A docking system for securing a wheelchair into a vehicle in which a docking shoe is firmly attached to either the frame of the wheelchair or to the floor of the vehicle, or both. A hierarchical message store is maintained. A transformed keyword tree generation unit generates a true positive transformed keyword tree and a false positive transformed keyword tree. The U-shaped actuator has first and second ends respectively coupled to the rotating members of the first and second pulldown mechanisms. The applying roller rotates to cause the applying liquid held in the holding space to adhere to an outer peripheral surface of the applying roller. The distal tip of the catheter is rendered radiopaque, at least at its distal-most end, to enable visualization of the position of the catheter and to facilitate placing the catheter in the desired position.