scholarly journals An Atomic Force Acoustic Microscopy Image Fusion Method Based on Grayscale Inversion and Selection of Best-Fit Intensity

2020 ◽  
Vol 10 (23) ◽  
pp. 8645
Author(s):  
Zhaozheng Chen ◽  
Xiaoqing Li ◽  
Mingyue Ding
Keyword(s):  
Mutual Information ◽  
Visual Information ◽  
Acoustic Microscopy ◽  
Atomic Force ◽  
Acoustic Images ◽  
Internal Structures ◽  
Microscopy Image ◽  
Information Fidelity ◽  
Best Fit ◽  
Selection Of

Atomic force acoustic microscopy (AFAM) can provide surface morphology and internal structures of the samples simultaneously, with broad potential in non-destructive imaging of cells. As the output of AFAM, morphology and acoustic images reflect different features of the cells, respectively. However, there are few studies about the fusion of these images. In this paper, a novel method is proposed to fuse these two types of images based on grayscale inversion and selection of best-fit intensity. First, grayscale inversion is used to transform the morphology image into a series of inverted images with different average intensities. Then, the max rule is applied to fuse those inverted images and acoustic images, and a group of pre-fused images is obtained. Finally, a selector is employed to extract and export the expected image with the best-fit intensity among those pre-fused images. The expected image can preserve both the acoustic details of the cells and the background’s gradient information well, which benefits the analysis of the cell’s subcellular structure. The experiments’ results demonstrated that our method could provide the clearest boundaries between the cells and background, and preserve most details from the morphology and acoustic images according to quantitative comparisons, including standard deviation, mutual information, Xydeas and Petrovic metric, feature mutual information, and visual information fidelity fusion.

Influence of Tip Wear on Atomic Force Acoustic Microscopy Experiments

2004 ◽  
Vol 838 ◽  
Keyword(s):  
Experimental Data ◽  
Contact Mechanics ◽  
Elastic Properties ◽  
Visual Information ◽  
Theoretical Models ◽  
Acoustic Microscopy ◽  
Sem Images ◽  
Atomic Force ◽  
Us Government ◽  
Tip Radius

ABSTRACTTip wear and its corresponding change in geometry is a major impediment for quantifying atomic force acoustic microscopy (AFAM). To better understand the process of tip wear and its influence on AFAM measurements of material elastic properties, we have performed a series of experiments and compared tip geometries calculated from experimental data with direct tip visualization in the scanning electron microscope (SEM). Using a sample with known elastic properties, the tip-sample contact stiffnesses for several different cantilevers were determined. Hertz and Derjaguin-Müller-Toporov (DMT) contact-mechanics models were applied to calculate values of the tip radius R from the experimental data. At the same time, values for R before and after each sequence of AFAM measurements were obtained from SEM images. Both methods showed that the tip radius increased with use. However, values of R calculated with the theoretical models varied indeterminately from those obtained from the SEM images. In addition, in some cases analysis of the AFAM measurements suggested a hemispherical tip, while the corresponding SEM images showed that the end of the tip was flat. We also observed other changes in tip shape, such as an increase in the tip width. By combining theoretical models for contact mechanics with visual information on the tip geometry we hope to better understand contact characteristic in AFM-based systems.Contribution of NIST, an agency of the US government; not subject to copyright.

scholarly journals A Fusion Method for Atomic Force Acoustic Microscopy Cell Imaging Based on Local Variance in Non-Subsampled Shearlet Transform Domain

2020 ◽  
Vol 10 (21) ◽  
pp. 7424
Author(s):  
Pengxin Cao ◽  
Xiaoqing Li ◽  
Mingyue Ding
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Acoustic Microscopy ◽  
Source Image ◽  
Fusion Method ◽  
Cell Region ◽  
Shearlet Transform ◽  
Local Variance ◽  
Atomic Force ◽  
Internal Structures

