A metal detection device, system and method are provided. The device includes a receiver that receives a signal pattern representing electromagnetic field disturbances over time caused by movement of metal doors in a detection region. The device further includes a memory in communication with the receiver. The memory stores a recorded signal pattern of a previously received signal pattern and at least one quality criterion. The device further includes a processor in communication with the memory. The processor determines pattern vitals indicating a quality of the received signal pattern. The processor further determines whether the at least one quality criterion is met based at least in part on the pattern vitals. The processor further updates the recorded signal pattern based at least in part on determining whether the at least one quality criterion is met.