We have chosen a goal sample size of 30 based on the following calculation. A sample size of 25 achieves 80% power to detect a mean of paired differences of 0.3 with a known standard deviation of differences of 0.5 and with a significance level (alpha) or 0.05 using a one-sided paired t-test. To allow for patient drop out or equipment failure, we will aim to enroll 30 patients.