Apparatus for sensing a motion

Abstract

The present disclosure provides an apparatus for sensing a motion. The apparatus comprises an optical fibre portion comprising a Bragg grating and an element for reducing an impact of an external force that is transversal to the Bragg grating. Further, the apparatus comprises a contact region arranged so that movement of a further region, that is in direct or indirect contact with the contact region and moves in a direction along a portion of the apparatus, causes movement of the optical fibre portion at the contact region. The apparatus also comprises a holder arranged for reducing movement of the optical fibre portion at a holding region when the optical fibre portion is moved at the contact surface. The apparatus is arranged so that movement of the contact region relative to the holding region causes a change in strain of the Bragg grating.

1 - 19 . (canceled) 
     
     
         20 . An apparatus for sensing a motion, the apparatus comprising:
 an elongated element having an interior region and at least a portion of the elongated member being flexible, the or each portion of the elongated element being more compressible or extendable in the direction of elongation than in a transversal direction; and   an optical fibre comprising at least one Bragg grating, at least a portion of the optical fibre being located within the interior region of the elongated element and being attached to the elongated element;   wherein the apparatus is arranged so that the flexibility of the or each portion of the elongated element enables a longitudinal movement of a first portion of the elongated element relative to a second portion of the elongated element and wherein the Bragg grating is positioned so that the movement of the first portion causes a change in strain of the Bragg grating; and   wherein the elongated element is arranged so that the optical fibre portion is largely protected from compression in a transversal direction.   
     
     
         21 . The apparatus of  claim 20  wherein the elongated element is a member that is formed at a position remote from the optical fibre portion and to which the optical fibre portion is then attached. 
     
     
         22 . The apparatus of  claim 20  wherein the elongated element is formed at the optical fibre portion and is provided in the form of a coating. 
     
     
         23 . The apparatus of  claim 20  wherein the elongated element is a tube in which the portion of the optical fibre is positioned. 
     
     
         24 . The apparatus of  claim 20  wherein the element is a spiral. 
     
     
         25 . The apparatus of  claim 24  wherein the element is provided in the form a coil spring. 
     
     
         26 . The apparatus of  claim 20  wherein the optical fibre portion is attached to the elongated element in an elastic manner. 
     
     
         27 . The apparatus of  claim 20  wherein the optical fibre portion is elastically attached to the elongated element substantially along the entire length of the optical fibre portion that is positioned within the interior region of the elongated element. 
     
     
         28 . The apparatus of  claim 20  comprising a series of Bragg gratings which are incorporated in the portion of the optical fibre that is positioned within the interior region of the elongated element so that the apparatus is arranged for sensing a distribution of an external longitudinal motion. 
     
     
         29 . A method of sensing a motion in an in-vivo environment, the method comprising:
 inserting an optical fibre portion, or an assembly including the optical fibre portion, into a body lumen so that side-portions of the optical fibre portion, or the assembly including the optical fibre portion, are in frictional contact with walls of the body lumen, the optical fibre portion comprising at least one Bragg grating;   exposing the optical fibre portion, or the assembly including the optical fibre portion, to a motion of the body lumen in a direction along the optical fibre portion in a manner such that the Bragg grating experiences a change in strain; and   detecting an optical response from the Bragg grating that is indicative of the change in strain.