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Laser speckle contrast imaging

Diogo Van Bavel, Roger de Moraes, Eduardo Tibirica
The incidence of cardiovascular diseases in vegetarian individuals is lower than that in the general population. Nevertheless, individuals who adhere to vegan diets have a higher prevalence of hyperhomocysteinemia with eventual adverse effects on vascular reactivity. Creatine supplementation (CrS) reduces plasma homocysteine levels and enhances vascular reactivity in the microcirculation. Thus, we investigated the effects of CrS on systemic microcirculation and homocysteine blood levels in strict vegan subjects...
December 3, 2018: Fundamental & Clinical Pharmacology
Abhishek Rege, Samantha I Cunningham, Yusi Liu, Karan Raje, Sachin Kalarn, M Jason Brooke, Lisa Schocket, Sunni Scott, Asifa Shafi, Luis Toledo, Osamah J Saeedi
Purpose: We assessed the image quality and reproducibility of blood flow measurements from a novel handheld laser speckle imager in handheld and stabilized use cases. Methods: Eleven dilated human subjects were imaged with the XyCAM Handheld Retinal Imager investigational device (XyCAM HRI) in the handheld and stabilized use case in nine consecutive imaging sessions. Subjects then underwent standard color fundus photography using a Topcon TRC 50DX. The vessel-to-background contrast of the XyCAM HRI red-free photo was compared to the fundus photograph, while the coefficient of variation of blood flow measurements in specific arteries and veins also was determined...
November 2018: Translational Vision Science & Technology
Victor Yurlov, Anatoliy Lapchuk, Kyunghun Han, Seong-Jin Son, Bok Hyeon Kim, Nan Ei Yu
Using a laser light source in imaging devices provides a wide color gamut, high brightness, resolution, and efficiency. At the same time, it creates a speckle pattern that deteriorates the image quality. This paper is related to the application of the moving binary code diffractive optical element (DOE) for speckle suppression in a laser display. Analytical optimization of DOE parameters is made in this paper. The optimal DOE pitch is found analytically. Limitation of the DOE code length is shown, and the highest possible code length is estimated...
October 20, 2018: Applied Optics
Linea L Ring, Rune B Strandby, Amalie Henriksen, Rikard Ambrus, Henrik Sørensen, Jens P Gøtze, Lars B Svendsen, Michael P Achiam
The mesenteric traction syndrome (MTS) is associated with prostacyclin (PGI2 ) facilitated systemic vasodilatation during surgery and is identified by facial flushing. We hypothesized that severe facial flushing would be related to the highest concentrations of plasma PGI2 and accordingly to the highest levels of skin blood flow measured by laser speckle contrast imaging (LSCI). Patients scheduled for major upper abdominal surgery were consecutively included. Within the first hour of the procedure, facial flushing was scored according to a standardized scale, and skin blood flow (LSPU) was continuously measured on the forehead and the cheeks by LSCI...
November 20, 2018: Journal of Clinical Monitoring and Computing
Dene Ringuette, Jacob Nauenberg, Philippe P Monnier, Peter L Carlen, Ofer Levi
Single-frame blood flow maps from laser speckle contrast imaging (LSCI) contain high spatiotemporal variation that obscures high spatial-frequency vascular features, making precise image registration for signal amplification challenging. In this work, novel bivariate standardized moment filters (BSMFs) were used to provide stable measures of vessel edge location, permitting more robust LSCI registration. Relatedly, BSMFs enabled the stable reconstruction of vessel edges from sparsely distributed blood flow map outliers, which were found to retain most of the temporal dynamics...
November 1, 2018: Biomedical Optics Express
Robin Mirdell, Aukje Nienke Lemstra-Idsardi, Simon Farnebo, Erik Tesselaar
This article contains the raw data from the article entitled: "The presence of synchronized perfusion dips in the microcirculation of the resting nail bed" Mirdell et al. (in press). A laser speckle contrast imager (LSCI) was used to make a total of 21 recordings of the perfusion in the resting nail bed of 10 healthy test subjects. The first 10 recordings were acquired after 5 min of acclimatization. An additional 10 recordings were acquired in the same test subjects, after 20 min of acclimatization...
December 2018: Data in Brief
Yuanqi Li, Yao Li, Daryl Omire-Mayor, Bin Bo, Hangdao Li, Shanbao Tong
Brain plasticity after amputation is related to the short-term unmasking of latent synapses as well as the long-term reorganization due to the sprouting new synaptic connections. The cortical functional reorganization has been reported along the intact somatosensory pathway after unilateral deafferentation. Cerebral blood flow (CBF) change serves as an important biomarker of the functional reorganization of brain. Using laser speckle contrast imaging (LSCI) technology, we performed a longitudinal study to unveil the cortical functional reorganization after forelimb amputation in rodent model, particularly along the intact somatosensory pathway...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Ming Chen, Dong Wen, Songlin Huang, Shen Gui, Zhihong Zhang, Jinling Lu, Pengcheng Li
Poor blood flow circulation can occur in the subcortical regions of the brain in many brain diseases. However, the limitations of light penetration imaging techniques hinder the detection of blood flow in deep brain tissues in vivo. Hence, in this Letter, we present a gradient index lens-based laser speckle contrast imaging system for time-lapse blood flow detection in subcortical regions of the brain. We monitored the hemodynamic changes in the thalamus of mouse models of acute hypoxia and transient middle cerebral artery occlusion as a proof of concept for practical applications...
