A portable printer includes an outer housing, a circuit board, a battery, an inner housing, at least one inkjet head, and a motor, all of which are housed in the outer housing. A cannula having a circumferential opening is inserted into cancellous bone and directed such that the circumferential opening faces the fracture. The protective panels are externally snitched to a low thermal burden material, such as a polyester mesh, that provides elasticity and completes the structure of the shorts. The viewing window is transmissive of a light image of the subject field. More specifically, it relates to a separation finger with remarkably improved durability which has a sharp tips and is capable of preventing paper jams, caused by, for example, adhesion of the toner, over extended periods of time. A base station searches for at least one candidate cooperation device for a source device, then an effective period timer, for an effective time command list for a list of candidate cooperation devices for a source device, is initiated, and a determination is made as to whether the list of candidate cooperation devices is valid.