Steerable instrument comprising a tube element

1 . A steerable instrument having a proximal end and a distal end and comprising a tubular body extending in a longitudinal direction along a central axis from said proximal end to said distal end,

said tubular body having an intermediate flexible zone and at least one distal deflectable zone,

said tubular body including at least one tube element made from a metal, the at least one tube element being provided with a first slotted structure in the intermediate flexible zone and a second slotted structure in the at least one distal deflectable zone,

the tubular body being provided with tangential rotation blocking elements arranged such as to form a plurality of cable channels, each cable channel accommodating one of a plurality of cables, the plurality of cable channels comprising a plurality of first cable channels and a plurality of second cable channels,

said plurality of cables being configured to be controlled at said proximal end by a steering device and being connected at said distal end to said at least one distal deflectable zone to allow deflection of said at least one distal deflectable zone by means of said steering device,

wherein said at least one tube element comprises an intermediate tube element that:

is arranged in at least a portion of said tubular body,

has an inner surface and an outer surface, said inner surface surrounding a first channel,

has a cross section structure with a uniform thickness along its entire length,

comprises said second slotted structure to provide said intermediate tube element with at least one deflectable section, and

is configured in the following shapes to provide said tangential rotation blocking elements:

a. said outer surface has a corrugated cross section along its entire length, the corrugated cross section defining said plurality of first cable channels each one accommodating at least a portion of one cable, and

b. said inner surface has a corrugated cross section along its entire length, the corrugated cross section of said inner surface defining said plurality of second cable channels each one accommodating at least a portion of one cable,

wherein the plurality of first cable channels face radially outward and the plurality of second cable channels face radially inward in respect of the intermediate tube element,

wherein said at least one tube element further comprises an outer tube element surrounding said intermediate tube element, the outer tube element contacting the intermediate tube element to define tapered portions of said plurality of first cable channels, and

wherein said tapered portions are at least partly filled by a material comprising at leas one of portions of said outer tube element extending radially inward or a liner arranged between said intermediate tube element and said outer tube element.

2 . The steerable instrument according to claim 1 , configured to have said plurality of first cable channels, each one accommodating at least said portion of one cable, wherein the outer tube element encloses said intermediate tube element so as to cover said plurality of first cable channels.

3 . The steerable instrument according to claim 1 , wherein said outer tube element is provided with at least one of a first outer tube element slotted structure in said at least one distal deflectable zone and a second outer tube element slotted structure in said intermediate flexible zone.

4 . The steerable instrument according to claim 1 , wherein said outer tube element is shaped such as to form a plurality of third cable channels, each third cable channel opposing one first cable channel of the plurality of first cable channels such as to form together a fourth cable channel accommodating one cable of the plurality of cables.

5 . The steerable instrument according to claim 1 , wherein the material is configured to prevent the plurality of cables from getting stuck in said tapered portions.

6 . The steerable instrument according to claim 1 , wherein said outer tube element has a uniform thickness along its entire length.

7 . The steerable instrument according to claim 1 , wherein said outer tube element is attached to said intermediate tube element at least at one or more locations at a proximal end of said at least one deflectable section.

8 . The steerable instrument according to claim 1 , wherein said intermediate tube element has a cross section structure with a uniform thickness along its entire length such that said outer surface and said inner surface have a same corrugated structure along its entire length.

9 . The steerable instrument according to claim 1 , configured to have said plurality of second cable channels, each one accommodating at least said portion of one cable, wherein the tubular body is provided with an inner tube element arranged within said intermediate tube element such as to cover said plurality of second cable channels.

10 . The steerable instrument according to claim 1 , wherein said intermediate tube element has a cross section structure with a uniform thickness along its entire length such that said outer surface and said inner surface have a same corrugated structure, said intermediate tube element comprising outer portions forming an outer circumference of said intermediate tube element, and inner portions each shaped such as to enclose an essentially closed channel.

11 . The steerable instrument according to claim 1 , wherein at least one of said the plurality of cables is enclosed in a separate tube.