Endoscopic needle stylet with enhanced-flexibility lengths
View Patent ↗A single-wire stylet may be constructed as an elongate single-wire, memory-metal alloy body with a generally cylindrical body profile, extending distally from a proximal end terminus, where embodiments include a polymeric distal tip member fixedly attached directly at a distal end of the single-wire body. At least one lengthwise portion of the single-wire body is at least partially in martensitic phase at operating temperatures at and below about 37° C. Where present, the polymeric distal tip member has a generally cylindrical body profile circumferentially bounded by an outer circumference substantially equal to or greater than that of the metal body. The polymeric distal tip member may be overmolded upon a distal-end tip length of an elongate single-wire, memory-metal alloy stylet body, where the distal end and/or discrete intermediate distal-portion length(s) that include martensitic-phase alloy and any polymeric member have greater flexibility than a proximal-most length of the alloy stylet body.
1. A stylet configured for use within an endoscopic needle, the stylet comprising:
a proximal end terminus and a distal end terminus;
an elongate single-wire, memory-metal alloy body with a generally cylindrical body profile that is circumferentially bounded by a first outer circumference, extending distally from the proximal end terminus;
a polymeric distal tip member fixedly attached directly at a distal end of the single-wire body;
where the polymeric distal tip member has a generally cylindrical body profile circumferentially bounded by a second outer circumference that is substantially equal to or greater than the first outer circumference;
where at least a lengthwise portion of the single-wire body is in martensitic phase at operating temperatures at and below about 37° C.,
where the polymeric distal tip member is overmolded upon and around a distal terminal-end length of the single-wire body, and
where the longitudinal distal terminal-end length of the single-wire body that is within the polymeric distal tip member occupies about one-half or less of the longitudinal length of the polymeric distal tip member.
2. The stylet of claim 1 , where the fixed attachment of the polymeric distal tip member to the single-wire body comprises one or more of overmolding, adhesive, epoxy, friction-fit interface, or any combination thereof.
3. The stylet of claim 1 , where a combined length of
the polymeric distal tip member
and
the lengthwise portion of the single-wire body in martensitic phase at operating temperatures at and below about 37° C.
comprises at least about one-tenth of a complete length of the stylet between its proximal end terminus and distal end terminus.
4. The stylet of claim 1 , where a combined length of
the polymeric distal tip member
and
the lengthwise portion of the single-wire body in martensitic phase at operating temperatures at and below about 37° C.
comprises no more than about one-half of the complete length of the stylet between its proximal end terminus and distal end terminus.
5. The stylet of claim 1 , where a length of the polymeric distal tip member comprises
at least about one-half of a complete length of the stylet between its proximal end terminus and distal end terminus, or
no more than about one-half of a complete length of the stylet between its proximal end terminus and distal end terminus.
6. The stylet of claim 1 , where the distal terminus of the polymeric distal tip member is hemispherical or otherwise rounded.
7. A needle assembly including the stylet of claim 1 , further comprising an endoscopic needle, where the stylet is disposed through a longitudinal lumen of the endoscopic needle.
8. A stylet configured for use within an endoscopic needle, the stylet comprising:
a proximal end terminus and a distal end terminus;
an elongate single-wire, memory-metal alloy body with a generally cylindrical body profile that is circumferentially bounded by a first outer circumference, extending distally from the proximal end terminus;
a polymeric distal tip member fixedly attached directly at a distal end of the single-wire body;
where the polymeric distal tip member has a generally cylindrical body profile circumferentially bounded by a second outer circumference that is substantially equal to or greater than the first outer circumference; and
where at least a lengthwise portion of the single-wire body is in martensitic phase at operating temperatures at and below about 37° C.,
where the polymeric distal tip member is overmolded upon and around a distal terminal-end length of the single-wire body,
where the second outer circumference is substantially equal to the first outer circumference, and the longitudinal distal terminal-end length of the single-wire body that is within the polymeric distal tip member comprises a third outer circumference that is less than the first outer circumference and the second outer circumference, and
where the longitudinal distal terminal-end length of the single-wire body that is within the polymeric distal tip member occupies about one-half or less of the longitudinal distal terminal-end length of the polymeric distal tip member.
9. The stylet of claim 8 , where the third outer circumference is about 65% to about 95% of the second outer circumference.
10. The stylet of claim 8 , where the second outer circumference is greater than the first outer circumference.
11. The stylet of claim 8 , where the first outer circumference is about 65% to about 95% of the second outer circumference.
12. The stylet of claim 8 , where a combined length of
the polymeric distal tip member
and
the lengthwise portion of the single-wire body in martensitic phase at operating temperatures at and below about 37° C.
comprises no more than about one-half of the complete length of the stylet between its proximal end terminus and distal end terminus.
13. The stylet of claim 8 , where a length of the polymeric distal tip member comprises
at least about one-half of a complete length of the stylet between its proximal end terminus and distal end terminus, or
no more than about one-half of a complete length of the stylet between its proximal end terminus and distal end terminus.
14. The stylet of claim 8 , where the distal terminus of the polymeric distal tip member is hemispherical or otherwise rounded.
15. A needle assembly including the stylet of claim 8 , further comprising an endoscopic needle, where the stylet is disposed through a longitudinal lumen of the endoscopic needle.
16. The stylet of claim 8 , where a combined length of
the polymeric distal tip member
and
the lengthwise portion of the single-wire body in martensitic phase at operating temperatures at and below about 37° C.
comprises at least about one-tenth of a complete length of the stylet between its proximal end terminus and distal end terminus.