A system for delivering treatment to a target treatment area, comprising: an operative member comprising a flexible circuit; and an expandable support device configured for delivery through a working channel and to the target treatment area, the expandable support device comprising: a solid support member formed of a material having highly elastic, having a yield strength from 400MPa to 1100MPa, or superelastic properties, the solid support member comprising: a perimeter; and a plurality of splines (1610,2005,2010) formed in a pattern interior to the perimeter of the solid support member and a plurality of voids between adjacent splines (1610, 2005,2010), wherein a width and a spacing of the plurality of splines (1610,2005,2010) is configured to promote expansion of the support member between a collapsed configuration and an expanded configuration, wherein when the solid support member is in the expanded configuration the expandable support device defines a flat outwardly facing support surface, the operative member comprising a flexible circuit being disposed on said flat outwardly facing support surface and capable of bending with the expandable support device on which it is disposed, characterised in that the flexible circuit comprises a plurality of electrodes patterned that mirror the pattern of the plurality of splines. an operative member comprising a flexible circuit; and an expandable support device configured for delivery through a working channel and to the target treatment area, the expandable support device comprising: a solid support member formed of a material having highly elastic, having a yield strength from 400MPa to 1100MPa, or superelastic properties, the solid support member comprising: a perimeter; and a plurality of splines (1610,2005,2010) formed in a pattern interior to the perimeter of the solid support member and a plurality of voids between adjacent splines (1610, 2005,2010), wherein a width and a spacing of the plurality of splines (1610,2005,2010) is configured to promote expansion of the support member between a collapsed configuration and an expanded configuration, wherein when the solid support member is in the expanded configuration the expandable support device defines a flat outwardly facing support surface, the operative member comprising a flexible circuit being disposed on said flat outwardly facing support surface and capable of bending with the expandable support device on which it is disposed, characterised in that the flexible circuit comprises a plurality of electrodes patterned that mirror the pattern of the plurality of splines. a solid support member formed of a material having highly elastic, having a yield strength from 400MPa to 1100MPa, or superelastic properties, the solid support member comprising: a perimeter; and a plurality of splines (1610,2005,2010) formed in a pattern interior to the perimeter of the solid support member and a plurality of voids between adjacent splines (1610, 2005,2010), wherein a width and a spacing of the plurality of splines (1610,2005,2010) is configured to promote expansion of the support member between a collapsed configuration and an expanded configuration, wherein when the solid support member is in the expanded configuration the expandable support device defines a flat outwardly facing support surface, the operative member comprising a flexible circuit being disposed on said flat outwardly facing support surface and capable of bending with the expandable support device on which it is disposed, a perimeter; and a plurality of splines (1610,2005,2010) formed in a pattern interior to the perimeter of the solid support member and a plurality of voids between adjacent splines (1610, 2005,2010), wherein a width and a spacing of the plurality of splines (1610,2005,2010) is configured to promote expansion of the support member between a collapsed configuration and an expanded configuration, wherein when the solid support member is in the expanded configuration the expandable support device defines a flat outwardly facing support surface, the operative member comprising a flexible circuit being disposed on said flat outwardly facing support surface and capable of bending with the expandable support device on which it is disposed,