Rigid and flexible thin-film multielectrode arrays for transmural cardiac recording

Thin-film transmural cardiac multielectric arrays were fabricated using integrated-circuit processing techniques. Improvements over conventional handmade arrays, such as a smaller cross-sectional area, a larger number of recording sites per needle, more accurately controlled size and spacing of the recording sites, smaller bipolar spacings, and higher throughput yield, allow for a higher density of closely spaced bipolar electrodes capable of monitoring complex voltage and gradient fields present during ventricular fibrillation and defibrillation. Both rigid and flexible arrays were fabricated and used in the acquisition of transmural electrical signals. In vitro and in vivo testing of the thin-film transmural cardiac multielectrode arrays indicates that there are no adhesion or delamination problems, and no implantation difficulties, and that unipolar and bipolar recordings during normal sinus rhythm and injury potentials in unipolar recordings are similar to those obtained using the handmade electrodes.