Magnetic element-equipped needle assemblies
A guidance system for assisting with the insertion of a needle into a patient is disclosed. The guidance system utilizes ultrasound imaging or other suitable imaging technology. The guidance system can include an imaging device including a probe for producing an image of an internal body target, such as a vessel. One or more sensors can be 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 can include a processor that uses data relating to the sensed characteristic to determine a 3-D position of the needle, and a display for depicting the position of the needle. A needle assembly including a hub, cannula, and magnetic element is also disclosed, in which a magnetic axis of the magnetic element can be configured to be coaxially or otherwise aligned with the cannula axis.
1 . A needle assembly for use with a handheld ultrasound probe, the handheld ultrasound probe including a plurality of magnetic sensors configured to detect a magnetic field, the needle assembly comprising:
a hub;
a needle distally extending from the hub along a longitudinal axis, the needle including an outer wall circumscribing a lumen and a distal needle tip; and
a cylindrical permanent magnet positioned in a cylindrical notch defined in the outer wall of the needle proximate the distal needle tip, the cylindrical permanent magnet producing a magnetic field strength capable of detection by the plurality of magnetic sensors of the handheld ultrasound probe,
further comprising the handheld ultrasound probe, wherein the plurality of magnetic sensors of the handheld ultrasound probe are embedded in a housing of the handheld ultrasound probe, and wherein the plurality of magnetic sensors consist of five magnetic sensors.
2 . The needle assembly as defined in claim 1 , wherein the cylindrical permanent magnet includes a magnetic axis that is substantially aligned with the longitudinal axis of the needle.
3 . The needle assembly as defined in claim 1 , wherein the cylindrical permanent magnet includes a first permanent magnet and a second permanent magnet that together form the cylindrical permanent magnet.
4 . The needle assembly as defined in claim 3 , wherein the first permanent magnet and the second permanent magnet are each substantially U-shaped.
5 . The needle assembly as defined in claim 1 , further comprising a needle holder configured to enable a user to hold and advance the needle during an ultrasound imaging and needle guidance procedure.
6 . The needle assembly as defined in claim 5 , wherein the needle holder is pistol-shaped and includes a trigger.
7 . The needle assembly as defined in claim 6 , wherein the trigger is configured to selectively advance the needle by moving the needle longitudinally away from a barrel of the needle holder upon actuation of the trigger.
8 . The needle assembly as defined in claim 1 , wherein the plurality of magnetic sensors are disposed in a planar configuration below a top face of the handheld ultrasound probe.
9 . The needle assembly as defined in claim 1 , wherein each of the plurality of magnetic sensors comprise three orthogonal sensor coils for enabling detection of the magnetic field in three spatial dimensions.