Determination of the Regional Function of the Heart

2002 ◽  
Author(s):  
Evren U. Azeloglu ◽  
Glenn R. Gaudette ◽  
Irvin B. Krukenkamp ◽  
Fu-Pen Chiang
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Speckle Pattern ◽  
Strain Tensor ◽  
Ccd Camera ◽  
Speckle Interferometry ◽  
Left Ventricular ◽  
Stroke Work ◽  
Regional Function

Unlike many other engineering designs, the heart, a pressure vessel, shows variations within its chambers and surface in terms of mechanical function. This necessitates a whole field technique with high spatial resolution. Computer aided speckle interferometry (CASI), a nondestructive examination technique, is herein developed for this purpose. A speckle pattern was created on the surface of isolated rabbit hearts. Images of the beating hearts werc acquired with a charge-couple device (CCD) camera for one second at a rate of 50 frames per second. CASI was used to determine the 2-D displacement vectors over regions of approximately 4 × 6 mm. Regional area stroke work (the integral of the left ventricular pressure with respect to area), the first invariant of the 2-D strain tensor, and the principle strains were used to determine the regional function. After occluding the blood supply to a region of the heart, significant changes were detected in all the previously mentioned parameters. Commonly used techniques cannot determine 2-D strain and lack the high spatial resolution of CASI. Determination of the 2-D strain can provide useful data on the functionality of the heart.

A Novel Technique for Measuring Regional Deformation With High Spatial Resolution in the Beating Heart

1999 ◽  
Author(s):  
Glenn R. Gaudette ◽  
Fu-Pen Chiang ◽  
Joseph Todaro ◽  
Irvin B. Krukenkamp
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Left Ventricular Pressure ◽  
Rabbit Heart ◽  
Speckle Interferometry ◽  
Left Ventricular ◽  
Beating Heart ◽  
Regional Function ◽  
Heterogeneous Distribution ◽  
Regional Deformation

Abstract Many diseases result in a heterogeneous distribution of regional function. This results in the need for a technique that can accurately measure deformation with high spatial resolution. We have developed computer aided speckle interferometry (CASI) to accomplish this task. Instead of tracking individual particles, CASI tracks clusters of particles. In the isolated beating rabbit heart, CASI was used to determine the simultaneous displacement of 625 points located in a region approximately 5.5 × 5.5 mm. These displacements were plotted as a function of the left ventricular pressure to generate a regional work loop, which has conventionally been used to determine regional function in the myocardium. In summary, we have developed a technique to measure regional function with high spatial resolution and applied it to the beating heart.

Using Computer Aided Speckle Interferometry to Measure Deformation in the Nonbeating Perfused Rabbit Heart

2000 ◽  
Author(s):  
Glenn R. Gaudette ◽  
Irvin B. Krukenkamp ◽  
Joseph Todaro ◽  
Fu-Pen Chiang ◽  
E. Guan
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Rabbit Heart ◽  
Speckle Interferometry ◽  
Ischemia And Reperfusion ◽  
Regional Function ◽  
Heterogeneous Distribution ◽  
Regional Deformation ◽  
Computer Aided ◽  
Individual Particles

Abstract Many diseases result in a heterogeneous distribution of regional function. This results in the need for a technique that can accurately measure deformation with high spatial resolution. We have developed computer aided speckle interferometry (CASI) to accomplish this task. Instead of tracking individual particles, CASI tracks clusters of particles. An isolated rabbit heart was arrested, and data was acquired in the perfused state, globally ischemic (15 min) state and reperfused state (10 min). CASI was used to determine the simultaneous deformation of over 1,000 points located in a region approximately 5.5 × 5.5 mm. A balloon was inserted into the left ventricle, and balloon pressure was increased from 5 to 20 mmHg. Ischemia and reperfusion resulted in a change in the epicardial deformation, leading to a change in principle strain from 2.8% to 4.5% (ischemia) to 2.8% (reperfused). A change in principle angle was also seen, with a 43° increase with 15 minutes of ischemia, and only a 10° change with reperfusion. In summary, we have a novel technique to measure regional deformation with high spatial resolution and found differences in the perfusion status of the heart.

Characterization and Control of Copper CMP with Optoacoustic Metrology

2001 ◽  
Vol 671 ◽  
Author(s):  
Michael Gostein ◽  
Paul Lefevre ◽  
Alex A. Maznev ◽  
Michael Joffe
Keyword(s):  
Film Thickness ◽  
Spatial Resolution ◽  
Chemical Mechanical Polishing ◽  
High Spatial Resolution ◽  
Mechanical Polishing ◽  
Length Measurement ◽  
And Control ◽  
Non Destructive

ABSTRACTWe discuss applications of optoacoustic film thickness metrology for characterization of copper chemical-mechanical polishing (CMP). We highlight areas where the use of optoacoustics for CMP characterization provides data complementary to that obtained by other techniques because of its ability to directly measure film thickness with high spatial resolution in a rapid, non-destructive manner. Examples considered include determination of planarization length, measurement of film thickness at intermediate stages of polish, and measurement of arrays of metal lines.

