An improved echo-tracker for studies on pulse waves in the fetal aorta

Publisher Summary This chapter presents comments on an improved echo-tracker for studies on pulse waves in the fetal aorta. In clinical studies, pulse wave velocity (PWV) has usually been investigated over long segments of the arterial tree, which, therefore, have come to include several types of vessels with different characteristics. The available methods for measuring pulse waves have previously been based upon volume changes caused by pressure pulsations. The pulse wave method for the investigation of the vascular system differs in many respects from the presently available diagnostic ultrasound methods, that is, the combinations of Doppler ultrasound and real-time ultrasonography. First, it is possible, non-invasively, to obtain information about quite new physiological parameters, such as the segmental pulse wave velocity and thereby the regional elastic properties of the vascular system. Second, conventional diagnostic ultrasound is extremely sensitive to the exact positioning of the ultrasound transducer for reproducible and consistent results. The velocity of the propagation of the pulse waves created by ventricular ejection represents an important parameter in the analyses of the behavior of the arterial tree. However, its clinical value has until now been limited because of the practical difficulties in making adequate pulse wave recordings. With the introduction of the new dual, auto-lock echo-tracker, pulse wave velocity measurements using radial dilatation as a parameter is, for the first time, within the reach of becoming a clinical routine.