High Speed Micro Holographic PIV Measurements of Microorganisms

2008 ◽  
Author(s):  
M. Zarzecki ◽  
F. J. Diez
Keyword(s):  
Velocity Field ◽  
High Speed ◽  
Fourier Transforms ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Imaging Method ◽  
Time Resolved ◽  
Feeding Methods ◽  
Holographic Particle Image Velocimetry ◽  
Three Components

Holographic particle image velocimetry (PIV) is a novel application of holography that allows for tracking of small particle sized objects in a small volume. Whereas regular PIV allows for the two in-plane components of the velocity field to be measured, and stereoscopic PIV allows for the three-components of the velocity field to be measured in a thin plane, holographic PIV allows for the three-components of the velocity to be measured for each individual particle present in the measuring volume, thus allowing to fully resolve fluid flows that are inherently 3D in nature. There are many examples of three dimensional flows in nature including turbulence flows, but another very interesting application very well suited for this technique involves tracking living microorganisms in order to study their motion and their means of propulsion. As part of this research a micro organism was tracked in three dimensions using a high speed microscopic holographic imaging method. The ability to track organisms in 3D allows better understanding and characterizing of their behavior including their propulsion methods, their feeding methods and their interaction with each other. The time resolved holograms were reconstructed in Matlab using Fast Fourier Transforms. A laser pointer was used as a source of coherent light, and a high speed PIV camera (Photron APX Ultima) was used to capture the images. A beam expander was used to increase the diameter of the laser beam allowing for a larger tracking area. Results with this system will show the trajectories in 3D of microorganisms as well as the three components of the velocity field showing the interaction of the organisms with their environment.

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

Three-dimensional reconstruction of metabolic data from quantitative autoradiography of rat brain

1984 ◽  
Vol 247 (3) ◽  
pp. E412-E419 ◽  
Author(s):  
L. S. Hibbard ◽  
R. A. Hawkins
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Image Data ◽  
Brain Structures ◽  
Three Dimensions ◽  
Quantitative Autoradiography ◽  
Alignment Algorithm ◽  
Computer Methods ◽  
Mathematical Properties ◽  
Dimensional Reconstruction

Quantitative autoradiography is a powerful method for studying brain function by the determination of blood flow, glucose utilization, or transport of essential nutrients. Autoradiographic images contain vast amounts of potentially useful information, but conventional analyses can practically sample the data at only a small number of points arbitrarily chosen by the experimenter to represent discrete brain structures. To use image data more fully, computer methods for its acquisition, storage, quantitative analysis, and display are required. We have developed a system of computer programs that performs these tasks and has the following features: 1) editing and analysis of single images using interactive graphics, 2) an automatic image alignment algorithm that places images in register with one another using only the mathematical properties of the images themselves, 3) the calculation of mean images from equivalent images in different experimental serial image sets, 4) the calculation of difference images (e.g., experiment-minus-control) with the option to display only differences estimated to be statistically significant, and 5) the display of serial image metabolic maps reconstructed in three dimensions using a high-speed computer graphics system.

Three Dimensional Imaging of LIGA-Made Microcomponents

2004 ◽  
Vol 126 (4) ◽  
pp. 813-821 ◽  
Author(s):  
Douglas Chinn ◽  
Peter Ostendorp ◽  
Mike Haugh ◽  
Russell Kershmann ◽  
Thomas Kurfess ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
High Speed ◽  
Three Dimensional ◽  
Point Clouds ◽  
Three Dimensions ◽  
Cad Model ◽  
Volumetric Imaging ◽  
Data Registration ◽  
Liga Technology ◽  
Coordinate Metrology

Nickel and nickel-alloy microparts sized on the order of 5–1000 microns have been imaged in three dimensions using a new microscopic technique, Digital Volumetric Imaging (DVI). The gears were fabricated using Sandia National Laboratories’ LIGA technology (lithography, molding, and electroplating). The images were taken on a microscope built by Resolution Sciences Corporation by slicing the gear into one-micron thin slices, photographing each slice, and then reconstructing the image with software. The images were matched to the original CAD (computer aided design) model, allowing LIGA designers, for the first time, to see visually how much deviation from the design is induced by the manufacturing process. Calibration was done by imaging brass ball bearings and matching them to the CAD model of a sphere. A major advantage of DVI over scanning techniques is that internal defects can be imaged to very high resolution. In order to perform the metrology operations on the microcomponents, high-speed and high-precision algorithms are developed for coordinate metrology. The algorithms are based on a least-squares approach to data registration the {X,Y,Z} point clouds generated from the component surface onto a target geometry defined in a CAD model. Both primitive geometric element analyses as well as an overall comparison of the part geometry are discussed. Initial results of the micromeasurements are presented in the paper.

