We checked for significant association (p<0.05) of device, measurement order and leg on blood flow parameters of interest using generalized linear latent and mixed model with a random effects term to account for repeated measures on a given subject using Stata10 (Stata Corp, college station, TX). Blood flow parameters are reported as mean and 95% confidence intervals (CI). A Wilcoxon signed rank test was used to analyse the verbal rating scores for patient comfort.