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Individual Optimization of the Insertion of a Preformed Cochlear Implant Electrode Array.

Rau TS, Lenarz T, Majdani O - Int J Otolaryngol (2015)

Bottom Line: Conclusion.This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion.Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.

ABSTRACT
Purpose. The aim of this study was to show that individual adjustment of the curling behaviour of a preformed cochlear implant (CI) electrode array to the patient-specific shape of the cochlea can improve the insertion process in terms of reduced risk of insertion trauma. Methods. Geometry and curling behaviour of preformed, commercially available electrode arrays were modelled. Additionally, the anatomy of each small, medium-sized, and large human cochlea was modelled to consider anatomical variations. Finally, using a custom-made simulation tool, three different insertion strategies (conventional Advanced Off-Stylet (AOS) insertion technique, an automated implementation of the AOS technique, and a manually optimized insertion process) were simulated and compared with respect to the risk of insertion-related trauma. The risk of trauma was evaluated using a newly developed "trauma risk" rating scale. Results. Using this simulation-based approach, it was shown that an individually optimized insertion procedure is advantageous compared with the AOS insertion technique. Conclusion. This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion. Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

No MeSH data available.


Related in: MedlinePlus

(a) Visualization of the curling behaviour of a preformed Contour Advance electrode array (RE06) using the 22 detected platinum contacts and the location of the Softip. The start configuration (on the left side) with stylet inside is characterized by a nearly straight configuration (compared with Figure 2(a)). Due to stylet extraction, the electrode array returns into its preformed spiral shape (right). By tracking the complete range of curling behaviour, the movement of the tip of the implant shows a typically sigmoidal curve. This curve is indicated using a bold blue line and is referred to as the curling profile of the electrode array (here RE06). Scale marks indicate 1 mm. (b) After determination of all curling profiles, four electrode arrays were selected and used in this study, which together cover the full range of curling behaviour investigated. RE01 and RE08 represent electrode arrays with a highly pronounced curling behaviour, measured as deflection of the tip from the straight configuration. RE06 was chosen to represent a moderate curling profile and RE07 to represent the flattest one.
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fig3: (a) Visualization of the curling behaviour of a preformed Contour Advance electrode array (RE06) using the 22 detected platinum contacts and the location of the Softip. The start configuration (on the left side) with stylet inside is characterized by a nearly straight configuration (compared with Figure 2(a)). Due to stylet extraction, the electrode array returns into its preformed spiral shape (right). By tracking the complete range of curling behaviour, the movement of the tip of the implant shows a typically sigmoidal curve. This curve is indicated using a bold blue line and is referred to as the curling profile of the electrode array (here RE06). Scale marks indicate 1 mm. (b) After determination of all curling profiles, four electrode arrays were selected and used in this study, which together cover the full range of curling behaviour investigated. RE01 and RE08 represent electrode arrays with a highly pronounced curling behaviour, measured as deflection of the tip from the straight configuration. RE06 was chosen to represent a moderate curling profile and RE07 to represent the flattest one.

Mentions: The curling behaviour of several CA electrode arrays has already been determined in a former study [10]. Using a custom-made micromanipulator, the stylet was extracted in increments of 0.1 mm to 0.25 mm. After each step, the resulting shape of the CA electrode array was digitally documented using a reflected-light microscope (MZ 6, Leica Microsystems GmbH, Wetzlar, Germany, in conjunction with DS-L1, Nikon Cooperation, Tokyo, Japan). In this way, a series of images was generated which records the curling behaviour of each implant. For further processing of these images, a semiautomatic image-processing procedure was developed and applied to identify the centre of all 22 platinum contacts as well as the tip of the silicone body. The second step involved fitting a mathematical function, consisting of a logarithmic spiral and up to three straight segments, through the points. Hence, the actual shape of the electrode array (depending on the extent to which the stylet is removed) was finally modelled by a continuous curve. Figure 3 shows the visualization of one CA electrode array as a result of stylet extraction. After projection in the x-y plane, the movement of the electrode tip exhibits a typical sigmoidal curve (highlighted in blue in Figure 3(a)). This “curling profile” of each electrode array was used to compare the differences in the specific curling behaviour of different arrays.


