Extracting clinically-actionable information from wearable physiological monitors

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 161-167).In this thesis I examine several ways of extracting information from wearable monitors so as to help make clinical decisions. Wearable physiological sensors are developing rapidly, and pose a possible part of the solution to the demands of an aging population and rising health care costs. It is important that the data produced by such sensors be processed into information that is clinically relevant and will have an impact on the practice of medicine. I collected data in an ambulatory setting from several wearable physiological sensors, including electrocardiogram, arterial blood pressure, pulse plethysmograph, respiration and acceleration. Using this data set, I demonstrated a few approaches - including signal processing, and algorithms based on the application of physiological models - to extract clinically relevant information. These approaches are potentially of interest to both device makers interested in developing wearable monitors, and to clinicians who will be using such monitors in the future.by Bryan Haslam.S.M

Are Supershells Powered by Multiple Supernovae? Modeling the Radio Pulsar Population Produced by OB Associations

Traditional searches for radio pulsars have targeted individual small regions such as supernova remnants or globular clusters, or have covered large contiguous regions of the sky. None of these searches has been specifically directed towards giant supershells, some of which are likely to have been produced by multiple supernova (SN) explosions from an OB association. Here we perform a Montecarlo simulation of the pulsar population associated with supershells powered by multiple SNe. We predict that several tens of radio pulsars could be detected with current instruments associated with the largest Galactic supershells (with kinetic energies >~ 10^{53} ergs), and a few pulsars with the smaller ones. We test these predictions for some of the supershells which lie in regions covered by past pulsar surveys. For the smaller supershells, our results are consistent with the few detected pulsars per bubble. For the giant supershell GSH 242-03+37, we find the multiple SN hypothesis inconsistent with current data at the 95% level. We stress the importance of undertaking deep pulsar surveys in correlation with supershells. Failure to detect any pulsar enhancement in the largest of them would put serious constraints on the multiple SN origin for them. Conversely, the discovery of the pulsar population associated with a supershell would allow a different/independent approach to the study of pulsar properties.Comment: accepted to ApJ; 17 pages, 2 figures, 1 tabl

The Timing of Nine Globular Cluster Pulsars

We have used the Robert C. Byrd Green Bank Telescope to time nine previously known pulsars without published timing solutions in the globular clusters M62, NGC 6544, and NGC 6624. We have full timing solutions that measure the spin, astrometric, and (where applicable) binary parameters for six of these pulsars. The remaining three pulsars (reported here for the first time) were not detected enough to establish solutions. We also report our timing solutions for five pulsars with previously published solutions, and find good agreement with past authors, except for PSR J1701-3006B in M62. Gas in this system is probably responsible for the discrepancy in orbital parameters, and we have been able to measure a change in the orbital period over the course of our observations. Among the pulsars with new solutions we find several binary pulsars with very low mass companions (members of the so-called "black widow" class) and we are able to place constraints on the mass-to-light ratio in two clusters. We confirm that one of the pulsars in NGC 6624 is indeed a member of the rare class of non-recycled pulsars found in globular clusters. We also have measured the orbital precession and Shapiro delay for a relativistic binary in NGC 6544. If we assume that the orbital precession can be described entirely by general relativity, which is likely, we are able to measure the total system mass (2.57190(73) M_sun) and companion mass (1.2064(20) M_sun), from which we derive the orbital inclination [sin(i) = 0.9956(14)] and the pulsar mass (1.3655(21) M_sun), the most precise such measurement ever obtained for a millisecond pulsar. The companion is the most massive known around a fully recycled pulsar.Comment: Published in ApJ; 33 pages, 5 figures, 7 table

Foreground simulations for the LOFAR - Epoch of Reionization Experiment

Future high redshift 21-cm experiments will suffer from a high degree of contamination, due both to astrophysical foregrounds and to non-astrophysical and instrumental effects. In order to reliably extract the cosmological signal from the observed data, it is essential to understand very well all data components and their influence on the extracted signal. Here we present simulated astrophysical foregrounds datacubes and discuss their possible statistical effects on the data. The foreground maps are produced assuming 5 deg x 5 deg windows that match those expected to be observed by the LOFAR Epoch-of-Reionization (EoR) key science project. We show that with the expected LOFAR-EoR sky and receiver noise levels, which amount to ~52 mK at 150 MHz after 300 hours of total observing time, a simple polynomial fit allows a statistical reconstruction of the signal. We also show that the polynomial fitting will work for maps with realistic yet idealised instrument response, i.e., a response that includes only a uniform uv coverage as a function of frequency and ignores many other uncertainties. Polarized galactic synchrotron maps that include internal polarization and a number of Faraday screens along the line of sight are also simulated. The importance of these stems from the fact that the LOFAR instrument, in common with all current interferometric EoR experiments has an instrumentally polarized response.Comment: 18 figures, 3 tables, accepted to be published in MNRA

Complementarity of Galactic radio and collider data in constraining WIMP dark matter models

In this work we confront dark matter models to constraints that may be derived from radio synchrotron radiation from the Galaxy, taking into account the astrophysical uncertainties and we compare these to bounds set by accelerator and complementary indirect dark matter searches. Specifically we apply our analysis to three popular particle physics models. First, a generic effective operator approach, in which case we set bounds on the corresponding mass scale, and then, two specific UV completions, the Z' and Higgs portals. We show that for many candidates, the radio synchrotron limits are competitive with the other searches, and could even give the strongest constraints (as of today) with some reasonable assumptions regarding the astrophysical uncertainties.Comment: 22 pages, 12 figure

The role of cranial CT in the investigation of meningitis

More patients with meningitis are undergoing CT and the number of inappropriate requests are increasing. There are few abnormal CT scans presenting a contraindication for lumbar puncture and the majority of these patients usually have clinical signs to suggest raised intracranial pressure