Atomic force acoustic microscopy (AFAM) is a measurement method that uses the probe and acoustic wave to image the surface and internal structures of different materials. For cellular material, the morphology and phase images of AFAM reflect the outer surface and internal structures of the cell, respectively. This paper proposes an AFAM cell image fusion method in the Non-Subsampled Shearlet Transform (NSST) domain, based on local variance. First, NSST is used to decompose the source images into low-frequency and high-frequency sub-bands. Then, the low-frequency sub-band is fused by the weight of local variance, while a contrast limited adaptive histogram equalization is used to improve the source image contrast to better express the details in the fused image. The high-frequency sub-bands are fused using the maximum rule. Since the AFAM image background contains a lot of noise, and improved segmentation algorithm based on the Otsu algorithm is proposed to segment the cell region, and the image quality metrics based on the segmented region will make the evaluation more accurate. Experiments with different groups of AFAM cell images demonstrated that the proposed method can clearly show the internal structures and the contours of the cells, compared with traditional methods.

scholarly journals Noninvasive Subcellular Imaging Using Atomic Force Acoustic Microscopy (AFAM)

Cells ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 314 ◽  
Author(s):  
Xiaoqing Li ◽  
Ang Lu ◽  
Wenjie Deng ◽  
Li Su ◽  
Jing Wang ◽  
...  
Keyword(s):  
Acoustic Microscopy ◽  
Strong Basis ◽  
Atomic Force ◽  
Cell Structures ◽  
Internal Structures ◽  
Nondestructive Imaging ◽  
Structural Image ◽  
Multiple Samples ◽  
Pseudo Color ◽  
Unique Potential

We report an imaging approach applying the atomic force acoustic microscopy (AFAM), which has unique potential for nondestructive imaging of cell internal structures. To obtain high spatial resolution images, we optimized the significant imaging parameters, including scanning speeds, feedback configurations and acoustic frequencies of an AFAM system, to increase the amplitude of the acoustic signal and to stabilize the morphological signals. We also combined the acoustic amplitude and phase signals, and generated pseudo-color figures for better illustration of subcellular features such as pseudopodia, membranes and nucleus-like. The subcellular structural image atlas can describe nanoscale details of multiple samples and provide clearer images of the subcellular features compared to other conventional techniques. This study builds a strong basis of transmission AFAM for cell imaging, which can help researchers to clarify the cell structures in diverse biological fields and push the understanding of biology evolution to a new stage.

Study of the elastic properties of sprayed SnO2 and SnS2 layers

2000 ◽  
Vol 77 (9) ◽  
pp. 705-715
Author(s):  
M Mnari ◽  
B Cros ◽  
M Amlouk ◽  
S Belgacem ◽  
D Barjon
Keyword(s):  
High Frequency ◽  
Chemical Structure ◽  
Spray Pyrolysis Technique ◽  
Acoustic Microscopy ◽  
Acoustic Parameters ◽  
Force Microscopy ◽  
Photovoltaic Application ◽  
Atomic Force ◽  
Acoustic Signature ◽  
Acoustic Images

SnO2 and SnS2 thin films have been prepared by the spray pyrolysis technique for photovoltaic application purposes and characterized by high-frequency acoustic microscopy (570 MHz).The surface acoustic images reveal contrasts explained by differences in topography according to atomic force microscopy studies. The acoustic signature V(z) of the systemslayer/substrate were modelled and refined to fit with the experimental V(z). The acoustic parameters of the layers were calculated using the results of the final simulation. The values of Young's modulus deduced from the acoustic parameters, 401 and 56 GPa for SnO2 and SnS2, respectively, are discussed in relation with the chemical structure and bonding involved. PACS Nos.: 43.35Ns and 62.65

scholarly journals Visual Information Fidelity with better Vision Models and better Mutual Information Estimates

2021 ◽  
Vol 21 (9) ◽  
pp. 2351
Author(s):  
Jesus Malo ◽  
BENYAMIN KHERAVDAR ◽  
QIANG LI
Keyword(s):  
Mutual Information ◽  
Visual Information ◽  
Information Fidelity

Atomic force acoustic microscopy characterization of carbon-based materials

2007 ◽  
Author(s):  
D. Passeri ◽  
A. Bettucci ◽  
M. Germano ◽  
A. Biagioni ◽  
M. Rossi ◽  
...  
Keyword(s):  
Acoustic Microscopy ◽  
Atomic Force ◽  
Microscopy Characterization ◽  
Carbon Based

scholarly journals Use of Ultrasound Microscopy for Ex Vivo Analysis of Acoustic Impedance in Mouse Liver with Steatohepatitis

