Developing an eye-safe Raman spectroscopy and fundus imaging device for point-of-care neurodiagnostics

Harris, Georgia ORCID: 0000-0001-8826-7057 (2024). Developing an eye-safe Raman spectroscopy and fundus imaging device for point-of-care neurodiagnostics. University of Birmingham. Ph.D.

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Abstract

Traumatic Brain Injury (TBI) is a prevalent issue for healthcare providers and presents challenges in terms of diagnostics. Current statistics state that approximately 70 million people suffer from a TBI worldwide each year, with a mild TBI (e.g. concussion) occurring every 15 seconds. It is estimated that half of the world’s population will have a TBI in their lives. Despite this burden, methods for TBI diagnostics are unreliable, slow and costly, and an alternative is necessary to make triaging decisions at the Point-of-Care (PoC). This thesis explores the use of Raman Spectroscopy to obtain biochemical information from the back of the eye to make non-invasive and neurologically relevant diagnoses. The structure of this thesis is like a sandwich, in which the experimental “filling” involves the experimental steps taken to achieve such a device.

Within Chapters 3, 4 and 5, I combine the necessary challenges to overcome in the designing, building, and testing of a working device that combines Raman spectroscopy and fundus imaging. Including creating a handheld fundus imaging system compatible with near-infrared wavelengths, assembling, and profiling a low-power, portable 830 nm laser diode system and using both to build the final neurodiagnostic system. Due to the experimental nature of this work, the materials and methods utilised are continuously iterated in response to data being collected,
therefore the contents of these chapters constantly alternate between methods and results. I think this is a refreshing way to communicate the steps taken in this journey from conception to prototype, a continuous narrative of meeting and overcoming roadblocks as opposed to a highlights reel. This is unlike the “bread” Chapters 2 and 6 that start and finish the thesis.

Chapter 2 extracts the work I completed towards a pre-existing project, which established the idea of eye-based Raman Spectroscopy. I joined this project upon the reopening of the university laboratories and therefore had to restore the system to
working condition and finalise the data collection. During this, I learnt many techniques used in developing my own portable device and made design decisions based on the project’s limitations. To accompany the experimental development of this work, Chapter 5 presents a reference library of spectral information and assigned peaks is obtained for a cohort of 18 prospective TBI biomarkers, utilised to profile injury of retinal spectra from the portable, eye-safe Raman prototypes.

To support the ongoing development of eye-based Raman spectroscopy for neurodiagnostics, a collaboration has also been established to develop a first of its kind LIVING-EYE system, capable of whole ex vivo eye testing with the potential to test tissue damage and simulate a complete pre-TBI to post-trauma model. The continued progress of the steps made in this thesis will aid healthcare providers, increase understanding of TBI pathology and improve neurological outcomes for TBI patients.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):