A trocar for performing a surgical procedure on a patient. The trocar includes a hollow cannula having a distal end and a proximal end, and a housing having a distal end attached to the proximal end of the cannula and a proximal end having a wall attached thereto. Wherein the wall has an aperture therethrough...http://www.google.com.au/patents/US20030004529?utm_source=gb-gplus-sharePatent US20030004529 - Trocar having an improved seal design
