Needles For Use With System For Guiding A Medical Instrument

Abstract

A guidance system for assisting with the insertion of a needle into a patient body is disclosed. The guidance system utilizes ultrasound imaging or other suitable imaging technology. In one embodiment, the guidance system comprises an imaging device including a probe for producing an image of an internal body portion target, such as a vessel. One or more sensors are included with the probe. The sensors sense a detectable characteristic related to the needle, such as a magnetic field of a magnet included with the needle. The system includes a processor that uses data relating to the sensed characteristic to determine a 3-D position of the needle. The system includes a display for depicting the position of the needle. A needle assembly including a hub, cannula, and magnetic element is also disclosed, wherein the cannula is substantially non-magnetic so as to not distort the magnetic field of the magnetic element.

What is claimed is: 
     
         1 . A needle assembly, comprising:
 a hub;   a cannula distally extending from the hub, the cannula including a substantially non-magnetic material so as to render the cannula substantially non-magnetic; and   a magnetic element included with at least one of the hub and the cannula, the magnetic element configured to enable the needle assembly to be tracked by a medical instrument tracking system during a procedure to insert the needle assembly into a body of a patient.   
     
     
         2 . The needle assembly as defined in  claim 1 , wherein the magnetic element is a permanent magnet. 
     
     
         3 . The needle assembly as defined in  claim 2 , wherein the magnetic element include neodymium. 
     
     
         4 . The needle assembly as defined in  claim 1 , wherein the magnetic element is permanently mounted with the hub. 
     
     
         5 . The needle assembly as defined in  claim 4 , wherein the magnetic element is cylindrically shaped and includes a central hole, a portion of the cannula received through the central hole of the magnetic element. 
     
     
         6 . The needle assembly as defined in  claim 1 , further comprising a needle safety component that is slidable along a longitudinal length of the cannula. 
     
     
         7 . The needle assembly as defined in  claim 6 , wherein the magnetic element is disposed in the needle safety component. 
     
     
         8 . The needle assembly as defined in  claim 1 , wherein the cannula is composed of a material of a magnetic permeability of about 1. 
     
     
         9 . The needle assembly as defined in  claim 1 , wherein the cannula is composed of a metallic alloy including nickel and chromium. 
     
     
         10 . The needle assembly as defined in  claim 1 , wherein the cannula is hollow and defines a longitudinal lumen. 
     
     
         11 . The needle assembly as defined in  claim 1 , wherein the magnetic element is removably included with the needle assembly. 
     
     
         12 . The needle assembly as defined in  claim 1 , wherein the cannula is configured to not substantially distort a magnetic field of the magnetic element. 
     
     
         13 . The needle assembly as defined in  claim 1 , wherein the magnetic element is an electromagnet. 
     
     
         14 . A guidance system for guiding insertion of a needle assembly into a body of a patient, comprising:
 an ultrasound imaging device including a probe for ultrasonically imaging an internal body portion target;   a magnetic element included with the needle assembly, the needle assembly further including:
 a hub; and 
 a cannula distally extending from the hub, the cannula including a substantially non-magnetic material; and 
   a plurality of magnetic sensors included with the guidance system that each sense a magnetic field of the magnetic element of the needle assembly; and   a processor that receives magnetic field data sensed by the sensors to determine a position of the needle in three spatial dimensions.   
     
     
         15 . The system as defined in  claim 14 , further comprising a display that depicts the determined position of the needle together with the image of the target. 
     
     
         16 . The system as defined in  claim 14 , wherein the magnetic sensors are disposed within the probe. 
     
     
         17 . The system as defined in  claim 16 , wherein at least a portion of the ultrasound probe is rendered non-magnetic via the inclusion of one or more components that include a magnetic permeability of about 1. 
     
     
         18 . The system as defined in  claim 17 , wherein at least one component of the ultrasound probe is composed of one or more materials that include a magnetic permeability of about  1 , the at least one component selected from the group consisting of a screw, a rivet, a strain relief grommet, a resistor, a capacitor, and combinations thereof. 
     
     
         19 . The system as defined in  claim 18 , wherein the at least one component is composed of at least one of brass and aluminum. 
     
     
         20 . The needle assembly as defined in  claim 14 , wherein the cannula is composed of a material of a magnetic permeability of about 1. 
     
     
         21 . The needle assembly as defined in  claim 20 , wherein the cannula is composed of a metallic alloy including nickel and chromium. 
     
     
         22 . The needle assembly as defined in  claim 14 , wherein the cannula is configured to not substantially distort a magnetic field of the magnetic element. 
     
     
         23 . The needle assembly as defined in  claim 14 , wherein the magnetic element is an electromagnet. 
     
     
         24 . A needle assembly, comprising:
 a hub;   a cannula distally extending from the hub, the cannula including a magnetizable material; and   a needle guard defining a volume configured to be removably attached to the needle assembly so as to cover the cannula, the needle guard including a magnetic material configured to magnetize the cannula when the cannula is disposed in the volume.   
     
     
         25 . The needle assembly as defined in  claim 24 , wherein the cannula includes stainless steel and wherein the needle guard is configured to protect a distal end of the cannula. 
     
     
         26 . The needle assembly as defined in  claim 24 , wherein the needle guard includes an inner sleeve including a thermoplastic and an outer sleeve including the magnetic material. 
     
     
         27 . The needle assembly as defined in  claim 24 , wherein the magnetic material includes neodymium. 
     
     
         28 . The needle assembly as defined in  claim 24 , wherein a proximal end of the needle guard is configured to removably attach to a portion of the hub in a friction fit arrangement. 
     
     
         29 . The needle assembly as defined in  claim 24 , wherein the needle guard includes a thermoplastic impregnated with a magnetic material. 
     
     
         30 . A method of making a needle assembly, the method comprising:
 attaching a cannula to a hub of the needle assembly, the cannula including a non-magnetic material so as to render the cannula substantially non-magnetic; and   including a magnetic element with at least one of the hub and the cannula.   
     
     
         31 . The method of making as defined in  claim 30 , wherein attaching the cannula further includes attaching a cannula composed of a material of a magnetic permeability of about 1. 
     
     
         32 . The method of making as defined in  claim 31 , wherein attaching the cannula further includes attaching a cannula composed of an metallic alloy including nickel and chromium. 
     
     
         33 . The method of making as defined in  claim 30 , wherein including the magnetic element includes attaching a cylindrical magnet including neodymium to a portion of the needle assembly. 
     
     
         34 . The method of making as defined in  claim 30 , wherein attaching the cannula further includes attaching the substantially non-magnetic cannula to the hub such that the cannula does not substantially distort a magnetic field of the magnetic element.