HabEx polarization ray trace and aberration analysis

The flux difference between a terrestrial exoplanet and a much brighter nearby star creates an enormous optical design challenge for space-based imaging systems. Coronagraphs are designed to block the star’s flux and obtain a high-dynamic-range image of the exoplanet. The contrast of an optical system is calculated using the point spread function (PSF). Contrast quantifies starlight suppression of an imaging system at a given separation of the two objects. Contrast requirements can be as small as 10^(−10) for earth-like planets. This work reports an analysis of the September 2017 Habitable Exoplanet Imaging Mission (HabEx) end-to-end optical system prescription for geometric and polarization aberrations across the 450 to 550 nm channel. The Lyot coronagraph was modeled with a vector vortex charge 6 mask but without adaptive optics (AO) to correct the phase of the Jones pupil. The detector plane irradiance was calculated for three states of the telescope/coronagraph system: (1) free of geometric and polarization aberrations; (2) isotropic mirror coatings throughout the end-toend system; and (3) isotropic mirrors with form birefringence on the primary mirror. For each of these three states the system response both with and without a coronagraph mask was calculated. Two merit functions were defined to quantify the system’s ability to attenuate starlight: (1) normalized polychromatic irradiance (NPI), and (2) starlight suppression factor (SSF). Both of these are dimensionless and their values are functions of position across the focal plane. The NPI is defined as the irradiance point-by-point across the detector plane with a coronagraph mask divided by the value of the on-axis irradiance without a coronagraph mask. The SSF is the irradiance point-by-point across the detector plane with a coronagraph mask divided by the pointby-point value of the irradiance across the detector plane without a coronagraph mask. Both the NPI and the SSF provide insights into coronagraph performance. Deviations from the aberration-free case are calculated and summarized in table 2. The conclusions are: (1) the HabEx optical system is well-balanced for both geometric and polarization aberrations; (2) the spatially dependent polarization reflectivity for the HabEx primary mirror should be specified to ensure the coating is isotropic; (3) AO to correct the two orthogonal polarization-dependent wavefront errors is essential

The Maine Obstetric Medical Simulation (MOMSim) Program Identifies and Categorizes Latent Safety Threats Across Rural Hospitals

Objective: Combine in-situ simulation with an HFMEA framework to identify and categorize common system wide LST and opportunities to improve patient safetyhttps://knowledgeconnection.mainehealth.org/lambrew-retreat-2023/1003/thumbnail.jp

Patient Transport in the Time of COVID-19: Using Health Care Failure Mode and Effect Analysis with Simulation to Test and Modify a Protocol

Introduction: In March 2020, in response to the COVID-19 pandemic, an interprofessional, interdisciplinary team at Maine Medical Center used Healthcare Failure Mode and Effect Analysis (HFMEA) and in situ simulation to rapidly identify and mitigate latent safety threats (LST) in patient transport protocols. Methods: Following HFMEA steps, stakeholders representing a variety of disciplines assembled to address transport of patients with COVID-19. A process map was created to describe the process. With hazard analysis using table-top simulation followed by in situ simulation, we identified, categorized, and scored LSTs. Mitigation strategies were identified during structured debriefing. Results: Fourteen LSTs were identified in the categories of infection prevention (4), care coordination (2), equipment (2), facilities (2), teams (2), clinical skills (1), and diagnosis and treatment (1). Of these, 10 had “critical” hazard scores. Mitigation solutions were tested with in situ simulation. Results were shared with leadership and led to changes in hospital-wide protocols. Discussion: The COVID-19 pandemic presented an urgent need to create or adapt protocols to keep patients and staff safe. Our team combined simulation with HFMEA methodology to improve the safety of protocols for transporting patients with COVID-19. Simulation enabled recreation of real-world experience that exposed LSTs more thoroughly than mental walkthroughs alone. Use of HFMEA methodology supported quantifying identified LSTs and proposing mitigation strategies, while in situ simulation facilitated testing many proposed strategies. Conclusions: HFMEA used with in situ simulation provides an effective method to efficiently and thoroughly probe a process for failure modes, providing practical mitigation strategies

