An access device places a medical article within a body space of a patient. The device has a needle section that includes an elongated body and a needle hub. The device further includes a dilator portion that has a dilator and a dilator hub. The dilator is coaxially disposed and slideable over the elongated body of the needle section. The device further includes a sheath section that has a sheath and a sheath hub. The sheath is coaxially disposed and slideable over the dilator. The device further includes a first locking mechanism operably disposed between the needle hub and the dilator hub to inhibit at least unintentional axial movement between the needle section and the dilator portion and a second locking mechanism operably disposed between the dilator hub and the sheath hub to inhibit at least unintentional axial movement between the dilator portion and the sheath section.
1. An access device for placing a medical article within a body space, comprising:
a needle section including an elongated body and a needle hub, the elongated body having distal and proximal ends, the distal end being configured for insertion into a patient's body, the proximal end being coupled with the needle hub;
a dilator portion including a dilator and a dilator hub, the dilator being coaxially disposed and slideable over the elongated body of the needle section with the dilator hub being disposed distal of the needle hub;
a sheath section comprising a sheath and a sheath hub, the sheath being coaxially disposed and slideable over the dilator with the sheath hub being disposed distal of the dilator hub;
a first locking mechanism operably disposed between the needle hub and the dilator hub to inhibit at least unintentional axial movement between the needle section and the dilator portion when said first locking mechanism is engaged; and
a second locking mechanism operably disposed between the dilator hub and the sheath hub to inhibit at least unintentional axial movement between the dilator portion and the sheath section when said second locking mechanism is engaged;
wherein each of said first and second locking mechanisms is configured to be engaged by moving the respective hubs in a non-axial manner relative to each other, and wherein the first locking mechanism is configured to move in a manner different from the manner in which the second locking mechanism is engaged.
2. The access device of claim 1 , wherein the second locking mechanism is configured to be engaged by rotating the dilator hub relative to the sheath hub about a common axis.
3. The access device of claim 2 , wherein the second locking mechanism comprises at least one key post and at least one key hole, and at least one of the dilator hub and the sheath hub includes the key post and the other one includes the corresponding key hole.
4. The access device of claim 2 , wherein the second locking mechanism includes a plurality of key posts disposed on the dilator hub and a plurality of key holes disposed on the sheath hub.
5. The access device of claim 1 , wherein the first locking mechanism is configured to be engaged by pivoting a member of the first locking mechanism about an axis lying generally transverse to a longitudinal axis common to the needle section and the dilator portion.
6. The access device of claim 5 , wherein the first locking mechanism includes a first clip pivotally attached to one of the needle hub and the dilator hub, the first clip including a tang disposed on an outer end that is configured and oriented to engage a corresponding catch disposed on the other one of the needle hub and the dilator hub.
7. The access device of claim 6 , wherein the first clip includes an actuating side and a pivot point, the pivot point lying between the actuating side and the tang.
8. The access device of claim 6 , wherein the first locking mechanism includes a second clip pivotally attached to the same hub to which the first clip is attached, the second clip being disposed on said hub in a position generally diametrically opposed to the first clip.
9. The access device of claim 6 , wherein the corresponding catch and clip have sufficient widths to inhibit relative rotation between the dilator hub and the needle hub.
10. An access device for placing a medical article within a body space, comprising:
a needle section including an elongated needle body with a sharp distal tip and a needle hub from which the needle body extends;
a dilator portion including a dilator and a dilator hub fixed to the dilator, the dilator being coaxially disposed and slideable over the needle body with the dilator hub being disposed distal of the needle hub;
a sheath section comprising a sheath and a sheath hub, the sheath being coaxially disposed and slideable over the dilator with the sheath hub being disposed distal of the dilator hub; and
a locking mechanism disposed within the dilator hub and selectively operating between the needle section and the dilator hub, the locking mechanism being configured to arrest axial movement of the needle body at least in the distal direction once the distal tip of the needle body is drawn into the dilator portion to sheath the distal tip.
11. The access device of claim 10 , wherein the locking mechanism comprises a receptacle and a tang biased toward the receptacle, the receptacle being formed on either the outer surface of the needle body or an inner surface of the dilator hub, and the tang extending from the other one of the needle body outer surface and the dilator hub inner surface.
12. The access device of claim 11 , wherein the receptacle comprises a hole in the needle body.
13. The access device of claim 11 , wherein the receptacle comprises an annular groove about the needle body.
14. The access device of claim 11 additionally comprising a second tang oriented to arrest axial movement of the needle body in a proximal direction.
15. The access device of claim 14 , wherein the first and second tangs engage said receptacle when the distal tip of the needle body is sufficiently withdrawn into the dilator portion.
16. The access device of claim 14 , wherein the locking mechanism includes another receptacle disposed so as to receive the second tang when the distal tip of the needle body is withdrawn into the dilator portion.
17. The access device of claim 11 , wherein the tang is attached to the dilator hub by a pivot coupling.
18. The access device of claim 11 , wherein the tang is configured to move in a direction generally transverse to a longitudinal axis of the needle body when engaging the receptacle.
19. An access device for placing a medical article within a body space, comprising:
a dilator hub having a passageway configured to receive an elongated needle, the needle having at least one side receptacle;
one or more fingers or tangs disposed in the dilator hub and configured to engage with the at least one side receptacle at least when the needle is retracted through the passageway; and
a locking plate and a slot, the slot being disposed in the dilator hub so as to slidingly receive the locking plate, wherein the one or more fingers or tangs are disposed on said locking plate.
20. An access device for placing a medical article within a body space, comprising:
a needle section including an elongated body and a needle hub, the elongated body having distal and proximal ends, the distal end being configured for insertion into a patient's body, the proximal end being coupled with the needle hub;
a dilator portion including a dilator and a dilator hub, the dilator being coaxially disposed and slideable over the elongated body of the needle section with the dilator hub being disposed distal of the needle hub and the dilator having a distal end;
a sheath section comprising a sheath and a sheath hub, the sheath being coaxially disposed and slideable over the dilator with the sheath hub being disposed distal of the dilator hub and the sheath having a distal end;
a first locking mechanism operably disposed between the needle hub and the dilator hub to inhibit at least unintentional axial movement between the needle section and the dilator portion when said first locking mechanism is engaged; and
a second locking mechanism operably disposed between the dilator hub and the sheath hub to inhibit at least unintentional axial movement between the dilator portion and the sheath section when said second locking mechanism is engaged;
wherein when the locking mechanisms are engaged to inhibit unintentional axial movement, a first distance between the distal end of the needle and the distal end of the dilator is greater than a second distance between the distal end of the dilator and a distal end of the sheath.
21. The access device of claim 20 , wherein the first distance is much greater than the second distance.
22. The access device of claim 20 , wherein the needle comprises a bore and at least one side opening in its side wall, and there is a space between the sheath section and the needle in communication with the side opening.
23. The access device of claim 22 , wherein the sheath is partially or completely clear, translucent, transparent, or semi-opaque.