Educational toy made in plastic versions. In the mid-1950s, more explicitly engineering-themed construction toys appeared, including plastic girders, columns, and panels that could be assembled into a model curtain wall skyscraper. Later, this Girder and Panel structural system was extended to a Hydro-Dynamic setup by adding pipes, valves, tanks, nozzles, and pumps to allow construction of model plumbing, HVAC, and chemical engineering systems like a simulated distillation column. Other extensions of the system supported suburban-style housing developments (Build-A-Home), or monorail transportation systems (Skyrail). The building toy Lego was originally developed by Ole Kirk Christiansen in Billund, Denmark, in the 1930s. The name
Lego Lab, the Danish toy company's experimental research department, and Cirec, a Colombian foundation for physical rehabilitation, the modular prosthetic incorporates myoelectric sensors that register the activity of the muscle in the stump and send a signal to control movement in the attachment. A processing unit in the body of the prosthetic contains an engine compatible with Lego Mindstorms, the company's robotics line, which lets the wearer build an extensive range of customised, programmable limbs. The definitive shape of the Lego bricks, with the inner tubes, was patented by the Lego Group in 1958. Several competitors have attempted to take advantage