Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Reexamination Certificate
1999-12-02
2003-11-25
Le, Que T. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
C250S356200, C356S028000
Reexamination Certificate
active
06653651
ABSTRACT:
BACKGROUND
1. Field of Invention
This invention relates to instrumentation for measuring fluid motion, specifically the measurement of fluid motion at multiple points.
2. Discussion of Prior Art
Particle Image Velocimetry (PIV) is a technique in which one can measure the velocity of the flow at many, often thousands, of points in the flow simultaneously. Accurate velocity measurements of fluid motion using Particle Image Velocimetry (PIV) are typically on the order of 1 mm (see U.S. Pat. No. 5,333,044 to Shaffer, 1994, U.S. Pat. No. 5,249,238 to Komerath, 1993, U.S. Pat. No. 5,708,495 to Pitz, 1998, U.S. Pat. No. 5,979,245 to Hirano et al. 1999, Northrup, et al., 1991, and a review by Adrian, 1991).
The PIV technique was extended by Urushihara, et al. (1993) and then by Keane et al. (1995) to obtain velocity measurements with spatial resolutions on the order of 100-200 microns.
The first attempt at micron resolution velocimetry was conducted by Brody et al. (1996). They estimated velocity by measuring the image streaks of 0.7 micron diameter particles through a microscope. The resulting velocity measurements were sparse, randomly spaced, low quality, and only accurate to within about 30% full scale. In addition this technique was limited to relatively low velocities.
Lanzillotto et al. (1996) used an X-ray micron-imaging technique to image 1-20 micron diameter emulsion droplets flowing in water. The technique requires a synchrotron to generate the X-rays. We estimate the spatial resolution of this technique to be about 40-100 microns. The accuracy of the technique is limited because of noise in the image field, the size of the emulsion droplets (1-20 microns), and the dispersion of the emulsion droplets relative to the working fluid.
Paul et al. (1997) used a technique related to PIV to analyze to motion of fluorescent dye. We approximate the spatial resolution of this experiment to be on the order of 100 &mgr;m×20 &mgr;m×20 &mgr;m, based on the displacement of the fluorescent dye between exposures, and the thickness of the light sheet used to uncage the fluorescent dye. This technique can be used to measure only one component of velocity with reasonable accuracy.
Hitt, Lowe & Newcomer (1996) used a technique related to PIV, known at Optical Flow, to measure in vivo blood flow in microvascular networks. They used seed particles with diameters on the order of 10 microns. Their measurements were noisy and have low accuracy. We estimate the spatial resolution of this technique to be at best 20 microns in each dimension.
Laser Doppler Velocimetry (LDV) has been a standard technique in fluid mechanics more than 25 years. However, LDV systems can only measure velocities at single points. The spatial resolution of LDV systems is usually on the order of a few millimeters. However, there have been several attempts to increase the spatial resolution to a few microns. Compton & Eaton (1996) used short focal length optics to obtain measurements with spatial resolutions of 35 microns×66 microns. Tieu, Machenzie, & Li (1995) built a dual-beam solid-state LDA system that had a measurement volume of approximately 5 &mgr;m×10 &mgr;m. Gharib, Modares & Taugwalder (1998) have developed a Miniature Laser Doppler Anemometer (MLDA), which can be designed to have a measurement diameter (spatial resolution) as small as 10 microns. These LDV systems are limited because they all measure velocity at only a single point.
The Optical Doppler Tomography (ODT) system developed by Chen et al. (1997) uses 1.7 micron diameter particles to measure velocity with a lateral and longitudinal spatial resolution of 5 microns and 15 microns, respectively. The system is noisy and is limited (like LDV) to pointwise measurements. Objects and Advantages
Accordingly, several objects and advantages of the current invention are:
(a) to measure flow velocity with higher spatial resolution than other Particle Image Velocimetry (PIV) techniques;
(b) to measure flow velocity at many (often hundreds to thousands) points simultaneously throughout the flow field;
(c) to measure flow velocity at regularly spaced grid points simultaneously throughout the flow field;
(d) to measure flow velocity with low noise and high accuracy;
(e) to measure flow velocity accurately very close to surfaces;
(f) to measure flow velocity over a large range of magnitudes;
(g) to measure flow velocity with high temporal resolution.
Additional objects and advantages are:
(a) to measure instantaneous structures in the flow field, including but not limited to air bubbles and meniscus shapes and positions in liquid flows;
(b) to measure high resolution velocity fields without using fluorescent particles;
(c) the ability to measure flow inside non-transparent devices;
Further objects and advantages will become apparent from a consideration of the drawings and ensuing description.
