Phacoemulsification machine with post-occlusion surge control system and related method

Abstract

A post-occlusion surge controller 90 for a phacoemulsification machine 30 is adapted to detect a post-occlusion surge in an aspiration conduit 41 of the machine 30, and to cause the conduit 41 to be vented in response to detecting the surge.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to phacoemulsification machines which are used in cataract eye surgery to remove cataract-affected eye lenses and, in particular, to phacoemulsification machines which are adapted to control post-occlusion surges which sometimes occur during cataract eye surgery when such machines are used. [0002] Although the invention will be described with reference to a particular type of phacoemulsification machine, it will be appreciated that this is by way of example only and that the invention may be used in connection with other types of phacoemulsification machines. BRIEF DISCUSSION OF THE PRIOR ART [0003] Phacoemulsification or phaco-machines are used in cataract eye surgery to remove cataract-affected eye lenses. FIG. 1 depicts a typical prior art peristaltic pump-based phaco-machine 30 which includes a hand-held probe 31 comprising a hollow infusion sleeve 32 surrounding a hollow phacoemulsification needle 33. Needle ...

AI Technical Summary

Benefits of technology

[0029] By detecting the post-occlusion surge in an aspiration conduit of the phacoemulsification machine, and venting the conduit in response to detecting the surge, the post-occlusion surge controller is able to limit the duration and the amplitude of the post-occlusion surge in the conduit. Limiting the duration and amplitude of the post-occlusion surge reduces the risk of injuring an eye which is being operated on with the machine when the post-occlusion surge occurs.

[0031] Preferably, the post-occlusion surge controller is adapted to detect the onset of the post-occlusion surge, and to cause the conduit to be vented in response to detecting the onset of the surge. This enables the conduit to be vented early on during the surge so that the amplitude and duration of the surge may be minimised.

[0036] It is also preferred that the valve controller includes a vent valve pre-energiser for pre-energising the solenoid of the vent valve to reduce the time required for the vent valve to respond to the high voltage pulse signal which is output to the solenoid by the high voltage pulse generator.

[0040] Preferably, the step of detecting the post-occlusion surge involves detecting the onset of the surge, and the step of venting the conduit is done in response to detecting the onset of the surge so that the amplitude and duration of the surge is minimised.

Problems solved by technology

Although increasing the resistance of the aspiration tube 41 or other components of the aspiration system of the machine 30 does reduce the amplitude of the post-occlusion surge, it has the disadvantage of prolonging the duration of the surge.

Adding resistance to the aspiration tube also has the significant disadvantage of reducing the flow rate, especially at vacuums below 150 mmHg.

Also, as the probe needle 33 is cooled by the flow of infusion fluid, adding resistance results in an increase in probe temperature which increases the possibility of the probe needle 33 causing wound burns to the eye 53.

However, there are limitations to the amount by which the compliance can be reduced because the compliant components of the machine 30 such as the pump tube 44 and the vacuum sensor 48 need to have some compliance in order for the machine 30 to operate properly.

However, if the bottle 36 is too high other problems result.

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