area around the needle 2 and facilitate measurement of low magnetic field strengths in an exemplary embodiment the sensor 5 may generate an electrical signal that is utilized by a processor 10 for taking a predetermined action for example if the signal indicates the needle 2 has been previously magnetized the processor 10 may 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 arrangement 1 may be integrally formed with an medical device or may be removably coupled thereto for example the arrangement 1 may be utilized with a plurality of different medical devices which utilize needles or components having needles fig2 is a schematic top cross sectional view of an exemplary embodiment of the needle 2 the magnetic shield 7 and the magnetic guide 6 in the exemplary embodiment the shield 7 circumferentially encloses the needle 2 and the guide 6 this configuration may limit noise e g due to ambient magnetic fields in the signal generated by the sensor 5 in other exemplary embodiments the shield 7.