Surgeons need precise data on their deformation and movements to guide endoscopes, catheters or bendable biopsy needles in minimally invasive procedures without a direct visual contact. Here, fibre Bragg grating (FBG) form sensors represent a tried-and-tested technology. They consist of a tube-shaped sensor carrier body into which FBG glass fibres have been cast. Using their expansion measurements, the shapes of the sensor carrier bodies can be established. In comparison to other measuring techniques such as electromagnetic tracking or imaging techniques, FBG form sensor technology has a number of advantages. It is electromagnetically compatible, and its biocompatibility as well as the sterilising capability of the fibres is positive in the field of medical engineering. In addition, a small fibre diameter and the option that this offers to miniaturise the form sensors are advantageous. The high readout rate for the measurement signals of 500 Hertz allows real-time shape acquisition. Scientists at the KIT have now developed a new variety of FBG form sensors: FBG glass fibres are not integrated in parallel, as has so far been the case, but as spirals in the flexible sensor carrier body. New data fusion algorithms enable a free distribution of the FBG structures in the sensor carrier body. As a result, the deformation flexibility of the form sensors can be enhanced enormously. The use of helical coils can reduce fibre strain, so that damage can be avoided even if the sensor is strongly deformed. The free distribution of FBG measurement points and an efficient evaluation of the measurement signals via innovative data fusion algorithms ensure more measuring accuracy. By means of the new algorithms, an observation of the surface deformation in addition to the sensor course is possible for the first time. The scientists envision a further application of the technology in mining. The FBG form sensors could be used to monitor deformations in cables and hosepipes.