in more detail hence fig1 shows that the catheter 10 is sized to extend from the distal end of a working channel of a standard bronchoscope a for example some common bronchoscopes have working channels with an internal diameter of about 2 8 mm while others have working channels with an internal diameter of about 2 65 mm hence the catheter 10 has an outside diameter of 2 8 mm or slightly less or preferably 2 65 mm or slightly less such that is slides freely within the working channels of these bronchoscopes a the catheter 10 generally includes a working channel 20 a location system 100 only a component of which is shown in fig1 an optical system 200 an optic cleaning system 300 a tool 400 a steering mechanism 500 and a catheter body 600 it is to be understood that the catheter 10 of the present invention is considered to be any device containing one or more of these features in any of their respective variations discussed below in any combination these components are being described individually specifically so as not to limit the scope of the present invention to one or more combinations of these features one skilled in the art will quickly realize that the number of components of the catheter 10 each described in various forms below would result in too many combinations to practically describe individually the location system 100 shown in fig2 x generally includes a sensor assembly 120 a location board 140 and a control system 180 the sensor assembly 120 may be passive or active a system using a passive sensor assembly 120 is.