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Objective: Brain-computer interfaces (BCIs) aim to provide a means for people with severe motor disabilities to control their environment directly with neural activity. In intracortical BCIs for people with tetraplegia, the decoder that maps neural activity to desired movements has typically been calibrated using 'open-loop' (OL) imagination of control while a cursor automatically moves to targets on a computer screen. However, because neural activity can vary across contexts, a decoder calibrated using OL data may not be optimal for 'closed-loop' (CL) neural control. Here, we tested whether CL calibration creates a better decoder than OL calibration even when all other factors that might influence performance are held constant, including the amount of data used for calibration and the amount of elapsed time between calibration and testing., Approach: Two people with tetraplegia enrolled in the BrainGate2 pilot clinical trial performed a center-out-back task using an intracortical BCI, switching between decoders that had been calibrated on OL versus CL data., Main Results: Even when all other variables were held constant, CL calibration improved neural control as well as the accuracy and strength of the tuning model. Updating the CL decoder using additional and more recent data resulted in further improvements., Significance: Differences in neural activity between OL and CL contexts contribute to the superiority of CL decoders, even prior to their additional 'adaptive' advantage. In the near future, CL decoder calibration may enable robust neural control without needing to pause ongoing, practical use of BCIs, an important step toward clinical utility.

Background: Previous studies showed a correlation between mean withdrawal times during screening colonoscopy and polyp/neoplasia detection rates., Objectives: To assess the effect of a monitoring and feedback program on withdrawal times, polyp/neoplasia detection rates, and patient satisfaction., Design: Comparison of retrospective and prospective data., Setting: Teaching hospital., Patients: Asymptomatic adults undergoing screening colonoscopy., Interventions: Monitoring and feedback program., Main Outcome Measurements: Withdrawal times, polyp and neoplasia detection rates, and patient satisfaction scores., Methods: We retrospectively reviewed 850 screening colonoscopies, recording withdrawal times, polyp findings, and patient satisfaction scores. All procedures were performed by 10 experienced gastroenterologists who were then informed that periodic confidential monitoring and feedback of withdrawal times, polyp detection rates, and satisfaction scores would be started. We then prospectively collected data on another 541 screening colonoscopies. We compared pre- and postmonitoring outcome measures., Results: Overall, after monitoring had begun, there was an increase in mean withdrawal times (from 6.57 to 8.07 minutes; P < .0001), and polyp detection rates (from 33.1% to 38.1%; P = .04, significance removed by Bonferroni correction). Nine of the 10 endoscopists increased their withdrawal times significantly. There was a small, nonsignificant increase in the neoplasia detection rate (from 19.6% to 22.7%; P = .17), but no significant change in mean satisfaction scores. Across endoscopists, there was a moderate correlation (r = 0.63; P = .04, significance removed by Bonferroni correction) between withdrawal times and polyp detection rates, but not between withdrawal times and satisfaction scores., Limitations: No randomization, possible response bias, confounding of intervention effects, and sample size limitations., Conclusions: Monitoring and feedback are associated with increases in mean withdrawal times and polyp detection rates, but not patient satisfaction scores. Neoplasia detection rates showed a statistically nonsignificant trend toward an increase., (Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

The design of a laparoscopic haptic device based on a 4-DOFs mechanism and Series Elastic Actuators (SEA) is described and the results of the theoretical and experimental examinations are presented. With a sufficient bandwidth and low impedance, the system provided a stable interaction with soft tissues, e.g., human liver, in virtual environments.

Although iron deficiency anemia is the most common nutritional deficiency worldwide and in the United States, the health effects of iron overload merit increased attention. In the United States, public health interventions such as fortification and enrichment of foods with iron were undertaken to reduce the prevalence of iron deficiency anemia and improve health. These measures, along with iron supplementation, remain controversial, because additional exposure to dietary iron places some segments of the population at increased risk of iron excess. The health consequences of unmistakable iron excess are exemplified by hemochromatosis, an iron storage disease associated with liver damage further exacerbated by alcohol consumption. Progressive liver damage associated with this condition is generally attributed to increased oxidative stress. In otherwise healthy individuals, more modest levels of iron storage may occur if iron is provided by supplements or otherwise added to the food supply. Increased iron intake and storage have been linked to a variety of chronic diseases. The associations are not firmly established but are of considerable public health importance.