Devices and methods for forming a restriction in a patient are disclosed. In one exemplary embodiment, a restriction system is provided including an implantable restriction device, an implantable port in fluid communication with the implantable restriction device, and an implantable pump in fluid communication...http://www.google.com.hk/patents/US8057492?utm_source=gb-gplus-share專利 US8057492 - Automatically adjusting band system with MEMS pump
