Methods of complementary pairing of memory cells are described. The invention can involve an elongated body configured to fit within the vessel of a lumen and at least one imaging sensor located on the elongated body configured to image an object in a forward direction. During operation, the immersion zone is located between the immersion element and the substrate and is at least temporarily filled with an immersion medium. Further components, for example a heat sink that may be in electrical communication with the EM shielding portion, may thereby also be connected to logical ground. The analysis may be continuous or periodic.