Background Nutritional treatment in the intensive care unit (ICU) has evolved from meeting nutritional requirements to manipulating patient outcome. Pharmaconutrition, referring to nutrients that are applied for their pharmacological properties, forms part of the standard nutritional care plan. The most abundant amino acid in the body, glutamine, is also the most-researched pharmaconutrient. It is an independent predictor of mortality in ICU patients, at both deficient and very high levels. Glutamine supplementation is recommended in the ICU setting for its proven outcome benefits. However, recent data showed that glutamine supplementation increases mortality risk in certain patient groups. Moreover, it suggested that not all ICU patients are glutamine deficient. Therefore, the main aim of this study was to investigate the plasma glutamine levels of adult ICU patients, on admission to the ICU. In addition, to elucidate the profile of ICU patients that can be expected to present with a glutamine deficiency or excess, with regards to gender, diagnosis and inflammatory markers. Methods In this observational, cross-sectional study, 60 mixed ICU adult patients admitted to two hospitals in the North West province were included in the study group. Blood sampling was conducted within 24 hours following ICU admission, to determine plasma glutamine, interleukin (IL)-6 and C-reactive protein (CRP) levels. Plasma glutamine levels were compared with those of a control group of healthy individuals, matched by age, race, and gender. Gender-related differences in plasma glutamine levels were investigated, as well as differences between patients with various medical conditions. The relationship between plasma glutamine levels and IL-6 or CRP was examined. Additionally, a CRP concentration cut-off point at which glutamine becomes deficient was determined by means of a receiver operating characteristic (ROC) curve. Results and discussion Intensive care unit patients had significantly lower plasma glutamine levels than healthy individuals on day one of ICU admission (p < 0.0001). However, only 38.3% (n = 23) had deficient plasma glutamine levels (< 420 μmol/L), while 6.7% (n = 4) presented with supra-normal levels (> 930 μmol/L). No significant difference could be detected between the plasma glutamine levels of male and female ICU patients (p = 0.116). Likewise, levels between diagnosis categories were also not significantly different (p = 0.325). There was a significant inverse association between plasma glutamine levels and CRP concentrations (r = -0.44, p < 0.05), and a trend towards an inverse association with IL-6 (r = - 0.23, p = 0.08). A CRP cut-off value of 95.5 mg/L was determined, above which plasma glutamine values became deficient; however, more research is needed to confirm this result. Conclusion and recommendations This research therefore showed that ICU patients, when compared with healthy individuals, had lower plasma glutamine levels on day one of admission to the ICU. However, not all were glutamine deficient, as the majority had normal and some presented with supra-normal plasma glutamine levels. An individualised approach should therefore be followed in identifying candidates for glutamine supplementation. The patients‟ condition alone may not be sufficient to predict glutamine status, but an association between plasma glutamine levels and CRP was firmly established, as well as a cut- off CRP-value above which glutamine can be expected to become deficient, which could be of use in this regard. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2015

