DRAINAGE UNIT WITH CONTROLLED NEGATIVITY RELIEF FEATURE

摘要

The present invention provides for an improved airflow sensitive float valve (38) interposed between the collection chamber (15) and one arm of the water seal chamber (16) for allowing the patient to draw as much vacuum pressure as is required during deep inspiration. The float valve also functions to provide for an automatic controlled release of excess negtive pressure in the collection chamber during either continuous auto-transfusion or when there is a low airflow rate condition present. By tailoring a specific amount of water to a given size chamber, the water column inside the water seal chamber is allowed to momentarily engage the floating mechanism before the water seal chamber is emptied of water, and a column of air is subsequently forced through the water column towards the momentarily sealed valve.