Since the invention and introduction of cerebral shunts in the 1950s, the two most important innovations have been the addition of an anti-gravitational valve plus a feature to adjust the valve setting magnetically. Despite these innovations the clinical outcome has not improved in any significant way, and shunts continue to have an unacceptable tendency to malfunction with revisions still commonplace (30% within 6 months). Moreover, shunts fail to provide normal and controlled drainage of CSF because the drainage profile of a shunt is very different from physiological drainage. With current shunts, too much or too little CSF can be drained depending on factors such as body position or the inconstant pressure within the absorption site (heart or abdomen). This lack of synchronisation can result in large variations in intracranial pressure preventing the patient from leading a normal life.