Individual Optimization of the Insertion of a Preformed Cochlear Implant Electrode Array.

Rau TS, Lenarz T, Majdani O - Int J Otolaryngol (2015)

(a) Visualization of the curling behaviour of a preformed Contour Advance electrode array (RE06) using the 22 detected platinum contacts and the location of the Softip. The start configuration (on the left side) with stylet inside is characterized by a nearly straight configuration (compared with Figure 2(a)). Due to stylet extraction, the electrode array returns into its preformed spiral shape (right). By tracking the complete range of curling behaviour, the movement of the tip of the implant shows a typically sigmoidal curve. This curve is indicated using a bold blue line and is referred to as the curling profile of the electrode array (here RE06). Scale marks indicate 1 mm. (b) After determination of all curling profiles, four electrode arrays were selected and used in this study, which together cover the full range of curling behaviour investigated. RE01 and RE08 represent electrode arrays with a highly pronounced curling behaviour, measured as deflection of the tip from the straight configuration. RE06 was chosen to represent a moderate curling profile and RE07 to represent the flattest one.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4581552&req=5

fig3: (a) Visualization of the curling behaviour of a preformed Contour Advance electrode array (RE06) using the 22 detected platinum contacts and the location of the Softip. The start configuration (on the left side) with stylet inside is characterized by a nearly straight configuration (compared with Figure 2(a)). Due to stylet extraction, the electrode array returns into its preformed spiral shape (right). By tracking the complete range of curling behaviour, the movement of the tip of the implant shows a typically sigmoidal curve. This curve is indicated using a bold blue line and is referred to as the curling profile of the electrode array (here RE06). Scale marks indicate 1 mm. (b) After determination of all curling profiles, four electrode arrays were selected and used in this study, which together cover the full range of curling behaviour investigated. RE01 and RE08 represent electrode arrays with a highly pronounced curling behaviour, measured as deflection of the tip from the straight configuration. RE06 was chosen to represent a moderate curling profile and RE07 to represent the flattest one.
Mentions: The curling behaviour of several CA electrode arrays has already been determined in a former study [10]. Using a custom-made micromanipulator, the stylet was extracted in increments of 0.1 mm to 0.25 mm. After each step, the resulting shape of the CA electrode array was digitally documented using a reflected-light microscope (MZ 6, Leica Microsystems GmbH, Wetzlar, Germany, in conjunction with DS-L1, Nikon Cooperation, Tokyo, Japan). In this way, a series of images was generated which records the curling behaviour of each implant. For further processing of these images, a semiautomatic image-processing procedure was developed and applied to identify the centre of all 22 platinum contacts as well as the tip of the silicone body. The second step involved fitting a mathematical function, consisting of a logarithmic spiral and up to three straight segments, through the points. Hence, the actual shape of the electrode array (depending on the extent to which the stylet is removed) was finally modelled by a continuous curve. Figure 3 shows the visualization of one CA electrode array as a result of stylet extraction. After projection in the x-y plane, the movement of the electrode tip exhibits a typical sigmoidal curve (highlighted in blue in Figure 3(a)). This “curling profile” of each electrode array was used to compare the differences in the specific curling behaviour of different arrays.

Bottom Line: Conclusion.This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion.Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.

ABSTRACT
Purpose. The aim of this study was to show that individual adjustment of the curling behaviour of a preformed cochlear implant (CI) electrode array to the patient-specific shape of the cochlea can improve the insertion process in terms of reduced risk of insertion trauma. Methods. Geometry and curling behaviour of preformed, commercially available electrode arrays were modelled. Additionally, the anatomy of each small, medium-sized, and large human cochlea was modelled to consider anatomical variations. Finally, using a custom-made simulation tool, three different insertion strategies (conventional Advanced Off-Stylet (AOS) insertion technique, an automated implementation of the AOS technique, and a manually optimized insertion process) were simulated and compared with respect to the risk of insertion-related trauma. The risk of trauma was evaluated using a newly developed "trauma risk" rating scale. Results. Using this simulation-based approach, it was shown that an individually optimized insertion procedure is advantageous compared with the AOS insertion technique. Conclusion. This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion. Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

No MeSH data available.


Related in: MedlinePlus