1,691 research outputs found

    NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 41)

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    Abstracts are provided for 131 patents and patent applications entered into the NASA scientific and technical information system during the period Jan. 1992 through Jun. 1992. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application

    Detecting Bladder Biomarkers for Closed-Loop Neuromodulation: A Technological Review

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    Neuromodulation was introduced for patients with poor outcomes from the existing traditional treatment approaches. It is well-established as an alternative, novel treatment option for voiding dysfunction. The current system of neuromodulation uses an open-loop system that only delivers continuous stimulation without considering the patient’s state changes. Though the conventional open-loop system has shown positive clinical results, it can cause problems such as decreased efficacy over time due to neural habituation, higher risk of tissue damage, and lower battery life. Therefore, there is a need for a closed-loop system to overcome the disadvantages of existing systems. The closed-loop neuromodulation includes a system to monitor and stimulate micturition reflex pathways from the lower urinary tract, as well as the central nervous system. In this paper, we reviewed the current technological status to measure biomarker for closed-loop neuromodulation systems for voiding dysfunction

    Bladder Volume Decoding from Afferent Neural Activity

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    RÉSUMÉ Lorsque les fonctions de stockage et de miction de la vessie échouent à la suite de traumatismes médullaires, ou en raison d'autres maladies neurologiques, de conditions de santé ou au vieillissement, des complications graves pour la santé du patient se produisent. Actuellement, il est possible de restaurer partiellement les fonctions de la vessie chez les patients réfractaires aux médicaments à l'aide des neurostimulateurs implantables. Pour améliorer l'efficacité et la sécurité de ces neuroprothèses, il faut un capteur de la vessie capable de détecter l’urine stockée afin de mettre en place un système en boucle fermée qui applique la stimulation électrique uniquement lorsque nécessaire. Le capteur peut également servir à aviser les patients ayant des sensations affaiblies pour les aviser en temps opportun le moment où la vessie doit être vidée ou quand un volume résiduel postmictionnel anormalement élevé reste après une miction incomplète. Dans cette thèse, on présente de nouvelles méthodes de mesure, ainsi qu’un processeur de signal numérique dédié pour décoder en temps réel le volume de la vessie à partir des enregistrements neuronaux afférents provenant des récepteurs naturels présents dans la paroi de la vessie. Nos principales contributions sont rapportées dans trois articles de journaux avec comité de lecture. On présente d'abord une revue exhaustive de la littérature comprenant des articles de journaux, des brevets et les livres les plus réputés portant sur l'anatomie, la physiologie et la physiopathologie du tractus urinaire inférieur ainsi que sur la mesure du volume ou la pression de la vessie. Cette étude nous a permis d'identifier les besoins qu'un capteur de la vessie doit satisfaire pour être utilisé dans des applications chroniques telles que celles proposées dans cette thèse. On présente aussi le résultat d’une analyse exhaustive des caractéristiques anatomiques et physiologiques de la vessie que nous avons identifiées d’avoir exercé une influence, ou même d’avoir empêché, la réalisation d'un tel capteur dans des études faites au cours des dernières années. Sur la base de cette étude et de l'évaluation systématique des méthodes de mesure pour la vessie, on a conclu que le principe de mesure le mieux adapté pour la surveillance chronique du volume de la vessie était la détection, la discrimination et le décodage de l'activité neuronale afférente découlant des récepteurs spécialisés du volume (mécanorécepteurs), au sujet desquels certains auteurs ont émis l'hypothèse de leur existence dans la muqueuse interne de la vessie. Ensuite, on présente la méthode de mesure qui permet d'estimer en temps réel le volume de la vessie à partir de l'activité afférente des mécanorécepteurs. Notre méthode a été validée avec les----------ABSTRACT Failure of the storage and voiding functions of the urinary bladder due to spinal cord injury (SCI), neural diseases, health conditions, or aging, causes serious complications in a patient's health. Currently, it is possible to partially restore bladder functions in drug-refractory patients using implantable neurostimulators. Improving the efficacy and safety of these neuroprostheses used for bladder functions restoration requires a bladder sensor (BS) capable of detecting urine volume in real-time to implement a closed-loop system that applies electrical stimulation only when required. The BS can also trigger an early warning to advise patients with impaired sensations when the bladder should be voided or when an abnormally high post-voiding residual volume remains after an incomplete voiding. In this thesis, we present new measurement methods and a dedicated digital signal processor for real-time decoding of the bladder volume through afferent neural signals arising from natural receptors present in the bladder wall. The main contributions of this thesis have been reported in three peer-reviewed journal papers. We first present a comprehensive literature review, including papers, patents and mainstay books of bladder anatomy, physiology, and pathophysiology. This review allowed us to identify the requirements (user needs) that a BS must meet for chronic applications, such as those proposed in this thesis. An exhaustive analysis of the particular anatomical and physiological characteristics of the bladder, which we realized had influenced or prevented the achievement of a BS for monitoring the bladder volume or pressure in past studies, are also presented. Based on this study and on a systematic assessment of the measurement methods published in past years, we determined the best measurement principle for chronic bladder volume monitoring: the detection, discrimination and decoding of the afferent neural activity stemming from specialized volume receptors (mechanoreceptors), on which some authors had hypothesized about its existence in the bladder inner mucosa. Next, we present methods that allows for a real-time estimation of bladder volume through the afferent activity of the bladder mechanoreceptors. Our method was validated with data acquired from anesthetized rats in acute experiments. It was possible to qualitatively estimate three states of bladder fullness in 100% of trials when the recorded afferent activity exhibited a Spearman’s correlation coefficient of 0.6 or better. Furthermore, we could quantitatively estimate the bladder volume, and also its pressure, using time-windows of properly chosen duration. The mea

    Sacral root afferent nerve signals for a bladder neuroprosthesis:from animal model to human

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    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 359)

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    This bibliography lists 164 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during Jan. 1992. Subject coverage includes: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance

    Selected Papers from the 2018 IEEE International Workshop on Metrology for the Sea

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    This Special Issue is devoted to recent developments in instrumentation and measurement techniques applied to the marine field. ¶The sea is the medium that has allowed people to travel from one continent to another using vessels, even today despite the use of aircraft. It has also been acting as a great reservoir and source of food for all living beings. However, for many generations, it served as a landfill for depositing conventional and nuclear wastes, especially in its deep seabeds, and we are assisting in a race to exploit minerals and resources, different from foods, encompassed in it. Its health is a great challenge for the survival of all humanity since it is one of the most important environmental components targeted by global warming. ¶ As everyone may know, measuring is a step that generates substantial knowledge about a phenomenon or an asset, which is the basis for proposing correct solutions and making proper decisions. However, measurements in the sea environment pose unique difficulties and opportunities, which is made clear from the research results presented in this Special Issue

    Wearable and Implantable Wireless Sensor Network Solutions for Healthcare Monitoring

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    Wireless sensor network (WSN) technologies are considered one of the key research areas in computer science and the healthcare application industries for improving the quality of life. The purpose of this paper is to provide a snapshot of current developments and future direction of research on wearable and implantable body area network systems for continuous monitoring of patients. This paper explains the important role of body sensor networks in medicine to minimize the need for caregivers and help the chronically ill and elderly people live an independent life, besides providing people with quality care. The paper provides several examples of state of the art technology together with the design considerations like unobtrusiveness, scalability, energy efficiency, security and also provides a comprehensive analysis of the various benefits and drawbacks of these systems. Although offering significant benefits, the field of wearable and implantable body sensor networks still faces major challenges and open research problems which are investigated and covered, along with some proposed solutions, in this paper
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