REFERENCES:
patent: 4919536 (1990-04-01), Komine
patent: 5124071 (1992-06-01), Katz
patent: 5249238 (1993-09-01), Komerath et al.
patent: 5333044 (1994-07-01), Shaffer
patent: 5594544 (1997-01-01), Horiuchi et al.
patent: 5708495 (1998-01-01), Pitz et al.
patent: 5979245 (1999-11-01), Hirano et al.
P.H. Paul, M.G. Garguilo and D.J. Rakestraw, “Imaging of Pressure and Electrokinetically Driven Flows through Open Capillaries”, Analytical Chemistry, vol. 70, No. 13, Jul. 1, 1998, pp. 2459-2467.*
RD Keane, RJ Adrian, Y Zhang, “Super-resolution Particle Imaging Velocimetry” Meas. Sci. Technol. vol. 6 (1995) pp. 754-768, United Kingdom.
Darren L. Hitt, Mary L. Lowe, Ryan Newcomer “Application of Optical Flow Techniques to flow velocimetry” Phys. Fluids., vol. 7, No. 1, pp. 6-8, Jan. 1995 American Institute of Physics.
D.L. Hitt and M.L. Lowe, “Confocal Imaging and Numerical Simulations of Converging Flow in Artificial Microvessels” Physics Dept. Loyala College, Baltimore, MD.
Darren L. Hitt, Mary L. Lowe, Juvena R. Tincher, J. Michael Watters, “A New Method for Blood Velocimetry in the Microcirculation” Microcirculation 1996 vol. 3, No. 3, pp. 259-263.
Ronald J. Adrian, “Particle-Imaging Techniques for Experimental Fluid Mechanics,” Annu. Rev. Fluid Mech. 1991 23:261-304.
M. Allen Northrup, Thomas J. Kulp, S. Michael Angel, “Fluorescent Particle Image Volocimetry: Application to Flow Measurement in Refractive Index-Matched Porous Media”, Applied Optics, vol. 30, No. 21, Jul. 20, 1991.
A.K. Tieu, M.R. Mackenzie, E.B. Li, “Measurements in Microscopic Flow with a Solid-State LDA”, Experiments in Fluids 19 (1995) 293-294, Springer-Verlag 1995.
James P. Brody, Paul Yager, Raymond E. Goldstein, Robert H. Austin, “Biotechnology at Low Reynolds Numbers” Biophysical Journal vol. 71 Dec. 1996 3430-3441.
A-M. Lanzillotto, T-S. Leu, M. Amabile, R. Samtaney, R. Wildes “A Study of Structure and Motion in Fluid Microsystems” American Institute of Aeronautics and Astronautics, Reston, VA 1997.
P.H. Paul, M.G. Garguilo, D.J. Rakestraw, “Imaging of Pressure-and Electrokinetically-Driven Flows Through Open Capillaries” Sandia National Laboratories Livermore, CA 1997.
Z. Hongping Chen, Thomas E. Milner, Digant Dave, J. Stuart Nelson, “Optical Doppler Tomographic Imaging of Fluid Flow Velocity in Highly Scattering Media”, pp. 64-66, Optic Letters/vol. 22, No. 1/Jan. 1, 1997.
J.G. Santiago, S.T. Wereley, C.D. Meinhart, D.J. Beebe, R.J. Adrian, “A Particle Image Velocimetry System for Microfluidics”, Experiments in Fluids 25(1998) 316-319 Springer-Verlag 1998.
Mory Gharib, Darius Modares, Fredereck Taugwalder, “Development of a Miniature and Microlaser Doppler Anemometer,” California Institute of Technology.
C.D. Meinhart, S.T. Wereley, J.G. Santiago, “PIV Measurements of a Microchannel Flow”, Experiments in Fluids, 1999.
Carl D. Meinhart, Steve T. Wereley, Juan G. Santiago, “A PIV Algorithm for Estimating Time-Averaged Velocity Fields”, ASME/JSME Fluids Engr'r Conf., ASME 1999.
Adrian Ronald J.
Meinhart Carl D.
Santiago Juan G.
Wereley Steve T.
Arant Gene W.
Le Que T.
Luu Thanh X.
LandOfFree
Micron resolution particle image velocimeter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Micron resolution particle image velocimeter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Micron resolution particle image velocimeter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3166837