Needle magnetizing arrangement

A needle magnetizing arrangement (1) comprising a controller (4) adapted to generate a first magnetic field (F) for magnetizing a needle (2), and a magnetic field sensor (5) adapted to generate a signal based on a second magnetic field (FR) of the needle (2).

This application is a 371 U.S. National Application of PCT/EP2013/072898, filed on Nov. 4, 2013, which claims priority to European Patent Application Nos. 12191829.6, filed on Nov. 8, 2012, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a needle magnetizing arrangement.

BACKGROUND OF THE INVENTION

In a conventional injection procedure, a user is generally advised to use a new injection needle or syringe for each injection to reduce a risk of cross contamination, infection and/or pain (e.g., when re-using blunt needles). However, the user may forget to change the needle or syringe before an injection thus subjecting themselves to the risks.

Some conventional injection devices utilize color coding to distinguish between used and unused injection needles and/or syringes. However, typically such color coding is in a small space on the injection device and can be difficult to see, especially for users with vision impairments.

In order to avoid these risks and overcome the problems associated with prior injection devices, there remains a need for a needle safety device, such as a needle magnetizing arrangement.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a needle magnetizing arrangement.

In an exemplary embodiment, a needle magnetizing arrangement according to the present invention comprises a controller adapted to generate a first magnetic field for magnetizing a needle, and a magnetic field sensor adapted to generate a signal based on a second magnetic field of the needle.

In an exemplary embodiment, the needle magnetizing arrangement further comprises a coil coupled to the controller. The controller passes current through the coil.

In an exemplary embodiment, the needle magnetizing arrangement further comprises a magnetic guide adapted to guide a flux of the second magnetic field toward the magnetic field sensor. The magnetic guide is coupled to the magnetic field sensor.

In an exemplary embodiment, the needle is coupled to a removably needle assembly or a syringe.

In an exemplary embodiment, the needle magnetizing arrangement further comprises a magnetic shield at least partially enclosing an area around the needle. The magnetic shield circumferentially encloses the area around the needle. The magnetic guide is enclosed by the magnetic shield. The magnetic shield is composed of Mu-metal, permalloy or electrical steel.

In an exemplary embodiment, the needle magnetizing arrangement further comprises a processor electrically coupled to the magnetic field sensor and adapted to receive the signal. The processor executes a predetermined action when the signal indicates a presence of the second magnetic field. The predetermined action is providing an audible or visual feedback.

In an exemplary embodiment, the arrangement is integrally formed with or removably coupled to an injection device. The predetermined action is preventing use of the injection device.

DETAILED DESCRIPTION

FIG. 1is a schematic view of an exemplary embodiment of a needle magnetizing arrangement1according to the present invention. In an exemplary embodiment, the arrangement1is used to magnetize a needle2which is attached to a removable needle assembly8. For example, the needle2may be a double-tipped needle in the needle assembly8which can be removably engaged (e.g., threaded) to a medicament delivery device and/or a medicament cartridge. In another exemplary embodiment, the needle2may be coupled to a syringe. Those of skill in the art will understand that the needle2may be coupled to any transcutaneous device.

In an exemplary embodiment, the needle magnetizing arrangement1comprises a controller4having a coil3. When activated, the controller4passes a current through the coil3to generate a magnetic field for magnetizing the needle2. Magnetizing the needle2may create magnetic poles2.1,2.2on the needle2, which exhibit a magnetic field F.

In an exemplary embodiment, the needle magnetizing arrangement1includes a magnetic field sensor5for determining a magnetic field strength of the needle2before and after the magnetization. A magnetic guide6disposed adjacent the sensor5may comprise a magnetically soft material for guiding a magnetic flux of the needle2to the magnetic field sensor5. The guide6may thus focus and/or amplify the magnetic field strength detectable by the magnetic field sensor5. A magnetic shield7may be arranged around the magnetic field sensor5and the needle2for limiting impact of ambient magnetic fields on the magnetic field sensor5. For example, the magnetic shield7may enclose an area around the needle2and facilitate measurement of low magnetic field strengths.

In an exemplary embodiment, the sensor5may generate an electrical signal that is utilized by a processor10for taking a predetermined action. For example, if the signal indicates the needle2has been previously magnetized, the processor10may prevent an injection procedure from occurring, may provide a feedback to a user, etc. When a new, magnetically neutral needle is detected, the processor may allow an injection procedure, may provide a feedback to a user, etc.

In an exemplary embodiment, the arrangement1may be integrally formed with an medical device or may be removably coupled thereto. For example, the arrangement1may be utilized with a plurality of different medical devices which utilize needles or components having needles.

FIG. 2is a schematic top cross sectional view of an exemplary embodiment of the needle2, the magnetic shield7and the magnetic guide6. In the exemplary embodiment, the shield7circumferentially encloses the needle2and the guide6. This configuration may limit noise (e.g., due to ambient magnetic fields) in the signal generated by the sensor5. In other exemplary embodiments, the shield7may partially enclose the needle2. In another exemplary embodiment, the guide6may be embedded wholly or partially in the shield7.

FIG. 3is a schematic view of an exemplary embodiment of the needle magnetizing arrangement1prior to use. Prior to use, the needle2is magnetically neutral.

FIG. 4is a schematic view of an exemplary embodiment of the needle magnetizing arrangement1during use. The magnetization controller4passes a current I through the coil3thereby generating a magnetic field F. In an exemplary embodiment, the magnetization controller4may generate the current I by discharging a capacitor9. As the needle2is exposed to the magnetic field F, the needle2is magnetized, thus providing a magnetic orientation with a north pole2.1and a south pole2.2. This magnetic orientation remains even after removing the magnetic field F by switching off the current I through the coil3. Hence, the needle2has a permanent (or semi-permanent) magnetic field FRas illustrated inFIG. 5.

Those of skill in the art will understand that the current I may passed through the coil3in the opposite direction thereby switching the orientation of the magnetic field F and reversing the magnetic orientation of the needle2.

Preventing re-use of needles may reduce the risk for causing the user pain when inserting a blunt needle and mitigate the risk of cross contamination by used non-sterile needles.

In an exemplary embodiment when using a needle2with a net magnetization of zero prior to use, the needle magnetizing arrangement1may be used to distinguish three different states of the needle2by detecting whether the net magnetization is different from zero and whether the north pole2.1points in a distal direction D or in a proximal direction P. The magnetization controller4may be arranged to accordingly magnetize the needle2. In order to detect a direction of the magnetic field FRthe magnetic field sensor5may for example be arranged as an XMR sensor using one of the magneto resistant quantum effects GMR (giant magneto resistance), AMR (anisotrope magneto resistance), CMR (colossal magnetor resistance), or TMR (tunnel magnetor resistance). If the direction of the magnetic field FRis irrelevant the magnetic field sensor5may also be a Hall sensor.

In another exemplary embodiment the magnetization controller4may be arranged to de-magnetize a magnetized needle2by driving an alternating current through the coil3. In this case an unused needle2could have an initial net magnetization different from zero while a used needle would be marked by de-magnetizing it.