A surgical instrument comprising a node rotatably mounted within a
restraining structure at the distal end of a shaft. The node can be
rotated allowing manipulation and orientation of a surgical tool extending
from the node at the distal end of the shaft through control remote from
the distal end of the shaft. Cameras may also be located at the distal end
of the shaft allowing stereoscopic imaging to be conveyed to an operator.
The surgical instrument is well suited for administering biologically
active substances to a desired location. The method of administration
comprises insertion of a flexible shaft comprising a channel, controlling
the location of the distal end of the shaft through control cables within
the shaft, and projecting the biologically active substance from the end
of the channel at the desired location.
