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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Comparison of Indwelling Pleural Catheters and Chemical Pleurodesis Through Tube Thoracostomy for the Management of Malignant Pleural Effusions

Srour, Nadim 24 November 2011 (has links)
BACKGROUND: Malignant and paramalignant pleural effusions are important complications of many malignancies. The two main management options debated in the literature are: 1) insertion of an indwelling pleural catheter (IPC) to achieve chronic drainage of the effusion, or 2) hospitalization with tube thoracostomy and subsequent chemical pleurodesis (CP) with talc or doxycycline to prevent fluid reaccumulation. We aimed to describe a large series of patients with malignant pleural effusions managed with an IPC, identify and validate factors identified in the literature as predictors of spontaneous pleurodesis in the IPC group and compare the group managed with IPC to patients managed with CP. METHODS: We designed a retrospective cohort study comparing patients with malignant and paramalignant pleural effusions managed either with CP between March 1, 2003 and February 28, 2006 or IPC insertion between May 1, 2006 and April 1, 2009. The CP group was identified through the prescription of talc or doxycycline and the IPC group from the IPC clinic database. Data were collected from paper and electronic records and from the Government of Ontario. RESULTS: We identified 193 consecutive patients with an ECOG performance status of less than 4 (ECOG less than 4 means that the patient is not completely disabled and confined to bed or chair) having undergone IPC insertion and 168 who were managed with CP. None of the variables we tested were significant predictors of spontaneous pleurodesis in the IPC group. Pleural effusion control rates at 6 months were higher in the IPC group than in the CP group (52.7% vs 34.0%, p<0.01) but the rate of freedom from pleural effusion at 180 days and catheter removal at 90 days was not significantly different (25.8% in the IPC group and 34.0% in the CP group p=0.14). Patients in the IPC group had a significantly longer median survival (148 days measured from the date of catheter insertion vs 133 days in the CP group, log-rank p<0.05). CONCLUSION: We found an intriguing possible survival benefit favouring management of malignant or paramalignant effusions with an IPC. Given possible biases due to the design of this study and uncertain explanatory mechanism, this needs to be confirmed in a randomized controlled trial. Quality of life, an important measure of success for these palliative procedures, should also be measured.
112

UltraminiaturizedPressure Sensor for Catheter Based Applications

Melvås, Patrik January 2002 (has links)
No description available.
113

Katheterablation von Vorhofflimmern

Piorkowski, Christopher 21 January 2011 (has links) (PDF)
Bedingt durch die zunehmende Prävalenz der Rhythmusstörung Vorhofflimmern mit den assoziierten Morbiditäts- und Mortalitätsrisiken ist die Entwicklung und Etablierung kurativer Therapieverfahren von klinischem und wissenschaftlichem Interesse. Entsprechend dem pathophysiologischen Verständnis der Arrhythmie-induzierenden Triggeraktivität und des Arrhythmie-erhaltenden Flimmersubstrat mit der vorrangigen anatomisch-strukturellen Lokalisation beider Entitäten im Übergangsbereich der großen Pulmonalvenentrichter in den posterioren linken Vorhof wurden katheterinterventionelle Ablationskonzepte als potentiell kurative Therapien entwickelt. Limitationen der praktischen Umsetzung theoretischer Linienkonzepte ergeben sich aus komplexen anatomischen Gegebenheiten und instabilen Zugangsbedingungen infolge Atmung und kardialer Mobilität. Aufbauend auf non-fluoroskopischen Navigationssystemen wurden Verfahren für vollständig Modell-integrierte Ansätze der Ablationslinienplatzierung entwickelt, bei denen Planung, Durchführung und Validierung der Ablation an anatomisch korrekten dreidimensionalen CT-Modellen des linken Vorhofes erfolgen. Zur Verbesserung instabiler Zugangsbedingungen wurden Verfahren der Katheternavigation mittels steuerbaren Schleusensystemen eingeführt und in entsprechenden Studien mit klinischen Endpunkten validiert. Zu objektivierbaren Erfassung von Energietransfer und myokardialer Läsionsbildung während der Ablation wurden katheterinterventionelle Kontakttechnologien, die auf der Messung lokaler komplexer Impedanzen zwischen Katheter und Gewebe beruhen, in der ersten klinischen Anwendung erprobt und validiert. Mit diesen technologischen Entwicklungen gelangen eine zunehmend akkuratere klinische Umsetzung theoretischer Ablationskonzepte und damit eine Etablierung des Therapiekonzeptes als klinisches Standardverfahren. Eine zur Abschätzung des Nutzen/Risiko-Profils nötige detaillierte Komplikationsanalyse stellte die Ösophagusverletzung als schwerste Komplikation heraus, die mit 0,3% selten auftrat, aber für nahezu alle langfristigen Folgeschäden verantwortlich war. Entwicklungen zur periprozeduralen Visualisierung des Ösophagus mit paralleler intraösophagealer Temperaturmessung sind Ansätze zur Vermeidung dieser Komplikation in der Zukunft. Bedingt durch das Auftreten und die postinterventionelle Zunahme asymptomatischer Flimmerrezidive ist die Frage eines objektiven Vorhofflimmermonitorings von entscheidender Bedeutung für die Beurteilung der Effektivität der Ablation sowie weitergehende klinische und wissenschaftliche Fragestellungen; wie die Indikation zur Antikoagulation oder den Vergleich von Rhythmus- und Frequenzkontrolle. 7-Tage-LzEKGs und transtelephonische EKGs wurden als Standard zum Monitoring innerhalb klinischer Vorhofflimmerstudien etabliert. Entwicklungen im Bereich implantierbarer kontinuierlicher Rhythmusmonitore werden in Zukunft das Netz zur Erfassung asymptomatischen Vorhofflimmerns weiter verdichten.
114

