Vascular Diagnosis by Analysis of Waveforms

Analysis of waveforms has, historically, served as the basis for noninvasive diagnosis of vascular disease. In attempting to understand the blood flow patterns associated with vascular disorders, investigators have assessed the morphology of waveforms recorded directly or indirectly from tissues and blood vessels by a variety of instruments. Phonoangiography, plethysmography, analogue recordings of continuous wave Doppler signals, and analysis of spectral waveforms recorded with pulsed Doppler have all been used for diagnosis of vascular disease. Decades of research with these instruments have revealed much about the nature of normal and abnormal blood flow patterns. Even so, clinicians in modern vascular laboratories are often confounded by alterations in waveform morphology and the characterization of waveforms remains controversial. In this and following articles, Dr. Beach and other experts in the field of noninvasive vascular diagnosis take us on a journey from where it all began to the present day, allowing us to take a look at what we now know and, most importantly, the questions that still remain.