Introduction

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.

Technical features

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
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).

Possible Applications

• Support to the fluid therapy management (emergency room, internal medicine, intensive care, dialysis…);
• Vascular stiffness assessment;
• Scientific research.

Advantages

• Non-invasive measurement;
• Objective measurement, operator-independent;
• Any commercial eco-Doppler machine, available in the hospital, is exploitable;
• Information content of vPWV is suitable for a wide range of diseases;
• Quick measure (ex., 6-8 measurements in 2 min).