Accurate Automation (United States)

International audience

A 70-year-old man was scheduled for open reduction and internal fixation of his right knee fracture. When the tourniquet was deflated after 150 minutes, his arterial blood pressure and heart rate decreased precipitously. The patient was deemed to exhibit pulseless electrical activity. Cardiopulmonary resuscitation was initiated. The bispectral index reading improved to 25 to 30, but his end-tidal carbon dioxide was still very low (5 mm Hg). Transesophageal echocardiography showed a pulmonary embolism. Feedback from echo imaging improved the quality of chest compressions and motivated the resuscitation team to maintain the diastolic blood pressure>25 mm Hg. Although capnographic guidance was ineffective by itself, echocardiography monitoring was very helpful for showing the intracardiac events.

Acute respiratory distress syndrome (ARDS) carries significant morbidity and mortality. No previous studies have investigated the long-term outcomes of ARDS patients in Taiwan. This study aimed to investigate the survival of ARDS patients after discharge from the hospital in Taiwan. Medical records from 150 ARDS patients discharged alive from the intensive care unit from January 2004 to June 2009 were reviewed. Survival of these patients was followed for 5 years, and prognostic factors were identified. Cumulative survival rates were 81.4% at 6 months, 79.0% at 1 year, 67.2% at 2 years, and 45.7% at 5 years. Independent prognostic factors influencing both 1- and 5-year survival rates were age, previous lung disease, and disposition after discharge. For 5-year survival, renal disease was also an independent risk factor. The mortality rate of ARDS survivors after intensive care unit discharge is still high in Taiwan. Three independent risk factors were found to affect the overall survival of these patients.

Despite limited prospective data, it is commonly believed that human immunodeficiency virus (HIV) and hepatitis infections are widespread in the penetrating trauma population, placing healthcare workers at risk for occupational exposure. Our primary study objective was to measure the prevalence of HIV (anti-HIV), hepatitis B (HB surface antigen [HBsAg]), and hepatitis C virus (anti-HCV) in our penetrating trauma population. We prospectively analyzed penetrating trauma patients admitted to Temple University Hospital between August 2008 and February 2010. Patients (n = 341) were tested with an oral swab for anti-HIV and serum evaluated for HBsAg and anti-HCV. Positives were confirmed with western blot, neutralization immunoassay, and reverse transcription polymerase chain reaction, respectively. Demographics, risk factors, and clinical characteristics were analyzed. Of 341 patients, 4 patients (1.2%) tested positive for anti-HIV and 2 had a positive HBsAg (0.6%). Hepatitis C was the most prevalent measured infection as anti-HCV was detected in 26 (7.6%) patients. Overall, 32 (9.4%) patients were tested positive for anti-HIV, HBsAg, or anti-HCV. Twenty-eight (75%) of these patients who tested positive were undiagnosed before study enrollment. When potential risk factors were analyzed, age (odds ratio, 1.07, p = 0.031) and intravenous drug use (odds ratio 14.4, p < 0.001) independently increased the likelihood of anti-HIV, HBsAg, or anti-HCV-positive markers. Greater than 9% of our penetrating trauma study population tested positive for anti-HIV, HBsAg, or anti-HCV although patients were infrequently aware of their seropositive status. As penetrating trauma victims frequently require expedient, invasive procedures, universal precautions are essential. The prevalence of undiagnosed HIV and hepatitis in penetrating trauma victims provides an important opportunity for education, screening, and earlier treatment of this high-risk population.

This chapter, along with Chapter 3, provides an overview of several ADP design techniques. While Chapter 3 deals more with the theoretical foundations, Chapter 4 is more devoted to practical issues such as problem formulation and utility functions. The authors discuss issues associated with designing and training adaptive critics using the design techniques introduced in Chapter 3.

The focus of this paper is to describe a neural adaptive control (NAC) technology derived using a Lyapunov synthesis technique. The NAC is a nonlinear adaptive controller which requires minimal plant information. It adapts its gains in real time to maintain the desired performance and to automatically compensate for changes in plant dynamics caused by system failures, environmental changes, or component damage. As such, the NAC control technology has the potential to enhance system performance by automatically optimizing its control laws for each operating regime. It can also increase reliability by automatically compensating for plant damage and system failures.

Adaptive Dynamic Programming (ADP) constitutes a potentially powerful approach to optimal control. An approximation to the Bellman cost functional is updated in real time. The technique is applicable to a broad class of nonlinear networks with unknown dynamics and is guaranteed to converge to the optimal control with stepwise stability. The goal of this paper is to describe an implementation of the ADP algorithm in which a radial basis function is used to define the approximate cost functional, which is updated locally in the neighborhood of the state trajectory each time the system is run. An application of the algorithm to a nonlinear flight control problem with unknown aircraft dynamics is presented.

The focus of this paper is the design and implementation of a full envelope, nonlinear aircraft controller that includes stability augmentation, tracking control, and flight-path generation. The control system is demonstrated using a 6 degree-of-freedom (DOF) high performance aircraft model with nonlinear kinematics, full-envelope nonlinear aerodynamics, first-order thrust model, and first-order actuator dynamics. Ideas from the field of intelligent control were used in the definition of the controller architecture. More specifically, "levels of intelligent control" were used to provide a systematic structure for the architecture. Several ideas from the field of computational intelligence were also used including neural networks, genetic algorithms, and adaptive critics.