Deployment of impedance sensing member 22 m or sensors 22 can be controlled such that telemetry can be used with impedance feedback to identify tissue types and map the topography of tissue masses, tumors or tissue structures. [0059] Impedance sensing members 22 m can also be deployed with curvature from members 18 to collectively define a volume 5 sv (also called sample volume 5 sv) that is volum