Non-contact blood flow determination using a laser speckle method

Rüth, B.

doi:10.1016/0030-3992(88)90060-6

Cited by 33 publications

(25 citation statements)

References 19 publications

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“…As an alternative to Laser Doppler flowmetry, LSCI was first introduced for the mapping of microvascular perfusion in various tissues including the skin and the retina (Briers 2001;Ruth 1990;Tamaki et al 1994), and was later adapted and found highly suitable to create flow maps of the superficial layers of cerebral cortex (Dunn et al 2001). LSCI flow maps are computed using fluctuating intensity of the random interference effect known as speckle; still, LSCI and laser Doppler flowmetry both derive flow information on the basis of the same physical phenomenon and yield comparable results (Briers 2001;Tew et al 2011).…”

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confidence: 99%

Demonstration of impaired neurovascular coupling responses in TG2576 mouse model of Alzheimer’s disease using functional laser speckle contrast imaging

et al. 2017

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Increasing evidence from epidemiological, clinical, and experimental studies indicates that cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including both vascular cognitive impairment (VCI) and Alzheimer's disease. Vascular contributions to cognitive impairment and dementia (VCID) include impairment of neurovascular coupling responses/functional hyperemia (Bneurovascular uncoupling^). Due to the growing interest in understanding and pharmacologically targeting pathophysiological mechanisms of VCID, there is an increasing need for sensitive, easy-to-establish methods to assess neurovascular coupling responses. Laser speckle contrast imaging (LSCI) is a technique that allows rapid and minimally invasive visualization of changes in regional cerebromicrovascular blood perfusion. This type of imaging technique combines high resolution and speed to provide great spatiotemporal accuracy to measure moment-to-moment changes in cerebral blood flow induced by neuronal activation. Here, we provide detailed protocols for the successful measurement in neurovascular coupling responses in anesthetized mice equipped with a thinned-skull cranial window using LSCI. This method can be used to evaluate the effects of anti-aging or anti-AD treatments on cerebromicrovascular health.Keywords Neurovascular coupling . Functional hyperemia . Laser speckle contrast imaging . Laser speckle contrast analysis . LASCA . Laser speckle imaging . LSI Neurovascular uncoupling in aging and Alzheimer's diseaseIt is well recognized that the brain consumes more energy than any other human organ. Over 20% of the body's total energy requirements are spent to fuel the brain, which in turn only accounts for 2% of the total body mass. Moment-to-moment regulation of cerebral blood flow (CBF) is crucial since inadequate supply of glucose and oxygen to an active region of the brain GeroScience (2017) 39:465-473

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confidence: 99%

Demonstration of impaired neurovascular coupling responses in TG2576 mouse model of Alzheimer’s disease using functional laser speckle contrast imaging

et al. 2017

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“…Recent advances in optical imaging provide a valuable tool to noninvasively monitor CBF, oxygenation, and cerebral metabolic rate of oxygen (CMRO 2 ) with high spatiotemporal resolution. [32][33][34] We used combined laser speckle flowmetry and multispectral reflectance imaging through an intact skull during focal ischemia in mice to test the impact of pharmacologically induced hypertension. Our data show that mild induced hypertension rapidly improves CBF, oxygenation, and CMRO 2 in both the core and penumbra and reduces infarct volume.…”

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confidence: 99%

Mild Induced Hypertension Improves Blood Flow and Oxygen Metabolism in Transient Focal Cerebral Ischemia

