The 15-foot-tall wind and light sculpture designed by Tom Wilkinson acts as a beacon indicating the entrance point to the new hospital wing. The wind turbine is Tom's own version of the Savonius turbine. The gentle helical curves at the top rotate at varying rates. The artist says of the work, 'sometimes the form will be still, sometimes turning sedately. The gentle undulations, rather like the motion of water stimulates alpha waves in the brain, instills a sense of calm'. When it gets dark the sculpture is lit by a circle of LED lights around the base of the turbine, which project colours upwards through the waves. The four colours – purple, malachite, orange and indigo – were chosen because they are refreshing and calming. In order to break the sense of routine, there is no set sequence to the lighting so Monday, for example, will not always be purple.