A guide device establishes a guide passage through a guide tube, through whichan operative tool can be deployed into an interior body region for use. A steeringassembly, in use, deflects or bends the distal end region of the guide tube, sothat the operative tool can be placed in a desired orientation with respect totissue. The steering assembly is desirable configured for single handed operationby the clinician. The steering assembly is also desirably configured to providea mechanical advantage sufficient to translate relatively small incrementsof clinician control into relatively larger increments of guide tube deflection.In one arrangement, the steering assembly includes a rack and pinion linkagesystem. In another arrangement, the steering assembly includes a pivoting leversystem.