Personal agency in women's recovery from depression: The impact of antidepressants and women's personal efforts

Background Women are twice as likely to experience depression and use antidepressants as men. Personal agency protects against depression; however, social factors contribute to lower levels of agency in women. Aims This study examines women's experiences of using antidepressant treatment along with the other activities and practices they engage in to support their recovery from depression. It aims to understand how these experiences promote or diminish women's sense of agency in regard to their recovery. Method Fifty women took part in telephone interviews focusing on experiences of antidepressants as well as personal efforts to recover. A thematic analysis examined the agency-promoting and agency-diminishing experiences of using antidepressant treatment and engaging in other activities. Results Antidepressants promoted agency when they gave women relief from depressive symptoms, allowing women to become more proactive in recovery. Women engaged in a range of activities they believed assisted recovery and hence enhanced agency. These included exercise, gaining social support, and engaging in therapy. Some, however, had shifted to long-term antidepressant use. Failed attempts to discontinue due to severe withdrawal symptoms, fear of a relapse, and the biochemical model of depression created a sense of dependence on antidepressants and thereby diminished personal agency in relation to recovery. Conclusions Antidepressants can support women to become agential in their recovery. However, long-term use signifies greater dependency on antidepressants, and personal agency is seen as insufficient. The fear of withdrawal symptoms and the biochemical model undermine women's sense of personal agency in relation to recovery

Hormone-sensing cells require Wip1 for paracrine stimulation in normal and premalignant mammary epithelium

10.1186/bcr3381Breast Cancer Research15

Comparison Of iNfliximab and ciclosporin in STeroid Resistant Ulcerative Colitis: pragmatic randomised Trial and economic evaluation (CONSTRUCT)

Background: The efficacy of infliximab and ciclosporin in treating severe ulcerative colitis (UC) is proven, but there has been no comparative evaluation of effectiveness. Objective: To compare the clinical effectiveness and cost-effectiveness of infliximab and ciclosporin in treating steroid-resistant acute severe UC. Method: Between May 2010 and February 2013 we recruited 270 participants from 52 hospitals in England, Scotland and Wales to an open-label parallel-group, pragmatic randomised trial. Consented patients admitted with severe colitis completed baseline quality-of-life questionnaires before receiving intravenous hydrocortisone. If they failed to respond within about 5 days, and met other inclusion criteria, we invited them to participate and used a web-based adaptive randomisation algorithm to allocate them in equal proportions between 5 mg/kg of intravenous infliximab at 0, 2 and 6 weeks or 2 mg/kg/day of intravenous ciclosporin for 7 days followed by 5.5 mg/kg/day of oral ciclosporin until 12 weeks from randomisation. Further treatment was at the discretion of physicians responsible for clinical management. The primary outcome was quality-adjusted survival (QAS): the area under the curve (AUC) of scores derived from Crohn’s and Ulcerative Colitis Questionnaires completed by participants at 3 and 6 months, and then 6-monthly over 1–3 years, more frequently after surgery. Secondary outcomes collected simultaneously included European Quality of Life-5 Dimensions (EQ-5D) scores and NHS resource use to estimate cost-effectiveness. Blinding was possible only for data analysts. We interviewed 20 trial participants and 23 participating professionals. Funded data collection finished in March 2014. Most participants consented to complete annual questionnaires and for us to analyse their routinely collected health data over 10 years. Results: The 135 participants in each group were well matched at baseline. In 121 participants analysed in each group, we found no significant difference between infliximab and ciclosporin in QAS [mean difference in AUC/day 0.0297 favouring ciclosporin, 95% confidence interval (CI) –0.0088 to 0.0682; p = 0.129]; EQ-5D scores (quality-adjusted life-year mean difference 0.021 favouring ciclosporin, 95% CI –0.032 to 0.096; p = 0.350); Short Form questionnaire-6 Dimensions scores (mean difference 0.0051 favouring ciclosporin, 95% CI –0.0250 to 0.0353; p = 0.737). There was no statistically significant difference in colectomy rates [odds ratio (OR) 1.350 favouring infliximab, 95% CI 0.832 to 2.188; p = 0.223]; numbers of serious adverse reactions (event ratio = 0.938 favouring ciclosporin, 95% CI 0.590 to 1.493; p = 0.788); participants with serious adverse reactions (OR 0.660 favouring ciclosporin, 95% CI 0.282 to 1.546; p = 0.338); numbers of serious adverse events (event ratio 1.075 favouring infliximab, 95% CI 0.603 to 1.917; p = 0.807); participants with serious adverse events (OR 0.999 favouring infliximab, 95% CI 0.473 to 2.114; p = 0.998); deaths (all three who died received infliximab; p = 0.247) or concomitant use of immunosuppressants. The lower cost of ciclosporin led to lower total NHS costs (mean difference –£5632, 95% CI –£8305 to –£2773; p < 0.001). Interviews highlighted the debilitating effect of UC; participants were more positive about infliximab than ciclosporin. Professionals reported advantages and disadvantages with both drugs, but nurses disliked the intravenous ciclosporin. Conclusions: Total cost to the NHS was considerably higher for infliximab than ciclosporin. Nevertheless, there was no significant difference between the two drugs in clinical effectiveness, colectomy rates, incidence of SAEs or reactions, or mortality, when measured 1–3 years post treatment. To assess long-term outcome participants will be followed up for 10 years post randomisation, using questionnaires and routinely collected data. Further studies will be needed to evaluate the efficacy and effectiveness of new anti-tumour necrosis factor drugs and formulations of ciclosporin.322 page(s