Abstract: A plunger-type control handle for controlling the deflection of a distal tip of a catheter. The control handle includes a spool driven by a gear, the spool being connected to the proximal end of at least one pull wire. For bi-directional deflection, a second proximal end of a pull wire is connected to the spool such that when one of the proximal ends is collected by the spool, the other of the proximal ends is released in an equal amount. The gear is operatively coupled to the plunger and engages a gear rack disposed on the control handle housing, such that when there is relative movement between the housing and the plunger, the gear and spool are rotated. In one embodiment, a switching mechanism is provided that reverses the rotation direction of the gear and spool, thereby providing full stroke resolution of the plunger in each of the bi-directional directions.

Abstract: An apparatus for detecting deformation of an elongate body may comprise a light source configured to sequentially provide light of multiple frequencies, an optical receiver configured to receive light from the light source, and a filter disposed between the light source and the optical detector. The filter may comprise multiple segments, each of the segments configured to filter light at one of the frequencies so as to alter the amount of light incident on said optical receiver. A total amount of light detected by the optical receiver may change during the sequence so as to be indicative of deformation of the elongate body.