14 research outputs found

    Computerised interpretation of fetal heart rate during labour (INFANT): a randomised controlled trial

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    Background. Continuous electronic fetal heart-rate monitoring is widely used during labour, and computerised interpretation could increase its usefulness. We aimed to establish whether the addition of decision-support software to assist in the interpretation of cardiotocographs affected the number of poor neonatal outcomes. Methods. In this unmasked randomised controlled trial, we recruited women in labour aged 16 years or older having continuous electronic fetal monitoring, with a singleton or twin pregnancy, and at 35 weeks’ gestation or more at 24 maternity units in the UK and Ireland. They were randomly assigned (1:1) to decision support with the INFANT system or no decision support via a computer-generated stratified block randomisation schedule. The primary outcomes were poor neonatal outcome (intrapartum stillbirth or early neonatal death excluding lethal congenital anomalies, or neonatal encephalopathy, admission to the neonatal unit within 24 h for ≄48 h with evidence of feeding difficulties, respiratory illness, or encephalopathy with evidence of compromise at birth), and developmental assessment at age 2 years in a subset of surviving children. Analyses were done by intention to treat. This trial is completed and is registered with the ISRCTN Registry, number 98680152. Findings. Between Jan 6, 2010, and Aug 31, 2013, 47062 women were randomly assigned (23515 in the decision-support group and 23547 in the no-decision-support group) and 46042 were analysed (22987 in the decision-support group and 23055 in the no-decision-support group). We noted no difference in the incidence of poor neonatal outcome between the groups—172 (0·7%) babies in the decision-support group compared with 171 (0·7%) babies in the no-decision-support group (adjusted risk ratio 1·01, 95% CI 0·82–1·25). At 2 years, no significant differences were noted in terms of developmental assessment. Interpretation. Use of computerised interpretation of cardiotocographs in women who have continuous electronic fetal monitoring in labour does not improve clinical outcomes for mothers or babies

    Model-Assisted Approach for Probability of Detection (POD) in High-Temperature Ultrasonic NDE Using Low-Temperature Signals

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    Advanced piezoelectric-based ultrasonic transducers offer the potential for in-coolant nondestructive testing (NDT) measurements at high temperatures (HTs), including during hot standby (~260°C) for liquid-sodium–cooled advanced small modular reactors. The reliability of the NDT measurements is typically quantified by the probability of detection (POD) measured at the corresponding temperature. Obtaining such data in liquid sodium is challenging. Using a model-assisted POD approach, a transfer function is reported that enables data obtained on low carbon steel specimens at room temperature to give an estimated POD at an HT. A primary source of the difference in POD between room temperature and HT is due to the transducer material temperature-dependent performance. This paper demonstrates the transfer function approach using data for modified lead zirconium titanate (PZT-5A). A physics-based model was developed using a finite element method and used to quantify reduction in the scattering amplitude for standard reflectors, side drilled holes (SDHs), for a range of sizes, from 15°C to 195°C. Scattering amplitudes for the room-temperature–simulated data are compared with the experimental data measured at 2.25 MHz. A temperature correction and transfer functions were developed to transform the simulated temperature effect in the physics-based model to compare with the experimental data. The model-based approach was validated with experimental data. It was seen and validated for a PZT-5A ultrasonic transducer operating at 2.25 MHz that the 95% POD at 15°C was 0.58 λ, and due to variation in temperature-dependent properties of PZT-5A, the 95% POD was achieved only for a 1.41 λ SDH diameter.This is the Submitted Manuscript of an article published by Taylor & Francis as Bilgunde, Prathamesh N. and Leonard Bond. "Model-Assisted Approach for Probability of Detection (POD) in High-Temperature Ultrasonic NDE Using Low-Temperature Signals." Nuclear Technology, 2018. Available online. DOI: 10.1080/00295450.2017.1419782. Posted with permission. </h1
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