[1] Penn State Univ, Intercoll Program Integrat & Biomed Physiol, University Pk, PA 16802 USA
[2] Penn State Univ, Dept Biomed Engn, University Pk, PA 16802 USA
[3] Worcester Polytech Inst, Dept Phys, Worcester, MA 01609 USA
[4] Univ Houston, Dept Biomed Engn, Houston, TX USA