HabEx polarization ray trace and aberration analysis

The flux difference between a terrestrial exoplanet and a much brighter nearby star creates an enormous optical design challenge for space-based imaging systems. Coronagraphs are designed to block the star’s flux and obtain a high-dynamic-range image of the exoplanet. The contrast of an optical system is calculated using the point spread function (PSF). Contrast quantifies starlight suppression of an imaging system at a given separation of the two objects. Contrast requirements can be as small as 10^(−10) for earth-like planets. This work reports an analysis of the September 2017 Habitable Exoplanet Imaging Mission (HabEx) end-to-end optical system prescription for geometric and polarization aberrations across the 450 to 550 nm channel. The Lyot coronagraph was modeled with a vector vortex charge 6 mask but without adaptive optics (AO) to correct the phase of the Jones pupil. The detector plane irradiance was calculated for three states of the telescope/coronagraph system: (1) free of geometric and polarization aberrations; (2) isotropic mirror coatings throughout the end-toend system; and (3) isotropic mirrors with form birefringence on the primary mirror. For each of these three states the system response both with and without a coronagraph mask was calculated. Two merit functions were defined to quantify the system’s ability to attenuate starlight: (1) normalized polychromatic irradiance (NPI), and (2) starlight suppression factor (SSF). Both of these are dimensionless and their values are functions of position across the focal plane. The NPI is defined as the irradiance point-by-point across the detector plane with a coronagraph mask divided by the value of the on-axis irradiance without a coronagraph mask. The SSF is the irradiance point-by-point across the detector plane with a coronagraph mask divided by the pointby-point value of the irradiance across the detector plane without a coronagraph mask. Both the NPI and the SSF provide insights into coronagraph performance. Deviations from the aberration-free case are calculated and summarized in table 2. The conclusions are: (1) the HabEx optical system is well-balanced for both geometric and polarization aberrations; (2) the spatially dependent polarization reflectivity for the HabEx primary mirror should be specified to ensure the coating is isotropic; (3) AO to correct the two orthogonal polarization-dependent wavefront errors is essential

Development of Maine Ongoing Outreach Simulation Education (MOOSE), a Novel Telesimulation Program, to Improve Neonatal Resuscitation in a Rural Community Hospital

Objective- To implement monthly neonatal resuscitation telesimulation team training sessions in a rural community hospital delivery room that is feasible, sustainable, and replicable at other sites.https://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1010/thumbnail.jp

A Simulation-Based Outreach Program Improves Delivery Room Team Confidence in Neonatal Resuscitation at Rural Community Hospitals

Objective- Our goal is to pilot the use of an onsite Neonatal Community Outreach Education Program to improve provider confidence with procedural skills and neonatal resuscitation in the delivery room.https://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1008/thumbnail.jp

Does Team Leader Gender Matter? A Bayesian Reconciliation of Leadership and Patient Care During Trauma Resuscitations

OBJECTIVE: Team leadership facilitates teamwork and is important to patient care. It is unknown whether physician gender-based differences in team leadership exist. The objective of this study was to assess and compare team leadership and patient care in trauma resuscitations led by male and female physicians. METHODS: We performed a secondary analysis of data from a larger randomized controlled trial using video recordings of emergency department trauma resuscitations at a Level 1 trauma center from April 2016 to December 2017. Subjects included emergency medicine and surgery residents functioning as trauma team leaders. Eligible resuscitations included adult patients meeting institutional trauma activation criteria. Two video-recorded observations for each participant were coded for team leadership quality and patient care by 2 sets of raters. Raters were balanced with regard to gender and were blinded to study hypotheses. We used Bayesian regression to determine whether our data supported gender-based advantages in team leadership. RESULTS: A total of 60 participants and 120 video recorded observations were included. The modal relationship between gender and team leadership (β = 0.94, 95% highest density interval [HDI], -.68 to 2.52) and gender and patient care (β = 2.42, 95% HDI, -2.03 to 6.78) revealed a weak positive effect for female leaders on both outcomes. Gender-based advantages to team leadership and clinical care were not conclusively supported or refuted, with the exception of rejecting a strong male advantage to team leadership. CONCLUSIONS: We prospectively measured team leadership and clinical care during patient care. Our findings do not support differences in trauma resuscitation team leadership or clinical care based on the gender of the team leader

