Apparatus for measuring the speed of a pressure wave propagating in the venous district of an individual and corresponding method

Management of the fluid therapy is a daily clinical issue and a debated subject on specialized scientific journals. The identification of non invasive indexes of volume status and/or of venous blood pressure, is of great interest for their potential support in the decision making about fluid administration. This novel device allows a non-invasive and operator-independent assessment of the velocity of a pulse wave travelling in a limb vein. The venous pulse wave velocity (vPWV) is directly related to the vessel stiffness that, in turn, is influenced by changes in blood volume and in venous blood pressure. The device is composed by 1) a pneumatic system (an inflatable cuff wrapped around the limb extremity), used to generate the pulse wave, and 2) a Doppler Ultrasound system, used to detect the propagation of the pulse wave at a more proximal site along the limb. Thanks to the interconnection between these two systems (most ultrasound devices grant this possibility) it is possible to estimate the pulse wave transit time directly on the screen and calculate the vPWV, after measuring the travelled distance (e.g., the limb length).