Dr. John O’Brien Profile

Dr. John O’Brien

at Univ of Cambridge School of Clinical Medicine

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 13 March 2024 Poster

Interrogating visual deficits in dementia using high-density diffuse optical tomography (HD-DOT)

Emilia Butters, Sruthi Srinivasan, Deepshikha Acharya, John O'Brien, Li Su, Gemma Bale

Proceedings Volume PC12828, PC1282810 (2024) https://doi.org/10.1117/12.3021131

Read Abstract +

Measures of vascular dysfunction may serve as valuable clinical markers for the early detection of dementia, and for monitoring its progression. Near-Infrared Spectroscopy (NIRS) can non-invasively measure brain oxygenation by quantifying concentration changes of oxygenated (HbO) and deoxygenated haemoglobin (HbR). NIRS shows much promise for clinical translation: it has few contraindications, it can be performed at the bedside, and it is low-cost. High-Density Diffuse Optical Tomography (HD-DOT) extends this method by combining high-density NIRS with anatomical information to produce volumetric or topographical maps of brain oxygenation. Here we present an observational cohort study for Alzheimer's disease, dementia with Lewy bodies or mild cognitive impairment (n=32), which for the first time evaluates the possibility of using HD-DOT to develop biomarkers for dementia. Our early findings show that visual stimulation elicits a reduction in the magnitude of concentration changes of both HbO and HbR in Alzheimer’s Disease compared to healthy controls.

SPIE Journal Paper | 10 February 2023 Open Access

Illuminating neurodegeneration: a future perspective on near-infrared spectroscopy in dementia research

Sruthi Srinivasan, Emilia Butters, Liam Collins-Jones, Li Su, John O’Brien, Gemma Bale

NPh, Vol. 10, Issue 02, 023514, (February 2023) https://doi.org/10.1117/12.10.1117/1.NPh.10.2.023514

KEYWORDS: Near infrared spectroscopy, Dementia, Brain, Design and modelling, Data modeling, Neuroimaging, Neurodegeneration, Image classification, Head, Magnetic resonance imaging

Read Abstract +

SignificanceDementia presents a global healthcare crisis, and neuroimaging is the main method for developing effective diagnoses and treatments. Yet currently, there is a lack of sensitive, portable, and low-cost neuroimaging tools. As dementia is associated with vascular and metabolic dysfunction, near-infrared spectroscopy (NIRS) has the potential to fill this gap.AimThis future perspective aims to briefly review the use of NIRS in dementia to date and identify the challenges involved in realizing the full impact of NIRS for dementia research, including device development, study design, and data analysis approaches.ApproachWe briefly appraised the current literature to assess the challenges, giving a critical analysis of the methods used. To assess the sensitivity of different NIRS device configurations to the brain with atrophy (as is common in most forms of dementia), we performed an optical modeling analysis to compare their cortical sensitivity.ResultsThe first NIRS dementia study was published in 1996, and the number of studies has increased over time. In general, these studies identified diminished hemodynamic responses in the frontal lobe and altered functional connectivity in dementia. Our analysis showed that traditional (low-density) NIRS arrays are sensitive to the brain with atrophy (although we see a mean decrease of 22% in the relative brain sensitivity with respect to the healthy brain), but there is a significant improvement (a factor of 50 sensitivity increase) with high-density arrays.ConclusionsNIRS has a bright future in dementia research. Advances in technology – high-density devices and intelligent data analysis—will allow new, naturalistic task designs that may have more clinical relevance and increased reproducibility for longitudinal studies. The portable and low-cost nature of NIRS provides the potential for use in clinical and screening tests.

DOWNLOAD PAPER

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

;

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years