Stylet with improved threadability
A low or non-torqueable stylet may have: a core wire including: a first pre-formed bend of a first angle of about 15-90°; a second pre-formed bend of a second angle of about 8-15°, the second pre-formed bend being distal of the first pre-formed bend, and the first pre-formed bend being longer than the second pre-formed bend; an intermediate portion of about 1-3 inches extending between the first pre-formed bend and the second pre-formed bend; and a distal portion of about 1-2 inches between the second pre-formed bend and a distal tip, the distal portion having a segment with a reduced width or diameter that increases 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.
1 . A stylet for accessing a superior vena cava of a patient, the stylet comprising:
a core wire and a tubular body disposed around the core wire, the core wire including:
a first pre-formed bend of a first angle;
a second pre-formed bend of a second angle, the second pre-formed bend being distal of the first pre-formed bend, and the first angle being greater than the second angle; and
a narrow segment being distal of the second pre-formed bend and having a reduced width or diameter that increases deflection of a distal tip,
wherein the core wire has a pre-formed shape including the first pre-formed bend and the second pre-formed bend, and the core wire being configured to elastically change from the pre-formed shape to a second shape during insertion of the stylet into a vasculature of the patient due to an anatomical insertion pathway of the vasculature; and
wherein a distal tip of the core wire extends distally from a distal end of the tubular body, the distal tip of the core wire being exposed for conducting an electrocardiogram signal, and the distal end of the tubular body being configured to prevent fluid from entering the tubular body.
2 . The stylet of claim 1 , wherein the first angle is about 15-90° with respect to a longitudinal axis of the stylet, and an arc length of the first pre-formed bend is about 3-7 inches.
3 . The stylet of claim 1 , wherein the second angle is about 8-15° with respect to a longitudinal axis of the stylet, and an arc length of the second pre-formed bend is about 0.2-0.5 inches.
4 . The stylet of claim 1 , wherein the first pre-formed bend and the second pre-formed bend are entirely within 10 inches from an end of the distal tip of the core wire.
5 . The stylet of claim 1 , wherein the first angle is about 60° with respect to a longitudinal axis of the stylet, and the second angle is about 10° with respect to the longitudinal axis of the stylet.
6 . The stylet of claim 1 , wherein the first pre-formed bend is longer than the second pre-formed bend.
7 . The stylet of claim 6 , wherein the first pre-formed bend has an arc length of at least 4 inches longer than the second pre-formed bend.
8 . The stylet of claim 1 , wherein the first pre-formed bend and the second pre-formed bend are in the same plane.
9 . The stylet of claim 1 , wherein the narrow segment includes a rounded and/or flattened cross-section.
10 . The stylet of claim 1 , wherein the core wire comprises a distal segment between the narrow segment and the distal tip, the distal segment having a width or diameter greater than the narrow segment.
11 . The stylet of claim 10 , wherein the distal tip has a width or diameter greater than the distal segment.
12 . The stylet of claim 1 , wherein the core wire includes a proximal taper proximal of the narrow segment and distal taper distal of the narrow segment.
13 . The stylet of claim 12 , wherein the proximal taper is longer than the distal taper.
14 . The stylet of claim 12 , wherein the proximal taper includes a first tapered portion and a second tapered portion, the first tapered portion being tapered at a greater angle than the second tapered portion.
15 . The stylet of claim 1 , wherein the tubular body has an opening in a sidewall to allow fluid contact with the core wire.
16 . The stylet of claim 1 , further comprising a navigation device disposed over the core wire and within the tubular body.
17 . The stylet of claim 16 , wherein the navigation device comprises a conductive coil.
18 . The stylet of claim 1 , wherein the stylet has minimal or no torquability.
19 . The stylet of claim 1 , wherein the core wire further comprises an intermediate portion of about 1-3 inches extending between the first pre-formed bend and the second pre-formed bend.
20 . The stylet of claim 1 , wherein the core wire further comprises a distal portion including the narrow segment, the distal portion extending about 1-2 inches from the second pre-formed bend to an end of the distal tip.
21 . The stylet of claim 1 , further comprising a housing member at a proximal end of the core wire.
22 . The stylet of claim 1 , wherein the core wire comprises a nickel titanium alloy.
23 . The stylet of claim 1 , wherein the distal tip is formed of one of a J-shape, a basket, or a mesh.
24 . An assembly comprising:
the stylet of claim 1 ; and
a second stylet that is conductive of an ECG signal.
25 . An assembly comprising:
the stylet of claim 1 ; and
a catheter disposed over the stylet.
26 . A low or non-torqueable stylet comprising:
a core wire including:
a first pre-formed bend of a first angle of about 15-90°;
a second pre-formed bend of a second angle of about 8-15°, the second pre-formed bend being distal of the first pre-formed bend, and the first pre-formed bend being longer than the second pre-formed bend;
an intermediate portion of about 1-3 inches extending between the first pre-formed bend and the second pre-formed bend; and
a distal portion of about 1-2 inches between the second pre-formed bend and an end of a distal tip, the distal portion having a narrow segment with a reduced width or diameter that increases deflection of the distal tip, wherein the first pre-formed bend and the second pre-formed bend are entirely within 10 inches from an end the distal tip of the core wire;
a navigation device disposed around the core wire; and
a tubular body disposed around the core wire and the navigation device;
wherein the core wire has a pre-formed shape including the first pre-formed bend and the second pre-formed bend, and the core wire being configured to elastically change from the pre-formed shape to a second shape during insertion of the stylet into a vasculature of the patient due to an anatomical insertion pathway of the vasculature; and
wherein a distal tip of the core wire extends distally from a distal end of the tubular body, the distal tip of the core wire being exposed for conducting an electrocardiogram signal, and the distal end of the tubular body being configured to prevent fluid from entering the tubular body.