Nanostructured PVDF-TrFE based piezoelectric pressure sensors on catheter for cardiovascular applications

Sharma, Tushar 10 March 2014 (has links)
The objective of this research is to develop a new class of miniaturized sensors on-catheter technology through the integration of functional nanomaterials and flexible microsystems, with high sensitivity, fast recovery time, reduced form factor, for in situ blood pressure and flow monitoring with minimal invasiveness. Real-time endovascular pressure measurement techniques are crucial to evaluate the hemodynamics, which indicates the physiological state of the cardiovascular system. Current technology relies on fluid filled catheter coupled to remote transducers to measure endovascular pressures and gradients. The fluid filled catheters are bulky, inherently inaccurate due to the tubing mechanical resonance, and with low signal integrity due to the vibration noises from the environment. Silicon based conventional pressure sensors have complications due to issues of catheter stiffness, biocompatibility or small form factor integration. We propose a paradigm shift in designing the endovascular pressure sensing technology, through developing compact flexible sensing structures using nanoengineered piezoelectric polymers which can be integrated on catheters without consuming the internal lumen space. We focused on designing novel nanostructures using PVDF-TrFE (Polyvinyledene fluoride trifluoroethylene), with well controlled [Beta]-crystalline phase to significantly improve the resulting sensor performance. The research objectives include: (1) Thin-film structures for higher piezoelectric effect without any mechanical stretching or poling requirements, (2) High density highly-aligned electrospun nanofibers through electrospinning towards enhanced sensitivity; (3) Core-shell electrospun nanofiber for tapping the near [Beta]-crystalline phase formation and high cyrstallinity by virtue of inherent stress and stretching involved in the fabrication procedure. For pressure sensor design and characterization, we worked on two main form factors designs: thin-film, and aligned electrospun nanofiber based sensors patterned on catheter tips which are ready to be deployed in intra-vascular environment. Testing results showed promising results from PVDF based pressure sensors. The average sensitivity of the PVDF sensors was found to be four times higher than commercial pressure sensor while the PVDF sensor had five fold shorter response time than commercial pressure sensor, making the PVDF sensors highly suitable for real-time pressure measurements using catheters. / text
115

Design and Development of an Anti-fouling Urinary Catheter Utilizing Active Surface Deformation

