Patent ID: 8439874

Claim:
An aspiration flow control system for an ophthalmic microsurgical system comprising: a vacuum device configured to control the level of a vacuum applied for establishing the flow of aspirated fluid from a surgical site; a vacuum sensor configured to communicate a signal representative of the sensed level of the vacuum being applied for establishing aspirated fluid flow; a flow measurement device configured to generate a signal indicative of the rate at which fluid flow is aspirated; a flow controller that monitors the vacuum sensor and the flow measurement device, and communicates a requested vacuum level to the vacuum device to establish a desired vacuum level, the flow controller being configured to implement a first feed back loop that compares the requested vacuum level with the actual sensed vacuum level and adjusts the requested vacuum to achieve the desired vacuum level, the flow controller being further configured to implement a second feedback loop that compares the sensed aspiration flow rate with a desired aspiration flow rate and adjusts the requested vacuum communicated to the vacuum device to achieve the desired aspirated fluid flow rate; a user command input device for enabling the input of a desired vacuum level, wherein the flow controller is configured to receive a desired vacuum level and to communicate a signal including a requested vacuum level to the vacuum device, wherein the vacuum device is configured to receive a signal from the flow controller that includes a requested vacuum level to be applied, and is further configured to receive signal information from the vacuum sensor indicative of the sensed vacuum level, and to generate a vacuum level based on the sensed vacuum level to achieve the requested vacuum communicated by the flow controller; and wherein the vacuum sensor provides an output signal indicative of the level of the vacuum being applied, which output signal is used to determine a time averaged vacuum signal based on periodic sampling of the output signal.