dc.contributor.advisor |
Taberner, A |
en |
dc.contributor.author |
Brennan, Kieran |
en |
dc.date.accessioned |
2019-11-07T02:47:29Z |
en |
dc.date.issued |
2019 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/48881 |
en |
dc.description.abstract |
Jet injection for transdermal drug delivery offers many benefits over the traditional needle and syringe approach, including the potential to reduce accidental injury and improve compliance. However, a major drawback is the lack of direct depth control, necessary for reliable drug uptake and pain reduction. The solution presented in this thesis is to monitor injection depth in real time, using diffuse optical imaging. To this end, a voice-coil jet injector is modified to couple a laser beam into the ejected fluid. The light-coupled jet produces a radial light distribution on the tissue surface, which varies with penetration depth. High-speed videography is used to measure the diffuse light emission from injections into ex vivo tissue. Solutions to the mathematical model of diffuse light transport are used to develop two inverse models, for recovering source depth from the surface light distribution. The models perform well when applied to phantom media, but produce large errors when applied to tissue. Improved results are demonstrated for two empirical models, fitted to experimental data with a source at a known depth in tissue. When applied to injections into fat tissue and tissue comprising skin and fat, errors remain almost entirely within 2mm. For samples of skin, fat, and muscle, a classifier is trained to distinguish light originating within the fat from that originating within the muscle. The classifier successfully identifies the layer of jet penetration a high proportion of the time, with misclassifications generated only near the fat-muscle boundary. Depth monitoring using diffuse optical imaging is practical with a fibre-based measurement probe, suitable for incorporation into an injection system. Once implemented in real time, this system could provide the information for feedback control of the injector motor, slowing the jet to disperse a drug in the target tissue layer. |
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dc.publisher |
ResearchSpace@Auckland |
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dc.relation.ispartof |
PhD Thesis - University of Auckland |
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dc.relation.isreferencedby |
UoA99265210713102091 |
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dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
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dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.rights.uri |
http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ |
en |
dc.title |
Jet Injection Depth Monitoring |
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dc.type |
Thesis |
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thesis.degree.discipline |
Bioengineering |
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thesis.degree.grantor |
The University of Auckland |
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thesis.degree.level |
Doctoral |
en |
thesis.degree.name |
PhD |
en |
dc.rights.holder |
Copyright: The author |
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dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
pubs.elements-id |
785382 |
en |
pubs.record-created-at-source-date |
2019-11-07 |
en |
dc.identifier.wikidata |
Q112552507 |
|