Abstract: According to one embodiment, a method includes providing a trocar having a flow path for passage of an insufflation gas and also having a region outside the flow path that is open at the distal end of the trocar. The method also includes supplying insufflation gas through the flow path of the trocar and determining a differential pressure between a first pressure in the flow path of the trocar and a second pressure in the region of the trocar outside the flow path. The method also includes controlling the supply of insufflation gas through the trocar based at least in part on the determined differential pressure.