Surgical need among the ageing population of Uganda

Background: Uganda’s ageing population (age 50 years and older) will nearly double from 2015 to 2050. HIV/AIDS, diabetes, stroke among other disease processes have been studied in the elderly population. However, the burden of disease from surgi- cally-treatable conditions is unknown. Objectives: To determine the proportion of adults above 50 years with unmet surgical need and deaths attributable to probable surgically-treatable conditions. Methods: A cluster randomized sample representing the national population of Uganda was enumerated. The previously vali- dated Surgeons Overseas assessment of surgical need instrument, a head-to-toe verbal interview, was used to determine any sur- gically-treatable conditions in two randomly-selected living household members. Deaths were detailed by heads of households. Weighted metrics are calculated taking sampling design into consideration and Taylor series linearization was used for sampling error estimation.   Results: The study enumerated 425 individuals above age 50 years. The prevalence proportion of unmet surgical need was 27.8% (95%CI, 22.1-34.3). This extrapolates to 694,722 (95%CI, 552,279-857,157) individuals living with one or more surgically treatable conditions. The North sub-region was observed to have the highest prevalence proportion. Nearly two out of five household deaths (37.9%) were attributed to probable surgically treatable causes.Conclusion: There is disproportionately high need for surgical care among the ageing population of Uganda with approximate- ly 700,000 consultations needed.Keywords: Surgical need, ageing population, Uganda

Optimizing Care for Ugandans with Untreated Abdominal Surgical Conditions

Background: Abdominal operations account for a majority of surgical volume in low-income countries, yet population-level prevalence data on surgically treatable abdominal conditions are scarce. Objective: In this study, our objective was to quantify the burden of surgically treatable abdominal conditions in Uganda. Methods: In 2014, we administered a two-stage cluster-randomized Surgeons OverSeas Assessment of Surgical Need survey to 4,248 individuals in 105 randomly selected clusters (representing the national population of Uganda). Findings: Of the 4,248 respondents, 185 reported at least one surgically treatable abdominal condition in their lifetime, giving an estimated lifetime prevalence of 3.7% (95% CI: 3.0 to 4.6%). Of those 185 respondents, 76 reported an untreated condition, giving an untreated prevalence of 1.7% (95% CI: 1.3 to 2.3%). Obstructed labor (52.9%) accounted for most of the 238 abdominal conditions reported and was untreated in only 5.6% of reported conditions. In contrast, 73.3% of reported abdominal masses were untreated. Conclusions: Individuals in Uganda with nonobstetric abdominal surgical conditions are disproportionately undertreated. Major health system investments in obstetric surgical capacity have been beneficial, but our data suggest that further investments should aim at matching overall surgical care capacity with surgical need, rather than focusing on a single operation for obstructed labor

Surgical need among the ageing population of Uganda

Background: Uganda\u2019s ageing population (age 50 years and older) will nearly double from 2015 to 2050. HIV/AIDS, diabetes, stroke among other disease processes have been studied in the elderly population. However, the burden of disease from surgically-treatable conditions is unknown. Objectives: To determine the proportion of adults above 50 years with unmet surgical need and deaths attributable to probable surgically-treatable conditions. Methods: A cluster randomized sample representing the national population of Uganda was enumerated. The previously validated Surgeons Overseas assessment of surgical need instrument, a head-to-toe verbal interview, was used to determine any surgically-treatable conditions in two randomly-selected living household members. Deaths were detailed by heads of households. Weighted metrics are calculated taking sampling design into consideration and Taylor series linearization was used for sampling error estimation. Results: The study enumerated 425 individuals above age 50 years. The prevalence proportion of unmet surgical need was 27.8% (95%CI, 22.1-34.3). This extrapolates to 694,722 (95%CI, 552,279-857,157) individuals living with one or more surgically treatable conditions. The North sub-region was observed to have the highest prevalence proportion. Nearly two out of five household deaths (37.9%) were attributed to probable surgically treatable causes. Conclusion: There is disproportionately high need for surgical care among the ageing population of Uganda with approximately 700,000 consultations needed. DOI: https://dx.doi.org/10.4314/ahs.v19i1.54 Cite as: Tran TM, Fuller AT, Butler EK, Muhumuza C, Ssennono VF, Vissoci JR, et al. Surgical need among the ageing population of Uganda. Afri Health Sci. 2019;19(1). 1778-1788. https:// dx.doi. org/10.4314/ ahs. v19i1.5