Label-free imaging of viruses and nanoparticles directly in complex solutions is important for virology, vaccine research, and rapid diagnostics. These fields would all benefit from tools that allow for more rapid and sensitive characterization of viruses. Traditionally, light microscopy has been used in laboratories for detection of parasites, fungi, and bacteria for both research and clinical diagnosis because it is portable and simple to use. However, virus particles typically cannot be explored using light microscopy without the use of secondary labels due to their small size and low contrast. Characterization and detection of virus particles therefore rely on more complex approaches such as electron microscopy, ELISA, or plaque assay. These approaches require a significant level of expertise, purification of the virus from its natural environment, and often offer indirect verification of the virus presence. A successful virus visualization technique should be rapid, sensitive, and inexpensive, while needing minimal sample preparation or user expertise. We have developed a disposable cartridge based platform for real-time, sensitive, and label free visualization of viruses and nanoparticles directly in complex solutions such as serum. To create this platform we combined an interference reflectance imaging technique (SP-IRIS) with a sealable microfluidic cartridge. Through empirical testing and numeric modelling, the cartridge parameters were optimized and a flow rate of ~3 µL/min was established as optimal. A complex 2-dimensional paper based capillary pump was incorporated into the polymer cartridge to achieve a constant flow rate. Using this platform we were able to reliably show virus detection in a 20 minute experiment. We demonstrate sensitivity comparable to laboratory-based assays such as ELISA and plaque assay, and equal or better sensitivity compared to paper based rapid diagnostic tests. These results display a platform technology that is capable of rapid multiplexed detection and visualization of viruses and nanoparticles directly in solution. This disposable cartridge based platform represents a new approach for sample-to-answer label-free detection and visualization of viruses and nanoparticles. This technology has the potential to enable rapid and high-throughput investigation of virus particle morphology, as well as be used as a rapid point-of-care diagnostic tool where imaging viruses directly in biological samples would be valuable.

archives@tulane.edu / This dissertation is rooted in clinical pathology research, and the main character is addressing limitations in current pathology evaluation workflows. Diagnostic procedures for cancer are typically conducted via core needle biopsy procedures; however, tissue sampling limitations often result in a low yield of samples containing cancer – there are no reliable intraoperative methods to determine if the “lesion is in the needle”. If biopsy procedures result in a diagnosis of cancer, surgical removal of the tumor is often the frontline curative therapy for many cancers. Importantly, histologic evaluation following the whole resected organ is necessary to determine the presence of residual cancer, yet current methods do not allow efficient determination of tumor removal completeness intraoperatively. To address limitations of current histopathology methods, what is critically needed is a point-of-procedure fresh tissue evaluation system that facilitates 1) rapid on-site imaging and evaluation, 2) less destruction, and 3) more complete assessment of tumor content in fresh specimens. A novel microscopy system using video-rate structured illumination (VR-SIM), has been developed with the intent of rapid, point-of-procedure histological screening of intact biopsy and whole surgical specimens. VR-SIM leverages widefield imaging, rapid acting fluorescent stains, and optical sectioning to provide high contrast digital images of tissue with histological relevance. The method is to replicate the standard approach as closely as possible, but replace the physical section with an optically sectioned digital image. The overall goal of this work is to perform technological and methodological refinements necessary to translate VR-SIM as a clinical tool for histologic evaluation of fresh tissue in diagnostic procedures, biobanking, and tumor margin assessment. This project will lay the groundwork for quantitative evaluation of VR-SIM as a clinical tool – with the goal of leading toward industrial design of a VR-SIM as a medical device for hospital use. Developing a new framework for integration of high throughput microscopy into the clinical and research workflow, as well as developing new methods for quantification and evaluation of clinical effectiveness these tools will be presented and discussed in the context of patient outcomes and economic impact. / 1 / David Tulman

In the developing world, there are large populations suffering from infectious diseases, many of whom are located in remote regions. With the rapid growth in microfluidic systems in recent years, complex functions of conventional diagnostic equipment have been miniaturized and integrated into small devices at the size of a credit card (so-called portable Point-of-care (POC) devices). In this thesis a novel approach to overcoming the challenge of in-field biological sample processing and preparation to produce high quality fluids that can be readily used for downstream testings is described and proof of concept experiments presented. This approach uses hydrodynamic effects and combines nanoporous membrane with microfluidic systems and to filter the cellular component of blood. Experiments presented here demonstrate successful cells filtration from whole blood. Employing hydrodynamic effects is also shown to be an effective and potentially useful technique to isolate cells and plasma within appropriate micro-architectures.

In the developing world, there are large populations suffering from infectious diseases, many of whom are located in remote regions. With the rapid growth in microfluidic systems in recent years, complex functions of conventional diagnostic equipment have been miniaturized and integrated into small devices at the size of a credit card (so-called portable Point-of-care (POC) devices). In this thesis a novel approach to overcoming the challenge of in-field biological sample processing and preparation to produce high quality fluids that can be readily used for downstream testings is described and proof of concept experiments presented. This approach uses hydrodynamic effects and combines nanoporous membrane with microfluidic systems and to filter the cellular component of blood. Experiments presented here demonstrate successful cells filtration from whole blood. Employing hydrodynamic effects is also shown to be an effective and potentially useful technique to isolate cells and plasma within appropriate micro-architectures.

No description available.

