Optical biomarkers of neonatal hypoxic ischemic (HI) brain injury can offer the advantage of continuous, cot-side assessment of the degree of injury; research thus far has focused on examining different optical measured brain physiological signals and feature combinations to achieve this. To maximize the breadth of physiological characteristics being taken into consideration, a multimodal optical platform has been developed, allowing unique physiological insights into brain injury. In this paper we present an assessment of severity of injury using a state-of-the-art hybrid broadband Near Infrared Spectrometer (bNIRS) and Diffusion Correlation Spectrometer (DCS) instrument called FLORENCE with a machine learning pipeline. We demonstrate in the preclinical neonatal model (the newborn piglet) that our approach can identify different HI insult severity (controls, mild, severe). We show that a machine learning pipeline based on k-means clustering can be used to differentiate between the controls and the HI piglets with an accuracy of 78%, the mild severity insult piglets from the severe insult piglets with an accuracy of 90% and can also differentiate the 3 piglet groups with an accuracy of 80%. So, this analytics pipeline demonstrates how optical data from multiple instruments can be processed towards markers of brain health.
Cerebral autoregulation (CA) as a mechanism to protect the brain from ischemia or hypoperfusion may play an important role related to post-stroke interventions such as the physiotherapy and the outcome. Here, we present a non-invasive assessment of the CA status by diffuse correlation spectroscopy (DCS) measures calculating the DCS moving correlation coeffcient CBFx with arterial blood pressure (ABP). The measurements are performed during the first mobilization after the onset of the symptoms. The CBFx is compared to values obtained in a healthy population showing signicantly higher values in the stroke population. This may pave the way for personalized treatment.
KEYWORDS: In vivo imaging, Single photon detectors, Superconductors, Nanowires, Spectroscopy, Signal to noise ratio, Sensors, Picosecond phenomena, Liquids, Tissues
Diffuse correlations spectroscopy (DCS) is a non-invasive optical technique that, studying the speckle intensity fluctuations of light diffused through a biological tissue, measures its microvascular blood flow. Typically, a long coherence length continuous wave source is used, which limits the possibility to resolve the photon path lengths. Recently, time-domain (TD) DCS was proposed, where a pulsed yet coherent light source is used to resolve the speckle fluctuations at different time-of-flights. Due to the constraint of single-speckle detection and time-resolved acquisition, the technique has a limited throughput which limits depth sensitivity. Here, we demonstrate TD DCS with a superconducting nanowire single-photon detector (SNSPD). The SNSPD has a high quantum efficiency and temporal resolution, while maintaining a very low background and no after-pulsing.We report results on phantom and in vivo experiments, which show the potentiality of the proposed detection system for highly accurate TD DCS experiments.
Functional diffuse correlation spectroscopy was used during various attention-demanding motor tasks, and test whether cerebral blood flow (CBF) changes differentiate between age groups or are related to mild cognitive impairment (MCI). Sixty-nine subjects were measured during single (ST) and dual motor tasks (DT); seventeen Cognitively Healthy Younger (<65y.o.,CH-Y), sixteen Cognitively Healthy Older Adults (CH-O), fifteen subjects amnestic - MCI, single-domain (aMCI - SD) and twenty-one amnestic - MCI, multi-domain (aMCI - MD). Results show elevated CBF during cognitively demanding DT statistically different (p <0.001) from reference test. No statistical difference was observed between CH and aMCI subjects (p = 0.36).
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.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.