Fiber-optic Fabry-Pérot interferometers for axial force sensing on the tip of a needle

Fiber-optic Fabry-Pérot interferometers for axial force sensing on the tip of a needle

Beekmans, Steven (Vrije Universiteit Amsterdam)
Lembrechts, T.
van den Dobbelsteen, J.J. (TU Delft Medical Instruments & Bio-Inspired Technology)
van Gerwen, D.J. (TU Delft Medical Instruments & Bio-Inspired Technology)

2017

A range of complex percutaneous procedures, such as biopsy or regional anesthesia, rely heavily on accurate needle insertion. Small variations in the mechanical properties of the pierced tissue can however cause deviations from the projected needle path and can thus result in inaccurate placement of the needle. Navigation of a rigid needle towards the target tissue is traditionally based on the surgeons capacity to interpret small variations in the needle insertion force. A more accurate measurement of these small force variations enables improvement in needle targeting, can potentially aid in enhancing force feedback in robotic needle placement and can provide valuable information on tissue-tool interaction. In this study we investigated several concepts for the design of a force sensor based on a fiber-optic Fabry-Pérot interferometer to measure needle-tissue interaction forces on the tip of a 18 G needle, where special attention was given to concepts for a sensor with (1), an intrinsic low cross-sensitivity to temperature and (2), elementary design and fabrication. Three concepts, using either a quartz capillary, an Invar capillary or a thin polyimide film as the force sensitive element were prototyped and subjected to both static and dynamic testing. The force transducer based on a quartz capillary presented the lowest cross-sensitivity to temperature ( 12mN/∘ C) and good accuracy (maximum measurement error of 65 mN /10 N ) in a measurement of static forces. However, limited strength of the sensor is expected to prevent usage of the quartz capillary in small diameter needles. The concepts for a sensor based on an Invar capillary or a thin polyimide film proved a higher cross-sensitivity to temperature ( 50mN/∘ C and 220mN/∘ C, respectively) and higher maximum measurement error (350 mN /10 N , 800 mN /10 N ), comparable to those of FBG-based sensors reported in literature, but are likely to be more suitable for integration in very small biopsy needles.

Fabry-Pérot interferometer
needle-tissue interaction force
low temperature cross-sensitivity
fiber optic force sensor
tip force sensing

http://resolver.tudelft.nl/uuid:7f49d45f-76db-4fb3-a574-bfdad3c91040

https://doi.org/10.3390/s17010038

1424-8220

Sensors, 17 (1)

Institutional Repository

journal article

© 2017 Steven Beekmans, T. Lembrechts, J.J. van den Dobbelsteen, D.J. van Gerwen