4. Research Method The target population will include subjects scheduled to receive anterior cruciate reconstruction at BC Children's Hospital by Dr. Chris Reilly. Subjects will prospectively be randomized into two groups. In the control group, tourniquet inflation pressures consistent with the current standard of care at BC Children Hospital will be used. In the experimental group, tourniquet inflation pressures will be determined by an automated calculation of limb occlusion pressure plus a predetermined safety margin. This technique has previously been shown to be equivalent to the Doppler technique for determining tourniquet inflation pressures, which is the gold standard. This is a non-inferiority trial with a power set at 0.8 and an alpha of 0.05. The estimated sample size is 21 patients in each group.