The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Michael John Haynes - One of the best experts on this subject based on the ideXlab platform.
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Vertebral arteries and neck rotation: Doppler Velocimeter interexaminer reliability.
Ultrasound in Medicine and Biology, 2000Co-Authors: Michael John Haynes, Robin Hart, John McgeachieAbstract:The purpose of this study was to test the interexaminer reliability of Doppler ultrasound (US) Velocimeter examination of vertebral arteries during contralateral cervical rotation. Vertebral arteries from 20 adults were insonated using a bidirectional Doppler Velocimeter at the suboccipital portal (standard technique) and C2 transverse process level (new technique) during contralateral cervical rotation. The data obtained by two examiners, regarding persistence or major reduction in Doppler signals, were compared. There was 93% agreement between the data from the two examiners, and the kappa score was 0.78 at p = 0.05. These results provide evidence to support the interexaminer reliability of bidirectional Doppler Velocimeter examination for the purpose of assessing the effects of contralateral rotation on vertebral artery blood flow.
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vertebral arteries and neck rotation Doppler Velocimeter and duplex results compared
Ultrasound in Medicine and Biology, 2000Co-Authors: Michael John HaynesAbstract:The purpose of this study was to test the validity of Doppler ultrasound (US) Velocimeter examination of vertebral arteries during contralateral (to the opposite side) cervical rotation. Vertebral arteries from 20 subjects were insonated using a bidirectional Doppler Velocimeter at the suboccipital portal (standard technique) and C2 transverse process level (new technique) during contralateral cervical rotation. The results, regarding persistence or major reduction in Doppler signals, were then compared with those from a colour-flow duplex US scanner using the same procedure. There was complete agreement between the combined suboccipital and C2 Velocimeter results and those from the duplex scanner (k = 1.00 at p = 0.01): both sensitivity (n = 5) and specificity (n = 34) were 100%. This study provides evidence to support the validity of bidirectional Doppler Velocimeter examination, by an experienced examiner, for the purpose of assessing the effects of contralateral rotation on vertebral artery blood flow.
Koichi Maru - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous Cross-Sectional Velocity Distribution Measurements Using Laser Doppler Velocimeter Employing 7 × 8 Spatial Encoding
2019 24th Microoptics Conference (MOC), 2019Co-Authors: Mayu Yukinari, Koichi MaruAbstract:A laser Doppler Velocimeter employing 7×8-channel spatially encoded measurement points is proposed for simultaneous cross-sectional velocity distribution measurements. The measurement points arranged in two dimensions are encoded by combining wavelength-division multiplexing and multiple bias-frequency encoding. The functionality of the proposed method was experimentally demonstrated.
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Non-mechanical scanning laser Doppler Velocimeter with directional discrimination using single transmission path
2013 Conference on Lasers and Electro-Optics Pacific Rim (CLEOPR), 2013Co-Authors: Takahiro Hata, Koichi MaruAbstract:A non-mechanical axial scanning laser Doppler Velocimeter (LDV) with directional discrimination using a single transmission path is proposed. The axial scan and directional discrimination has been demonstrated experimentally using a sensor probe setup.
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nonmechanical axial scanning laser Doppler Velocimeter with directional discrimination
Applied Optics, 2012Co-Authors: Koichi Maru, Takahiro HataAbstract:An axial scanning laser Doppler Velocimeter (LDV) with directional discrimination not requiring any moving mechanism in its probe is proposed. The proposed LDV utilizes frequency shift induced by acousto-optic modulators (AOMs) for discriminating the direction of velocity. The measurement position is axially scanned by changing the wavelength of the light input to the probe. The experimental result reveals that both the axial scan and the directional discrimination can be realized by using the proposed method without any moving element in the probe.
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Non-Mechanical Dual-Axis Scanning Laser Doppler Velocimeter
IEEE Sensors Journal, 2012Co-Authors: Koichi MaruAbstract:A dual-axis scanning laser Doppler Velocimeter (LDV) without any moving mechanism in its sensor probe is proposed. In this LDV, the measurement position is scanned in both axial and transversal directions with one probe. The direction of the scan is changed by changing the polarization of the beam input to the probe. The results of the experiment using a setup of the sensor probe consisting of bulk optical components indicate that the measurement position can be successfully scanned in both axial and transversal directions. The scan ranges are estimated to be 54.8 mm over the wavelength range of 20 nm for axial scan and 20.8 mm over the wavelength range of 32 nm for transversal scan.
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Integrated Wavelength-Insensitive Differential Laser Doppler Velocimeter Using Planar Lightwave Circuit
Journal of Lightwave Technology, 2009Co-Authors: Koichi Maru, Yusaku FujiiAbstract:In this paper, a design of an integrated wavelength-insensitive laser Doppler Velocimeter (LDV) has been proposed using planar lightwave circuit (PLC). The proposed LDV uses arrayed waveguide gratings (AWGs) that can be fabricated using PLC technology. Its characteristics are simulated using a design model based on grating equations for AWGs. The simulation results indicate that wavelength-insensitive operation can be almost obtained by optimizing the design parameters of the proposed structure without assembly of bulk diffractive gratings or other optical elements.
