The patient admitted that several years ago he had a small subdermal metallic implant inserted into middle finger to allow magnetization of metal objects.

Insertion of a small magnet (neodym) is a form of body modification and is performed for several reasons according to Wikipedia:

1. to pick up small metal objects using magnetism
2. allow sensory perception of magnetism, a 'sixth sense'
3. augment ultrasonic or infra-red signals into a touch sensation ('even though scientifically magnets have no relation to either infra-red radiation or ultrasonic sound waves and cannot possibly react to either phenomenon' ¹)

​These implants are often inserted in less than ideal sterile conditions, therefore one should assess for signs of infection.