A graft fixation system for fixing graft material in a bone tunnel includes an expandable fixation member having a graft receiving eyelet disposed proximate its distal end, opposed bone engaging elements disposed about its periphery, and an expansion plug receiving opening defined in its proximal end. The plurality of duct leafs articulate and cause the one or more adjustable ducts to converge and diverge to selectively disposing a fluid about the one or more impellers. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. The housing includes second and third electronic accessories at least partially controlled by a microprocessor. The number of cycles between the first cycle and the determination cycle is a function of the delay value such that reject timing is variable with respect to the first cycle. The assembly includes a cutting part capable of making a hole through a well tubular; a substance chamber for storage of the substance and a substance injecting part capable of injecting the substance into the annular space.