Ventricular function in the newborn lamb

1965 ◽  
Vol 208 (5) ◽  
pp. 931-937 ◽  
Author(s):  
S. Evans Downing ◽  
Norman S. Talner ◽  
Thomas H. Gardner
Keyword(s):  
Ventricular Function ◽  
Diastolic Pressure ◽  
Systemic Arterial Pressure ◽  
Left Ventricular ◽  
Stroke Work ◽  
Ventricular Mechanics ◽  
Inotropic State ◽  
Ejection Rate ◽  
Norepinephrine Infusion

The present study was initiated with the objective of evaluating in the newborn those aspects of ventricular mechanics which form the basis of the Frank-Starling relation, and which permit a determination of changes in the inotropic state of the heart. Left ventricular function was studied in lambs, 12 hr to 5 days old, utilizing a preparation designed to permit control and measurement of systemic arterial pressure (AP), cardiac output, heart rate (HR), and temperature. Continuous measurements of arterial Po2 and pH were made. These data permitted the construction of ventricular function curves relating stroke volume, mean ejection rate, and stroke work and power to left ventricular end-diastolic pressure, at constant AP and HR. In all preparations the Frank-Starling relation was found to be operative. Norepinephrine infusion, 1–2 µg/kg per min, resulted in a substantial increment of both force and speed parameters, thereby demonstrating the ability of the newborn heart to alter its inotropic state. Severe metabolic acidosis did not inhibit the response of the myocardium to norepinephrine.

scholarly journals Determination of Lateral Modulation Apodization Functions Using a Regularized, Weighted Least Squares Estimation

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Chikayoshi Sumi
Keyword(s):  
Least Squares ◽  
Spatial Resolution ◽  
Soft Tissues ◽  
Displacement Vector ◽  
Weighted Least Squares ◽  
Strain Tensor ◽  
Estimation Method ◽  
Modulation Method ◽  
Value Decomposition

Recently, work in this group has focused on the lateral cosine modulation method (LCM) which can be used for next-generation ultrasound (US) echo imaging and tissue displacement vector/strain tensor measurements (blood, soft tissues, etc.). For instance, in US echo imaging, a high lateral spatial resolution as well as a high axial spatial resolution can be obtained, and in tissue displacement vector measurements, accurate measurements of lateral tissue displacements as well as of axial tissue displacements can be realized. For an optimal determination of an apodization function for the LCM method, the regularized, weighted minimum-norm least squares (WMNLSs) estimation method is presented in this study. For designed Gaussian-type point spread functions (PSFs) with lateral modulation as an example, the regularized WMNLS estimation in simulations yields better approximations of the designed PSFs having wider lateral bandwidths than a Fraunhofer approximation and a singular-value decomposition (SVD). The usefulness of the regularized WMNLS estimation for the determination of apodization functions is demonstrated.

Submicrometre-resolution polychromatic three-dimensional X-ray microscopy

2012 ◽  
Vol 46 (1) ◽  
pp. 153-164 ◽  
Author(s):  
B. C. Larson ◽  
L. E. Levine
Keyword(s):  
Spatial Resolution ◽  
Elastic Strain ◽  
Strain Tensor ◽  
Three Dimensional ◽  
Direct Determination ◽  
Phase Identification ◽  
Sn Whisker ◽  
X Ray ◽  
Elastic Strain Tensor

The ability to study the structure, microstructure and evolution of materials with increasing spatial resolution is fundamental to achieving a full understanding of the underlying science of materials. Polychromatic three-dimensional X-ray microscopy (3DXM) is a recently developed nondestructive diffraction technique that enables crystallographic phase identification, determination of local crystal orientations, grain morphologies, grain interface types and orientations, and in favorable cases direct determination of the deviatoric elastic strain tensor with submicrometre spatial resolution in all three dimensions. With the added capability of an energy-scanning incident beam monochromator, the determination of absolute lattice parameters is enabled, allowing specification of the complete elastic strain tensor with three-dimensional spatial resolution. The methods associated with 3DXM are described and key applications of 3DXM are discussed, including studies of deformation in single-crystal and polycrystalline metals and semiconductors, indentation deformation, thermal grain growth in polycrystalline aluminium, the metal–insulator transition in nanoplatelet VO2, interface strengths in metal–matrix composites, high-pressure science, Sn whisker growth, and electromigration processes. Finally, the outlook for future developments associated with this technique is described.

scholarly journals Strain resolution of scanning electron microscopy based Kossel microdiffraction

2014 ◽  
Vol 47 (5) ◽  
pp. 1699-1707 ◽  
Author(s):  
D. Bouscaud ◽  
A. Morawiec ◽  
R. Pesci ◽  
S. Berveiller ◽  
E. Patoor
Keyword(s):  
Strain Tensor ◽  
Ccd Camera ◽  
Local Strain ◽  
X Ray Diffraction ◽  
Determination Process ◽  
Ni Alloy ◽  
Kossel Technique ◽  
Strain Determination ◽  
Scanning Electron

Kossel microdiffraction in a scanning electron microscope enables determination of local elastic strains. With Kossel patterns recorded by a CCD camera and some automation of the strain determination process, this technique may become a convenient tool for analysis of strains. As for all strain determination methods, critical for the applicability of the Kossel technique is its strain resolution. The resolution was estimated in a number of ways: from the simplest tests based on simulated patterns (of an Ni alloy), through analysis of sharp experimental patterns of Ge, to estimates obtained byin situtensile straining of single crystals of the Ni-based superalloy. In the latter case, the results were compared with those of conventional X-ray diffraction and synchrotron-based Kossel diffraction. In the case of high-quality Ge patterns, a resolution of 1 × 10−4was reached for all strain tensor components; this corresponds to a stress of about 10 MPa. With relatively diffuse patterns from the strained Ni-based superalloy, under the assumption of plane stress, the strain and stress resolutions were 3 × 10−4and 60 MPa, respectively. Experimental and computational conditions for achieving these resolutions are described. The study shows potential perspectives and limits of the applicability of semiautomatic Kossel microdiffraction as a method of local strain determination.

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