1999 Fiscal Year Final Research Report Summary
Development of Portable Fiber-Optic Laser Doppler Velocimetry Sensor for Measurement of Local Flow Velocity of Blood and Opaque Multi-Phase Fluids
| Project/Area Number |
09555067
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Fluid engineering
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| Research Institution | Kansai University |
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Principal Investigator |
OHBA Kenkichi Kansai University, Faculty of Engineering, Professor, 工学部, 教授 (30029186)
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| Co-Investigator(Kenkyū-buntansha) |
SAKURAI Atsushi Kansai University, Faculty of Engineering, Assistant, 工学部, 助手 (50162334)
BANDO Kiyoshi Kansai University, Faculty of Engineering, Professor, 工学部, 教授 (70156545)
SATO Yukinari Kanomax Research Institute Co., LTD., Vice President, 副社長
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| Project Period (FY) |
1997 – 1999
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| Keywords | Fiber optic sensor / Laser Doppler velocimetry sensor / Blood flow measurement / Opaque fluid flow measurement / Distributed index lens / Obliquely truncated conical head / Sensor head incorporated inside syringe needle / Insertion into blood vessel |
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| Research Abstract |
In order to measure the local velocity field in opaque fluids like blood and/or multi-phase fluids, a new fiber-optic laser Doppler velocimetry sensor has been developed. In the course of the present research for the development the followings have been elucidated :
After obtaining the characteristics of laser light extinction in bovine blood of several different dilution rates and in mixtures of white pigment and water, the flow velocity of diluted bovine blood contained in an annular open channel which is placed on a rotating disc has been measured by using the present fiber optic sensor. Its pickup consists of a distributed index lens of 2mm in diameter attached at the tip of two fibers being joined side by side in parallel. Although the sensor is capable of making a accurate measurement of local velocity of diluted blood up to 20%, it cannot measure the velocity of thicker blood, because the blood used is considered to has worse quality than intact blood in vivo.
The sensor head has
… More
been improved ; Firstly, its tip is shaped to have an obliquely truncated cone in order to decrease a disturbance of flow by the head and also to diminish undesirable light scattered from the tip of the head. Secondly, a smaller DIL lens of 1mm in diameter is adopted instead of the 2mm- diameter DIL lens to make it inserted inside of the needle of a hypodermic syringe. Thirdly, a mono-fiber optical system is adopted instead of the dual-fiber optical system to increase the sensitivity for opaque fluid. Fourthly, a bonding agent of being hardened by ultraviolet light is used between the fiber and the DIL lens to diminish an undesirable scattered light. As a result, the maximum measurable concentration of the semi-opaque suspension fluid is increase to be four times greater than the original one.
By inserting the improved sensor head incorporated inside the syringe needle into a modeled blood vessel of silicone rubber, a high concentration suspension fluid of white pigment as a model blood flowing in the tube has been measured. As a result, the velocity distribution of a paraboloid of revolution characterizing the developed steady laminar flow is accurately obtained. Hence, it can be concluded that the prospect of success is good to measure the local blood velocity in blood vessel in vivo by directly inserting the sensor head into the vessel. Less
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