Modeling and prediction of surgical procedure times

Accurate prediction of medical operation times is of crucial importance for cost efficient operation room planning in hospitals. This paper investigates the possible dependence of procedure times on surgeon factors like age, experience, gender, and team composition. The effect of these factors is estimated for over 30 different types of medical operations in two hospitals, by means of ANOVA models for logarithmic case durations. The estimation data set contains about 30,000 observations from 2005 till 2008. The relevance of surgeon factors depends on the type of operation. The factors found most often to be significant are team composition, experience, and daytime. Contrary to widespread opinions among surgeons, gender has nearly never a significant effect. By incorporating surgeon factors, the accuracy of out-of-sample prediction of case durations of about 1,250 surgical operations in 2009 is improved by up to more than 15 percent as compared to current planning procedures.planning;ANOVA model;European hospital;current procedure terminology (CPT);health care management;lognormal distribution;operation room;surgeon factors

Multiple Model Adaptive Control of the Vista F-16

Multiple model adaptive control (MMAC) is investigated using the high-fidelity, nonlinear, six-degree-of-freedom Simulation Rapid-Prototyping Facility VISTA F-16. Detection of single actuator and sensor failures is considered, with an MMAC algorithm initially pursued which allows a controller specifically designed for each particular failure condition to replace the standard F-16 Block 40 flight control system (FCS) once the failure is detected. The synthesis of certain discrete-time LQG/PI controllers (those using control variables linearly dependent on state derivatives) is shown to be unattainable due to numerical difficulties. A novel control technique, termed control redistribution, is introduced which redistributes control commands (that would normally be sent to failed actuators) to the non-failed actuators, accomplishing the same control action on the aircraft. Multiple model adaptive estimation-based control redistribution is demonstrated to detect single failures in less than one second and to provide a response nearly identical to that anticipated from a fully functional aircraft in the same environment. Moreover, this method directly employs the proven Block 40 FCS, and no other, thereby guaranteeing desirable closed loop performance. A description of modifications necessary for in-flight testing is also provided. This research represents the most realistic simulation of multiple model adaptive control for flight control to date

Medical Response, Search and Recovery during the Space Shuttle Columbia Accident Investigation

On February 1, 2003, the Space Shuttle Columbia broke apart during atmospheric re-entry on mission STS-107. After an event such as this, with high visibility and international interest, the operational challenge of recovering the crewmembers could not be underestimated. The Space Shuttle Program is organized to respond to a vehicle mishap using the resources of the Mishap Investigation Team (MIT). On the afternoon of Feb. 1, 2003, the MIT deployed to Barksdale Air Force Base (AFB), Louisiana. This location became the investigative center and interim storage location for crewmembers received from the Lufkin, Texas Disaster Field Office (DFO). The Lufkin DFO served as the primary area for all operations, including staging assets and deploying field teams for search, recovery and security of crewmember remains. More than 2,000 people from numerous organizations were involved with the recovery of the crew. All seven crewmembers of STS-107 were recovered and ceremonial last rights were administered. Astronaut and military personnel escorted the crew with honor to the MIT at Barksdale AFB, Louisiana. At Barksdale AFB a temporary morgue was established in an aircraft hangar and operated for approximately two weeks during which time coordination with the DFO field recovery teams, Armed Forces Institute of Pathology (AFIP) medical personnel, and the crew surgeons was on going. Families of crewmembers and NASA management were notified daily of the current findings. Working under the leadership of the MIT Lead, the medical team developed and executed a short-term plan to identify and relocate the crew with a military honor guard and protocol to the medical examiner at the Armed Forces Port Mortuary, Dover AFB, Delaware. After operations at Barksdale AFB were concluded the medical team transitioned back to Houston and a long-term plan was developed and implemented which involved the Air Force Mortuary Affairs at Randolph AFB, Texas. This plan was coordinated with search teams in the field, Barksdale AFB Mortuary Affairs, KSC security, AFIP, and the crew surgeons at JSC

John Glenn's Return to Flight - Flight Surgeons Perspective

No abstract availabl

Loss of Signal, Aeromedical Lessons Learned from the STS-107 Columbia Space Shuttle Mishap

Loss of Signal, a NASA publication to be available in May 2014 presents the aeromedical lessons learned from the Columbia accident that will enhance crew safety and survival on human space flight missions. These lessons were presented to limited audiences at three separate Aerospace Medical Association (AsMA) conferences: in 2004 in Anchorage, Alaska, on the causes of the accident; in 2005 in Kansas City, Missouri, on the response, recovery, and identification aspects of the investigation; and in 2011, again in Anchorage, Alaska, on future implications for human space flight. As we embark on the development of new spacefaring vehicles through both government and commercial efforts, the NASA Johnson Space Center Human Health and Performance Directorate is continuing to make this information available to a wider audience engaged in the design and development of future space vehicles. Loss of Signal summarizes and consolidates the aeromedical impacts of the Columbia mishap process-the response, recovery, identification, investigative studies, medical and legal forensic analysis, and future preparation that are needed to respond to spacecraft mishaps. The goal of this book is to provide an account of the aeromedical aspects of the Columbia accident and the investigation that followed, and to encourage aerospace medical specialists to continue to capture information, learn from it, and improve procedures and spacecraft designs for the safety of future crews. This poster presents an outline of Loss of Signal contents and highlights from each of five sections - the mission and mishap, the response, the investigation, the analysis and the future

