During electrode array insertion while cochlear implantation, the electrode array
has friction with the sensitive endocochlear lining and causes mutual mechanical trauma.
Both, the impact of insertion speed on electrode friction and the relationship between
electrode insertion force and friction has not been investigated yet. In this study,
friction forces and coefficients between a 31.5 mm standard cochlear electrode array
and endocochlear lining mimicking tissue have been acquired, depending on different
insertion speeds (0.1, 0.5, 1.0, 1.5 and 2.0 mm/s). Additionally, the electrode insertion
forces during the placing into a scala tympani model were recorded and correlated
with the friction coefficient. Within these experiments the lowest friction coefficient
occurs at 0.1 mm/s (0.24 ± 0.13), rises to a maximum at 1.5 mm/s (0.59 ± 0.12) and
falls again at 2 mm/s (0.45 ± 0.11). Similar patterns were observed for recorded insertion
forces. Consequently, a high correlation coefficient (0.9) between the insertion force
and friction coefficient was calculated. The present study reveals a non-linear increase
in electrode array friction, when insertion speed raises, and reports a high correlation
between friction and electrode insertion force. Knowledge of this parameters is important
for the assessment of intracochlear trauma and for future robotic insertion of electrode
arrays.
Poster-PDF
A-1451.pdf