Shin

Nakagawa

Jones

et al. 2008

Stroke

128

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Background and Purpose-In focal ischemic cortex, cerebral blood flow autoregulation is impaired, and perfusion passively follows blood pressure variations. Although it is generally agreed that profound hypotension is harmful in acute stroke, the hemodynamic and metabolic impact of increased blood pressure on the ischemic core and penumbra are less well understood. We, therefore, tested whether pharmacologically induced hypertension improves cerebral blood flow and metabolism and tissue outcome in acute stroke using optical imaging with high spatiotemporal resolution. Methods-Cerebral blood flow, oxyhemoglobin, and cerebral metabolic rate of oxygen were measured noninvasively using simultaneous multispectral reflectance imaging and laser speckle flowmetry during distal middle cerebral artery occlusion in mice. Hypertension was induced by phenylephrine infusion starting 10 or 60 minutes after ischemia to raise blood pressure by 30% for the duration of ischemia; control groups received saline infusion. Results-Mild induced hypertension rapidly increased cerebral blood flow, oxyhemoglobin, and cerebral metabolic rate of oxygen in both the core and penumbra and prevented the expansion of cerebral blood flow deficit during 1 hour distal middle cerebral artery occlusion. Induced hypertension also diminished the deleterious effects of periinfarct depolarizations on cerebral blood flow, oxyhemoglobin, and cerebral metabolic rate of oxygen without altering their frequency. Consistent with this, mild induced hypertension reduced infarct volume by 48% without exacerbating tissue swelling when measured 2 days after 1 hour transient distal middle cerebral artery occlusion. Conclusions-Our data suggest that mild induced hypertension increases collateral cerebral blood flow and oxygenation and improves cerebral metabolic rate of oxygen in the core and penumbra, supporting its use as bridging therapy in acute ischemic stroke until arterial recanalization is achieved. (Stroke. 2008;39:1548-1555.)

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“…The biospeckle is a method that uses an optical phenomenon of the light Laser, already known in other areas, however only recently has been used in the analysis of biological phenomena and in medicine 30,31,32,33 . From its discovery, efforts have been determined in the exploration of the biospeckle as tool no destructive to evaluate the biological activity 23,34,35 .…”

Section: Discussionmentioning

confidence: 99%

The optical analysis of the abdominal wall using the biospeckle after implants of polypropylene mesh in rats

Nieri

Peres

Silva³

et al. 2009

Acta Cir. Bras.

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Purpose:To evaluate an experimental animal model to study the abdominal tissue activity considering its interaction with a polypropylene mesh, through the use of one of the optical phenomena of light Laser, the biospeckle. Methods: Fifty Wistar male rats were divided into four groups: Group 1: ten animals not submitted to surgery; Group 2: ten animals submitted to surgery without polypropylene mesh; Group 3: 20 animals submitted to surgery followed by the mesh placement; Group 4: (sham) with ten animals. None of the animals presented post surgical complications being submitted to the optical tests at the 20th postoperative day. Results: The analysis from the biospeckle tests, comparing the medians and standard deviations with T Student test, indicated that no significative difference was observed on the abdominal wall tissue activity in the four groups considered, with and without polypropylene mesh prosthesis implantation. Conclusion: The animal model is viable and the biospeckle open ways for a great number of experiments to be developed in evaluating tissue activity. Key words: Hernia, Abdominal. Polypropylenes. Lasers. Rats. RESUMO Objetivo:Avaliar o modelo experimental animal para o estudo da atividade tecidual da parede abdominal em sua interação com a prótese de polipropileno, através da utilização de um dos fenômenos ópticos da luz Laser, o biospeckle. Métodos: Foram utilizados 50 ratos Wistar machos, divididos em quatro grupos: Grupo 1 com 10 animais não operados e controles; Grupo 2 com 10 animais submetidos a cirurgia sem a colocação de prótese; Grupo 3 com 20 animais submetidos a cirurgia com colocação de prótese de polipropileno pré-peritonial; Grupo 4 (Sham) com 10 animais. Nenhum animal apresentou complicações pós-operatórias, sendo que no 20º PO foram submetidos ao ensaio óptico. Resultados: A comparação das médias e o desvio padrão das medidas da atividade tecidual da parede abdominal, com e sem implantação da prótese de polipropileno obtidas dos grupos de animais, pelo teste T de Student, não evidenciou diferença estatística significativa (p>0.05). Conclusão: A análise dos dados obtidos permitiu concluir que o modelo animal é viável e que o biospeckle abre caminhos para toda uma linha de experimentos a ser desenvolvida em avaliar atividade tecidual.

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Non-contact blood flow determination using a laser speckle method

Cited by 33 publications

References 19 publications

Demonstration of impaired neurovascular coupling responses in TG2576 mouse model of Alzheimer’s disease using functional laser speckle contrast imaging

Demonstration of impaired neurovascular coupling responses in TG2576 mouse model of Alzheimer’s disease using functional laser speckle contrast imaging

Mild Induced Hypertension Improves Blood Flow and Oxygen Metabolism in Transient Focal Cerebral Ischemia

The optical analysis of the abdominal wall using the biospeckle after implants of polypropylene mesh in rats

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