P M Farr - One of the best experts on this subject based on the ideXlab platform.
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the study of plaques of psoriasis using a scanning laser Doppler Velocimeter
British Journal of Dermatology, 1993Co-Authors: E L Speight, T J H Essex, P M FarrAbstract:Summary A scanning laser-Doppler Velocimeter. able to measure blood flux over a large area without contact with the skin surface, was used for the objective measurement of the vascular changes in psoriasis. Individual plaques were scanned, and tracings of the visible plaque edge taken on to a cellulose-acetate sheet from which area measurements were made using a digitizing tablet. Mean blood flux within plaques was increased fourfold compared with mean background flux. There was a highly significant linear correlation between plaque area measured by tracing and scanning, but area measured by scanning was greater. Detailed study of blood flux outside the visible plaque edge with the scanner, and with a conventional Iaser-Doppler instrument, showed this was due to a 2–4 mm rim of increased blood flux around plaques. The scanning laser-Doppler Velocimeter allows rapid measurement of psoriasis in terms of mean blood flux and area of increased blood flux, and should be useful in the assessment of psoriasis severity and the response to treatment.
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The study of plaques of psoriasis using a scanning laser‐Doppler Velocimeter
British Journal of Dermatology, 1993Co-Authors: E L Speight, T J H Essex, P M FarrAbstract:Summary A scanning laser-Doppler Velocimeter. able to measure blood flux over a large area without contact with the skin surface, was used for the objective measurement of the vascular changes in psoriasis. Individual plaques were scanned, and tracings of the visible plaque edge taken on to a cellulose-acetate sheet from which area measurements were made using a digitizing tablet. Mean blood flux within plaques was increased fourfold compared with mean background flux. There was a highly significant linear correlation between plaque area measured by tracing and scanning, but area measured by scanning was greater. Detailed study of blood flux outside the visible plaque edge with the scanner, and with a conventional Iaser-Doppler instrument, showed this was due to a 2–4 mm rim of increased blood flux around plaques. The scanning laser-Doppler Velocimeter allows rapid measurement of psoriasis in terms of mean blood flux and area of increased blood flux, and should be useful in the assessment of psoriasis severity and the response to treatment.
M Martinelli - One of the best experts on this subject based on the ideXlab platform.
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distributed laser Doppler Velocimeter
Optics Letters, 1991Co-Authors: Valeria Gusmeroli, M MartinelliAbstract:A monobeam laser Doppler Velocimeter that permits continuous recovery of the flow velocity profile along the beam is described. The scheme applies the coherence-multiplexing concept to backscattering Doppler detection. A theoretical analysis of the distributed Velocimeter is given, along with a description of an experiment with a superluminescent diode source inserted in an all-fiber-optic scheme. The velocity profile of water flow in a duct is reported. The results confirm the exceptional capabilities offered by this Velocimeter in experimental fluid mechanics.
E L Speight - One of the best experts on this subject based on the ideXlab platform.
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the study of plaques of psoriasis using a scanning laser Doppler Velocimeter
British Journal of Dermatology, 1993Co-Authors: E L Speight, T J H Essex, P M FarrAbstract:Summary A scanning laser-Doppler Velocimeter. able to measure blood flux over a large area without contact with the skin surface, was used for the objective measurement of the vascular changes in psoriasis. Individual plaques were scanned, and tracings of the visible plaque edge taken on to a cellulose-acetate sheet from which area measurements were made using a digitizing tablet. Mean blood flux within plaques was increased fourfold compared with mean background flux. There was a highly significant linear correlation between plaque area measured by tracing and scanning, but area measured by scanning was greater. Detailed study of blood flux outside the visible plaque edge with the scanner, and with a conventional Iaser-Doppler instrument, showed this was due to a 2–4 mm rim of increased blood flux around plaques. The scanning laser-Doppler Velocimeter allows rapid measurement of psoriasis in terms of mean blood flux and area of increased blood flux, and should be useful in the assessment of psoriasis severity and the response to treatment.
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The study of plaques of psoriasis using a scanning laser‐Doppler Velocimeter
British Journal of Dermatology, 1993Co-Authors: E L Speight, T J H Essex, P M FarrAbstract:Summary A scanning laser-Doppler Velocimeter. able to measure blood flux over a large area without contact with the skin surface, was used for the objective measurement of the vascular changes in psoriasis. Individual plaques were scanned, and tracings of the visible plaque edge taken on to a cellulose-acetate sheet from which area measurements were made using a digitizing tablet. Mean blood flux within plaques was increased fourfold compared with mean background flux. There was a highly significant linear correlation between plaque area measured by tracing and scanning, but area measured by scanning was greater. Detailed study of blood flux outside the visible plaque edge with the scanner, and with a conventional Iaser-Doppler instrument, showed this was due to a 2–4 mm rim of increased blood flux around plaques. The scanning laser-Doppler Velocimeter allows rapid measurement of psoriasis in terms of mean blood flux and area of increased blood flux, and should be useful in the assessment of psoriasis severity and the response to treatment.