A modified Fresnel-based algorithm for 3D microwave imaging of metal objects

2018 ◽  
Vol 11 (4) ◽  
pp. 313-325
Author(s):  
Farshad Zamiri ◽  
Abdolreza Nabavi
Keyword(s):  
High Speed ◽  
Fourier Transforms ◽  
Low Cost ◽  
Three Dimensional ◽  
Computation Time ◽  
Microwave Imaging ◽  
Reconstruction Algorithms ◽  
Clock Frequency ◽  
Pipeline Architecture ◽  
The Impact

AbstractMicrowave holography technique reconstructs a target image using recorded amplitudes and phases of the signals reflected from the target with Fast Fourier Transform (FFT)-based algorithms. The reconstruction algorithms have two or more steps of two- and three-dimensional Fourier transforms, which have a high computational load. In this paper, by neglecting the impact of target depth on image reconstruction, an efficient Fresnel-based algorithm is proposed, involving only one-step FFT for both single- and multi-frequency microwave imaging. Numerous tests have been performed to show the effectiveness of the proposed algorithm including planar and non-planar targets, using the raw data gathered by means of a scanner operating in X-band. Finally, a low-cost and high-speed hardware architecture based on fixed-point arithmetic is introduced which reconstructs the planar targets. This pipeline architecture was tested on field programmable gate arrays operating at 200 MHz clock frequency, which illustrates more than 30 times improvement in computation time compared with a computer.

Time-Resolved Thermoreflectance Imaging for Thermal Testing and Analysis

2013 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Dustin Kendig ◽  
Ali Shakouri
Keyword(s):  
Thermal Imaging ◽  
High Speed ◽  
Near Infrared ◽  
Infrared Emission ◽  
Dynamic Imaging ◽  
Thermal Testing ◽  
Imaging Method ◽  
Time Resolved ◽  
Microelectronic Devices ◽  
Lock In

Abstract High speed, time-resolved, thermoreflectance imaging is a novel way to locate defects or regions of potential failures in microelectronic devices. This paper reports on our thermoreflectance technique for dynamic imaging of circuit temperature distributions. This transient imaging method is based on a precise electrical lock-in technique with image processing similar to an old fashioned animation movie. An ordinal shutter speed camera is used in conjunction with an illumination LED that is pulsed for sampling the temperature distribution. This paper presents the method and gives a description of the system hardware. A theoretical comparison to lock-in thermography, which is based on infrared emission imaging, will be given. Limitations of thermoreflectance and the driving factors for spatial and time resolution will be discussed. Finally, we highlight and provide examples of near infrared (NIR) wavelength imaging, to enable both through-silicon thermal imaging and emission imaging in the same system. The combination of these two techniques is expected to enable hotspot temperatures and any anomalous emission sites to be correlated, hopefully leading to a better understanding of the nature of the defect.

Diffusion of Slightly Buoyant Droplets in Isotropic Turbulence

2006 ◽  
Author(s):  
Balaji Gopalan ◽  
Edwin Malkiel ◽  
Joseph Katz
Keyword(s):  
High Speed ◽  
Isotropic Turbulence ◽  
Three Dimensional ◽  
Time History ◽  
Region Of Interest ◽  
Frame Rate ◽  
Three Dimensions ◽  
Velocity Autocorrelation Function ◽  
Mean Flow ◽  
Dispersion Tensor

We study the diffusion of slightly buoyant droplets in isotropic turbulence using High Speed Digital Holographic PIV. Droplets (Specific Gravity 0.85) are injected in the central portion of an isotropic turbulence facility with weak mean flow. Perpendicular digital inline holograms are recorded in a 37 × 37 × 37 mm3 region of interest using two high speed cameras. Data are recorded at 250 frames per second (2000 frames per second is the maximum possible frame rate). An automated program is developed to obtain two dimensional tracks of the droplets from two orthogonal images and match them to get three dimensional tracks. Cross correlation of droplet images are used for measuring their velocities. The time series are low pass filtered to obtain accurate time history of droplet velocities. Data analysis determines the PDF of velocity and acceleration in three dimensions. The time history also enables us to calculate the three dimensional Lagrangian velocity autocorrelation function for different droplet radii. Integration of these functions gives us the diffusion coefficients. For shorter time scales, when the diffusion need not be Fickian we can use the three dimensional trajectories to calculate the generalized dispersion tensor and measure the time elapsed for diffusion to become Fickian.

scholarly journals A FRAMEWORK FOR RELIABLE THREE-DIMENSIONAL UNDERGROUND UTILITY MAPPING FOR URBAN PLANNING

2018 ◽  
Vol XLII-4/W10 ◽  
pp. 209-214 ◽  
Author(s):  
R. van Son ◽  
S. W. Jaw ◽  
J. Yan ◽  
V. Khoo ◽  
R. Loo ◽  
...  
Keyword(s):  
Urban Planning ◽  
High Speed ◽  
Large Scale ◽  
Three Dimensional ◽  
Research Literature ◽  
Three Dimensions ◽  
3D Mapping ◽  
Literature Study ◽  
Underground Utilities ◽  
Utility Services

