Abstract: An apparatus includes an end effector having loop members with electrodes thereon and is usable with catheter-based systems to measure or provide electrical signals. The end effector can include three loop members that are non-coplanar when expanded unconstrained that become contiguous to a planar surface when the loop members are deflected against the surface, a mechanical linkage that joins the loop members at a distal vertex of the end effector, electrodes having surface treatment to enhance surface roughness of the electrodes, twisted pair electrode wires, a bonded spine cover, and/or any combination thereof.

Abstract: Examples presented herein generally include systems and methods which can contact electrodes to cardiac tissue while sensing electrical potential from fluids near the tissue. The electrodes in contact with the tissue can be carried by an end effector and can be used to sense and/or ablate the tissue they contact. A reference electrode can be insulated by a shaft connected to the end effector so that the reference electrode can sense the electrical potentials from the fluids near the tissue while being prevented, by the shaft geometry, from contacting the cardiac tissue. In some examples, the reference electrode can be tubular, having an inner surface that is configured to contact and sense electrical potentials from the fluids and an electrically insulated outer surface. Configured as such, the reference electrode can serve as an extension of an irrigation tube extending through the shaft.

Abstract: An apparatus includes a cylindrical shaft and an outwardly flared feature. The cylindrical shaft is sized for insertion into an insertion port of a cardiovascular catheter guiding sheath. The cylindrical shaft includes a proximal end, a distal end, and a lumen extending from the proximal end to the distal end. The lumen is sized to receive an end effector and catheter of a cardiovascular catheter instrument. The outwardly flared feature is at the proximal end of the cylindrical shaft. The outwardly flared feature defines an angled surface leading into the lumen.