The subelectronic converter was a brain implant invented by Imperial designer Nasdra Magrody that enabled Force-sensitive subjects to control droids remotely. One known recipient was Irek Ismaren, who used the implant to control the Eye of Palpatine.
The subelectronic converter allowed Ismaren to visualize the programming of computerized devices, and, through the Force, override it. The subelectronic computer allowed him to apply his existing skill in Alter Mind. It took many months of practice to master.