Modified Beer-Lambert law for blood flow

Baker, Wesley B.; Parthasarathy, Anand; Busch, David R.; Mesquita, Rickson C.; Greenberg, Joel; Yodh, Arjun G.

doi:10.1364/boe.5.004053

Cited by 202 publications

(153 citation statements)

References 81 publications

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“…Photons with long path lengths reach deep into the tissue as in TD. However, these photons that migrate deeply into the tissue undergo a higher number of scattering events with red blood cells and accumulate more photon momentum transfer along their paths, thus generating an amplified contribution to the earlier decay of the correlation function that in turn is analyzed in a way to increase DCS sensitivity to longer path length photons, in other words the earlier delay times [35,36]. This has been thoroughly tested in case of the adult human brain, where the underlying brain tissue with its higher blood flow contributes preferentially to the DCS signal compared to the superficial skull bone.…”

Section: Resultsmentioning

confidence: 99%

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

et al. 2016

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Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600–1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care.

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Section: Resultsmentioning

confidence: 99%

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

et al. 2016

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“…Slab-layered models were proposed to reduce the partial volume effect (Jaillon et al , 2006; Li et al , 2005; Verdecchia et al , 2016). A recently developed method, “Modified Beer-Lambert law for blood flow”, has been proved to be effective in pressure modulation experiments to reduce the skin-effect on cerebral blood flow measurements (Baker et al , 2014; Baker et al , 2015). However, those methods ignored the influence of irregular tissue geometries.…”

Section: Summary and Future Perspectivesmentioning

confidence: 99%

Clinical applications of near-infrared diffuse correlation spectroscopy and tomography for tissue blood flow monitoring and imaging

Shang

2017

Physiol. Meas.

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Blood flow is one such available observable promoting a wealth of physiological insight both individually and in combination with other metrics. Near-infrared diffuse correlation spectroscopy (DCS) and, to a lesser extent, diffuse correlation tomography (DCT), have increasingly received interest over the past decade as noninvasive methods for tissue blood flow measurements and imaging. DCS/DCT offers several attractive features for tissue blood flow measurements/imaging such as noninvasiveness, portability, high temporal resolution, and relatively large penetration depth (up to several centimeters). This review first introduces the basic principle and instrumentation of DCS/DCT, followed by presenting clinical application examples of DCS/DCT for the diagnosis and therapeutic monitoring of diseases in a variety of organs/tissues including brain, skeletal muscle, and tumor. Clinical study results demonstrate technical versatility of DCS/DCT in providing important information for disease diagnosis and intervention monitoring.

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“…Gaussian filtering was used to remove the respiratory, heartbeat and other motion artifacts from the data [47][48][49][50][51]. The modified BeerLambert law [52] was used to convert the raw intensity values to the oxygenated and deoxygenated hemoglobin concentration changes (i.e., ∆HbO and ∆HbR). The modified BeerLambert law is given as …”

Section: Signal Acquisition and Processingmentioning

confidence: 99%

Passive BCI based on drowsiness detection: an fNIRS study

Khan

Hong

2015

Biomed. Opt. Express

180

136

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Abstract:We use functional near-infrared spectroscopy (fNIRS) to discriminate the alert and drowsy states for a passive brain-computer interface (BCI). The passive brain signals for the drowsy state are acquired from the prefrontal and dorsolateral prefrontal cortex. The experiment is performed on 13 healthy subjects using a driving simulator, and their brain activity is recorded using a continuous-wave fNIRS system. Linear discriminant analysis (LDA) is employed for training and testing, using the data from the prefrontal, left-and right-dorsolateral prefrontal regions. For classification, eight features are tested: mean oxyhemoglobin, mean deoxyhemoglobin, skewness, kurtosis, signal slope, number of peaks, sum of peaks, and signal peak, in 0~5, 0~10, and 0~15 second time windows, respectively. The results show that the best performance for classification is achieved using mean oxyhemoglobin, the signal peak, and the sum of peaks as features. The average accuracies in the right dorsolateral prefrontal cortex (83.1, 83.4 and 84.9% in the 0~5, 0~10 and 0~15 second time windows, respectively) show that the proposed method has an effective utility for detection of drowsiness for a passive BCI.

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Modified Beer-Lambert law for blood flow

Cited by 202 publications

References 81 publications

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

Clinical applications of near-infrared diffuse correlation spectroscopy and tomography for tissue blood flow monitoring and imaging

Passive BCI based on drowsiness detection: an fNIRS study

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