The overall aim of the present thesis was to study aspects of patient safety in critically ill patients with special focus on airway management, respiratory complications and nursing procedures. Study I describes a method called pharyngeal oxygen administration during intubation in an experimental acute lung injury model. The study showed that pharyngeal oxygenation prevented or considerably increased the time to life-threatening hypoxemia at shunt fractions by at least up to 25% and that this technique could be implemented in airway algorithms for the intubation of hypoxemic patients. In study II, we investigated short-term disconnection of the expiratory circuit from the ventilator during filter exchange in critically ill patients. We demonstrated that when using pressure modes in the ventilator, there was no indication of any significant deterioration in the patient's lung function. A bench test suggests that this result is explained by auto-triggering with high inspiratory flows during the filter exchange, maintaining the airway pressure. Study III was a clinical observational study of critically ill patients in which adverse events were studied in connection with routine nursing procedures. We found that adverse events were common, not well documented, and potentially harmful, indicating that it is important to weigh the risks and benefits of routine nursing when caring for unstable, critically ill patients. In study IV, we conducted a retrospective database study in patients with pelvis fractures treated in the intensive care unit. We found that the incidence of respiratory failure was high, that the procedure involved in surgical stabilization affected the respiratory status in patients with lung contusion, and that the mortality was low and probably not influenced by the respiratory condition. In conclusion, the results obtained in the present thesis have increase our knowledge in important areas in the most severely ill patients and have underlined the need for improvements in the field of patient safety.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The US Army Research Laboratory currently uses a variety of ballistic diagnostic systems for gathering aerodynamic information pertaining to gun launched munitions. Sensors are a vital component of each of these diagnostic systems. Since multiple sensors are commonly used, they are often configured into a sensor suite or inertial measurement unit (IMU). In order to gather information on smaller diameter projectiles, a small diameter IMU was designed using commercial-off-the-shelf (COTS) sensors and components. This IMU was first designed with a 21.6mm diameter and then later reintegrated into a 17.5mm diameter unit. The IMU provides up to ten sensor data channels which can be used to make in-flight projectile motion measurements. These measurements are then used in the determination of the projectile's aerodynamics. It has been successfully flight tested on a variety of projectiles. It has been used in conjunction with an on-board recorder (OBR) to take measurements on 40mm and 25mm projectiles. It has also been used in a telemetry based system on-board a flare stabilized 25mm projectile. This paper covers the design of the IMU and gives examples of various sensor data.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Historically, different aspects of the configuration of an airborne instrumentation system were specified in a variety of different software applications. Instrumentation setup software handled the definition of measurements and PCM Formats while separate applications handled pre-flight checkout, calibration and post-flight data analysis. This led to the manual entry of the same data multiple times. Industry standards such as TMATS strive to address this problem by creating a data-interchange format for passing setup information from one application to another. However, a better alternative is to input all of the relevant setup information about the sensor and the measurement when it is initially created in the instrumentation vendor’s software. Furthermore, an additional performance enhancement can be achieved by adding the ability to perform sensor calibration and engineering unit conversions to pre-flight data visualization software that is tightly coupled with the instrumentation setup software. All of the setup information can then be transferred to the ground station for post-flight processing and data reduction. Detailed reports can also be generated for each measurement. This paper describes the flow of data through an integrated airborne instrumentation setup application that allows sensors and measurements to be defined, acquired, calibrated and converted from raw counts to engineering units. The process of performing a sensor calibration, configuring engineering unit conversions, and importing calibration and transducer data sheets will also be discussed.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The Space Sensing & Vehicle Control Branch of the Air Force Research Laboratory and Voss Scientific, Albuquerque, NM, are developing an advanced PC and COTS-based satellite telemetry processing, analysis and display system known as the PC-Satellite Telemetry Server (PC-STS). This program grew out of a need to develop less expensive, more capable, more flexible, and expandable solutions to the satellite telemetry analysis requirements of the Air Force. Any new system must employ industry standard, open architecture, network and database protocols allowing for easy growth and migration to new technologies, as they become available. Thus, the PC-STS will run on standard personal computers and the Windows NT operating system. The focus of this work and this paper is the Telemetry Server component, and in particular, the custom-built decommutation board. The decommution board will be capable of processing frame formatted and CCSDS packet telemetry. It will be capable of fully decommutating telemetry data, converting raw data to engineering units, and providing this data to the Telemetry Server host. Time tagged engineering units or minor frames of telemetry will be transmitted to the Telemetry Server processor via on-board memory buffers. The decom board uses the PCI bus, programmable DSPs, considerable on-board memory, and a SCSI bus for local archiving. This paper presents the general architecture of the PC-STS, and discusses specific design considerations. These include trade-offs made during the design of the board’s hardware and software, operational specifications, and graphical user interfaces to program, monitor, and control the board.

In object oriented programming (OOP) class objects are individual units of code that encapsulate the desired functionality of each object. AOP is an attempt to handle the cross-cutting concerns that represent functionality needed by a class, but is not specific to that class. The cross-cutting functionality is implemented in AOP by using a class-like structure, the aspect. Aspects do not have their own context and as such are dependent upon other objects for their context. By not having their own context it is difficult to test the functionality of aspects. This study investigated the effectiveness of using class interfaces and mock objects to unit test aspects. This was accomplished by having the mock object inherit from the same interface as the base code, so that the mock object could be swapped in for the aspect.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / To meet challenging constraints on telemetry system weight and volume, a custom Light-Weight Instrumentation System was developed to collect vehicle environment and dynamics on a short-duration exo-atmospheric flight test vehicle. The total telemetry system, including electronics, sensors, batteries, and a 1 watt transmitter weighs about 1 kg. Over 80 channels of measurement, housekeeping, and telemetry system diagnostic data are transmitted at 128 kbps. The microcontroller-based design uses the automotive industry standard Controller Area Network to interface with and support in-flight control functions. Operational parameters are downloaded via a standard asynchronous serial communications interface. The basic design philosophy and functionality is described here.

Drag embedment anchors (DEAs, or anchors) are used as foundations to secure mobile offshore drilling units (MODUs) in soft clay soils on the sea floor. In 2004 and 2005, Hurricanes Ivan, Katrina, and Rita caused the mooring failures of 17 mobile offshore drilling units moored with anchors. Since then, a great deal of research has been conducted regarding anchor performance and reliability. This report provides an overview of anchor research and industry practice to date, and discusses the results of two research experiments to assess anchor performance. One experiment investigated the effect that embedding anchors in the same soil path several times had on bearing force. The second experiment investigated what effect changing the direction of the horizontal load vector relative to the anchor shank had on embedded anchor bearing force. The results of these experiments suggest that remolding clay may have an effect on anchor bearing force capacity, and that repeatable results are obtainable when testing the effect of changing the direction of applied horizontal load. / text