Levering, Vrad Wilson 1 January 2015 (has links)
<p>There are over 30 million Foley urinary catheters used annually, and the greatest problem with Foley catheters is catheter-associated urinary tract infections (CAUTIs). CAUTIs are the number one cause of hospital-acquired infections and make up to 40% of nosocomial infections. Biofilms on urinary catheters are critical to the progression of symptomatic CAUTIs, but are difficult to treat due to the protective effect of the biofilm matrix against antibiotics. The anti-fouling catheter technology proposed and demonstrated herein uses a mechanical, non-antibiotic approach to physically remove biofilms and thereby provide an appealing option for potentially stopping the progression of symptomatic infections. Additionally, because the anti-fouling technology is mechanical, it can circumvent the persistent failings of chemical and biological approaches that have failed to address catheter-associated urinary tract infections for the last 50+ years since Foley catheters were introduced. </p><p>We designed and optimized urinary catheter prototypes capable of on-demand removal of biofilms from the previously-inaccessible main drainage lumen of catheters. The concept uses pressure-actuated chambers in elastomer constructs to generate regio-selective strain and thereby remove biofilms. We first grew mature Proteus mirabilis crystalline biofilms on flat silicone elastomer substrates, and showed that application of strain to the substrate debonded the biofilm, and that increasing the strain rate increased biofilm detachment. A quantitative relationship between the applied strain rate and biofilm debonding was found through an analysis of the biofilm segment length and the calculated driving force for debonding. We then constructed proof-of-concept prototypes of sections of anti-fouling catheter shafts using silicone and 3D printed reverse molding in methods akin to those used for soft robotics. The proof-of-concept prototypes demonstrated release of mature P. mirabilis crystalline biofilms from their strained surfaces, and prompted our development of more advanced multi-lumen prototypes. The multi-lumen prototypes were designed and optimized using successive rounds of finite element modeling to adjust the number and postion of intra-wall inflation lumens. We then constructed prototypes based on the optimized design with clinically relevant dimensions and showed they were able to generate greater than 30% strain on the majority of the luminal surface, and along their full length. Those catheter prototypes were able to on-demand, and repeatedly, remove greater than 80% of a mixed community biofilm of P. mirabilis and E. coli. In summary, this study shows (1) strain in the elastomeric substrate actively debonds crystalline biofilms in vitro (2) modeling based on characterization of biofilm properties and understanding of substrate strain informs and facilitates prototype catheter design (3) urinary catheter prototypes utilizing inflation-induced substrate strain are capable of on-demand and repeatedly removing biofilms in vitro.</p> / Dissertation
116

Imaging Tissue Engineered Blood Vessel Mimics with Optical Coherence Tomography

Bonnema, Garret January 2008 (has links)
Optical coherence tomography (OCT) is a technology that enables 2D cross-sectional images of tissue microstructure. This interferometric technique provides resolutions of approximately 10-20 um with a penetration depth of 1-2 mm in highly scattering tissues. With the use of fiber optics, OCT systems have been developed for intravascular imaging with a demonstrated improvement in both resolution and dynamic range compared to commercial intravascular ultrasound systems. OCT studies of normal, atherosclerotic, and stented arteries indicate the ability of OCT to visualize arterial structures. These results suggest OCT may be a valuable tool for studying luminal structures in tissue engineered constructs.In the present study, new endoscopic OCT systems and analysis techniques were developed to visualize the growth and response of the cellular lining within a tissue engineered blood vessel mimic (BVM). The BVM consists of two primary components. A biocompatible polymeric scaffold is used to form the tubular structure. Human microvessel cells from adipose tissue are sodded on to the inner surface of the scaffold. These constructs are then developed and imaged within a sterile bioreactor.Three specific aims were defined for the present study. First, an OCT longitudinal scanning endoscope was developed. With this endoscope, a study of 16 BVMs was performed comparing images from OCT and corresponding histological sections. The study demonstrated that endoscopic imaging did not visually damage the mimic cellular lining. OCT images showed excellent correlation with corresponding histologicalsections. Second, a concentric three element endoscope was developed to provide radial cross-sections of the BVM. OCT images using this endoscope monitored lining development on three types of polymeric scaffolds. In the third specific aim, automated algorithms were developed to assess the percent cellular coverage of a stent using volumetric OCT images.The results of the present study suggest that OCT endoscopic systems may be a valuable tool for assessing and optimizing the development of tissue engineered constructs. Conversely, the BVMs modeled the arterial response to deployed stents allowing the development of automated OCT analysis software. These results suggest that blood vessel mimics may be used to advance OCT technology and techniques.
117

Exploratory Study Describing Outcomes Attributable to Catheter-Associated Bloodstream Infection (CA-BSI) with Staphylococcus aureus in Non-ICU Patients at Grady Memorial Hospital during 2006

