A novel approach for cardiotocography paper digitization and classification for abnormality detection

Cardiotocography (CTG) is a clinical procedure that is used to track and gauge the severity of fetal distress. Although CTG is the most often used equipment to monitor and assess the health of the fetus, the high rate of false positive results due to visual interpretation significantly contributes to needless surgical delivery or delayed intervention. In this study, a novel approach is introduced where both printing CTG paper is digitized and a machine learning approach is employed to detect the abnormality in the digitized CTG signal. Image processing-based preprocessing steps are employed to make the printing of CTG paper more convenient to extract the CTG signal. Various signal-processing techniques are used to calibrate the extracted CTG signal. Then, Empirical Mode Decomposition (EMD) is used to decompose the CTG signal into its frequency components and instantaneous frequency and spectral entropy features are extracted. After feature normalization and feature selection with ReliefF algorithm, support vector machines (SVM) is used for the classification of the normal and abnormal classes. A novel dataset is used in the experimental works and various performance evaluation metrics are used for the evaluation of the achievement of the proposed method. 10-fold cross-validation-based experiments show that the proposed method is quite efficient in abnormality detection in printing CTG papers where an average accuracy score of around 90.0% is produced

Study of the Term Neonatal Brain Injury with combined Diffuse Optical Tomography and Electroencephalography

This thesis describes the application of combined diffuse optical tomography (DOT) and electroencephalography (EEG) in the investigation of neonatal term brain injury. With hypoxic ischaemic encephalopathy (HIE) and perinatal stroke being the most frequent contributors to brain injury in the term neonatal population, the first part of the thesis focuses on the description and ongoing requirement for their further investigation. In continuation to that, the characteristics and unique properties of both DOT and EEG are described and explored. The combination of these two modalities was utilised in elucidating the relationship between neuronal activity and cerebral haemodynamics both in physiological processes as well as in disease, by the infant’s cot side. This work differs to previous studies using near-infrared technologies and EEG, as a denser whole head array was used, offering the potential of 3-dimensional image reconstruction of the cortical haemodynamic events in relation to electro-cortical activity. These methods were applied in the study of critically ill infants presenting with seizures in the first few days of life. The relevant results are presented in three separate chapters of the thesis. Distinct neurophysiological phenomena such as seizures and burst suppression were detected and studied in association to underlying HIE. On the grounds of a pre-existing pilot study of our research group, distinct prolonged de-oxygenated cortical areas were identified following electrical seizure activity. Further exploration of infants with seizures provided limited supporting evidence. The investigation of burst suppression in HIE led to the first ever identification of repeated, waveform, cortical haemodynamic events in response to bursts of electrical activity with some spatial correlation to regions of brain injury. Further analysis of the low frequencies within the diffuse optical signal in cases of perinatal stroke, showed a consistent interhemispheric difference between the healthy and stroke-affected brain regions. The limitations, prospects and conclusions are presented in the final chapter. The use of simultaneous DOT and EEG offers a unique neuro-monitoring and neuro-investigating tool in the neonatal intensive care environment, which is safe, portable, and cost-effective, Ongoing research is required for the exploration and development of the methodology and its potential diagnostic properties

Changes in Cord Blood Dendritic Cells as Biomarkers of Fetal Exposure to Stressor Stimuli

