BACKGROUND In pediatric echocardiography, pulse wave Doppler, and tissue Doppler imaging velocities are widely used to assess cardiac function. Current reference values and Z scores, allowing adjustment for growth are limited by inconsistent methodologies and small sample size. Using a standardized approach for parametric modeling and Z score quality assessment, we propose new pediatric referen...

We report development of optical parametric oscillator (OPO)-based mid-infrared laser system that utilizes a periodically poled nonlinear crystal pumped by a near-infrared (NIR) laser. We obtained a mid-infrared average output of 8 W at an injection current of 20 A from a quasi-phase-matched OPO using an external cavity configuration. Laser tissue ablation efficiency is substantially affected b...

Rotating nonlinear waves of excitation in the heart cause dangerous cardiac arrhythmias. Frequently, ventricular arrhythmias occur as a result myocardial infarction and are associated with rotation around post-infarction scar. In this paper, we perform detailed silico analysis scroll an anatomical model human ventricles generic scar surrounded by gray zone modified properties tissue. Our includ...

This research is based on experimental and numerical investigations of human lumbar spine. Human intervertebral discs usually exhibit highly anisotropic mechanical responses in a finite strain regime under physiological loading conditions. Human disc body units basically consist of a fluid filled cavity (nucleus pulposus) approximately at the disc center and surrounding tissue reinforced by col...

We demonstrate the capabilities of the coherent anti-Stokes Raman scattering (CARS) microscope and its multimodal operation to image a histological section of human intestinal tissue. The imaging of unstained and stained sections using various nonlinear optical contrasts was performed. The CARS configuration of our microscope allows probing which does not require a preliminary staining of tissu...

Lung tissue presents substantial nonlinear phenomena not accounted for by linear models; however, nonlinear approaches are less available. Our aim was to characterize the behavior of total harmonic distortion, an index of nonlinearity, in lung tissue strips under sinusoidal deformation at a single frequency as a function of strain amplitude and operational stress. To that end, lung parenchymal ...

Trabecular plates play an important role in determining elastic moduli of trabecular bone. However, the relative contribution of trabecular plates and rods to strength behavior is still not clear. In this study, individual trabeculae segmentation (ITS) and nonlinear finite element (FE) analyses were used to evaluate the roles of trabecular types and orientations in the failure initiation and pr...

We present the development of a 5 mm, piezo-actuated, ultrafast laser scalpel for fast tissue microsurgery. Delivery of micro-Joules level energies to the tissue was made possible by a large, 31 μm, air-cored inhibited-coupling Kagome fiber. We overcome the fiber's low NA by using lenses made of high refractive index ZnS, which produced an optimal focusing condition with 0.23 NA objective. The ...

Slow, large deformations of human brain tissue—accompanying cranial vault deformation induced by positional plagiocephaly, occurring during hydrocephalus, and in the convolutional development—has surprisingly received scarce mechanical investigation. Since the effects of these deformations may be important, we performed a systematic series of in vitro experiments on human brain tissue, revealin...

in this paper, we use a combination of legendre and block-pulse functionson the interval [0; 1] to solve the nonlinear integral equation of the second kind.the nonlinear part of the integral equation is approximated by hybrid legen-dre block-pulse functions, and the nonlinear integral equation is reduced to asystem of nonlinear equations. we give some numerical examples. to showapplicability of...