The Library
Development of terahertz signal processing methods for the study of human skin
Tools
Barker, Xavier Emilio Ramirez (2023) Development of terahertz signal processing methods for the study of human skin. PhD thesis, University of Warwick.
|
PDF
WRAP_Theses_Barker_2023.pdf - Submitted Version - Requires a PDF viewer. Download (30Mb) | Preview |
Official URL: http://webcat.warwick.ac.uk/record=b3949638
Abstract
Terahertz (THz) light is an electromagnetic wave with frequencies between 0.1 and 10 THz, bounded by microwave and infrared light. There is increasing interest in THz for biomedical research, primarily due to its strong attenuation by water molecules and non-ionizing nature which enables the use of THz light for the study of in vivo human skin. Skin consists of a large proportion of water and the hydration level of skin can be linked to many diseases and injuries, thus THz measurements can extract useful information related to this. In this thesis, different signal processing techniques are introduced and used for many in vivo skin studies. As the THz response of skin is easily impacted by many factors, an investigation into numerous such factors is conducted to aid in creating a measurement protocol. This measurement protocol will help to control variables which affect the skin during in vivo skin studies to ensure accurate results. Finite rate of innovation methods exploit signals with a finite number of degrees of freedom per unit time, such as THz pulsed signals. Such methods have not been applied to experimental THz measurements in published research before my work. The method is shown to produce accurate results at very low sampling rates for in vivo skin measurements and used to study an adhesive bandage applied to the volar forearm. This low sampling rate enables much quicker measurement times. In order to separate out overlapping reflections and extract more useful sample information, a sparse deconvolution method is introduced. I extend upon this method to include a reconstruction of individual sample reflections. This method is applied to investigate the effects of thin transdermal drug delivery patches on the skin. It is shown that this sparse method can accurately monitor the hydration level of the skin beneath these patches and links this to the type of patch applied. Studies on skin products applied to both real and artificial skin, in the form of hydrogel, are conducted in this thesis. This hydrogel is shown to effectively mimic real skin, and is used to investigate a promising product of crude algae extract which is currently in development and thus cannot be applied to real skin. Finally, a summary of the work performed in this thesis is given and areas of future work are identified.
Item Type: | Thesis (PhD) | ||||
---|---|---|---|---|---|
Subjects: | Q Science > QC Physics Q Science > QP Physiology R Medicine > RL Dermatology |
||||
Library of Congress Subject Headings (LCSH): | Terahertz technology, Medical technology, Skin -- Research -- Methodology, Skin -- Measurement, Signal processing, Hydration, Colloids, Transdermal medication | ||||
Official Date: | March 2023 | ||||
Dates: |
|
||||
Institution: | University of Warwick | ||||
Theses Department: | Department of Physics | ||||
Thesis Type: | PhD | ||||
Publication Status: | Unpublished | ||||
Supervisor(s)/Advisor: | MacPherson, Emma | ||||
Format of File: | |||||
Extent: | xxii, 134 pages : illustrations | ||||
Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |