A medical device system is disclosed including a high-density arrangement of transducers, which may be configured to ablate, stimulate, or sense characteristics of tissue inside a bodily cavity, such as an intra-cardiac cavity. High-density arrangements of transducers may be achieved, at least in part, by overlapping elongate members on which the transducers are located, and varying sizes, shapes, or both of the transducers, especially in view of the overlapping of the elongate members. Also, the high-density arrangements of transducers may be achieved, at least in part, by including one or more recessed portions in an elongate member in order to expose one or more transducers on an underlying elongate member in a region adjacent an elongate-member-overlap region.