<p><strong>Abstract.</strong> To optimise the use of limited available land, land-scarce cities such as Singapore are increasingly looking towards the underground in search of more space. A good understanding of what already exists underground is essential for the planning of underground spaces. In particular, utility services make up a significant part of what exists underground. To meet planning needs, the Singapore government has initiated efforts towards bringing records of existing utility networks together in a single database and share its contents to support planning, design, and construction of underground developments. However, these records can not be relied on to support these critical processes: They are not guaranteed to represent today’s state of the underground, are not accurate or of unknown accuracy, are inconsistently modelled, and may indicate as-design information instead of as-built information. This lack of reliability leads to an increase in cost and a loss in efficiency caused by the need to repeatedly survey to locate existing utility services on-site, and can have potentially disastrous outcomes when an excavation would damage existing services. Technological advances in utility surveying and mapping devices such as Ground Penetrating Radar (GPR) and gyroscopic pipeline mapping devices offer the potential of accurately mapping utilities in three dimensions (3D) at a large scale and high speed. However, a better understanding of the benefits and limitations of these technologies in a practical context is needed, as well as their suitability for mapping to support applications such as urban planning and land administration. The Digital Underground project is a collaboration between Singapore-ETH Centre, Singapore Land Authority and the City of Zürich that aims to develop a roadmap towards a reliable 3D utility map of Singapore. To enable the development of utility mapping standards and guidelines, the 3D mapping workflow for underground utilities is studied extensively based on market research, literature study, and case studies. This work presents the beginnings of a framework for 3D mapping of underground utilities as one of the initial results of the Digital Underground project as it is in progress. From these experiences, it can be concluded that, together with existing data, data captured using various surveying methods can indeed contribute to the establishment and maintenance of a consolidated and reliable utility map. To this end, a multi-sensor, multi-data 3D mapping workflow is proposed to integrate data captured using different surveying techniques during different moments in the development lifecycle of utilities. Based on this framework, this work also identifies areas for improvement and critical gaps to be bridged that will ultimately form part of the roadmap.</p>

Three-Dimensional Evaluation of Facial Asymmetry in Cleft Lip and Palate

1994 ◽  
Vol 31 (2) ◽  
pp. 116-121 ◽  
Author(s):  
Frank Ras ◽  
Luc L.M.H. Habets ◽  
Floris C. Van Ginkel ◽  
Birte Prahl-Andersen
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Facial Asymmetry ◽  
Three Dimensions ◽  
Control Group ◽  
Craniofacial Anomalies ◽  
Facial Landmarks ◽  
Three Components

The purpose of the present study was to describe facial asymmetry in three dimensions in individuals with an operated complete unilateral cleft lip and palate (UCLP) and in individuals without craniofacial anomalies (controls). Three-dimensional coordinates for 16 bilateral and 10 midsagittal facial landmarks were determined for the UCLP group (N=49) and the control group (N=80) by means of stereophotogrammetry. The total asymmetry was measured and resolved for transverse, vertical, and sagittal components. It can be concluded that all three components are Important in studies on facial asymmetry. Individuals with UCLP show more facial asymmetry in the vertical direction than controls. They demonstrate more facial asymmetry in the region related to the cleft than controls. And, males in general demonstrate more asymmetry of the nose than females.

scholarly journals Time-resolved scanning ion conductance microscopy for three-dimensional tracking of nanoscale cell surface dynamics

2021 ◽  
Author(s):  
Samuel M. Leitao ◽  
Barney Drake ◽  
Katarina Pinjusic ◽  
Xavier Pierrat ◽  
Vytautas Navikas ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Cellular Structures ◽  
Surface Dynamics ◽  
Dynamic Changes ◽  
Ion Conductance ◽  
Time Resolved ◽  
Scanning Ion Conductance Microscopy ◽  
3D Information

Understanding cellular function requires high-resolution information about cellular structures as well as their evolution over time. The major challenge is to obtain three-dimensional (3D) information at nanometer resolution without affecting the viability of the cells and avoiding interference with the process. Here, we develop a scanning ion conductance microscope (SICM) for high-speed and long term imaging that can resolve spatiotemporally diverse processes on the cell membrane. We tracked dynamic changes in live cell morphology with nanometer details and temporal ranges of sub-second to days, imagining diverse processes ranging from endocytosis, micropinocytosis, and mitosis, to bacterial infection and cell differentiation in cancer cells. This technique enables a detailed look at membrane events and may offer insights into cell-cell interactions for infection, immunology, and cancer research.

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