DCs are central to fetal defences and it was postulated that phenotypic changes on CBDCs in response to infectious/stressor stimuli could identify compromised fetuses. Investigations were performed on whole blood using monoclonal antibody labelling and flow cytometry. Functional studies included endocytosis of Dextran particles and MLR. Both plasmacytoid (HLA-DR⁺CD11c⁻) and myeloid (HLA-DR⁺CD11c⁺) DCs were identified in CB. Additionally CB contained a DC subset with a HLA-DR⁺CD11c⁻CD45^intermediate(inm) phenotype. This population expressed lower levels of CD45 and HLA-DR and did not express plasmacytoid (CD123, BDCA2, and CD45RA) or myeloid (CD33 and CD13) markers. All subsets exhibited endocytosis and unlabelled CBDCs exhibited lymphocytic stimulatory capacity. Both myeloid and plasmacytoid CBDC subsets showed no change with gestation. The CD11c⁻ CD45^inm subset decreased with increasing gestation representing 31.33% of total DCs in preterm, 21.26% in term CB and 1.54% in adult PB. CD11c⁻CD45inm DC numbers expressing CD40, CD86 and production of IL-12 increased significantly with stressors. The myeloid and the plasmacytoid subsets showed no upregulation of CD40 and CD86 with stressors. The myeloid subset decreased while the plasmacytoid subset increased IL-12 production with stressors. Neutrophilic activation markers of CD11b and CD16 showed significant correlation with the stressed CB samples which exhibited proinflammatory DC responses, thus validating the clinical classification. These data indicate that CB contains plasmacytoid and myeloid DC populations as seen in adult PB. Additionally this study has identified a hitherto unreported CBDC subset with an immature phenotype, exhibiting endocytosis and phenotypically distinct from plasmacytoid DCs. Of the three subsets, only the CD11c⁻CD45^inm subset showed a costimulatory response to stressors suggesting this subset to be the most kinetic; changing with advancing gestation as well as exposure to stressors. Thus investigating phenotypic changes on CBDC subsets, especially on the CD11c⁻CD45^inm subset, could serve to identify fetuses exposed to stressor stimuli and at risk of adverse sequelae.Open Acces

Ultrasound Imaging

This book provides an overview of ultrafast ultrasound imaging, 3D high-quality ultrasonic imaging, correction of phase aberrations in medical ultrasound images, etc. Several interesting medical and clinical applications areas are also discussed in the book, like the use of three dimensional ultrasound imaging in evaluation of Asherman's syndrome, the role of 3D ultrasound in assessment of endometrial receptivity and follicular vascularity to predict the quality oocyte, ultrasound imaging in vascular diseases and the fetal palate, clinical application of ultrasound molecular imaging, Doppler abdominal ultrasound in small animals and so on

Novel analytical approaches for biomarker detection in neonatology

La principal motivación de esta tesis doctoral es el análisis de biomarcadores basados en moléculas pequeñas de relevancia en el periodo neonatal, específicamente, en situaciones de asfixia perinatal y estrés oxidativo. Se han desarrollado métodos analíticos novedosos y se han adaptado para lidiar con los retos que suponen las muestras en neonatología, empleando enfoques mínimamente invasivos y pequeñas cantidades de muestra. Se han implementado diferentes procesados de muestra para el análisis de orina, sangre y leche humana como la extracción en fase sólida y diferentes tipos de desprotenización. Los métodos analíticos desarrollados están basados en: cromatografía líquida acoplada a espectrometría de masas tándem (LC-MS/MS) para el análisis de biomarcadores relacionados con la síntesis de fosfolípidos, biomarcadores de daño oxidativo a ADN, proteínas y lípidos; cromatografía de gases acoplada a espectrometría de masas (GC-MS) para el análisis de biomarcadores del metabolismo energético; espectroscopía Raman amplificada por superficies (SERS) para el análisis de glutatión. Los diferentes métodos desarrollados se han aplicado con éxito en la evaluación temprana de la asfixia perinatal, el análisis de los compuestos relacionados con el metabolismo energético bajo tratamiento de hipotermia terapéutica, el análisis de nuevos biomarcadores de peroxidación lipídica después de la asfixia perinatal, el análisis del estrés oxidativo en leche materna, y el análisis directo de glutatión en micromuestras de sangre. Por tanto, se ha demostrado la aplicabilidad potencial de las tecnologías analíticas avanzadas en la toma de decisiones clínicas.The main motivation of this PhD thesis is the assessment of small molecule biomarkers with relevance in the neonatal period, and more specifically, in situations of perinatal asphyxia and oxidative stress of the newborn. Novel analytical methods have been developed and tailored to deal with the limitations of sampling in the neonatal population, employing minimally invasive approaches and small sample amounts. Different sample pre-processing steps are implemented within the workflows for the analysis of urine, blood, and human milk including Solid Phase Extraction and different deproteinizations. The employed analytical methods are based on Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) for the analysis of phospholipid synthesis-related biomarkers, DNA & protein oxidative damage compounds, and lipid peroxidation products; Gas chromatography-Mass spectrometry (GC-MS) for the analysis of biomarkers of the energy metabolism; and Surface Enhanced Raman Spectroscopy (SERS) for the analysis of glutathione. The different developed methods have been successfully applied in the early assessment of severity of perinatal asphyxia, the analysis of the energy metabolism-related compounds under therapeutic hypothermia treatment, the analysis of novel lipid peroxidation biomarkers after perinatal asphyxia, the analysis of oxidative stress in human milk, and the direct analysis of glutathione in blood microsamples. Therefore, it has been demonstrated the potential applicability of the advanced analytical technologies into the clinical decision-making