Albritton, Alene 24 April 2009 (has links)
Background: Catheter-associated bloodstream infections have been extensively studied in Intensive Care Unit Patients. However, less is known about the effect these infections have on non-ICU patients. This study attempted to elucidate the nature of the problem effecting non-ICU patients through descriptive analysis. Methods: Data were collected for all non-ICU patients with Staphylococcus aureus (S. aureus) infections at Grady Memorial Hospital in 2006. Demographic and hospitalization information was collected. The hospital epidemiologist responsible for surveillance of infection control programs determined outcomes attributable to the S. aureus infections. Data were entered into an Excel spreadsheet and then imported into EpiInfo 2007. Results: There were 91 S. aureus bloodstream infections documented, 38 infections in non-ICU patients and 52 infections in ICU patients. The descriptive information we accumulated offered potentially important different points between patients with MSSA and MRSA. We found more MRSA infection than MSSA infection in both the non-ICU and ICU patients. Additionally, in both groups those with MRSA infection had a length of stay at least twice as long as patients with MSSA, longer time from admission to positive blood culture, and longer time from positive blood culture to discharge. The most common type of morbidity found was sepsis, which was also the most common morbidity found in those who died. Conclusions: Our hypothesis that non-ICU patients would have increased morbidity and mortality directly attributable to the CA-BSI with S. aureus was proven to be false. Although still an issue, the morbidity and mortality was not as different as we thought it would be. While our hypothesis was proven false, this research provides information that would be well served through further studies.
118

Komplikationer hos patienter med PICC

Karevaara, Anette January 2013 (has links)
SAMMANFATTNING Bakgrund: PICC är en central infart som används inom vården för att kunna ge kärlretande läkemedel. Komplikationer vid användning av PICC kan vara infektion, trombos, tromboflebit eller stopp i katetern.  Syfte: Syftet med studien är att undersöka förekomsten av komplikationer av PICC hos onkologiska patienter samt för att se om det finns några skillnader mellan olika diagnosgrupper och behandlingar med avseende på förekomsten av djupa ventromboser (DVT) och infektioner. Syftet är också att ta reda på hur länge en PICC sitter och hur vanligt det är att en PICC felplaceras.  Metod: Metoden som används är en retrospektiv, deskriptiv, kvantitativ undersökning. I studien ingår alla onkologpatienter som fått en PICC år 2009-2011 (n=677). Data samlades in med hjälp av journalgranskning.  Resultat: Förekomsten av DVT var 5,6 %. Patienter som fick behandling med Capecitabin hade statistiskt signifikant mer DVT jämfört med andra behandlingar. Patienter som fick behandling med R-CHOP hade statistiskt signifikant mindre DVT jämfört med andra behandlingar. Antalet infektioner var 3 %. Stopp i katetern drabbade 1,8 % av patienterna, 17 % hade besvär med rodnad under förbandet, 12 % av alla katetrar åkte ut 4 cm eller mer och 2,5 % av katetrarna felplacerades vid inläggningen. En PICC var insatt i medelvärde 92 dagar, median 105 dagar.  Slutsats: Förekomsten av komplikationer av PICC var låg hos onkologiska patienter med undantag för hudbesvär som förekom hos var sjätte patient. Behandlingar innehållande Capecitabin förefaller öka risken för DVT men fler studier behövs för att öka kunskaperna om detta. PICC är en säker venös infart vid behandling med cytostatika. / ABSTRACT Background: PICC (peripherally inserted central catheter) is a central line used in healthcare to provide vascular irritant drugs. Complications with PICC can be infection, thrombosis, thrombophlebitis or occlusion of the catheter.  Aim: The aim of the study is to examine the incidence of complications of PICC in oncology patients and to see if there are any differences between diagnostic groups and treatments for the presence of deep venous thrombosis (DVT) and infection. The aim is also to find out for how long time a PICC is inserted and how common it is for a PICC misplaced.  Method: The method used is a retrospective, descriptive, quantitative survey. The study includes all oncology patients who received a PICC years 2009-2011 (n=677). Data were collected through medical record review.  Results: The incidence of DVT was 5,6 %. Patients treated with Capecitabin had statistically significantly more DVT compared with other treatments. Patients treated with R-CHOP had statistically significantly less DVT compared with other treatments. The incidence of infections was 3 %. Occlusion of the catheter affected 1,8 % of patients, 17 % had problems with redness under the dressing, 12 % of all catheters went out four cm or more and 2,5 % of the catheters were misplaced at insertion. A PICC was inserted in mean 92 days, median 105 days.  Conclusion: The complication rate of PICC was low in oncology patients with the exception of skin problems that occurred in every sixth patient. Treatments containing Capecitabin appears to increase the risk of DVT but more studies are needed to raise awareness of this. PICC is a safe venous access for chemotherapy.
119

Perifer venkateter : förebyggande av komplikationer / Peripheral intravenouscathete : prevention of complications

