scholarly journals Ex vivo infiltration of fibroblasts into the tendon deteriorates the mechanical properties of tendon fascicles but not those of tendon bundles

2007 ◽  
Vol 22 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Yasunari Ikema ◽  
Harukazu Tohyama ◽  
Ei Yamamoto ◽  
Fuminori Kanaya ◽  
Kazunori Yasuda
Keyword(s):  
Mechanical Properties ◽  
Ex Vivo

scholarly journals Harmonic motion imaging of human breast masses: an in vivo clinical feasibility

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Niloufar Saharkhiz ◽  
Richard Ha ◽  
Bret Taback ◽  
Xiaoyue Judy Li ◽  
Rachel Weber ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Malignant Tumors ◽  
Ex Vivo ◽  
Benign Tumors ◽  
Cancerous Tissue ◽  
Breast Masses ◽  
Harmonic Motion ◽  
Harmonic Motion Imaging ◽  
Motion Imaging

Abstract Non-invasive diagnosis of breast cancer is still challenging due to the low specificity of the imaging modalities that calls for unnecessary biopsies. The diagnostic accuracy can be improved by assessing the breast tissue mechanical properties associated with pathological changes. Harmonic motion imaging (HMI) is an elasticity imaging technique that uses acoustic radiation force to evaluate the localized mechanical properties of the underlying tissue. Herein, we studied the in vivo feasibility of a clinical HMI system to differentiate breast tumors based on their relative HMI displacements, in human subjects. We performed HMI scans in 10 female subjects with breast masses: five benign and five malignant masses. Results revealed that both benign and malignant masses were stiffer than the surrounding tissues. However, malignant tumors underwent lower mean HMI displacement (1.1 ± 0.5 µm) compared to benign tumors (3.6 ± 1.5 µm) and the adjacent non-cancerous tissue (6.4 ± 2.5 µm), which allowed to differentiate between tumor types. Additionally, the excised breast specimens of the same patients (n = 5) were imaged post-surgically, where there was an excellent agreement between the in vivo and ex vivo findings, confirmed with histology. Higher displacement contrast between cancerous and non-cancerous tissue was found ex vivo, potentially due to the lower nonlinearity in the elastic properties of ex vivo tissue. This preliminary study lays the foundation for the potential complementary application of HMI in clinical practice in conjunction with the B-mode to classify suspicious breast masses.

scholarly journals Ex-Vivo Force Spectroscopy of Intestinal Mucosa Reveals the Mechanical Properties of Mucus Blankets

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Javier Sotres ◽  
Skaidre Jankovskaja ◽  
Kristin Wannerberger ◽  
Thomas Arnebrant
Keyword(s):  
Mechanical Properties ◽  
Intestinal Mucosa ◽  
Ex Vivo ◽  
Force Spectroscopy

scholarly journals Simulated-Physiological Loading Conditions Preserve Biological and Mechanical Properties of Caprine Lumbar Intervertebral Discs in Ex Vivo Culture

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33147 ◽  
Author(s):  
Cornelis P. L. Paul ◽  
Hendrik A. Zuiderbaan ◽  
Behrouz Zandieh Doulabi ◽  
Albert J. van der Veen ◽  
Peter M. van de Ven ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ex Vivo ◽  
Intervertebral Discs ◽  
Loading Conditions ◽  
Physiological Loading ◽  
Ex Vivo Culture

scholarly journals The visceral pericardium: macromolecular structure and contribution to passive mechanical properties of the left ventricle

2007 ◽  
Vol 293 (6) ◽  
pp. H3379-H3387 ◽  
Author(s):  
Paul D. Jöbsis ◽  
Hiroshi Ashikaga ◽  
Han Wen ◽  
Emily C. Rothstein ◽  
Keith A. Horvath ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Left Ventricular ◽  
Opening Angle ◽  
Passive Stiffness ◽  
Photon Excitation ◽  
Before And After

Much attention has been focused on the passive mechanical properties of the myocardium, which determines left ventricular (LV) diastolic mechanics, but the significance of the visceral pericardium (VP) has not been extensively studied. A unique en face three-dimensional volumetric view of the porcine VP was obtained using two-photon excitation fluorescence to detect elastin and backscattered second harmonic generation to detect collagen, in addition to standard light microscopy with histological staining. Below a layer of mesothelial cells, collagen and elastin fibers, extending several millimeters, form several distinct layers. The configuration of the collagen and elastin layers as well as the location of the VP at the epicardium providing a geometric advantage led to the hypothesis that VP mechanical properties play a role in the residual stress and passive stiffness of the heart. The removal of the VP by blunt dissection from porcine LV slices changed the opening angle from 53.3 ± 10.3 to 27.3 ± 5.7° (means ± SD, P < 0.05, n = 4). In four porcine hearts where the VP was surgically disrupted, a significant decrease in opening angle was found (35.5 ± 4.0°) as well as a rightward shift in the ex vivo pressure-volume relationship before and after disruption and a decrease in LV passive stiffness at lower LV volumes ( P < 0.05). These data demonstrate the significant and previously unreported role that the VP plays in the residual stress and passive stiffness of the heart. Alterations in this layer may occur in various disease states that effect diastolic function.

scholarly journals Ex Vivo Stretch Reveals Altered Mechanical Properties of Isolated Dystrophin-Deficient Hearts

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e32880 ◽  
Author(s):  
Matthew S. Barnabei ◽  
Joseph M. Metzger
Keyword(s):  
Mechanical Properties ◽  
Ex Vivo

Mechanical properties of native and ex vivo remodeled porcine saphenous veins

2005 ◽  
Vol 38 (9) ◽  
pp. 1770-1779 ◽  
Author(s):  
Rebecca J. Gusic ◽  
Matus Petko ◽  
Richard Myung ◽  
J. William Gaynor ◽  
Keith J. Gooch
Keyword(s):  
Mechanical Properties ◽  
Ex Vivo ◽  
Saphenous Veins

Appropriate Objective Functions for Quantifying Iris Mechanical Properties Using Inverse Finite Element Modeling

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Anup D. Pant ◽  
Syril K. Dorairaj ◽  
Rouzbeh Amini
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Objective Function ◽  
Inverse Modeling ◽  
Measurement Errors ◽  
Ex Vivo ◽  
Treatment Strategies ◽  
Objective Functions ◽  
Estimation Of Parameters

Quantifying the mechanical properties of the iris is important, as it provides insight into the pathophysiology of glaucoma. Recent ex vivo studies have shown that the mechanical properties of the iris are different in glaucomatous eyes as compared to normal ones. Notwithstanding the importance of the ex vivo studies, such measurements are severely limited for diagnosis and preclude development of treatment strategies. With the advent of detailed imaging modalities, it is possible to determine the in vivo mechanical properties using inverse finite element (FE) modeling. An inverse modeling approach requires an appropriate objective function for reliable estimation of parameters. In the case of the iris, numerous measurements such as iris chord length (CL) and iris concavity (CV) are made routinely in clinical practice. In this study, we have evaluated five different objective functions chosen based on the iris biometrics (in the presence and absence of clinical measurement errors) to determine the appropriate criterion for inverse modeling. Our results showed that in the absence of experimental measurement error, a combination of iris CL and CV can be used as the objective function. However, with the addition of measurement errors, the objective functions that employ a large number of local displacement values provide more reliable outcomes.

Sign in / Sign up

Export Citation Format

Share Document