# US 8,465,457 B2 · Minimizing resistance to catheter advancement during vascular cannulation

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- Number: US 8,465,457 B2
- Document ID: US8465457B2
- Status: Granted
- Kind: B2
- Application number: 13/314,885
- Filed: 2011-12-08
- Published: 2012-06-14
- Granted: 2013-06-18
- Earliest claimed: 2010-12-08
- Applicants: David G. Silverman; Sally A. Kniffin
- Inventors: David G. Silverman; Sally A. Kniffin
- Web page: https://patentgrep.com/patent/US8465457B2

## CPC

- A61M 25/0606: {"Over-the-needle" catheter assemblies, e.g. I.V. catheters}
- A61M 5/158: Needles {for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body}
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

A hypodermic needle minimizing resistance to catheter advancement during vascular cannulation includes a needle shaft and a needle tip including an open needle bevel extending along middle and proximal portions of the open bevel until a distal end of the needle shaft, wherein a most distal portion of the open bevel is filled to prevent flashback. The hypodermic needle also includes a catheter overlying the needle shaft in the resting position.

## Claims

### Claim 1

A hypodermic needle minimizing resistance to catheter advancement during vascular cannulation, comprising:
a needle shaft having a needle tip;
the needle tip extending to a distal point in alignment with a longitudinal axis extending along a wall of the needle shaft, the needle tip including an open needle bevel extending diametrically across a full extent of the needle, an open portion of the open needle bevel extending along middle and proximal portions of the open needle bevel until a distal end of the needle shaft, wherein a most distal portion of the open needle bevel is filled so that contact of the open portion of the open needle bevel with a vessel is delayed until approximately 2-5 mm of the needle tip is in the vessel to delay flashback from the open portion of the open needle bevel, the open needle bevel being filled as dead space to ensure that flashback cannot occur until a region of the open needle bevel with greater than a prescribed width has passed through an anterior vessel wall;
a catheter having a constant diameter along, its length, the catheter overlying the needle shaft in the resting position;
wherein a distance from the catheter to a distal tip of the open needle bevel is greater than a distance from the catheter to a most distant point of flashback via the open portion of the open needle bevel, thereby delaying flashback until approximately 2-5 mm of the needle tip is in the vessel to ensure an adequate size path is formed in a vessel wall so as to minimize resistance to advancement of the catheter during vascular cannulation.