Effect of position influence and environmental changes in hybrid torque-position BMI.

2013-01-24T00:22:25Z (GMT) by Pratik Y. Chhatbar Joseph T. Francis
<p>(<b>A</b>) Decreasing position influence (, see methods) from 200 (n = 32) to 100 (n = 46; 42) to 20 (n = 75) and (<b>B</b>) from 20 (n = 127; 92) to 0 (pure torque control; n = 116; 77) moved the FSV locations away from the movement start-point and towards the target (<i>P</i><0.05), indicating more ballistic movement profiles. (<b>C</b>) Increased viscous gain-fields (Increased Load, IL, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052286#pone-0052286-t001" target="_blank"><b>Table 1</b></a>; right; n = 74) from before (Equal Load, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052286#pone-0052286-t001" target="_blank"><b>Table 1</b></a>; left; n = 77) moved the FSV locations towards the movement start-point and decreased the FSV vector lengths (<i>P</i><0.05), indicating decreased movement velocities under high resistance. (<b>D</b>) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052286#s1" target="_blank">Introduction</a> of new viscous gain-fields (New Load, NL, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052286#pone-0052286-t001" target="_blank"><b>Table 1</b></a>; right; n = 81) within the bounds of ongoing low- and high- gain fields (Routine Load, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052286#pone-0052286-t001" target="_blank"><b>Table 1</b></a>; left; n = 76) led to no statistically significant differences in the FSV locations or vectors. Same conventions as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052286#pone-0052286-g001" target="_blank"><b>Figure 1</b>, <b>E</b>, <b>F</b></a> are used. Means and standard deviations of the FSV locations and vectors of different sessions (mean FSV location: base of arrow; standard deviation of FSV location: dashed circle, scaled 10%; mean FSV vector: arrow itself; standard deviation of FSV vector: thin solid line circle, scaled 10%) are overlaid in between the FSV plots for easy comparison; blue: from the FSV plot on the left, red: from the FSV plot on the right. The arm was restrained at the bottom left (75° shoulder and 85° elbow angles, <b>A</b>, <b>D</b>) or at the center (25° shoulder and 85° elbow angles, <b>B</b>, <b>C</b>) of the workspace unless indicated as F, free or unrestrained arm.</p>