Torque-transmitting steering mechanism for a steerable tool

A mechanical transmission system, MTS (100), for a steerable tool (500) which steerable tool (500) has a proximal end (20) and distal end (40) and comprises a shaft region (532), a bendable proximal part, BPP (534) that is omnidirectionally moveable, and a bendable distal part, BDP, (530) that is omnidirectionally moveable and moves responsive to movement of the BPP (534), which MTS (100) comprises a plurality of longitudinal members, LM (110) each having a proximal (20) and distal end (40), arranged in a longitudinal direction around a fictive tube (120), and has a corresponding transmission shaft region, TSR (132), transmission bendable proximal part, TBPP (134) and transmission bendable distal part, TBDP (130), wherein a plane section (114) of at least one LM (110) demonstrates an anisotropic area moment of inertia, and the majority of the LMs (110) are each axially rotationally constrained at 1 or more constraining points along the TBDP (130) or along the TSR (132) wherein the LMs are longitudinally slidable with respect to each discrete constraining point, and the MTS (100) is configured such that the BDP (530) tip is axially rotationable in a bent position by a complementary rotation of the BPP (534)