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This qualitative study investigated factors that guide caregiver decision making and ethical trade-offs for advanced neurotechnologies used to treat children with drug-resistant epilepsy. Caregivers with affected children were recruited to semi-structured focus groups or interviews at one of 4 major epilepsy centers in Eastern and Western Canada and the USA (n = 22). Discussions were transcribed and qualitative analytic methods applied to examine values and priorities (eg, risks, benefits, adherence, invasiveness, reversibility) of caregivers pertaining to novel technologies to treat drug-resistant epilepsy. Discussions revealed 3 major thematic branches for decision making: (1) features of the intervention-risks and benefits, with an emphasis on an aversion to perceived invasiveness; (2) decision drivers-trust in the clinical team, treatment costs; and (3) quality of available information about neurotechnological options. Overall, caregivers' definition of treatment success is more expansive than seizure freedom. The full involvement of their values and priorities must be considered in the decision-making process.

This qualitative study investigated factors that guide physicians' choices for minimally invasive and neuromodulatory interventions as alternatives to conventional surgery or medical management for pediatric drug-resistant epilepsy. North American physicians were recruited to one of 4 focus groups at national conferences. Discussions were analyzed using qualitative content analysis. A pragmatic neuroethics framework was applied to interpret results. Discussions revealed 2 major thematic branches: (1) clinical decision making and (2) ethical considerations. Under clinical decision making, physicians emphasized scientific evidence and patient candidacy when assessing neurotechnologies for patients. Ongoing seizures without intervention was important for safety and neurodevelopment. Under ethical considerations, resource allocation, among other financial considerations for technology adoption, were considerable sources of pressure on decision making. Access to neurotechnology was a salient theme differentiating Canadian and American contexts. When assessing novel neurotechnological interventions for pediatric drug-resistant epilepsy, physicians balance clinical and ethical factors to guide decision making and best practice.

New methods, designed for the commercial-scale production of Frisch collar CdZnTe gamma ray spectrometers, are described in detail in the following work. Past methods required considerable skilled labor, were not readily automatable, and batch processing was only supported through a portion of the fabrication process. Advances in dielectric materials technology allow for new processes that readily apply the required dielectric film between the CdZnTe crystal and the conductive collar. The processes use spray or chemical vapor deposition methods to accurately achieve a specific thickness. Furthermore, application of the conductive collar was improved to facilitate commercial manufacturing. Comparisons in device performance are presented between the previous and new methods to illustrate the effectiveness and robustness of the new fabrication method. Parylene N performed well as the dielectric layer, while nickel-based paint, high-purity silver-based paint, and a silver-suspension Electrodag all performed well as the conductive layer, each maintaining spectral performance. Index Terms--CdZnTE, gamma-ray spectroscopy detectors.

Strengthening the crystal lattice of lanthanide halides, which are brittle, anisotropic, ionic crystals, may prove to increase the availability and ruggedness of these scintillators for room-temperature gamma-ray spectroscopy applications. Eight aliovalent dopants for Ce[Br.sub.3] were explored in an effort to find the optimal aliovalent strengthening agent. Eight dopants, Ca[Br.sub.2], Sr[Br.sub.2], Ba[Br.sub.2], Zr[Br.sub.4], Hf[Br.sub.4], Zn[Br.sub.2], Cd[Br.sub.2], and Pb[Br.sub.2], were explored at two levels of doping, 500 and 1000 ppm. From each ingot, samples were harvested for radioluminescence spectrum measurement and scintillation testing. Of the eight dopants explored, only Ba[Br.sub.2] and Pb[Br.sub.2] were found to clearly decrease total light yield. Zn[Br.sub.2] and Cd[Br.sub.2] dopants both affected the radioluminescence emission spectrum very little as compared to undoped Ce[Br.sub.3]. Hf[Br.sub.4] - and Zn[Br.sub.2]-doped Ce[Br.sub.3] exhibited the highest light yields. Index Terms--Aliovalent doping, crystal growth, scintillation detectors, solid solution hardening.

