scholarly journals Frictional Behavior of Cochlear Electrode Array Is Dictated by Insertion Speed and Impacts Insertion Force

2021 ◽  
Vol 11 (11) ◽  
pp. 5162
Author(s):  
Dana Dohr ◽  
Nicklas Fiedler ◽  
Wolfram Schmidt ◽  
Niels Grabow ◽  
Robert Mlynski ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Cochlear Implant ◽  
Electrode Array ◽  
Mechanical Trauma ◽  
Electrode Arrays ◽  
Friction Behavior ◽  
Insertion Force ◽  
Friction Coefficients ◽  
Electrode Insertion ◽  
The Impact

Background: During cochlear implantation, the electrode array has significant friction with the sensitive endocochlear lining and causes mutual mechanical trauma while the array is being inserted. Both, the impact of insertion speed on electrode friction and the relationship of electrode insertion force and friction have not been adequately investigated to date. Methods: In this study, friction coefficients between a CI electrode array (31.5 mm) and a tissue simulating the endocochlear lining 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. Results: It was shown that the friction coefficient reached the lowest value at an insertion speed of 0.1 mm/s (0.24 ± 0.13), a maximum occurred at 1.5 mm/s (0.59 ± 0.12), and dropped again at 2 mm/s (0.45 ± 0.11). Similar patterns were observed for the insertion forces. Consequently, a high correlation coefficient (0.9) was obtained between the insertion forces and friction coefficients. Conclusion: The present study reveals a non-linear increase in electrode array friction, when insertion speed raises and reports a high correlation between friction coefficient and electrode insertion force. This dependence is a relevant future parameter to evaluate and reduce cochlear implant insertion trauma. Significance statement: Here, we demonstrated a dependence between cochlear electrode insertion speed and its friction behavior and a high correlation to insertion force. Our study provides valuable information for the evaluation and prevention of cochlear implant insertion trauma and supports the optimization of cochlear electrode arrays regarding friction characteristics.

Optimal Path Planning for Robotic Insertion of Steerable Electrode Arrays in Cochlear Implant Surgery

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Jian Zhang ◽  
J. Thomas Roland ◽  
Spiros Manolidis ◽  
Nabil Simaan
Keyword(s):  
Path Planning ◽  
Cochlear Implant ◽  
Optimal Path ◽  
Electrode Array ◽  
Scala Tympani ◽  
Electrode Arrays ◽  
Insertion Force ◽  
Optimal Path Planning ◽  
Cochlear Implant Surgery ◽  
Electrode Insertion

This paper presents an optimal path planning method of steerable electrode arrays for robot-assisted cochlear implant surgery. In this paper, the authors present a novel design of steerable electrode arrays that can actively bend at the tip. An embedded strand in the electrode array provides an active steering degrees-of-freedom (DoF). This paper addresses the calibration of the steerable electrode array and the optimal path planning for inserting it into planar and three-dimensional scala tympani models. The goal of the path planning is to minimize the intracochlear forces that the electrode array applies on the walls of the scala tympani during insertion. This problem is solved by designing insertion path planning algorithms that provide best fit between the shape of the electrode array and the curved scala tympani during insertion. Optimality measures that account for shape discrepancies between the steerable electrode array and the scala tympani are used to solve for the optimal path planning of the robot. Different arrangements of DoF and insertion speed force feedback (ISFF) are simulated and experimentally validated in this paper. A quality of insertion metric describing the gap between the steerable electrode array and the scala tympani model is presented and its correspondence to the insertion force is shown. The results of using 1DoF, 2DoF, and 4DoF electrode array insertion setups are compared. The 1DoF insertion setup uses nonsteerable electrode arrays. The 2DoF insertion setup uses single axis insertion with steerable electrode arrays. The 4DoF insertion setup allows full control of the insertion depth and the approach angle of the electrode with respect to the cochlea while using steerable electrode arrays. It is shown that using steerable electrode arrays significantly reduces the maximal insertion force (59.6% or more) and effectively prevents buckling of the electrode array. The 4DoF insertion setup further reduces the maximal electrode insertion forces. The results of using ISFF for steerable electrodes show a slight decrease in the insertion forces in contrast to a slight increase for nonsteerable electrodes. These results show that further research is required in order to determine the optimal ISFF control law and its effectiveness in reducing electrode insertion forces.

scholarly journals Evaluation of Intracochlear Trauma Caused by Insertion of Cochlear Implant Electrode Arrays through Different Quadrants of the Round Window

