International Journal of Experimental and Computational Biomechanics (2 papers in press)

Regular Issues

• Evaluating effect of amputees physical parameters on pressure at lower-limb prosthetic socket  
  by Chitresh Nayak, Deepak Unune, Amit Singh, Himanshu Choudhary 
  Abstract: Intrasocket pressures can cause the tissue trauma or discomfort to amputees wearing the prosthetic devices. This paper presents a methodology for evaluating the role of amputees physical parameters viz. height, weight, and stump length on pressure generated at the prosthetic limb/socket interface using regression technique. An experimental setup has beed developed for force investigation of the lower-limb socket using the FlexiForce sensor. The intrasocket pressure values at lateral tibia, gastrocnemius, patella tendon bearing, kick point, medial tibia, medial gastrocnemius, popliteal depression, and lateral gastrocnemius on the transtibial residual limb have been collected for three different conditions viz. walking, full load and half load for ten patients. Mathematical models for pressure at three loading conditions have been developed using regression analysis using which the effective pressure at considered specific regions can be correlated with physical parameters. The models suggested that the weight of amputee is a strong predictor of pressure at the socket. The developed methodology will assist the amputee-specific socket design ensuring comfortable socket fitting.
  Keywords: Stump-socket interface; pressure measurement; regression analysis; socket fitting.
  
  
• Experimental Design for Testing and Analysis of z-Type Self-Expanding Endovascular Stents  
  by Joel Scott, Darrel Doman, Clifton Johnston 
  Abstract: Stent migration and endoleak are common failure mechanisms for endovascular repair. Both can be partially attributed to a lack in understanding of the mechanical properties of endovascular stents. An alternative radial extensometer and machine vision system have been developed to both raise the quality of published radial force data, as well as to create and present an option for economical stent testing. The apparatus has shown promise as an accurate, repeatable and reliable system for stent evaluation. Previous results by Johnston et al. examining z-type endovascular stents have been verified. Results showed that smaller stent diameters exhibit higher radial force than larger diameter stents, contrary to the expected outcomes due to increasing drag on increasing diameter stents. Stent orientation has been shown to contribute up to 8.8% error in radial force introduced by non-symmetrical brazed joints. The presence of a stent cover is shown to have negligible impact on stent radial force data above 10% reduction in area.
  Keywords: Experimental Design; Testing; Analysis; z-type Endovascular Stent; Mechanical Engineering; Medical Devices; Machine Vision; Radial Extensometer; Self-Expanding; Stent.