[Digital analysis of ultrasound M images for determining the dynamic behavior of the posterior ocular wall]

A computer-assisted interactive method for M-scan analysis is presented. The digital M-scan, which is taken from the posterior wall of the human eye - in vivo - , is a sequence of digitised, broadband r.f.-time amplitude echograms (center frequency: 15 MHz). The effect of pulsation in the normal posterior wall of the eye and the dynamic changes and tissue movements after stress conditions can be pointed out and estimated quantitatively. A detected set of dynamic features can be used for an exact determination of the layers of the posterior ocular wall. For the indication of the dependence between changes of the thickness of the layers and the heart rate, the finger pulse is digitised and stored synchronously to the echograms. Good correlation will be expected for the movements in the choroid of the eye and the heart rate. The registration of the dynamics is performed in the color-coded M-scan by an adapted image processing software. Results of the M-scan analysis are presented as examples of the normal posterior wall.