an apparatus comprising an electrode subsystem configured to interface to biological tissue , an electronic subsystem electrically coupled to the electrode subsystem by a connector , and a guide tube disposed over at least a portion of the electrode subsystem and the connector . the guide tube includes material to provide stiffness to the electrode subsystem and the connector in an axial direction of the guide tube . the guide tube material is removable from the electrode subsystem and the connector over the electronic subsystem when the electrode subsystem is positioned to interface to the biological tissue and while the electronic subsystem remains electrically coupled to the electrode subsystem .