Patent ID: 8894640

Claim:
A method of detecting an air bubble in a fluid flow, comprising the steps of: providing an optical sensor unit including a light-emitting element and a light-receiving element, the optical sensor unit operably associated with a fluid path; determining a first reference value based on air flow in the fluid path passing through the optical sensor unit; determining a second reference value based on fluid flow in the fluid path passing through the optical sensor unit; using the optical sensor unit to monitor fluid flow in the fluid path to detect an air bubble in the fluid flow using at least one of the first reference value or the second reference value; when an air bubble in the fluid flow is detected by the optical sensor unit, outputting an electrical signal from the optical sensor unit to a flow diverter apparatus and an electrosurgical energy source in response to detection of the air bubble in the fluid flow; and adjusting energy output of the electrosurgical energy source in response to the electrical signal from the optical sensor unit.