Biomechanical Model of Human Index Finger During Examination

We have developed a mathematical model based on the Hunt-Crossley’s viscoelastic contact formulation for predicting the contact forces in the upper-body. The simulations were carried out in OpenSim software package and the simulations results were compared to experimentally recorded contact forces measured using a pressure algometer for assessing pressure pain sensitivity in the pelvic region 1. We observed a very good agreement between the model prediction and algometer data. Our simulation revealed that by pressing down on the tissue both normal and frictional contact forces increase up to a point- ceiling effect. Moreover, viscoelastic properties of the examinee’s tissue were associated with force; specifically, as the stiffness of the tissue declined both normal and frictional contact forces similarly declined albeit in a different way. Once the contact force reaches a peak point (irrespective of the baseline stiffness of the tissue) additional pressure application by the examiner was associated with incremental decrease in both normal and frictional (wasted) contact force.

Physical Characterization of Latex from Artocarpus heterophyllus Lam. (Jackfruit) and Four Related Artocarpus spp.

This study focused on the physical properties of latex extracted from five species of Artocarpus J.R.Forster & G.Forster, namely: A. altilis (Parkinson) Fosberg, A. blancoi Merr, A. camansi Blanco, A. heterophyllus Lam., and A. ovatus Blanco as potential natural adhesives. Surface morphology showed that all five Artocarpus spp. have no specific forms, but otherwise flexible and viscoelastic. Contact angle measurements showed that all samples of Artocarpus spp. were hydrophilic with low contact angle values owing to the contents of natural source of the latex. FTIR analysis matched all Artocarpus latex samples to that of Polyvinyl acetate. Highest resin content was found on A. ovatus with all the species containing natural resin. It was also confirmed that out of the three stress strain analyses, A. camansi had the highest values for tensile strength, A. ovatus had the highest values for Young’s modulus of elasticity and the highest percentage elongation values belonged to A. heterophyllus. Adhesive shear strengths with maximum force values were highest in A. ovatus. Through cluster analysis, out of the eight variables tested A. heterophyllus was the outgroup being attributed to its latex gum-like property. All the above tests and analyses suggested that latex of all five Artocarpus spp. were similar in characteristics to polymer adhesive. Among which A. camansi and A. ovatus exhibited high results on adhesive strength tests.