There is disclosed a method of gaining access to a lateral side of a spinal column for a spinal fusion procedure at a surgical site. The network access nodes each have a network address associated therewith which is unique on the network, the first network access node having a first network address associated therewith. A self-lubricating surface coating composition is also provided, as well as several methods of making the bearings. A low pressure area created by the fan is used to assist in drawing the cooling exhaust airflow through the compartment, to thus form a closed loop cooling air recirculation system using only clean, filtered exhaust airflow to maintain the beater brush motor cool during use.