A Stochastic optimization approach to laser speckle contrast imaging for a better estimation of blood flow DOI

Murali Krishnamoorthy,

Soumyajit Sarkar,

Susweta Das

et al.

Published: Jan. 1, 2024

We have recently proposed the use of stochastic differential equations to simulate speckle intensity with pre-defined probability density function and auto-correlation for applications in imaging tissue blood flow. Here, we extend above-mentioned model compute better estimates flow from measurements using a optimization approach. validate method simulations, tissue-mimicking phantoms, − vivo human experiments.

Language: Английский

Validation of the Openwater wearable optical system: cerebral hemodynamic monitoring during a breath-hold maneuver DOI Creative Commons
Christopher G. Favilla, Sarah Carter,

Brad Hartl

et al.

Neurophotonics, Journal Year: 2024, Volume and Issue: 11(01)

Published: March 8, 2024

SignificanceBedside cerebral blood flow (CBF) monitoring has the potential to inform and improve care for acute neurologic diseases, but technical challenges limit use of existing techniques in clinical practice.AimHere, we validate Openwater optical system, a novel wearable headset that uses laser speckle contrast monitor microvascular hemodynamics.ApproachWe monitored 25 healthy adults with system concurrent transcranial Doppler (TCD) while performing breath-hold maneuver increase CBF. Relative (rBF) was derived from changes contrast, relative volume (rBV) average intensity.ResultsA strong correlation observed between beat-to-beat rBF TCD-measured velocity (CBFv), R=0.79; slope linear fit indicates good agreement, 0.87 (95% CI: 0.83 −0.92). Beat-to-beat rBV CBFv were also strongly correlated, R=0.72, as expected two variables not proportional; smaller than changes, 0.18 0.17 0.19). Further, agreement found waveform morphology related metrics.ConclusionsThis first vivo validation highlights its hemodynamic monitor, additional is needed disease states.

Language: Английский

Citations

10
A comprehensive overview of diffuse correlation spectroscopy: theoretical framework, recent advances in hardware, analysis, and applications DOI Creative Commons
Quan Wang, Mingliang Pan, Lucas Kreiß

et al.

NeuroImage, Journal Year: 2024, Volume and Issue: 298, P. 120793 - 120793

Published: Aug. 15, 2024

Diffuse correlation spectroscopy (DCS) is a powerful tool for assessing microvascular hemodynamic in deep tissues. Recent advances sensors, lasers, and learning have further boosted the development of new DCS methods. However, newcomers might feel overwhelmed, not only by already-complex theoretical framework but also broad range component options system architectures. To facilitate entry to this exciting field, we present comprehensive review hardware architectures (continuous-wave, frequency-domain, time-domain) summarize corresponding models. Further, discuss applications highly integrated silicon single-photon avalanche diode (SPAD) sensors DCS, compare SPADs with existing other components (lasers, correlators), as well data analysis tools, including learning. Potential medical diagnosis are discussed an outlook future directions provided, offer effective guidance embark on research.

Language: Английский

Citations

4
ATLAS: a large array, on-chip compute SPAD camera for multispeckle diffuse correlation spectroscopy DOI Creative Commons

Alistair Gorman,

N. Finlayson, Ahmet T. Erdogan

et al.

Biomedical Optics Express, Journal Year: 2024, Volume and Issue: 15(11), P. 6499 - 6499

Published: Sept. 2, 2024

We present ATLAS, a 512 × single-photon avalanche diode (SPAD) array with embedded autocorrelation computation, implemented in 3D-stacked CMOS technology, suitable for correlation spectroscopy applications, including diffuse (DCS). The shared per-macropixel SRAM architecture provides 128 macropixel resolution, parallel minimum lag-time of 1 µs. demonstrate the direct, on-chip computation function sensor, and its capability to resolve changes decorrelation times typical body tissue real time, at long source-detector separations similar those achieved by current leading optical modalities cerebral blood flow monitoring. Finally, we suitability in-vivo measurements through cuff-occlusion forehead cardiac signal measurements.

Language: Английский

Citations

2
Tunable dynamical tissue phantom for laser speckle imaging DOI Creative Commons
Soumyajit Sarkar,

Murali Krishnamoorthy,

Hari M. Varma

et al.

Biomedical Optics Express, Journal Year: 2024, Volume and Issue: 15(8), P. 4737 - 4737

Published: June 17, 2024

We introduce a novel method to design and implement tunable dynamical tissue phantom for laser speckle-based in-vivo blood flow imaging. This approach relies on stochastic differential equations (SDE) control piezoelectric actuator which, upon illuminated with source, generates speckles of pre-defined probability density function auto-correlation. The validation experiments show that the can generate dynamic closely replicate both surfaces as well deep reasonably wide range accuracy.

Language: Английский

Citations

1
A Stochastic optimization approach to laser speckle contrast imaging for a better estimation of blood flow DOI

Murali Krishnamoorthy,

Soumyajit Sarkar,

Susweta Das

et al.

Published: Jan. 1, 2024

We have recently proposed the use of stochastic differential equations to simulate speckle intensity with pre-defined probability density function and auto-correlation for applications in imaging tissue blood flow. Here, we extend above-mentioned model compute better estimates flow from measurements using a optimization approach. validate method simulations, tissue-mimicking phantoms, − vivo human experiments.

Language: Английский

Citations

0