Invasive medical devices including magnetic region and systems and methods
Devices, systems, and methods are described including an invasive medical device with a magnetic region. The magnetic region can include a discontinuity in the magnetic region providing a diameter transition, a plurality of spaced magnetic regions can be provided or the magnetic regions can be encoded with data. Systems and methods are described that include ways to read the data.
1. A needle assembly comprising:
an elongate shaft having a diameter, an outer surface, a distal tip, and a proximal end, the diameter of the elongate shaft sized to be inserted within an intravenous catheter, at least a portion of the elongate shaft having a first magnetic region and a discontinuity in the first magnetic region providing an increased diameter region relative to the diameter of the elongate shaft, the discontinuity comprising a magnetic adhesive.
2. The needle assembly of claim 1 , wherein the needle assembly comprises a hypodermic needle.
3. The needle assembly of claim 2 , wherein the shaft is disposed within intravenous catheter tubing.
4. The needle assembly of claim 3 , wherein the magnetic adhesive increases the diameter of the shaft of the hypodermic needle.
5. The needle assembly of claim 3 wherein the magnetic adhesive on the outer surface of the shaft of the hypodermic needle.
6. The needle assembly of claim 5 , wherein the magnetic adhesive includes an additive selected from a paramagnetic additive, a ferromagnetic additive and combinations thereof.
7. The needle assembly of claim 6 , wherein the additive includes a component selected from the group consisting of powdered iron, magnetic iron oxide, magnetic titanium oxide, magnetic powdered steel, and a magnetic iron alloy, and mixtures thereof.
8. The needle assembly of claim 7 , wherein the magnetic iron alloy includes one or more of nickel, zinc, and copper.
9. The needle assembly of claim 8 , wherein the additive further comprises a component selected from chromium, magnesium, molybdenum and combinations thereof.
10. The needle assembly of claim 3 , wherein the hypodermic needle comprises martensitic stainless steel.
11. A system including the needle assembly of claim 3 , wherein the hypodermic needle is part of a needle subassembly further including a needle hub mounted to the proximal end of the hypodermic needle, and the system further comprises a catheter adapter assembly.
12. The system of claim 11 , the catheter adapter assembly including catheter tubing and a catheter adapter body, wherein the shaft is slidably engaged with the intravenous catheter tubing.
13. The system of claim 12 , wherein the catheter adapter assembly further comprises a magnetic feature.
14. The system of claim 13 , wherein the magnetic feature comprises a permanent magnet with north and south poles on axis with the catheter and hypodermic needle and a known geometrical relationship to one or more features fixed on the catheter adapter assembly providing a measurement datum that is measurable by ultrasound probe magnetic sensors.