Pulse Flowmeter and with “gold standard” electromagnetic flowmeters
To determine if this measurement technique accurately measures Peripheral Pulse Volume (PPV) and Mean Nutrient Flow (perfusion), simultaneous measurements were made with the impedance based Pulse Flowmeter and with “gold standard” electromagnetic flowmeters. We elected to make such comparisons in an isolated perfused kidney preparation, as the kidney is an organ with well-defined and accessible arterial and venous supplies. Selectively averaged PPV correlated well with PPV as determined by flow probe measurements. Pulse Flow (HR x PPV) correlated very well with mean flow (at physiologic flow levels), supporting the use of changes in PPV to predict changes in perfusion. Thus, in the isolated vascular bed of the kidney, this technique appears to satisfactorily measure PPV as well as to predict changes in mean flow over a wide range of flow values.