Three-dimensional interface geometry of the human heart with the artificial heart.

The interface geometry of human and artificial hearts was defined. It included: 1) the approximate mitral orifice and mitral orifice planes; 2) the approximate tricuspid orifice and tricuspid orifice planes; 3) the long and short diameters of the aorta; 4) the long and short diameters of the pulmonary artery; and 5) the angles between the mitral orifice and tricuspid orifice planes, as well as the axes of the aorta and pulmonary artery. The orifice plane was defined as a plane such that the sum of the squared distances between the plane and points on the orifice contour was minimized. A standard coordinate system was also defined, whose origin was the centroid of the approximate mitral orifice. Its X-Y plane was the approximate mitral orifice plane. One set of interface parameters was determined using magnetic resonance images of a volunteer's heart. The angle between the approximate mitral orifice plane and tricuspid plane was found to be 19.9 degrees. The areas of the approximate mitral and tricuspid orifices were 1020 and 1655 mm2, respectively. The approximate mitral orifice was covered by a 44 x 40 mm rectangle and the approximate tricuspid orifice was covered by a 59 x 41 mm rectangle. This interface geometry is important, not only in the manufacture of artificial hearts of precise dimensions, but also in avoiding complications due to their long-term use.