A post-occlusion chamber collapsecanceling system for a surgical apparatus that detectsthe breaking of occlusions by tissue fragments inthe distal end of the aspiration path and produces aresponse comprising a transitory blockage of thedistal end the aspiration path to terminate the chambercollapse and a simultaneous transitory venting ofthe aspiration line to relieve the vacuum, in a waythat post-occlusion chamber collapses are cancelled.Disclosed herein, in a preferred embodiment, is asurgical system and related method for preventingcollapse of a body chamber being operated upon,due to a vacuum surge following a clearing of anocclusion in an aspiration path of the surgical system,comprising: an occlusion-break sensor (300) forsensing the clearing of the occlusion； a normally-openocclusion valve (57), temporarily closing in responseto the occlusion-break sensor sensing the clearing ofthe occlusion, thereby occluding fluid flow throughthe aspiration path and controllably stabilizing theocclusion break, thereby preventing the vacuumsurge and consequent body chamber collapse；and a normally- closed venting valve temporarilyopening in response to the occlusion-break sensorsensing the clearing of the occlusion, to reduce thevacuum thereby preventing the vacuum surge andconsequent body chamber collapse. In an alternativeembodiment, the normally-open occlusion valve maybe omitted.
