Global ETD Search

81	A Comparative Analysis of Local and Global Peripheral Nerve Mechanical Properties During Cyclical Tensile Testing Doering, Onna Marie 05 1900 (has links) Indiana University-Purdue University Indianapolis (IUPUI) / Understanding the mechanical properties of peripheral nerves is essential for chronically implanted device design. The work in this thesis aimed to understand the relationship between local deformation responses to global strain changes in peripheral nerves. A custom-built mechanical testing rig and sample holder enabled an improved cyclical uniaxial tensile testing environment on rabbit sciatic nerves (N=5). A speckle was placed on the surface of the nerve and recorded with a microscope camera to track local deformations. The development of a semi-automated digital image processing algorithm systematically measured local speckle dimension and nerve diameter changes. Combined with the measured force response, local and global strain values constructed a stress-strain relationship and corresponding elastic modulus. Preliminary exploration of models such as Fung and 2-Term Mooney-Rivlin confirmed the hyperelastic nature of the nerve. The results of strain analysis show that, on average, local strain levels were approximately five times smaller than globally measured strains; however, the relationship was dependent on global strain magnitude. Elastic modulus values corresponding to ~9% global strains were 2.070 ± 1.020 MPa globally and 10.15 ± 4 MPa locally. Elastic modulus values corresponding to ~6% global strains were 0.173 ± 0.091 MPa globally and 1.030 ± 0.532 MPa locally. mechanical testing peripheral nervous system tensile testing images processing digital image analysis digital image correlation sciatic nerve mechanical analysis mechanical properties sciatic nerve rabbit image processing techniques neuroengineering applications medical devices strain analysis strain analysis techniques
82	Novel Carbon-Nanotube Based Neural Interface for Chronic Recording of Glossopharyngeal Nerve Activity Kostick, Nathan H. 01 June 2018 (has links) No description available. Biomedical Engineering
83	La formation de synapses par les neurones périphériques sur des surfaces synthétiques Ma, Xiya 08 1900 (has links) No description available. synaptogenèse microsphère poly-D-lysine polyglycérol hyperbranché synaptophysine VAchT cellules souches pluripotentes neurones moteurs nerf sciatique système nerveux périphérique synaptogenesis microsphere hyperbranched polyglycerol synaptophysin iPSC motor neurons sciatic nerve peripheral nervous system
84	On the Role of, and Intervention in, Oxygen-Conserving Reflexes in Sudden Unexpected Death in Epilepsy Ethan N Biggs (13199502) 04 August 2022 (has links) <p>Sudden unexpected death in epilepsy (SUDEP) is a fatal complication of epilepsy that kills 1̃2 of every 10,000 epileptic patients every year. SUDEP has proven difficult to study because it frequently occurs unobserved and cannot be predicted. What limited clinical data exists suggests that SUDEP occurs as a cardiorespiratory collapse immediately following a seizure. In this work, I explore how a group of autonomic reflexes termed collectively as “oxygen‐conserving reflexes (OCRs)” lead to sudden death when activated during seizures. I also demonstrate multiple physiological parallels between the OCR‐mediated deaths that I report and the clinical data on cases of human SUDEP. Additionally, I explore the neural pathway underlying OCRs, identify the carotid body as a potential target for intervention, and demonstrate the efficacy of electroceutical intervention in reducing the mortality risk of OCR activation during seizures. This work seeks to both offer a neural explanation for SUDEP as well as present a promising target and means for potential intervention.</p> Systems physiology Autonomic nervous system Central nervous system Peripheral nervous system Sensory systems Neurosciences not elsewhere classified Biomedical instrumentation Medical devices Neural engineering Analog electronics and interfaces Electronic instrumentation oxygen-conserving reflexes diving reflex mammalian diving reflex chemoreflex laryngeal chemoreflex epilepsy SUDEP sudden death SIDS carotid body carotid sinus carotid sinus nerve nerve stimulation peripheral nerve stimulation electrical nerve stimulation Autonomic nervous system (ANS) autonomic reflexes pathophysiology apnea seizure

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