US Patent 7413559 Gas flow trocar arrangement

A trocar assembly for use in surgery in a patient, comprising an elongated outer tubular member having a first or proximal end and a second or distal end. The proximal end has a housing enclosing a fluid pressure chamber therein. The distal end of the outer tubular member has a gaseous fluid discharge arrangement therethrough, through which a medical instrument is disposed for surgical manipulation of the patient.