Retraction of tissue for single port entry, robotically assisted medical procedures

A method for retracting extraneous tissue using a surgical instrument, wherein the surgical instrument includes a tool guide, a balloon, and an expandable retractor, wherein the balloon is disposed around the tool guide so that the tool guide extends within a core formed in the balloon, wherein the expandable retractor is disposed around the balloon, wherein the expandable retractor is constructed so that the expandable retractor is expanded and locks in an expanded configuration when the balloon is expanded to sufficient volume, and wherein the expandable retractor is constructed so that expandable retractor remains locked without external support when the balloon is deflated and no longer contacts an inner surface of the expandable retractor, the method comprising:

• positioning the surgical instrument so that the expandable retractor retracts the extraneous tissue when the expandable retractor is expanded to and locked in its expanded configuration;
• expanding the balloon so that the expandable retractor is expanded to and locked in its expanded configuration to retract the extraneous tissue;
• deflating the balloon so that the balloon no longer contacts the inner surface of the expandable retractor while the expandable retractor remains locked without external support so as to continue retracting the extraneous tissue;
• and
• moving a tool inserted in the tool guide towards a target tissue.