Symmetrical drive system for an implantable restriction device

Apparatus for regulating the functioning of a patient's organ or duct, comprising:

• an elongated member having a first end and a second end;
• a fastener disposed on the first end of the elongated member, the fastener configured to engage the second end of the elongated member so that the elongated member forms a loop around the organ or duct;
• a tension element disposed for movement within the elongated member, the tension element having opposite first and second ends, wherein the first end includes a flexible first member and the second end includes a flexible second member;
• and
• a symmetrical drive system including a single motor directionally controlling the flexible first member and the flexible second member for simultaneously loosening or tightening the flexible first member and the flexible second member, the symmetrical drive system being coupled to the tension element such that the tension element and the symmetrical drive system define a complete circular loop, the symmetrical drive system including a drive element associated with and engaging the tension element for causing the tension element to control the tension applied by the elongated member against a patient's body organ or duct such that applied tension is uniformly distributed along the tension element, wherein the symmetrical drive system draws the tension element at both the first end of the tension element and the second end of the tension element, and simultaneously applies pressure to the first end of the tension element and the second end of the tension element, thereby uniformly distributing the applied tension along a length of the tension element starting at the first end of the tension element and ending at the second end of the tension element.