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Graziela de Souza Queiroz Martins ◽  
Rubens Vuono Brito Neto ◽  
Robinson Koji Tsuji ◽  
Eloisa Maria Mello Santiago Gebrim ◽  
Ricardo Ferreira Bento
Keyword(s):  
Cochlear Implant ◽  
Round Window ◽  
Electrode Array ◽  
Hearing Preservation ◽  
Round Window Membrane ◽  
Residual Hearing ◽  
Electrode Arrays ◽  
Minimal Trauma ◽  
Electrode Insertion ◽  
Temporal Bones

Hypothesis. This study aimed to evaluate whether there is a difference in the degree of intracochlear trauma when the cochlear implant electrode arrays is inserted through different quadrants of the round window membrane.Background. The benefits of residual hearing preservation in cochlear implant recipients have promoted the development of atraumatic surgeries. Minimal trauma during electrode insertion is crucial for residual hearing preservation.Methods. In total, 25 fresh human temporal bones were subjected to mastoidectomy and posterior tympanotomy. The cochlear implant electrode array was inserted through the anterosuperior quadrant of the round window membrane in 50% of the bones and through the anteroinferior quadrant in the remaining 50%. The temporal bones were dehydrated, embedded in epoxy, serially polished, stained, viewed through a stereomicroscope, and photographed with the electrode arraysin situ. The resulting images were analyzed for signs of intracochlear trauma.Results. Histological examinations revealed varying degrees of damage to the intracochlear structures, although the incidence and severity of intracochlear trauma were not influenced by the quadrant of insertion.Conclusions. The incidence and severity of intracochlear trauma were similar in all samples, irrespective of electrode array insertion through the anterosuperior or anteroinferior quadrant of the round window membrane.

Preservation of residual hearing following cochlear implantation: comparison between three surgical techniques

2007 ◽  
Vol 122 (3) ◽  
pp. 246-252 ◽  
Author(s):  
S Berrettini ◽  
F Forli ◽  
S Passetti
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Surgical Techniques ◽  
Electrode Array ◽  
Lateral Wall ◽  
Hearing Preservation ◽  
Acoustic Stimulation ◽  
Residual Hearing ◽  
Electrode Arrays ◽  
Electrode Insertion

AbstractThe preservation of residual hearing is becoming a high priority in cochlear implant surgery. It allows better speech understanding and ensures long-lasting and stable performance; it also allows the possibility, in selected cases, of combining electro-acoustic stimulation in the same ear.We present the results of a retrospective study of the conservation of residual hearing in three different groups of patients who had undergone cochlear implantation using three different cochlear implant electrode arrays, combined with three different surgical techniques for the cochleostomy. The study aimed to evaluate which approach allowed greater preservation of residual hearing.The best residual hearing preservation results (i.e. preservation in 81.8 per cent of patients) were achieved with the Contour Advance electrode array, using the Advance Off-Stylet technique and performing a modified anterior inferior cochleostomy; this combination enabled reduced trauma to the lateral wall of the cochlea during electrode insertion.

scholarly journals Theoretical Studies of the Interaction between Screw Surface and Material in the Mixer

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 962
Author(s):  
Andrzej Marczuk ◽  
Vasily Sysuev ◽  
Alexey Aleshkin ◽  
Petr Savinykh ◽  
Nikolay Turubanov ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
High Efficiency ◽  
Animal Feed ◽  
Structural Features ◽  
Power Demand ◽  
Friction Coefficients ◽  
Length Unit ◽  
Mixing Chamber ◽  
Size Of Particles ◽  
The Impact

Mixing is one of the most commonly used processes in food, animal feed, chemical, cosmetic, etc., industries. It is supposed to provide high-quality homogenous, nutritious mixtures. To provide appropriate mixing of materials while maintaining the process high efficiency and low energy consumption it is crucial to explore and describe the material flow caused by the movement of mixing elements and the contact between particles. The process of mixing is also affected by structural features of the machine components and the mixing chamber, speed of mixing, and properties of the mixed materials, such as the size of particles, moisture, friction coefficients. Thus, modeling of the phenomena that accompany the process of mixing using the above-listed parameters is indispensable for appropriate implementation of the process. The paper provides theoretical power calculations that take into account the material speed change, the impact of the material friction coefficient on the screw steel surface and the impact of the friction coefficient on the material, taking into account the loading height of the mixing chamber and the chamber loading value. Dependencies between the mixer power and the product degree of fineness, rotational speed of screw friction coefficients, the number of windings per length unit, and width of the screw tape have been presented on the basis of a developed model. It has been found that power increases along with an increase in the value of these parameters. Verification of the theoretical model indicated consistence of the predicted power demand with the power demand determined in tests performed on a real object for values of the assumed, effective loading, which was 65–75%.

