A bed lifting system is provided for lifting a bed above a surface. The electronically guided spinal rod system insures that the spinal rod will be accurately positioned while allowing the operator complete freedom to choose its specific path into the screw inserter rod access slots. The physical action may include selecting a button, or inputting biometric data to switch among running access units. The methods of the invention are amenable to the large-scale synthesis and purification of oligonucleotides.