A circulatory assist system is disclosed, the system including an implantable electrical device having an electric motor, an implantable controller connected to the implantable electrical device, and an implantable power source connected to the controller for supplying power to the controller. The controller is attachable to a first side of a percutaneous connector. A second side of the percutaneous connector, opposite to the first side, allows external connectivity to said controller. (Fig. 2)