The spectral performance as a function of the dielectric layer thickness for several CdZnTe Frisch collar devices was investigated. Seven different planar bar shaped detectors were fabricated from Redlen Technologies CdZnTe, and many Frisch collar devices were prepared from each planar device. The optimum dielectric layer thickness was experimentally determined for each device. The result of the optimal thickness study was verified through three-dimensional geometry modeling of the potential and electric field. It is shown that there exists an optimal dielectric layer thickness for best performance for CdZnTe Frisch collar devices with aspect ratios (L/W) greater than 2.5. Index Terms--CdZnTe Frisch collar detector, dielectric thickness.

Frisch-ring CdZnTe detectors have demonstrated both good energy resolution, < 1% FWHM at 662 keV, and good efficiency in detecting gamma rays, highlighting the strong potential of CdZnTe materials for such applications. We are designing a hand-held gamma-ray spectrometer based on Frisch-ring detectors at Brookhaven National Laboratory. It employs an 8 x 8 CdZnTe detector array to achieve a high volume of 19.2 [cm.sup.3], so greatly improving detection efficiency. By using the front-end application-specific integrated circuits (ASICs) developed at BNL, this spectrometer has a small profile and high energy-resolution. It includes a signal processing circuit, digitization and storage circuits, a high-voltage module, and a universal serial bus (USB) interface. In this paper, we detail the system's structure and report the results of our tests with it. Index Terms--CdZnTe, CZT detector array, Frisch-ring detector, gamma-ray spectrometer.

Low dislocation density, high-purity, and low inclusion concentration [Cd.sub.0.9][Zn.sub.1]Te (CZT) and CdTe crystals were grown by a vertical Bridgman technique using in-house zone refined precursors. The grown crystals were sequentially processed using optimized chemo-mechanical processes to fabricate planar and Frisch collar detectors. Infrared transmission and scanning electron microscopy studies have shown that EIC grown CZT and CdTe crystals have significantly lower Te inclusions and defect densities than commercially available spectrometer grade crystals. The charge transport properties (electron and hole mobility-lifetime products, [micro][[tau].sub.e] & [micro][[tau.sub.h]) of various detectors have been evaluated by Hecht analysis. The detectors have been tested for spectral response using 59.5 and 662 keV [gamma]-ray sources. The CZT detectors with planar electrodes showed 2.6% FWHM at 662 keV. By adding a Frisch collar, the detectors' spectra improved significantly. The Frisch collar detectors proved to be very promising for assembling large-area arrays with excellent energy resolution at relatively low manufacturing cost. Index Terms--[Cd.sub.0.9][Zn.sub.0.1] Te, CdTe, Frisch-collar, low defect density, semiconductor detectors.

Abstract Background Utility scores are used to estimate Quality Adjusted Life Years (QALYs), applied in determining the cost-effectiveness of health care interventions. In studies where no preference based measures are collected, indirect methods have been developed to estimate utilities from clinical instruments. The aim of this study was to evaluate a published method of estimating the EuroQol-5D (EQ-5D) and Short Form-6D (SF-6D) (preference based) utility scores from the Health Assessment Questionnaire (HAQ) in patients with inflammatory arthritis. Methods Data were used from 3 cohorts of patients with: early inflammatory arthritis (5 years duration) stable rheumatoid arthritis (RA); and RA being treated with anti-TNF therapy. Patients completed the EQ-5D, SF-6D and HAQ at baseline and a follow-up assessment. EQ-5D and SF-6D scores were predicted from the HAQ using a published method. Differences between predicted and observed EQ-5D and SF-6D scores were assessed using the paired t-test and linear regression. Results Predicted utility scores were generally higher than observed scores (range of differences: EQ-5D 0.01 - 0.06; SF-6D 0.05 - 0.10). Change between predicted values of the EQ-5D and SF-6D corresponded well with observed change in patients with established RA. Change in predicted SF-6D scores was, however, less than half of that in observed values (p < 0.001) in patients with more active disease. Predicted EQ-5D scores underestimated change in cohorts of patients with more active disease. Conclusion Predicted utility scores overestimated baseline values but underestimated change. Predicting utility values from the HAQ will therefore likely underestimate the QALYs of interventions, particularly for patients with active disease. We recommend the inclusion of at least one preference based measure in future clinical studies.