Humans in Space: Summarizing the Medico-Biological Results of the Space Shuttle Program

As we celebrate the 50th anniversary of Gagarin's flight that opened the era of Humans in Space we also commemorate the 30th anniversary of the Space Shuttle Program (SSP) which was triumphantly completed by the flight of STS-135 on July 21, 2011. These were great milestones in the history of Human Space Exploration. Many important questions regarding the ability of humans to adapt and function in space were answered for the past 50 years and many lessons have been learned. Significant contribution to answering these questions was made by the SSP. To ensure the availability of the Shuttle Program experiences to the international space community NASA has made a decision to summarize the medico-biological results of the SSP in a fundamental edition that is scheduled to be completed by the end of 2011 beginning 2012. The goal of this edition is to define the normal responses of the major physiological systems to short-duration space flights and provide a comprehensive source of information for planning, ensuring successful operational activities and for management of potential medical problems that might arise during future long-term space missions. The book includes the following sections: 1. History of Shuttle Biomedical Research and Operations; 2. Medical Operations Overview Systems, Monitoring, and Care; 3. Biomedical Research Overview; 4. System-specific Adaptations/Responses, Issues, and Countermeasures; 5. Multisystem Issues and Countermeasures. In addition, selected operational documents will be presented in the appendices. The chapters are written by well-recognized experts in appropriate fields, peer reviewed, and edited by physicians and scientists with extensive expertise in space medical operations and space-related biomedical research. As Space Exploration continues the major question whether humans are capable of adapting to long term presence and adequate functioning in space habitats remains to be answered We expect that the comprehensive review of the medico-biological results of the SSP along with the data collected during the missions on the space stations (Mir and ISS) provides a good starting point in seeking the answer to this question

Leptonic decays of the eta meson with the WASA detector at CELSIUS

Decay channels of the eta meson with at least one lepton pair in the final state are discussed. Preliminary results on electron-positron pair production from the pd->He eta reaction from the WASA experiment at CELSIUS are presented.Comment: 8 pages, 7 figures, prepared for Symposium on Meson Physics at COSY-11 and WASA-at-COSY, Cracow, 17-22 June 200

Changes in Socioeconomic Status as Predictors of Cardiovascular Disease Incidence and Mortality: A 10-Year Follow-Up of a Polish-Population-Based HAPIEE Cohort

Although the inverse association between socioeconomic status (SES) and cardiovascular disease (CVD) is well established, research on the effect of changes in the SES throughout life on CVD risk in populations with different social backgrounds remains scarce. This study aimed to assess the relationship between childhood SES, adulthood SES, and changes in SES over time, and CVD incidence and mortality in a Polish urban population. In addition, the predictive performance of the SES index was compared with education alone. A cohort study with a 10-year follow-up was conducted, in which a random sample of 10,728 residents in Kraków aged 45–69 years were examined. The SES was assessed at baseline using data on education, parents’ education, housing standard at the age of 10 years, professional activity, household amenities, and difficulties in paying bills and buying food. SES categories (low, middle, and high) were extracted using cluster analyses. Information on new CVD cases was obtained from questionnaires in subsequent phases of the study and confirmed by reviewing clinical records. Data on deaths and causes were obtained from the residents’ registry, Central Statistical Office, and the participants’ families. The effect of the SES index on the risk of CVD was assessed using Cox proportional hazard models. In male and female participants, the CVD incidence and mortality were observed to be 27,703 and 32,956 person-years (384 and 175 new CVD cases) and 36,219 and 40,048 person-years (159 and 92 CVD deaths), respectively. Childhood SES was not associated with CVD incidence and mortality. A protective effect of high adulthood SES against CVD mortality was observed in men and women (HR = 0.59, 95% CI = 0.31–0.97; HR = 0.33, 95% CI = 0.14–0.75, respectively). In women, downward social mobility was related to 2.24 and 3.75 times higher CVD incidence and mortality, respectively. In men, a protective effect against mortality was observed in upward mobility (HR = 0.50, 95% CI = 0.29–0.84). Model discrimination was similar for the SES index and education alone for the association with CVD incidence. In women, the SES index was a slightly better predictor of CVD mortality than education alone (C-index = 0.759, SE = 0.0282 vs. C-index = 0.783, SE = 0.0272; p = 0.041). In conclusion, high adulthood SES, but not childhood SES, may be considered to be a protective factor against CVD in urban populations in high-CVD-risk regions. No effects of critical periods in early life were observed on CVD risk. In later life, social mobility was found to affect CVD mortality in both men and women. In men, a protective effect of upward mobility was confirmed, whereas in women, an increased CVD risk was related to downward mobility. It can be concluded that CVD prevention may be beneficial if socioeconomic potentials are strengthened in later life