An infusion pressure monitoring system for a phacoemulsification or vitrectomy machine to be operated by a health care provider includes an irrigation path configured to carry an irrigation solution to a surgical site and a fluid sensor configured to detect a fluid parameter in the irrigation path. An input device receives a variable fluid flow command from the health care provider commanding an irrigation fluid flow through the irrigation path at a flow rate corresponding to the command. A controller communicates with both the fluid sensor and the input device. The controller determines an expected fluid pressure value and a dynamically variable threshold pressure value based upon the variable fluid flow command.
