Quantitative approaches to directly measure infant movement have not utilized miniature electronics technology, nor been used effectively in evaluating neurological dysfunctions' affect on movement. This thesis presents a new quantitative technique for measuring infant general movements (GMs) using micro-electromechanical accelerometers, while discussing future improvements for this technology and possible benefits to present methods of diagnosing cerebral palsy. For decades, GMs have interested neurologists because characteristics can indicate neurological dysfunctions. Motions over the entire body that show fluency, variation, and complexity characterize normal GMs. Analyzing these movements can accurately predict neurological dysfunction - cerebral palsy, in particular. This research describes a technique to make consistent, quantitative measurements of GMs using accelerometers on infant limbs. Signal processing techniques can find patterns, later determined characteristic of neurological dysfunctions. Such analyses complement the current technique of video footage review. Additionally, data could be reanalyzed using updated signal processing algorithms. An accurate collection of data allows physicians to quickly review an infant's entire history of motion studies. Physical information can be inferred from the data. Correlation techniques have compared motions from different limbs to examine coordination. Evidence suggests this may help indicate dysfunction. High-speed data acquisition enables the study of high-frequency motions, possibly undetectable with the human eye. This research has successfully recorded acceleration and video during GMs from four limbs on multiple infants. Signal processing techniques have been applied to create various graphical representations. The direct measurement of movement makes this work unique, enabling a graphical analysis tool for physicians based on physical performance. / Master of Science

General movements (GMs) are the spontaneous gross motor movements involving the whole body. GMs progressively develop as an infant ages. Several recent research studies involving the qualitative assessment of the GMs in infants have validated that GMs, or the lack of, are an accurate way diagnosing a neurological dysfunction in the early stages of infancy. One study has shown that definitely abnormal movements occurring between 10-20 weeks post-term accurately predicted cerebral palsy in infants with an accuracy of 85 to 98 percent [1]. The qualitative method of assessing an infant's GMs is an accurate way of predicting a neurological dysfunction, however, requires the review of hours of video footage by a trained physician. This process is not only time consuming and costly but is subjective in the sense that the results cannot be easily transferred among different institutions. It is also difficult to conduct longitudinal studies without first reviewing the entire history of video footage of the infant's GMs. Improvements can be made to the qualitative GMs assessment method by utilizing recent advances in technology that "can make data collection and analysis more efficient, without compromising competency" [2]. In particular, preliminary research has shown that data collected from"wired" micro-electrical-mechanical systems (MEMS) accelerometers attached to the wrist and ankles of an infant is a feasible way of collecting and characterizing the motion patterns that infants display during GMs [3]. The work presented in this thesis is directed towards improving the past research that used "wired" accelerometers to acquire acceleration signals from the limbs of infants. This thesis describes the process of transitioning the "wired" accelerometers to the wireless level, designing a user-friendly interface to graphically interpret the acceleration data, and assessing the designed system through clinical trials on normal and at-risk infants using the design system. / Master of Science

Introduction: À la naissance, les signatures du microbiote intestinal sont différentes entre le nourrisson né à terme et le Preterme (PT), signalant un possible explication des déficits neurodéveloppementaux chez le PT via l’axe de communication entre le cerveau et l’intestin. Cette étude vise à démontrer que le microbiote intestinal peut être un biomarqueur précoce d’une évaluation neuromotrice anormale à l’âge corrigé du terme chez les PT. Méthodes: Des échantillons fécaux ont été collectés à la naissance et à l’âge corrigé du terme dans cette cohorte de PT. L’ADN génomique a été extrait pour chaque échantillon et amplifié dans la région V3-V4 de l’ARNr 16S. L’analyse bio-informatique du microbiote a été réalisée grâce à QIIME2 (v2020.2). À l’âge corrigé du terme, l’évaluation neuromotrice sera faite à l’aide de deux tests neuromoteurs: « Amiel-Tison Test » (ENTAT) et « Global Motor Assessment » (GMA). Résultats: L’analyse PCoA a permis de délimiter l’évaluation neuromotrice anormale à l’âge corrigé du terme en utilisant l’ENTAT combiné au GMA comme évaluation neuromotrice. En utilisant l’indice de dissimilarité du Bray-Curtis comme mesure de β-diversité, la PCoA démontre une plus forte similarité au niveau des MI des PTs à évaluation neuromotrice normaux à la naissance. L’analyse corrélationnelle nous montre que l’indice Shannon de diversité-α est plus élevé à la naissance chez les PTs avec une évaluation neuromotrice normal (*P=0.56), qui continue d’augmenter à l’âge corrigé du terme, se traduisant par un gain de biodiversité dans le MI de l’enfant avec une évaluation neuromotrice normal. Les mesures d’abondance relatives de genres bactériens nous démontrent une plus forte prévalence de pathogènes opportunistes, ainsi qu’une faible présence de bactéries commensales à la naissance et à l’âge corrigé du terme dans le groupe à évaluation neuromotrice anormale. Conclusion: Les niveaux de bactéries opportunistes sont plus élevés à l’âge corrigé du terme chez les PT à évaluation neuromotrice anormal de même qu’une raréfaction de bactéries commensales. La diversité du microbiote intestinale à l’âge corrigé du terme est aussi réduite chez les PT à évaluation neuromotrice anormale. / Background: The early developmental window of the gut microbiome occurs in parallel with the nervous system development, which may be influenced by early life exposure including variation in gut microbiota colonization. Emerging evidence are now highlighting how gut microbiota signatures are distinct between term and preterm infants (PT). This study aims to explore if gut microbiota colonization, as an early biomarker, is associated with abnormal neuromotor examination at term-corrected age in infants PT. Methods: Fecal samples of thirty-four participants were collected at birth and from 26 participants at term-corrected age at term-corrected age from a longitudinal observational cohort of PT. Genomic DNA was extracted and V3-V4 region from 16S rRNA was amplified. Taxonomy abundance tables were generated from the FASTQ data obtained, using QIIME2 (v2020.2) for further analysis. At term-corrected age, two neuromotor examination were performed to evaluate neuromotor outcomes: The Amiel-Tison Test (ENTAT) and the Global Motor Assessment (GMA). Results: PCoA cluster analysis allowed to delineate abnormal neuromotor assessment at term-corrected age using ENTAT examination alone or in combination with GMA. In fact, using Bray-Curtis distance for β-diversity, PCoA shows a better clusterisation at birth of normal neuromotor examination than the abnormal neuromotor examination. Correlational analyses showed that Shannon diversity is higher at birth in PT with a normal neuromotor examination (*P=0.56), which increases at term-corrected age translating a gain in biodiversity in infant with a normal neuromotor examination. Relative abundance analysis showed a higher prevalence of opportunistic pathogens at birth and at term-corrected age in the abnormal neuromotor examination group, along with a rarefaction of commensal bacteria. Summary: Opportunistic pathogen levels are higher at term-corrected age in PT presenting an abnormal neuromotor examination along with a rarefaction of their commensal bacteria of their gut microbiota. This preliminary analysis also indicates that an early life poor bacterial diversity in the gut microbiota could be predictive of abnormal neuromotor examination at term-corrected age in infants PT.