File:Method-of-pulse-wave-analisys.png

English: a) A peripheral waveform is recorded (e.g., from the brachial artery). b) This waveform is analyzed by a mathematical algorithm based on a transfer function, with a certain amplitude and phase characteristics. c) The central waveform is then reconstructed. From this waveform, central systolic (SBP) and diastolic blood pressure (DBP), and pulse pressure (PP) are derived. The systolic peak defines the central arterial systolic pressure (CASP). The augmentation index (AIx) is computed as the ratio between the augmentation pressure (AP, the difference between the reflected wave, P1, and the forward wave, P2) and PP, expressed as a percentage. d) Pulse wave velocity (PWV) may be computed according to the foot-to-foot method for example of carotid-femoral PWV(cfPWV) by multiplying the carotid-femoral distance (ΔL) by 0.8 and dividing the result by the time interval (Δt) between the foot of the carotid and femoral waveform. e) Alternatively, for ambulatory estimation, PWV may be derived by multiplying the surrogate length of the aorta (ΔL, jugulum-symphisis distance or superficial morphological distance corresponding to the projection of the aorta on the body surface) by 2 and by a constant (k) and by dividing the result by the reflected wave transit time (RWTT, the time interval between the forward and the reflected wave)