A registration device includes an attachment piece (106) configured to conform with and attach to an imaging probe (102), in particular an internal or external ultrasound probe such as a TEE probe. A pathway (105) formed in or on the attachment piece is configured to receive an optical shape sensing device (OSS fiber) such that the optical shape sensing device can free float (no tip fixation) to permit longitudinal twisting within the pathway. The pathway includes a distinctive geometry for shaping the OSS device such that the distinctive geometry provides a template pattern (107) within an image collected using the imaging probe module to permit registration between imaging coordinates and OSS coordinates. A registration module (130) is configured to compare a stored shape template (121) with an image (134) including the template pattern to permit the registration (unique transformation).
