The linear viscoelastic response of an ordered dense emulsion is explored by numerical simulation. At concentrations below maximum packing, the stress relaxation is dominated by a single time scale associated with lubrication, which diverges at maximum packing. For concentrations above maximum packing, the stress relaxation is dominated by fast time scales of the order of the drop relaxation ti...

Long-chained polymers in alginate hydrogels can form networks by either ionic or covalent crosslinks. This paper shows that the type of crosslinks can markedly affect the stress-relaxation behavior of the gels. In gels with only ionic crosslinks, stress relaxes mainly through breaking and subsequent reforming of the ionic crosslinks, and the time scale of the relaxation is independent of the si...

INTRODUCTION Mechanical characterization of articular cartilage, soft tissues and gels is important for biomechanical reference data and for functional assessment of biopsied or engineered tissue. Common techniques include dynamic mechanical spectroscopy [1] and stress relaxation [2], with the latter often favored for technical simplicity. While reliable, stress relaxation measurements of carti...

In isovolumically beating hearts, the speed of left ventricular (LV) relaxation is uniquely determined by peak active stress (ςmax). In contrast, such a succinct description of relaxation is lacking for the ejection beats, although ejection is generally thought to hasten relaxation. We set out to determine how ejection modifies the relaxation-ςmax relationship obtained in the isovolumically bea...

This paper proposes a hybrid soft tissue model that consists of a multilayer structure and many spheres for surgical simulation system based on meshless. To improve accuracy of the model, tension is added to the three-parameter viscoelastic structure that connects the two spheres. By using haptic device, the three-parameter viscoelastic model (TPM) produces accurate deformationand also has bett...

There is a well-established adverse reciprocal relationship between stress and multiple sclerosis (MS). However, stress management in these patients has been parsimoniously studied. In this parallel randomized controlled trial, relapsing-remitting MS patients were randomly assigned to undergo either an 8-week stress management program (n=31; relaxation breathing and progressive muscle relaxatio...

Because it is not known whether ejection influences the negative effect of the Ca2+-sensitizing drugs on ventricular relaxation, we extended our previous analysis of stress-dependent relaxation in isovolumic beats to encompass ejecting beats and evaluated the relationships between both the time of onset of relaxation and the rate of relaxation and wall stress in a broader analysis framework. Fu...

The viscoelastic behaviour of a biological material is central to its functioning and is an indicator of its health. The Fung quasi-linear viscoelastic (QLV) model, a standard tool for characterizing biological materials, provides excellent fits to most stress-relaxation data by imposing a simple form upon a material's temporal relaxation spectrum. However, model identification is challenging b...