Saeed Samaei

Western University | UWO

Significance The ability to monitor cerebral blood flow (CBF) at the bedside is essential to managing critical-care patients with neurological emergencies. Diffuse correlation spectroscopy (DCS) is ideal because it is non-invasive, portable, and inexpensive. We investigated a near-infrared spectroscopy (NIRS) approach for converting DCS measurement...

Diffuse correlation spectroscopy (DCS) is a powerful tool for assessing microvascular hemodynamic in deep tissues. Recent advances in sensors, lasers, and deep learning have further boosted the development of new DCS methods. However, newcomers might feel overwhelmed, not only by the already complex DCS theoretical framework but also by the broad r...

Optical methods can provide noninvasive approach for continuous cerebral blood flow (CBF) monitoring in humans in vivo. Diffuse correlation spectroscopy (DCS) is an established modality for qualitative CBF monitoring. DCS decodes the CBF from an analysis of the temporal correlations of the light scattered by the tissue. This, however, requires ultr...

We developed and applied parallel interferometric near-infrared spectroscopy ( π NIRS) for rapid cerebral blood flow and absorption monitoring. By operating ~100-500x faster than competing optical techniques, we can monitor prefrontal cortex activation in humans in vivo.

Interferometric near-infrared spectroscopy (iNIRS) is an optical method that noninvasively measures the optical and dynamic properties of the human brain in vivo. However, the original iNIRS technique uses single-mode fibers for light collection, which reduces the detected light throughput. The reduced light throughput is compensated by the relativ...

https://fnirs.org/2022/01/01/sfnirs2022_349/

https://isott2022.com/index.php/program

Significance: Multi-laboratory initiatives are essential in performance assessment and standardization-crucial for bringing biophotonics to mature clinical use-to establish protocols and develop reference tissue phantoms that all will allow universal instrument comparison. Aim: The largest multi-laboratory comparison of performance assessment in...

We developed and applied parallel interferometric near-infrared spectroscopy (NIRS) for rapid cerebral blood flow and absorption monitoring. By operating ~100-500x faster than competing optical techniques, we can monitor prefrontal cortex activation in humans in vivo.

Time-domain diffuse correlation spectroscopy (TD-DCS) is an emerging optical technique that enables noninvasive measurement of microvascular blood flow with photon path-length resolution. In TD-DCS, a picosecond pulsed laser with a long coherence length, adequate illumination power, and narrow instrument response function (IRF) is required, and sat...

Hybrid device for the study of blood flow index and hemoglobins concentrations changes was developed. Diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy were applied to study brain hemodynamics of healthy adults human during the Valsalva maneuver.

The blood flow is responsible for distributing nutrients and oxygen to all organs in the body. Any disorders in blood flow may lead to irreversible diseases or injuries. So, modalities for perfusion measurements would be essential at the clinical sites, especially in monitoring patients with cerebral blood flow (CBF) impairments. On the other hand,...

Time-domain diffuse optics exploits near infrared light pulses diffused in turbid samples to retrieve their optical properties e.g., absorption and reduced scattering coefficients. Typically, interference effect are discarded, but speckle effects are exploited in other techniques e.g., diffuse correlation spectroscopy (DCS) to retrieve information...

Performance assessment and standardization are indispensable for instruments of clinical relevance in general and clinical instrumentation based on photon migration/diffuse optics in particular. In this direction, a multi-laboratory exercise was initiated with the aim of assessing and comparing their performances. 29 diffuse optical instruments bel...

Monitoring of human tissue hemodynamics is invaluable in clinics as the proper blood flow regulates cellular-level metabolism. Time-domain diffuse correlation spectroscopy (TD-DCS) enables noninvasive blood flow measurements by analyzing temporal intensity fluctuations of the scattered light. With time-of-flight (TOF) resolution, TD-DCS should deco...

Hybrid device for the study of blood flow index and hemoglobins concentrations changes was developed. Diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy were applied to study brain hemodynamics of healthy adults human during the Valsalva maneuver.

Near infrared light pulses, multiply scattered by random media, carry useful information regarding the sample key constituents and their microstructures. Usually, the photon diffusion equation is used to interpret the data, which neglects any interference effect in the detected light fields. However, in several experimental techniques, such as diff...

A multi-laboratory exercise, involving 29 diffuse optical instruments, aimed at performance assessment of diffuse optics instruments on standardized protocols is presented. The overarching methodology and future actions will also be discussed.

Open Data philosophy is becoming more popular among scientists. Open Data approach aims to transform science by making high-quality and well-documented scientific data open to everybody in order to promote collaboration and transparency. In diffuse optical and near-infrared spectroscopy community, a large measurement dataset collected with state-of...

Performance assessment of instruments is a growing demand in the diffuse optics community and there is a definite need to get together to address this issue. Within the EU Network BITMAP1, we initiated a campaign for the performance evaluation of 10 diffuse optical instrumentation from 7 partner institutions adopting a set of 3 well accepted, stand...

Time-resolved diffuse correlation spectroscopy makes the potential to measure blood flow at different tissue layers. We developed an instrument based on a commercial laser module, and validated its sensitivity to particle movements at different depths.