Occlusion detection in vacuum-based ophthalmic surgical systems

An ophthalmic surgery system comprising:

• a processor and a memory coupled to the processor;
• a handpiece operatively connected to the processor;
• an aspiration subsystem including:
• a vacuum-based aspiration pump operatively connected to the processor,
• an aspiration line coupled between the handpiece and the vacuum-based aspiration pump, and
• an aspiration pressure transducer for sensing a pressure within the aspiration line and operatively coupled to the aspiration line and the processor;
• an irrigation subsystem including:
• an irrigation source having an irrigation fluid,
• an irrigation line coupled to the handpiece and the irrigation source,
• a positive displacement pump operatively coupled to the irrigation line between the irrigation source and the handpiece, the positive displacement pump operatively coupled to the processor, and
• an irrigation pressure transducer coupled to the irrigation line for sensing an irrigation pressure within the irrigation line, the irrigation pressure transducer operatively coupled to the processor;
• and
• wherein the memory comprises executable instructions that, when executed by the processor, cause the processor to:
• determine a flow rate of the irrigation fluid through the irrigation line, based on at least a rotation rate of the positive displacement pump and the pressure sensed by the irrigation pressure transducer,
• determine if a vacuum is being commanded by the vacuum-based aspiration pump, and
• provide an occlusion warning to a user when the determined flow rate is below a threshold level and the vacuum is being commanded.

A method of providing occlusion detection in a vacuum-based ophthalmic surgical system, the method comprising:

• receiving, by a computing device, operational data from a positive displacement pump and pressure data from an irrigation pressure transducer both operatively coupled to an irrigation line, wherein the irrigation line connects a handpiece to a source of irrigation fluid;
• determining, by the computing device, whether vacuum is being commanded, by a user input, of a vacuum-based aspiration pump coupled to the handpiece;
• calculating, by the computing device, a flow rate of the irrigation fluid through the irrigation line, based on the operational data and the pressure data;
• comparing, by the computing device, the calculated flow rate to a threshold;
• and
• providing by the computing device, an occlusion warning only when the calculated flow rate is below the threshold and the vacuum is being commanded.