Disclosed is an ultrasonic IRIS inspection system and a method of providing automatically compensated concentric B-scans by means of curve-fitting the unadjusted tube boundaries from inspection data, and from the curve fitted theoretical circle, using non-linear regression analysis to determine an adjusted center. Content, such as audio, video or audiovisual data is segmented into discrete units. This diode junction opposes the p-n junction between the collector or drain region of the transistor and its base region, so as to suppress reverse current flow in the transistor. While the quench signal is in logic state HIGH, a quenched oscillator is being turned ON and the oscillation amplitude builds-up until a steady-state level is reached. The disc has a contact surface which enlarges with a compression of the artificial intervertebral disc and which adjoins one of the end plates so that the elastic properties of the artificial intervertebral disc show a non-linear behaviour with increasing deformation at least with respect to a compression force. The resistance of the window to thermal stresses is considerably improved thereby.