A physical connection between a human brain and an electronic device. Also called a "neural interface," "mind-machine interface" (MMI) or "brain-computer interface" (BCI), the brain-machine interface (BMI) is focused on managing the movement of prosthetic limbs and enabling vision for the blind. The first interfaces were prototyped with animals in the 1990s and humans later in the decade. Non-Invasive and Invasive Brain-machine interfaces may be non-invasive, with sensors on the head detecting brainwaves. As of 2012, the most precise functionality has been with sensors implanted in the brain tissue. The sensor detects the firing rate of a neuron, and the firing pattern can be mapped to the person's thoughts that in turn control specific robotic motions. Implantation is dangerous and controversial; experts predicting wireless, non-invasive systems will win out in the future.