The design, construction and performance of the MICE scintillating fibre trackers

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierCharged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented.This work was supported by the Science and Technology Facilities Council under grant numbers PP/E003214/1, PP/E000479/1, PP/E000509/1, PP/E000444/1, and through SLAs with STFC-supported laboratories. This work was also supportedby the Fermi National Accelerator Laboratory, which is operated by the Fermi Research Alliance, under contract No. DE-AC02-76CH03000 with the U.S. Department of Energy, and by the U.S. National Science Foundation under grants PHY-0301737,PHY-0521313, PHY-0758173 and PHY-0630052. The authors also acknowledge the support of the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan

Doctor of Philosophy

dissertationThe Utah Electrode Array (UEA) is a brain-implanted microelectrode recording device that has shown promise to assist patients with motor-control disabilities. Unfortunately, the UEA suffers from a foreign body response (FBR) that results in device movement away from implantation target, encapsulation of devices in meningeal origin tissue, loss of cortical tissue, and persistent neuroinflammation in the brain. These issues affect device functionality, and thus biocompatibility, and hinder widespread implementation of this technology. This dissertation examines whether device anchoring or extracellular matrix (ECM)-based device coating strategies can influence the biocompatibility of chronically implanted UEAs in the rat cortex. Results show that unanchored UEAs have a reduced FBR in comparison to those anchored to the skull, but also suffer from device movement as a result of cortical tissue remodeling, likely attributable to implantation-associated injury. To address implantation-associated injury, ECM was explored as a surface adsorbed device coating and was shown to be both hemostatic and immunomodulatory with in vitro assays. An apparatus was developed to coat Avitene™, an FDA-approved neurosurgical hemostatic ECM, onto the complex surface geometry of the UEA. Compared to uncoated control devices in a chronic rat model, Avitene™ coated devices experienced an enhanced FBR characterized by larger lesion cavities, enhanced meningeal encapsulation, and increased neuroinflammation, attributed to a higher degree of proinflammatory macrophages found surrounding the device coating. These result imply that future ECM-based coatings should include immunomodulatory components that address device-adherent macrophage activation state. Critical improvements in device anchoring and modulation of the FBR are still necessary to improve the biocompatibility of the UEA. Reducing the prevalence of FBR-related device failure is a necessary step that will require further attention before patients can benefit from this technology