Wimer, Jeremiah R.; Westman-Forbes, Amaya K.; Wu, Jingxian; Sexton, Kevin W.; Jensen, Hanna K.; Saunders, Robert; Jensen, Morten O. (2026).Ìý.ÌýBiomedical Signal Processing and Control, 126, 110985.Ìý
Accurately assessing whether a patient has enough circulating blood and body fluid is especially important in children, but existing methods can be invasive or difficult to perform. This pilot study explored whether peripheral venous pressure (PVP) waveforms—signals recorded from a vein—could be used to detect a patient’s intravascular volume status (the amount of fluid circulating in the blood vessels). The researchers analyzed PVP waveforms from 18 pediatric patients and used a modified integral pulse frequency modulation (IPFM) model to separate meaningful physiological signals, such as heartbeats, heart rate variability, and breathing patterns, from noise. These processed signals were then used to train machine learning models to classify patients as resuscitated (adequately restored fluid levels) or hypovolemic (having abnormally low blood volume). Models trained using the IPFM-extracted heartbeat signal achieved nearly 100% testing accuracy, outperforming models trained on the processed PVP waveforms (95.8%) or the original PVP data (90.1%). The findings suggest that the IPFM approach can improve the detection of dehydration-related changes by removing information that is not relevant to volume status. However, because the study included only a small number of patients, larger studies are needed to determine whether the method performs as well in broader clinical populations. The authors also note that because dehydration and blood loss produce similar changes in PVP waveforms, this approach may also be useful for detecting hemorrhage.

Fig. 2.ÌýFiltered PVP signal  and its slow-changing moving average .