Laser Speckle Displacement Cardiography

Laser speckle is an interference phenomenon which is the result of the interference of the scattered radiations due to the roughness of the surface. By the superposition of the speckle patterns during systolic phase of the cardiac cycle, by time average speckle interfocometry and point-wise filtering methods, the absolute displacements at various locations on the chest above cardiac region are determined. The displacement cardiograph is constructed by IBM 370/155 computer in the form of a three dimensional plot. The results provide the displacement pattern of the complete heart and show that in normal subjects the displacements above the left and right ventricles, aortic and pulmonary outflow tracts are significantly higher than that of the septum region. Depending on the clinical status of the heart in cardiac patients, these patterns show the respective variations.