Probe with improved threading capability

A low tortuousness or non-tortuousness probe may have: a core wire including: a first preformed bend at a first angle of about 15-90 DEG; a second pre-formed bend at a second angle of about 8-15 DEG, the second pre-formed bend being distal to the first pre-formed bend, and the first pre-formed bend being longer than the second pre-formed bend; an intermediate portion extending between the first preformed bend and the second preformed bend by about 1-3 inches; and a distal portion between the second pre-formed bend and a distal tip of about 1-2 inches, the distal portion having a segment that decreases in width or diameter, thereby increasing deflection of the distal tip; a tubular body disposed around the core wire; and a navigation device disposed around the core wire and within the tubular body. 一种低可扭转性或不可扭转的探针可具有：芯线，其包含：约15-90°的第一角度的第一预成型弯曲；约8-15°的第二角度的第二预成型弯曲，所述第二预成型弯曲在所述第一预成型弯曲的远侧，且所述第一预成型弯曲长于所述第二预成型弯曲；在所述第一预成型弯曲和所述第二预成型弯曲之间延伸约1-3英寸的中间部分；以及在所述第二预成型弯曲和远侧尖端之间的约1-2英寸的远侧部分，所述远侧部分具有一段，其宽度或直径减小，从而增加所述远侧尖端的偏转；管