Mechanisms of Seizure during Pregnancy and Preeclampsia

Eclampsia is defined as de novo seizure in a woman with the hypertensive complication of pregnancy known as preeclampsia (PE), and is a leading cause of maternal and fetal morbidity and mortality worldwide. The pathogenesis of eclamptic seizure remains unknown, but is considered a form of hypertensive encephalopathy where an acute rise in blood pressure causes loss of cerebral blood flow (CBF) autoregulation and hyperperfusion of the brain that results in vasogenic edema formation and subsequent seizure. However, eclamptic seizure can occur during seemingly uncomplicated pregnancies, in the absence of hypertension and PE, suggesting that normal pregnancy may predispose the brain to hypertensive encephalopathy or seizure, independently of PE. The overall goal of this dissertation was to investigate the effect of pregnancy and PE on the cerebrovasculature and neurophysiological properties that may promote brain injury and eclamptic seizure. For this dissertation project, a rat model of PE was established that combined placental ischemia, induced by restricting blood flow to the uteroplacental unit, and maternal endothelial dysfunction that was induced by a prolonged high cholesterol diet. Rats with PE developed several PE-like symptoms, including elevated blood pressure, fetal growth restriction, placental dysfunction, and were in a state of oxidative stress and endothelial dysfunction. We found that pregnancy had an overall protective effect on the maintenance of CBF that was potentially due to a nitric-oxide dependent enhancement of the vasodilation of cerebral arteries to decreased intravascular pressure. Further, maintenance of CBF during acute hypertension was similar in pregnancy and PE. Thus, it does not appear that pregnancy and PE are states during which CBF autoregulation is compromised in a manner that would promote the development of hypertensive encephalopathy. However, the brain was found to be in a hyperexcitable state during normal pregnancy that was augmented in PE, and could contribute to onset of eclamptic seizure. Under chloral hydrate anesthesia, generalized seizure was induced by timed infusion of the convulsant pentylenetetrazole (PTZ), with simultaneous electroencephalography that was stopped at the first onset of spikewave discharge indicative of electrical seizure. Seizure threshold was determined as the amount of PTZ required to elicit seizure. Compared to the nonpregnant state, seizure threshold was ~44% lower in pregnant rats and ~80% lower in rats with PE. Further, pregnant rats were more susceptible to seizure-induced vasogenic edema formation than the nonpregnant state. Mechanisms by which pregnancy and PE lowered seizure threshold appeared to be through pregnancy-associated decreases in cortical gamma-aminobutyric acid type A receptor (GABAAR) subunits and PE-induced disruption of the blood-brain barrier (BBB) and microglial activation, indicative of neuroinflammation. Magnesium sulfate (MgSO4), the leading treatment for seizure prophylaxis in women with PE, restored seizure threshold to control levels by reversing neuroinflammation in PE rats, without affecting BBB permeability. Overall, this dissertation provides evidence that pregnancy increases susceptibility of the brain to seizure and vasogenic edema formation that likely contribute to the onset of eclampsia during seemingly uncomplicated pregnancies. Further, the pathogenesis of eclampsia during PE likely involves breakdown of the BBB and subsequent neuroinflammation, resulting in a state of greater seizure susceptibility that is ameliorated by MgSO4 treatment