Acoustics ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 3-10
Author(s):  
Hideki Kumagai ◽  
Kazuto Kobayashi ◽  
Sachiko Yoshida ◽  
Koji Yokoyama ◽  
Norio Hirota ◽  
...  
Keyword(s):  
Acoustic Impedance ◽  
Ex Vivo ◽  
Acoustic Microscopy ◽  
Control Group ◽  
Scanning Acoustic Microscopy ◽  
Central Frequency ◽  
Deficient Diet ◽  
Acoustic Images ◽  
Ultrasound Microscopy

Scanning acoustic microscopy reveals information on histology and acoustic impedance through tissues. The objective of the present study was to investigate whether acoustic impedance values in the liver over time reflect the progression of steatohepatitis through different grades and stages, and whether this approach can visualize histologic features of the disease. Mice were divided into two groups: a control group and a steatohepatitis group prepared by keeping the mice on a methionine and choline-deficient diet for 56 weeks. The hepatic lobe was excised for measurement of impedance and observation of microscopic structure using a commercially available scanning acoustic microscopy system with a central frequency of 320 MHz. Scanning acoustic microscopy revealed that acoustic impedance through liver tissue with steatohepatitis temporarily decreased with the degree of fat deposition and then increased in parallel with the progression of inflammation and fibrosis. However, the acoustic images obtained did not allow discrimination of detailed microstructures from those seen using light microscopy. In conclusion, estimation of acoustic impedance appears to have potential clinical applications, such as for monitoring or follow-up studies.

scholarly journals Measurement of the Indentation Modulus and the Local Internal Friction in Amorphous SiO2 Using Atomic Force Acoustic Microscopy

2016 ◽  
Vol 61 (1) ◽  
pp. 9-12
Author(s):  
B. Zhang ◽  
H. Wagner ◽  
M. Büchsenschütz-Göbeler ◽  
Y. Luo ◽  
S. Küchemann ◽  
...  
Keyword(s):  
Internal Friction ◽  
Amorphous Materials ◽  
Contact Stiffness ◽  
Ultrasonic Transducer ◽  
Amorphous Material ◽  
Acoustic Microscopy ◽  
Damping Factor ◽  
Indentation Modulus ◽  
Amorphous Sio2 ◽  
Atomic Force

Abstract For the past two decades, atomic force acoustic microscopy (AFAM), an advanced scanning probe microscopy technique, has played a promising role in materials characterization with a good lateral resolution at micro/nano dimensions. AFAM is based on inducing out-of-plane vibrations in the specimen, which are generated by an ultrasonic transducer. The vibrations are sensed by the AFM cantilever when its tip is in contact with the material under test. From the cantilver’s contactresonance spectra, one determines the real and the imaginary part of the contact stiffness k*, and then from these two quantities the local indentation modulus M' and the local damping factor Qloc-1 can be obtained with a spatial resolution of less than 10 nm. Here, we present measured data of M' and of Qloc-1 for the insulating amorphous material, a-SiO2. The amorphous SiO2 layer was prepared on a crystalline Si wafer by means of thermal oxidation. There is a spatial distribution of the indentation modulus M' and of the internal friction Qloc-1. This is a consequence of the potential energy landscape for amorphous materials.

Input Vector Identification and System Model Construction by Average Mutual Information

2000 ◽  
Author(s):  
Paul B. Deignan ◽  
Peter H. Meckl ◽  
Matthew A. Franchek ◽  
Salim A. Jaliwala ◽  
George G. Zhu
Keyword(s):  
Mutual Information ◽  
System Model ◽  
Input Output ◽  
Output Data ◽  
Average Mutual Information ◽  
Virtual Sensors ◽  
Input Signals ◽  
Model Independent ◽  
Intelligent Model ◽  
Selection Of

Abstract A methodology for the intelligent, model-independent selection of an appropriate set of input signals for the system identification of an unknown process is demonstrated. In modeling this process, it is shown that the terms of a simple nonlinear polynomial model may also be determined through the analysis of the average mutual information between inputs and the output. Average mutual information can be thought of as a nonlinear correlation coefficient and can be calculated from input/output data alone. The methodology described here is especially applicable to the development of virtual sensors.

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