Single-cell system using monolithic PMUTs-on-CMOS to monitor fluid hydrodynamic properties.

In this work, a single cell capable of monitoring fluid density, viscosity, sound velocity, and compressibility with a compact and small design is presented. The fluid measurement system is formed by a two-port AlScN piezoelectric micromachined ultrasonic transducer (PMUT) with an 80 µm length monolithically fabricated with a 130 nm complementary metal-oxide semiconductor (CMOS) process. The electrode configuration allows the entire system to be implemented in a single device, where one electrode is used as an input and the other as an output. Experimental verification was carried out by exploiting the features of piezoelectric devices such as resonators and acoustic transducers, where a frequency shift and amplitude variation are expected because of a change in density and viscosity. A sensitivity of 482 ± 14 Hz/kg/m3 demonstrates the potential of the system compared to other dual-electrode PMUTs. In addition, according to the acoustic measurement, the sound velocity, fluid compressibility, and viscosity coefficient can be extracted, which, to the best of our knowledge, is novel in these PMUT systems.

B-type natriuretic peptide reference interval of newborns from healthy and pre-eclamptic women: a prospective, multicentre, cross-sectional study.

OBJECTIVE: To define and compare the reference interval of B-type natriuretic peptide (BNP) in healthy newborns (HN) from healthy mothers and with severe pre-eclampsia. DESIGN: Prospective, multicentre, cross-sectional study. SETTING: Four obstetric wards of second-level academic hospitals. PARTICIPANTS: 167 HN, from 146 healthy and 21 severe pre-eclamptic women. We included newborns from healthy mothers with full-term pregnancies (38 to 42 gestational weeks), who received adequate prenatal care and who had Apgar scores ≥7 at 0 and 5 min. Newborns with chromosomopathies identified during prenatal consultations, those with respiratory distress and those with cardiac or pulmonary disease detected in the first paediatric evaluation were excluded from this study. In the group of pre-eclamptic women, we considered the same inclusion criteria, but the patients also had to meet the diagnostic criteria for pre-eclampsia with severity features, according to the American College of Obstetricians and Gynaecologists guidelines. The same exclusion criteria used for the healthy group were applied to the pre-eclampsia-associated newborn. INTERVENTIONS: A single blood sample from the umbilical cord artery after delivery (vaginal or caesarean section). PRIMARY OUTCOME: Reference level of BNP in HN. RESULTS: In the HN group, the median BNP was 12.15 pg/mL (IQR 7.7-16.8 pg/mL) and in the pre-eclamptic group 20.8 pg/mL (IQR 5.8-46.5 pg/mL). The reference interval for BNP in HN was 5pg/mL (95% CI 5 to 5) to 34 pg/mL (95% CI 28.4 to 38.8). We identified higher expression of BNP in newborns from pre-eclamptic women overall (p=0.037, r=0.16) and in newborns exposed to stress conditions, such as complications during labour and delivery (p=0.004, r=0.33). CONCLUSIONS: In HN, BNP concentrations at birth were lower than reported in other similar populations. In neonates with stress conditions, the higher expression of this biomarker establishes another possible link between stress and the cardiovascular response. TRIAL REGISTRATION NUMBER: NCT02574806; Pre-results.

Stress transient hypertrophic cardiomyopathy and B-type natriuretic peptide role.

This report describes a transient hypertrophic cardiomyopathy with right-ventricle outlet tract obstruction (RVOTO) induced by perinatal stress due to a major surgical procedure in a female newborn with congenital abnormalities. On day 10, she presented with heart failure, abnormal B-type natriuretic peptide (BNP), and an echocardiogram showing normal wall thickness. An in-hospital follow-up echocardiogram showed biventricular hypertrophy and RVOTO. At discharge, the infant was asymptomatic, with a normal echocardiogram and BNP. Transient RVOTO triggered by surgical stress and abnormal BNP have not been reported previously. Pathophysiology, the role of BNP, and clinical characteristics are discussed.