Modelling metabolism in the neonatal brain

Acute changes in cerebral blood flow and oxygen delivery directly affect brain tissue metabolism, often leading to severe life-long disabilities or death. These events can occur during birth with dire consequences to the infant. In order to identify and monitor these events in the neonatal brain clinicians often use non-invasive techniques such as near-infrared spectroscopy (NIRS) and magnetic resonance spectroscopy (MRS). However, clinical interpretation of these signals is challenging. This thesis describes a number of mathematical and computational models of cerebral blood flow, oxygenation and metabolism regulation to assist signals integration from multimodal measurements and to investigate brain tissue metabolic activity in neonatal preclinical and clinical studies. The scope of this work is to construct a set of useful computational tools that will illuminate brain tissue and cellular physiology that give rise to changes in clinical measurements, and hence offer information of clinical significance. The models are composed of differential equations and algebraic relations that mimic the network regulating cellular metabolism. They integrate NIRS and MRS measurements that offer insights into oxygenation and a variety of metabolic products such as ATP and pH. These models are thus able to explore the relation between measured signals and the physiology and biochemistry of the brain. The first three models presented in this thesis focus on the piglet brain – a preclinical animal model of the human neonatal brain. Previously published models are extended to simulate intracellular pH and used to investigate hypoxia-ischaemia experiments conducted in piglets, predicting NIRS and MRS measurements. The fourth model is an adaptation of the piglet model to the human term neonate, to investigate data from bedside NIRS monitoring of patients with birth asphyxia. Finally a previously published, simpler adult model is adapted to the preterm neonate, simulating data from functional response studies and a functional NIRS study in neonates using a visual stimulus

Nutrients in Infancy

Infants are not just small adults; they have a complex set of nutrient requirements and interactions to account for the high metabolic rate, growth, immunological and cognitive development, etc. Each year there are 138 million births, including 30 million from the least developed countries, where health is most at risk. Nutrition during infancy establishes growth patterns and development which moderate short term and long term health and life expectancy. There is continuing progress in understanding the nutrient composition of breastmilk and the importance nutritious and timely complementary foods. Nutrients at particular risk in the first years of life are iron, iodine, and vitamins A and D. There are still gaps in our knowledge on the influence of maternal diet, body composition and nutritional status on breastmilk nutrients. Interaction of nutrients with the human microbiome and gastro-intestinal tract hormonal secretion are developing fields. While breastmilk remains the “gold standard of pediatric nutrition”, the provisions of nutrients providing for optimal health in infant formulae, including nutrients and probiotics remains an area of research. The assessment of body composition for research and clinical practice has progressed rapidly and is important in understanding later obesity. After six months of age, there are new issues of the interaction of weaning foods and later family foods with the maturing gastro-intestinal tract to promote health and growth. Infant nutrition is made more difficult (and interesting) by the many cultural beliefs related to feeding practices. Developments in all of these fields of research into pediatric nutrition will be explored in this special issue together with state of the art reviews

Perinatal hipoxic ischemic injury in the auditory pathway and the effect of several neuroprotective agents

192 p.Despite improvements in neonatology, perinatal hypoxic-ischemic (HI) encephalopathy remains one of the main causes of disabilities in term-born infants. This specific pathology underlies many neurological disorders such as learning difficulties, language and attention deficit, hyperactivity disorders and cerebral palsy. Moreover, it is also a notable risk factor for hearing impairments which affect neonates.Insult from hypoxia-ischemia causes immediate neuronal injury and exhaustion of cellular energy stores, as the main cause of HI brain injury is the deprivation of glucose and oxygen supply, which initiates a multi-faceted cascade of biochemical events. The combined effects of cellular energy failure, acidosis, glutamate release, intracellular calcium accumulation, lipid peroxidation, and nitric oxide neurotoxicity provoke, in many cases, the death of the cells, either by necrosis or apoptosis, a divergence that will depend on the severity of the insult, the maturational state of the cell or the brain region affected, among others. After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury, various neuroprotective therapies have been developed for alleviating brain injury.The aim of this work is to evaluate with morphofunctional, molecular and cellular methods the effect of a panel of antioxidants on HI-induced auditory deficits. To this end, we studied the effects of Nicotine, Melatonin, Resveratrol and DHA on the neonatal auditory system via measurement of auditory evoked potentials and characterization of the morphological, molecular and cellular integrity of the IC