Chronic Obstructive Pulmonary Disease (COPD) is currently one of the most prevalent lung diseases around the world, which runs an insidious course, measured over years, with an often-undiagnosed initial phase. Present clinical treatment approach for COPD results in repeated clinical visits and extended hospital stays burdening the available healthcare infrastructures, economy, and also impacting patient quality of life. To alleviate this burden, modern healthcare approaches focus on developing patient-centric solutions in which the patients should be able to request and receive quality medical assistance at their convenience, if possible from their respective homes. In this thesis work, a medical perspective on the treatment and managing of COPD is first understood in order to enunciate the functional requirements of a developing home healthcare system as an alternative to clinical treatment of COPD. Thereafter, an investigative study is carried out to explore recent developments in ICT technologies and their role in healthcare. Later, suitable sensing platforms and communication standards are identified in order to develop a working prototype of a Point of Care (POC) terminal as a proof-of-concept. The POC comprising of a breathing training device and a care application running on an android based smart device is used to measure and monitor breathing patterns of the patients and motivate them for better results and continuous improvement. An optimization exercise for low power consumption is performed on the breathing training device to facilitate additional mobility and long-term monitoring for the same. Through the observations and evaluations, scope for improvement in future versions of the device is also identified.

It is important for health clinics to capture clinical laboratory results such as point-of-care testing (POCT) data in order to meet personal health information needs while increasing patient throughput and improving clinical and economical outcomes. Personal health information needs should be exchanged at three levels: among patients and providers, across a community, and across the country. Health information technology is an important tool in addressing such a need while providing efficiency, safety, and quality. Electronically stored clinical data are necessary to attain the benefit of health information technology, so that the provider can achieve greater patient safety and efficiency through provider order entry, disease management, and clinical decision support. In any field of health care and medicine it is important to carefully document all forms of data. The purpose of this study was to examine the workflow associated with the collection of clinical lab data at the point of care. Staff members at an ambulatory, multi-specialty primary care clinic in Indianapolis, Indiana, were observed via a continuous time-motion study. Flowcharts were created for the step-by-step workflow process of a general POCT, lab, and for each role observed. Analysis of the subjects’ interview responses revealed the content of the pros and cons of possible data transfer modes from an electronic medical record (EMR) to a health information exchange (HIE). The tables derived from the time-motion study table were then analyzed, resulting in the creation of tables summarizing the approximate total time and percentage involved for each category of tasks observed. It was found that the majority of the time spent throughout the workflow process is on behalf of the nurse vs. the medical records clerk, who is involved, the least amount of time. The nurse plays the role of directing the entire workflow process of point of care testing and clinical laboratory tests. It was observed that the POCT results are recorded directly into a patient’s chart, resulting in no electronic documentation, while clinical laboratory test results are stored electronically in an EMR and printed out for chart storage. The processing task category takes the most amount of time throughout the duration of workflow process for POCT, clinical laboratory test, and the observed subject. Changes in the workflow process would most likely affect the phlebotomist; least likely affect the primary care provider, while the nurse, check-out clerk, and medical records clerk would be minimally affected. Overall, a change in the workflow process for a provider such as the medical facility observed in the study would create a higher patient intake and faster result turnaround, resulting in quality patient care. The use of data transfer of POCT and the clinical laboratory from an EMR to a HIE would create a broader depth of content that would be available for healthcare providers locally, regionally, nationally, and ultimately internationally.

No description available.

Point-of-care DNA diagnostics for resource-limited settings require high sensitivity and low limits of detection but is constrained by a limitation on the complexity of instrumentation and resource consumption. To assist in the research and development of such technology, rapid-prototyping offers quick turnaround times from ideation to proof-of-concept testing at reduced costs. All-solution processed electrodes which exhibit micro/nano-scale wrinkling and porosity were rapidly-prototyped. Probe density was shown to be tunable with these electrodes and densities were greater than planar electrodes due to a surface area enhancement. Such electrodes also demonstrated favorable characteristics for the electrocatalytic detection of DNA hybridization. Characterization of hybridization efficiency for DNA biosensors often require the determination of probe and target DNA densities in separate experiments, relying on averaged measurements which lose device specificity. A new method to quantify hybridization efficiency was developed which allows the label-free, sequential determination of probe DNA and target DNA density in one experiment, allowing electrode-specific characterization of hybridization efficiency. / Thesis / Master of Applied Science (MASc)

No / Expecting ambulance clinicians to dependably differentiate the life-threatening organ dysfunction caused by sepsis from an inflammatory response to a non-infectious aetiology, relying upon vital signs and a physical examination of the patient alone, must be considered unrealistic. Although lactate measurement has been integrated into numerous prehospital sepsis screening tools, it is not yet measured routinely within UK ambulance services. Research has generally focused on whether handheld point-of-care lactate measurement devices are as accurate as laboratory analysis of venous or arterial samples. The weight of literature has concluded negatively in relation to this. However, there is potential for handheld devices to be used independently to monitor trends in lactate elimination or accumulation to inform decisions on the efficacy of prehospital interventions, or simply to report categorical data in terms of whether lactate levels are elevated or not. This offers UK paramedics the opportunity to improve sepsis care through the enhanced assessment of risk and acuity, the identification of patients with cryptic shock, more aggressive fluid resuscitation and advanced notification to receiving units.