 


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Figure 1: (a) Hufnagel–Lucite valve, (b) Starr–Edwards, (c) Smeloff–Cutter,
(d) McGovern–Cronie, (e) DeBakey–Surgitool and (f) Cross–Jones.

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Figure 2: Caged-ball valve.

Created: February 17, 2008