No description available.

Thesis (M. S.)--University of Hong Kong, 2007. / Also available in print.

Thesis (M.S.)--Ohio State University, 2007. / Includes bibliographical references (leaves 70-73). Available online via OhioLINK's ETD Center

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (leaves 61-64).

Venous thromboembolism (VTE) is a common disorder which causes significant morbidity and mortality. Upper extremity deep vein thrombosis(UEDVT) is a relatively understudied subtype of VTE which is commonly associated with central venous catheters, cancer, and thrombophilia. The goal of this project was to better characterize the risk of UEDVT and to design and execute a pilot study that will demonstrate the efficacy of a strategy preventing the occurrence of VTE in a high-risk population for UEDVT. This M.Sc project, was conducted in three parts. Chapter 1 of the thesis outlines a systematic review of the literature which assessed the risk of VTE in UEDVT patients by search for and including data from studies with patients with prospectively enrolled symptomatic UEDVT. Chapter 2 describes the development and final protocol of the TRIM-Line pilot study, a randomized open-label study comparing 90 days of rivaroxaban 10mg po daily against the current standard of care (observation) in patients with active cancer and central venous catheters, two known risk factors for VTE. Finally in Chapter 3 the TRIM-Line study was executed as a pilot trial involving The Ottawa Hospital and the Juravinski Cancer Centre located in Hamilton. The study was conducted from March 2019 until February 2020. 105 patients underwent randomization at the two Canadian centres. The study met its prespecified feasibility endpoint average enrolment rate of 7.5 per month (95% CI:4.56, 10.44) at the coordinating Ottawa Hospital site and 2.0 per month (95% CI:0.87, 3.13) for the Juravinski Cancer Centre site. The randomized controlled trial met its enrollment targets and demonstrated that a full scale randomized controlled trial on the topic of prevention of cancer associated venous thromboembolism is feasible.

No description available.

In this project, problems related to loss of free flow in central venous catheter and implanted subcutaneous ports have been investigated. The catheters investigated in this project are intended for children with cancer diseases. The initial hypothesis was that the length, radius and curvature of the catheter would affect the flow. Two other things that can have a negative impact on the flow are if the catheter is squashed or kinked. Experiments and simulations have been performed in order to test the hypothesis and investigate how a deformation of the catheter affects the flow. The results from the experiments and simulations show that the length and radius of the catheter have major impact on the pressure drop, and hence the flow. The curvature of the catheter has less impact on the flow as long as the catheter is not kinked. Experiments with squashed catheters show a decrease in outlet pressure with a decrease of the catheter lumen. / Denna projektrapport ämnar undersöka problem relaterade till fritt flöde i centrala venkatetrar och inopererade subkutana portar. Katetrarna som testats i detta projekt är till för barn med cancersjukdomar. Den ursprungliga hypotesen var att längden, radien och krökningen hos katetern påverkar flödet. Ytterligare två saker som skulle kunna ha negativ effekt på flödet är om katetern är klämd eller veckad. För att testa hypotesen om hur deformationer av katetern påverkar flödet har experiment och simuleringar utförts. Resultaten från experiment och simuleringar visar att kateterns längd och radie har störst effekt på tryckfallet och därmed flödet. Krökningen på katetern har mindre betydelse, så länge katetern inte är veckad. Experiment med klämd kateter visar att utloppstrycket minskar med minskad kateterlumen.

The design, fabrication, and in-vivo testing of an implantable device to measure the pressure-volume (PV) relationship in the hearts of conscious, untethered rats is presented. Volume is measured using a tetrapolar catheter positioned in the left-ventricle which emits a 20kHz current field across the LV blood pool and parallel heart tissue and measures the resulting voltage. The admittance method is used to instantaneously remove the contribution of the parallel heart muscle and Wei’s non-linear blood conductance-to-volume equation is used to calculate volume. Pressure is measured with a strain gauge sensor at the tip of the catheter. The implant was designed to be small, light, and low-power. An average implant occupies 5 cm3, weighs 8g, and on a single charge collects data for 2 months taking 43 samples per day. Collected data is transmitted wirelessly via RF to a base station where it is recorded. The functionality of the implant and measurement system was verified in six rat experiments. In all experiments, ambulatory PV loops were measured on implantation day. Viable pressure data was recorded for 11 days in one rat; in another rat viable admittance data was collected for 10 days. Changing catheter position and non-constant blood resistivity are considered as sources of error in the volume measurement. Pressure drift due to changing atmospheric pressure is considered as a source of error in the pressure measurement. Lastly, alternative uses for the implant and directions for future improvement are considered. / text

published_or_final_version / abstract / Surgery / Master / Master of Surgery

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.