Inducer

An Inducer was a machine used to 'seed' humans who had taken the Adipose pill. It could also receive messages.

Matron Cofelia managed to 'seed' a million humans. The Doctor managed to overide the Matron's Inducer with a second one inside a cupboard. He did this by attaching two capsule-like-necklaces to the machine. The Doctor's Inducer received a message from the Adipose First Family and worked out that they would kill their accomplice, Matron Cofelia. (DW: Partners in Crime)