Thesis

The development of miniaturised and integrated ECMO system

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2012
Thesis identifier
  • T13163
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Background: Extracorporeal membrane oxygenation (ECMO) is a treatment used to temporarily replace the function of the heart and/or lungs over an extended period of time to allow for organ recovery. The first successful use of an extracorporeal life support system over an extended period of time was achieved in 1972. Since then ECMO has been responsible for saving the lives of many thousands of patients, particularly in the neonatal population. Despite this technical success, ECMO is associated with high morbidity and mortality rates due to the invasive nature of the treatment and the technical complexity of the system. Complications associated with ECMO can be considered in two categories; patient related and technical complications or failures. These complications include but are not limited to haemolysis, thrombosis and inflammatory response. After extensive review of the medical literature and consideration of ECMO system design requirements it was determined that a miniaturized and integrated system represents a natural evolution of life support technology, addressing the failings of current system designs. Such a system should allow for reduced blood contact surface area, reduce priming volume, increased accessibility of the patient to other treatments and should allow for rapid deployment of the system, which has been shown to be essential in improving patient outcomes. Materials and Methods: The work strategy adopted throughout employed the following steps: concept development, computational design and simulation, physical testing and ultimately animal testing under clinically mimetic conditions. Computational simulation was used as a tool for design optimization and to provide quantitative and qualitative feedback on the performance of the physical prototypes. This allowed the number of design iterations to be reduced minimizing the time and cost associated with an iterative design based strategy. Physical testing was conducted under clinically mimetic conditions wherever possible to ensure that the performance of each component and the complete integrated design was satisfactory prior to animal testing.;Results: This project has produced a miniaturized blood pump, oxygenator and heat exchange system and corresponding computer models. Physical testing of each component indicated that the designs were capable of achieving acceptable hydrodynamic and haemodynamic performance. These results were verified with the computational models, which showed a close correlation. Testing of the integrated strategy showed that the complete device was capable of meeting the performance requirements of a live animal experiment, producing acceptable levels of oxygen transfer, heat addition and overcoming significant pressure head over an extended period of time. The results of the large animal testing indicated that the miniaturized and integrated design was capable of reliably producing acceptable gas exchange, temperature maintenance and blood flow rate allowing for the successful support of a live animal over an extended period of time. The following are the main achievements of this work; 1) The use of computational models to reduce the iterative load associated complex device development was confirmed as viable. 2) We were able to utilize an integrated rapid prototyping approach to develop working prototypes of individual components for laboratory testing. 3) There was a clear correlation between the results predicted by computational methods and those obtained in the laboratory. 4) We were able to employ computational design approach to optimizing integration thereby reducing the number of rapid prototypes required for testing. 5) It is possible to produce a fully integrated low foot print, priming volume and blood-material contact surface area EMCO system with adequate performance characteristics suitable for clinical use. 6) The integrated ECMO system was proven computationally and in the lab was compatible with deployment under near clinical conditions. 7) The integrated ECMO design was proven capable of partially supporting a large animal under clinically mimetic conditions over an extended period of time. 8) A novel heat exchange technology was developed that allows the miniaturized and integrated system to be independent of a mains water supply.
Resource Type
Note
  • Strathclyde theses - ask staff. Thesis no. : T13163
DOI
Date Created
  • 2012
Former identifier
  • 947423

Relations

Items