Date of Award

2021

Document Type

Master Thesis

Degree Name

Master of Engineering (Research)

Department

Mechanical, Biomedical & Manufacturing Engineering

First Advisor

Dr Gareth O'Donnell

Second Advisor

Prof. Ger Kelly

Abstract

Neurovascular guide catheters are used to treat problems affecting blood vessels within the brain through minimally invasive procedures. Catheters are inserted into the patient via their femoral or brachial arteries and manually navigated to the brain to deliver treatment. This procedure replaces the requirement to cut into the patient’s skull and brain tissue but is limited by reduction of blood vessel lumen diameter and increase in tortuosity of blood vessels deep in the brain. During these procedures, catheters can sometimes fail by kinking or fracturing into two pieces. The rate of failure by fracture of a particular neurovascular catheter device is seen as unacceptably high by its manufacturer. Investigation into the cause of this failure has been carried out using test methods performed by hand. However, these test methods are not standardised and are largely based on the intuition or expertise of the person carrying out the test. Nevertheless, these tests are commonly used as there are no international standards for measuring the mechanical properties of neurovascular catheter shafts. The aim of the current research is to address this discrepancy in the biomedical device industry by developing a standardised measurement system to replace the manual test methods. The most significant contribution from this research is the fulfilment of this aim. The resulting measurement system can be used to quantify the effect of process and design changes on catheter performance, aiding in the development of better performing, next generation neurovascular catheters to be used in future cutting-edge surgeries. It is the first of its kind to achieve sensitivity great enough to quantify the effect of varying lamination temperature on the catheter’s resistance to kinking. This measurement system was developed using materials testing frames, preconditioning of specimens, micro-CT imaging, DOE, ANOVA, and t-tests. Additional outcomes from this research are review of applicability of simple tensile, buckle, three-point bend tests and four-point bend tests for the measurement of the effect of varying lamination temperature on the catheter’s resistance to kinking. Additionally, the sequence of events within the neurovascular catheter structure leading to failure have been identified.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Access Level

info:eu-repo/semantics/openAccess

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