Mechanical ventilation (MV) therapy has been utilised in the intensive care unit (ICU) for 50 years to treat patients with respiratory illness by supporting the work of breathing, providing oxygen and removing carbon dioxide. MV therapy is utilised by 30-50% of ICU patients, and is a major driver of increased length of stay, increased cost and increased mortality. For patients suffering from acute respiratory distress syndrome (ARDS), the optimal MV settings are highly debated. ARDS patients suffer from a lack of recruited alveoli, and the application of positive end expiratory pressure (PEEP) is often used to maintain recruitment to maximise gas exchange and minimise lung damage. However, determining what level of PEEP is best for the patient is difficult. In particular, it involves a complex trade off between patient safety and ventilation efficacy. Currently, no clinical protocols exist to determine a patient-specific “best” PEEP. Model-based approaches provide an alternative patient-specific method to help clinical diagnosis and therapy selection. In particular, model-based methods can utilise a mix of both engineering and medical principles to create patient-specific models. The models are used for optimising ventilation settings and providing greater physiological insight into lung status than is currently available. Two model-based approaches are presented here. First, a quasi-static, minimal model of lung mechanics is presented based solely on fundamental lung physiology and mechanics. Secondly, a model of dynamic functional residual capacity (dFRC) is developed and presented based on model-based status of lung stress and strain. These models are validated with retrospective clinical data to evaluate the potential of such model-based approaches. Finally, the models are further validated with real time clinical data over a broader spectrum of pressure-volume ranges than prior studies to evaluate the clinical viability of model-based approaches to optimise MV therapy. When validated with real-time clinical trials data, the outputs of the recruitment model provide a range of optimal patient-specific values of PEEP based on different clinically and physiologically derived criteria. The recruitment model is also shown to have the ability to track the disease state of ARDS over time. The dFRC model introduces the PEEP stress parameter, β, which represents a unique population constant. The dFRC model suggests that clinically reasonable estimates of dFRC can be achieved by using this novel value of β, rather than the current, potentially hazardous, methods of deflating the lung to atmospheric pressure. Finally, a third model, combining the principles of recruitment and gas exchange is introduced. The combined model has the ability to estimate cardiac output (CO) changes with respect to PEEP changes during MV therapy. In addition, the model relates the coupled areas of circulation and pulmonary management, as well as linking these MV decision support models to oxygenation based clinical endpoints. A proof of concept is shown for this model by combining two different retrospective datasets and highlighting its ability to capture clinically expected drops in CO as PEEP increases. The model allows valuable cardiovascular circulation data to be predicted and also provides an alternative method and clinical end point by which PEEP could be optimised. The model requires further clinical validation before clinical use, but shows significant promise. The models developed and tested in this research enable rapid parameter identification from minimal, readily available clinical data, and thus provide a novel way of guiding therapy. The models can potentially provide clinicians with information to select an optimal patient-specific level of PEEP using only standard ventilation data, such as pressure-volume curves. In addition, the development of a dFRC stress model provides a unique population constant, β. Overall, the modelling approaches developed and validated in this research provide several novel methods of guiding therapy setting mechanical ventilation parameters and tracking and assess a patient’s lung condition. This research thus creates and provides novel validated methods for improving MV therapy with minimal cost or added invasiveness.

This thesis presents a proof of concept study for the better integration of the electrophysiological and modelling aspects of neuroscience. Members of these two sub-disciplines collaborate regularly, but due to differing resource requirements, and largely incompatible spheres of knowledge, cooperation is often impeded by miscommunication and delays. To reduce the model design time, and provide a platform for more efficient experimental analysis, a rapid iterative model design method is proposed. The main achievement of this work is the development of a rapid model evaluation method based on parameter estimation, utilising a combination of evolutionary algorithms (EAs) and graphics processing unit (GPU) hardware acceleration. This method is the primary force behind the better integration of modelling and laboratorybased electrophysiology, as it provides a generic model evaluation method that does not require prior knowledge of model structure, or expertise in modelling, mathematics, or computer science. If combined with a suitable intuitive and user targeted graphical user interface, the ideas presented in this thesis could be developed into a suite of tools that would enable new forms of experimentation to be performed. The latter part of this thesis investigates the use of excitability-based models as the basis of an iterative design method. They were found to be computationally and structurally simple, easily extensible, and able to reproduce a wide range of neural behaviours whilst still faithfully representing underlying cellular mechanisms. A case study was performed to assess the iterative design process, through the implementation of an excitability-based model. The model was extended iteratively, using the rapid model evaluation method, to represent a vasopressin releasing neuron. Not only was the model implemented successfully, but it was able to suggest the existence of other more subtle cell mechanisms, in addition to highlighting potential failings in previous implementations of the class of neuron.