Because coronary artery calcified plaques can hinder or eliminate stent deployment, interventional cardiologists need a better way to plan interventions, which might include one of the many methods for calcification modification (e.g., atherectomy). We are imaging calcifications with intravascular optical coherence tomography (IVOCT), which is the lone intravascular imaging technique with the ability to image the extent of a calcification, and using results to build vesselspecific finite element models for stent deployment.

The stiffness of arterial wall in response to cardiovascular diseases has been associated with the changes in extracellular matrix (ECM) proteins, ie., collagen and elastin. Vascular smooth muscle cells (VSMCs) helped to regulate the ECM reorganizations and thus contributed to arterial stiffness. This article reviewed experimental and computational studies for quantifying the roles of ECM proteins and VSMCs in mechanical properties of arteries, including nanostructure and mechanical properties of VSMCs and ECMs, cell-ECM interaction, and biomimetic gels/scaffolds induced contractile properties and phenotype changing of VSMCs. This work will facilitate our understanding of how the microenvironments and mechanotransduction impact and regulate the arterial adaptation.

Particle composites with biopolymer matrix and metal particles have been recently prepared from a range of different materials and their mechanical properties is highly affected by the manufacturing process. 3D printing offers many benefits in the fabrication of composites, including high accuracy, cost effective and customized geometry. A novel 3D printed PLLA composite reinforced with steel particles was proposed. The composite samples were printed by fused filament fabrication (FFF). Mechanical properties of each phase, as well as the interphase layer, were characterized by performing nanoindentation tests. Accordingly, the obtained mechanical properties were imported into a Representative Volume Element (RVE) model in order to calculate the macro-mechanical properties and also study the effect of matrix degradation on the elastic modulus of the composite when exposed to different loading scenarios. The obtained results showed that adding 10 % volume fraction of steel particles can enhance the elastic modulus of PLLA polymer by 31 %. Moreover, the implemented 3D printing approach generated a thin interphase layer with great adhesion to the particles. Degradation of interphase layer was studied by applying imperfect bonding between the particles and the matrix. Degradation of interphase can reduce the elastic modulus of the composite by 70 % and 7% under tensile and compressive loads, respectively. Shear modulus of the composite with 10 % of particles decreases by 36 % when debonding occurs. In this case the shear modulus of the composites are lower than that for the pure PLLA polymer.

Bioresorbable polymers, such as polylactic acid (PLA) and poly-L-lactic acid (PLLA), has been extensively used in biomedical applications because of its resorption. The mechanical behavior of magnesium (Mg) particle reinforced poly-L-lactic acid (PLLA) composites was characterized in this work using a three-dimensional representative volume element. The influences of Mg weight fraction, imperfect bonding between particle and polymer matrix, and the coating layer on the mechanical behaviors of the composites were quantified. Results clearly demonstrated that the effective Young’s modulus and yield strength of the composite was enhanced by the Mg particles, especially its MgO coating. In addition, the imperfect interfacial bonding between the Mg particle and PLLA bonding mitigated the mechanical advantage of the composite, which was in good agreement with the documented experimental observations.

Abusive head trauma (AHT) is a leading cause of death and disability in children. Retinal hemorrhage (RH) is a sign which helps physicians to make the correct decision of the possibility of AHT. However, in some cases, retinal hemorrhage is caused by accidental trauma. Therefore, distinguishing the pattern of retinal hemorrhage caused by AHT or accidental trauma is crucial. The main aim of this project is to simulate eyeball movement during baby shaking to find out stress distribution pattern on the posterior pole of the eyeball, caused by AHT, which is aligned with the pattern of blood spots in that region and then correlate that with clinical findings.

To maximize the controllable energy absorption of corrugation troughs as observed in the single sided corrugated (SSC) tube, we proposed and tested a new structure design, i.e., double-sided corrugated (DSC) tube made of Al 6060-T6 aluminum alloy or CF1263 carbon/epoxy composite. Finite element models were developed to test the mechanical advantage of the DSC tube in comparison with both SSC and classical straight (S) tubes under axial crushing. Results have shown that the total absorbed energy of the DSC aluminum tube with 14 corrugations was 330% and 32% higher than that of the SSC tube with 14 corrugations and the S-tube, respectively. The initiation and progression of the crushing process for different tube configurations were characterized, leading to the mechanism of energy absorption. Plastic deformation in terms of PPEQ is the key parameter correlating with the energy absorption capacity. To overcome the lower specific absorbed energy (SAE) in the DSC tube compared to that in the S-tube, the CF1263 carbon/epoxy composite laminate was adopted and the corresponding SAE was 5.9 times higher than that of the aluminum one. Moreover, the influence of the number of corrugations on the crushing behaviors of the DSC tube was also inspected. A minimal straight tube section was suggested for a controllable smooth crushing behavior regardless of its advantage in SAE. This work might shed light on designing future thin-walled energy absorber devices with better control of crushing behaviors for minimal injuries and damages.