1986 Fiscal Year Final Research Report Summary
High resolution apparatus for the measurement of brain microcirculation(blood, cerebrospinal fluid flow) by statistical processing of laser signal
| Project/Area Number |
59870048
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | Nagoya University |
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Principal Investigator |
KAGEYAMA NAOKI Nagoya University School of Medicine, 医学部, 教授 (90022813)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAZAKI YASUMITU Toyohasi University of Technology, 教授 (00023169)
KUCHIWAKI HIROJI Nagoya University School of Medicine, 医学部, 講師 (60135340)
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| Project Period (FY) |
1984 – 1986
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| Keywords | Blood / Cerebrospinal fluid / Laser doppler shift / Safty limit / LDV |
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| Research Abstract |
The aim of this study is noninvasively to measure blood or cerebrospinal fluid(CSF) flow through a wall of a small vessel with a diameter of 1-2 mm using laser doppler method(LDV).
Optical density of the laser beam(He-Ne, 632.8 nm, 27 mW) in blood or through the blood vessel wall (200 u) was enough for detecting laser doppler shift(dF) at the outside of the vessel. Flow velocity of CSF was evaluated through a semitranslucent tube of the ventriculo-peritoneal shunt. An experimental simulation of flow velocity was equipped by Harvard pump.
The most sensitive optical pathway was fringe mode for detecting dF. Simultaneous monitorings of dF were performed with an oscilloscope, a spectrum analyser and Fast Fourier Transformation(FFT). An optical fiber was used for receiving dF by a forward scattering system. Following points were important; 1) use of low cut filter(less than 1 kHz), 2) reliable cut off dF was able to obtain with averaging results of FFT by increasing of sampling number.
By these method linear relationships between dF and velocity of blood and CSF. Dangerous effects in the use of LDV to the wall of the blood vessels were histopathologically evaluated. Irradiations within 60 min as well as power of less than 13.5 mW of He-Ne laser beam (size 200 u) were found a safty limit in the examinations of LDV.
In conclusion, our study and apparatus of LDV are usefull for the noninvasive evaluations of the flow state in small vessels of the clinical materials.
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Research Products
(8 results)