November 15, 2018: Optics Letters
Loukman Omarjee, Antoine Larralde, Vincent Jaquinandi, Olivier Stivalet, Guillaume Mahe
RATIONALE: Buerger disease (BD) is a nonatherosclerotic, inflammatory, segmental vascular occlusive disease, which affects small and medium-sized arteries and veins and is triggered by substantial tobacco exposure. Angiographic findings consistent with BD are required for diagnosis. Laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) could represent potential noninvasive alternative techniques to angiography. PATIENT CONCERNS: We report the case of a 49-year-old smoker who developed an ischemic ulcer in the distal segment of the second finger of the left hand...
October 2018: Medicine (Baltimore)
Samir Henni, Jeanne Hersant, Laurent Loufrani, Guillaume Duval, Anne Humeau-Heurtier, Jeremie Riou, Pierre Abraham
BACKGROUND: Forearm cutaneous blood flux (CBF) measurement with post-occlusive reactive hyperemia (PORH) is uncomfortable and may not be devoid of risks. We aimed to investigate post-compression reactive hyperemia (PCRH) with a custom-made indenter that was designed to be easily used routinely by inexperienced observers. METHODS: Medical students evaluated PCRH with 1- to 4-min pressure applications of 16 to 34 kPa and PORH with 3-min forearm cuff occlusion using laser speckle contrast imaging in 15 healthy volunteers...
November 3, 2018: Microvascular Research
Kajsa Tenland, Khashayar Memarzadeh, Johanna Berggren, Cu Dinh Nguyen, Ulf Dahlstrand, Jenny Hult, Karl Engelsberg, Sandra Lindstedt, Rafi Sheikh, Malin Malmsjö
BACKGROUND: A previous study in pigs has shown that the pedicle of the tarsoconjunctival flap does not appear to have adequate blood perfusion. The aim of this study was to monitor perfusion in tarsoconjunctival flaps in patients with large lower eyelid defects resulting from tumor surgery. METHODS: The modified Hughes procedure was performed in 13 patients. Blood perfusion was monitored using laser Doppler velocimetry and laser speckle-contrast imaging. RESULTS: Blood flow decreased gradually from the pedicle base to the end of the flap and was 19% at the flap base, 11% in the middle of the flap, and 4% in the distal end of the flap...
October 30, 2018: Ophthalmic Plastic and Reconstructive Surgery
Matthieu Roustit, Joris Giai, Olivier Gaget, Charles Khouri, Myriam Mouhib, Adrien Lotito, Sophie Blaise, Christophe Seinturier, Fabien Subtil, Adeline Paris, Claire Cracowski, Bernard Imbert, Patrick Carpentier, Sunita Vohra, Jean-Luc Cracowski
Background: Treatment of Raynaud phenomenon (RP) with phosphodiesterase-5 inhibitors has shown moderate efficacy. Adverse effects decrease the risk-benefit profile of these drugs, and patients may not be willing to receive long-term treatment. On-demand single doses before or during exposure to cold may be a good alternative. Objective: To assess the efficacy and safety of on-demand sildenafil in RP. Design: Series of randomized, double-blind, n-of-1 trials...
November 20, 2018: Annals of Internal Medicine
Jiachi Hong, Yang Wang, Xiao Chen, Jingling Lu, Pengcheng Li
Laser speckle contrast imaging can be used to estimate changes in blood flow velocity in either the spatial or temporal domain. Temporal speckle contrast analysis provides higher spatial resolution than spatial speckle contrast does. However, owing to limitations of the statistical sample size in practical applications, the speckle contrast obtained consistently fluctuates around an accurate value. It is important to reveal the quantitative relationship between the statistical sample size and fluctuations of temporal speckle contrast...
November 1, 2018: Optics Letters
Titilope A Fasipe, Sung-Ha Hong, Qi Da, Christian Valladolid, Matthew T Lahey, Lisa M Richards, Andrew K Dunn, Miguel A Cruz, Sean P Marrelli
Background and Purpose- VWF (von Willebrand factor) strings mediate spontaneous platelet adhesion in the vascular lumen, which may lead to microthrombi formation and contribute to stroke pathology. However, the mechanism of VWF string attachment at the endothelial surface is unknown. We tested the novel hypothesis that VWF strings are tethered to the endothelial surface through an interaction between extracellular vimentin and the A2 domain of VWF. We further explored the translational value of blocking this interaction in a model of ischemic stroke...
