Noninvasive Monitor of Vascular Volume Fluid Shifts

The PV[O]H device probes capillaries noninvasively with a single color of light and uses the elastically remitted light as one signal and the inelastically (Stokes scattered) light as another signal. The algorithm processes these two signals to provide an extremely sensitive, precise and accurate simultaneous measurement of relative changes in total intravascular blood volume, plasma volume, red cell volume, interstitial volume and hemoglobin oxygenation (SpO2). The relationship between the intravascular plasma volume and the mean arterial pressure (MAP), allows the device to display MAP in a real time numerical or graphical readout. The device simultaneously provides cardiac pulse rate and breathing rate and is calibrated in terms of hematocrit (Hct) against an FDA approved gold standard device. Because of the relationship between Hct and the extracellular fluid load i.e. interstitial fluid volume this device allows fast monitoring of fluid shifts between the intravascular and extravascular compartments. We will produce 1) a simple working version that can monitor two locations simultaneously and determine the feasibility of 2) producing a wearable 3) whether the probing light source can be a light emitting diode and 4) if it can be used for at least one hour on a single battery charge.