Brain implant between neural systems and computer chips. This work is part of a wider research field called brain-computer interfaces. (Brain-computer interface research also includes technology such as EEG arrays that allow interface between mind and machine but do not require direct implantation of a device.) Neural implants such as deep brain stimulation and Vagus nerve stimulation are increasingly becoming routine for patients with Parkinson's disease and clinical depression respectively. Brain implants electrically stimulate, block or record (or both record and stimulate simultaneously) signals from single neurons or groups of neurons (biological neural networks) in the brain. The blocking technique is called
Signals, Crane and Subway, Charters Towers railway station mechanical signals were controlled from signal cabins, which dealt with the traffic on a particular block of railway line. Signal cabins coordinated signals that indicated whether or not a section of track was clear of other traffic. Early signals were mechanical, while later signals were operated electrically. The most common form of mechanical signal was the semaphore signal. These consisted of a metal framed tower with one or more arms that could be inclined at different angles, with the arm at the horizontal signalling "danger", or do not proceed. Mechanical signals were usually worked by a wire cable running from