October 2018: Stroke; a Journal of Cerebral Circulation
Mathew J Gallagher, Florence R A Hogg, Argyro Zoumprouli, Marios C Papadopoulos, Samira Saadoun
The effect of traumatic spinal cord injury (TSCI) on spinal cord blood flow (SCBF) in humans is unknown. Whether intervention to achieve the recommended mean arterial pressure (MAP) guideline of 85-90 mm Hg improves SCBF is also unclear. Here, we use laser speckle contrast imaging intraoperatively to visualize blood flow at the injury site in 22 patients with acute, severe spinal cord injuries (American Spinal Injuries Association Impairment Scale, grades A-C). In 17 of 22 patients, injury-site metabolism was also monitored with a microdialysis catheter placed intradurally on the surface of the injured cord...
November 16, 2018: Journal of Neurotrauma
Ryo Karakawa, Tomoyuki Yano, Hidehiko Yoshimatsu, Mitsunobu Harima, Koji Kanayama, Takuya Iida, Masayuki Sawaizumi
Fingertip replantation is a technical challenge for microsurgeons. For successful fingertip replantation, it is important to monitor the replanted fingertip vascularity for the early detection and revision of vascular compromise. Laser speckle contrast imaging (LSCI) is a camera-based technique that measures the perfusion by illuminating the tissue with a 785-nm-wavelength divergent laser beam. This creates a speckle pattern over the illuminated area. We present a case in which postoperative monitoring of the replanted fingertip microcirculation using LSCI allowed for successful Tamai zone I fingertip replantation...
September 2018: Plastic and Reconstructive Surgery. Global Open
Robin Mirdell, Aukje Nienke Lemstra-Idsardi, Simon Farnebo, Erik Tesselaar
OBJECTIVES: Laser speckle contrast imaging (LSCI) has seen limited use in the study of perfusion dynamics such as vasomotion. The aim of this study was to investigate the effects of a prolonged seated position on perfusion dynamics in the nail bed using LSCI. METHODS: Perfusion was recorded in digits II to IV bilaterally for 20 min during two separate sessions in ten healthy volunteers. The acclimatization period was 5 min for the 1st session and 20 min for the 2nd...
October 12, 2018: Microvascular Research
Christoph R Behem, Michael F Graessler, Hans O Pinnschmidt, Anna Duprée, Harleen K Sandhu, E Sebastian Debus, Sabine H Wipper, Constantin J C Trepte
OBJECTIVES: In the presence of ischaemia/reperfusion (I/R) induced endothelial injury, volume administration may not correlate with increased microcirculation. The aim of this study was to evaluate intestinal microcirculation after standardised sequential volume loading in an animal model of I/R injury following supracoeliac aortic clamping. METHODS: This was a prospective exploratory pilot animal study. Intestinal I/R injury was induced in eight pigs during experimental thoraco-abdominal aortic repair...
October 8, 2018: European Journal of Vascular and Endovascular Surgery
Olga A Sindeeva, Olga I Gusliakova, Olga Inozemtseva, Arkady S Abdurashitov, Ekaterina P Brodovskaya, Meiyu Gai, Valery V Tuchin, Dmitry A Gorin, Gleb B Sukhorukov
This paper presents the synthesis of highly biocompatible and biodegradable poly-lactide-co-glycolide (PLGA) microchamber arrays sensitive to low-intensity therapeutic ultrasound (1 MHz, 1-2W, 1 min). A reliable method was elaborated that allowed the microchambers to be uniformly filled with epinephrine hydrochloride (EH), with the possibility of varying the cargo amount. The maximum load of EH was 4.5 μg per array of 5 mm x 5 mm (about 24 pg of EH per single microchamber). A gradual, spontaneous drug release was observed to start on the first day, which is especially important in the treatment of acute patients...
October 9, 2018: ACS Applied Materials & Interfaces
W G Xie, F Lei, J Wang, J Xu, J J Ruan, Z Li
Objective: To observe the clinical effects of sequential treatments of pulsed dye laser (PDL) and ablative fractional carbon dioxide laser on early stage hypertrophic burn scars. Methods: From January 2016 to December 2017, 221 patients with 228 hypertrophic scars in all parts of body within 6 months post healing, conforming to the study criteria and treated in our department, were included in this prospective study. They were first treated by PDL, repeated at an interval of one month until the vascularity score of scar fell below 2 points, and then treated by ablative fractional carbon dioxide laser, repeated at an interval of 3 months...
September 20, 2018: Zhonghua Shao Shang za Zhi, Zhonghua Shaoshang Zazhi, Chinese Journal of Burns
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