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In vitro simulators give the chance to mimic specific human physiological/unphysiological conditions to test medical devices, accelerating innovation cycles, and rapidly exploring new effective solutions. Specifically, in this work, we consider a Pulse Duplicator in use at the Healing Research Laboratory, at the University of Padova, Italy. It allows assessing the performance of prosthetic heart valves under simulated cardiac conditions by generating a controlled pulsatile flow obtained by setting specific system characteristics such as the peripheral resistance and the compliance. In order to conduct effective prosthetic heart valve tests, the Pulse Duplicator has to be manually tuned to provide suitable hemodynamics waveforms (i.e. flow and pressure waves). To assist this time-consuming and not trivial task, we present a Phase Plane Analysis of a particular signal (i.e., the left ventricular pressure) in order to capture additional hemodynamic characteristics of clinical interest that can serve system tuning purposes.

Background: Minor painful procedure are very frequent in nursery; control of pain can be obtained by farmacological and non farmacological methods. We investigated the effect of different nursing during procedure with a randomized controlled trial.Methods: Forty-four healthy, full term (2500–4000 g) newborns (21 male, 23 female) were assessed during heel lance procedure for newborn screening. The newborns were randomly allocated with a computer-generated random numbers list to receving “nurse care” or “mother care” for the procedure. In both cases newborns were nursed in a standard way before, during and after the procedure, the person giving care being the only difference between the two groups. In order to obtain blindness of assessors, video tapes of the face of the baby were recorded. A nurse unaware of the person who gave care analyzed the tapes and gave a validated score of pain (Neonatal Facial Code System, NFCS [Grunau & Craig 1987]) 4 times (at the beginning of the procedure, during blood sampling, at the end of the procedure, and 10 minutes after). Results are expressed as mean and SD (table); analysis were performed with Mann-Whitney U non parametric test because of skweness of distributions.Results: Facial scores at the end of the procedure were reduced in the “mother group” compared to the “nurse group” (3.00 ±2.77 vs 0.45±1.33, P < 0.001). At other observation points, the differences in facial scores between the two groups of newborns did not reach statistical significance. Duration of crying during the blood collection was not significantly different (96.0±58.2 vs 73.8±43.5). Mother care was effective in reducing responses to pain upon heel lance in the period following completion of the procedure in healthy full term newborns.Conclusion: This non farmacological strategy can be useful for reducing behavioural responses to minor procedural pain in newborns.