Cervin, Monica, Karlsson, Ann-Charlotte January 2014 (has links)
Bakgrund: Ungefär hälften av alla vuxna som vårdas på sjukhus erhåller en perifer venkateter (PVK) för intravenöst behandling. Det finns risk för lindriga eller allvarliga komplikationer. Den vanligaste komplikationen är tromboflebit och den allvarligast är infektion. I Sverige är det sjuksköterskan som ansvarar för insättning, skötsel, borttagande och dokumentation av PVK. Omvårdnaden vid handhavande av PVK är eftersatt och sjuksköterskan bör förvissa sig om att deras kunskaper är uppdaterad och evidensbaserad för att minska risken för komplikationer. Syfte: Studiens syfte var att beskriva faktorer av betydelse som kan förebygga PVK relaterade komplikationer med fokus på tromboflebit och infektion. Metod: En litteraturstudie som är baserad på 15 artiklar, 2009-2014. Resultat: Faktorer av betydelse för att förebygga tromboflebit och infektion i samband med PVK är inläggningsteknik, anatomisk placering, PVK storlek, slutna- eller öppna system och hur länge en PVK är in situ. Utbildning av personalen och feedback förbättrade handhavandet av PVK och följsamheten till riktlinjer. Slutsats: Flera faktorer påverkar om patienten utvecklar tromboflebit eller infektion i samband med PVK. Flera går att förebygga genom att följsamheten till riktlinjer förbättras och utförda omvårdnadsåtgärder dokumenteras. / Background:About half of all adults who are being cared for in hospital receivea peripheral venous catheter (PVC) for intravenous treatment. There is a risk of mild or serious complications. The most common complication is thrombophlebitis and the most serious is infection. In Sweden it isthe nurse who is responsible for the insertion, management, removal and documentation of PVC. Nursing care in PVCis neglected and the nurse should ensure that their knowledge is up-to-date and evidence-based in order to reduce the risk of complications.Aim:The aim of the studywas to describe factors that can prevent PVCrelated complications with focus on thrombophlebitis and infection.Method:Aliterature review based on 15articles, 2009-2014. Results:Factors of importance to prevent thrombophlebitis and infection associated with the PVCis insertion technique, anatomic location, PVCsize, closed or open system and how long PVCis in situ. Staff training and feedback improved management of PVCand adherence to guidelines. Conclusion:Several factors affect if the patient developsfrom thrombophlebitis or infection associated with PVC. Many are preventable by adherence to the guidelines be improved and performed nursing interventions should be documented.
120

Comparison of Indwelling Pleural Catheters and Chemical Pleurodesis Through Tube Thoracostomy for the Management of Malignant Pleural Effusions

Srour, Nadim 24 November 2011 (has links)
BACKGROUND: Malignant and paramalignant pleural effusions are important complications of many malignancies. The two main management options debated in the literature are: 1) insertion of an indwelling pleural catheter (IPC) to achieve chronic drainage of the effusion, or 2) hospitalization with tube thoracostomy and subsequent chemical pleurodesis (CP) with talc or doxycycline to prevent fluid reaccumulation. We aimed to describe a large series of patients with malignant pleural effusions managed with an IPC, identify and validate factors identified in the literature as predictors of spontaneous pleurodesis in the IPC group and compare the group managed with IPC to patients managed with CP. METHODS: We designed a retrospective cohort study comparing patients with malignant and paramalignant pleural effusions managed either with CP between March 1, 2003 and February 28, 2006 or IPC insertion between May 1, 2006 and April 1, 2009. The CP group was identified through the prescription of talc or doxycycline and the IPC group from the IPC clinic database. Data were collected from paper and electronic records and from the Government of Ontario. RESULTS: We identified 193 consecutive patients with an ECOG performance status of less than 4 (ECOG less than 4 means that the patient is not completely disabled and confined to bed or chair) having undergone IPC insertion and 168 who were managed with CP. None of the variables we tested were significant predictors of spontaneous pleurodesis in the IPC group. Pleural effusion control rates at 6 months were higher in the IPC group than in the CP group (52.7% vs 34.0%, p<0.01) but the rate of freedom from pleural effusion at 180 days and catheter removal at 90 days was not significantly different (25.8% in the IPC group and 34.0% in the CP group p=0.14). Patients in the IPC group had a significantly longer median survival (148 days measured from the date of catheter insertion vs 133 days in the CP group, log-rank p<0.05). CONCLUSION: We found an intriguing possible survival benefit favouring management of malignant or paramalignant effusions with an IPC. Given possible biases due to the design of this study and uncertain explanatory mechanism, this needs to be confirmed in a randomized controlled trial. Quality of life, an important measure of success for these palliative procedures, should also be measured.

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