scholarly journals The Importance of Intraoperative Plain Radiographs during Cochlear Implant Surgery in Patients with Normal Anatomy

2021 ◽  
Vol 11 (9) ◽  
pp. 4144
Author(s):  
Ohad Cohen ◽  
Jean-Yves Sichel ◽  
Chanan Shaul ◽  
Itay Chen ◽  
J. Thomas Roland ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Cost Effective ◽  
X Rays ◽  
Normal Anatomy ◽  
Electrode Arrays ◽  
Plain Radiographs ◽  
Hearing Function ◽  
Tertiary Center ◽  
Cochlear Implant Surgery

Although malpositioning of the cochlear implant (CI) electrode array is rare in patients with normal anatomy, when occurring it may result in reduced hearing outcome. In addition to intraoperative electrophysiologic tests, imaging is an important modality to assess correct electrode array placement. The purpose of this report was to assess the incidence and describe cases in which intraoperative plain radiographs detected a malpositioned array. Intraoperative anti-Stenver’s view plain X-rays are conducted routinely in all CI surgeries in our tertiary center before awakening the patient and breaking the sterile field. Data of patients undergoing 399 CI surgeries were retrospectively analyzed. A total of 355 had normal inner ear and temporal bone anatomy. Patients with intra or extracochlear malpositioned electrode arrays demonstrated in the intraoperative X-ray were described. There were four cases of electrode array malposition out of 355 implantations with normal anatomy (1.1%): two tip fold-overs, one extracochlear placement and one partial insertion. All electrodes were reinserted immediately; repeated radiographs were normal and the patients achieved good hearing function. Intraoperative plain anti-Stenver’s view X-rays are valuable to confirm electrode array location, allowing correction before the conclusion of surgery. These radiographs are cheaper, faster, and emit much less radiation than other imaging options, making them a viable cost-effective tool in patients with normal anatomy.

Electrode design and insertional depth-dependent intra-cochlear pressure changes: a model experiment

2017 ◽  
Vol 132 (3) ◽  
pp. 224-229 ◽  
Author(s):  
P Mittmann ◽  
A Ernst ◽  
I Todt
Keyword(s):  
Cochlear Implant ◽  
Fluid Pressure ◽  
Electrode Array ◽  
Lateral Wall ◽  
Peak Frequency ◽  
Peak Amplitude ◽  
Residual Hearing ◽  
Electrode Arrays ◽  
Pressure Peak ◽  
Pressure Changes

AbstractBackground:Preservation of residual hearing is one of the major goals in modern cochlear implant surgery. Intra-cochlear fluid pressure changes influence residual hearing, and should be kept low before, during and after cochlear implant insertion.Methods:Experiments were performed in an artificial cochlear model. A pressure sensor was inserted in the apical part. Five insertions were performed on two electrode arrays. Each insertion was divided into three parts, and statistically evaluated in terms of pressure peak frequency and pressure peak amplitude.Results:The peak frequency over each third part of the electrode increased in both electrode arrays. A slight increase was seen in peak amplitude in the lateral wall electrode array, but not in the midscalar electrode array. Significant differences were found in the first third of both electrode arrays.Conclusion:The midscalar and lateral wall electrode arrays have different intra-cochlear fluid pressure changes associated with intra-cochlear placement, electrode characteristics and insertion.

scholarly journals Effect of cochlear implant electrode insertion on middle-ear function as measured by intra-operative laser Doppler vibrometry

2009 ◽  
Vol 123 (7) ◽  
pp. 723-729 ◽  
Author(s):  
N Donnelly ◽  
A Bibas ◽  
D Jiang ◽  
D-E Bamiou ◽  
C Santulli ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Middle Ear ◽  
Low Frequency ◽  
Laser Doppler ◽  
Frequency Function ◽  
Laser Doppler Vibrometry ◽  
Variable Effect ◽  
Custom Made ◽  
Electrode Insertion ◽  
The Impact

AbstractHypothesis:The aim of this study was to investigate the impact of cochlear implant electrode insertion on middle-ear low frequency function in humans.Background:Preservation of residual low frequency hearing with addition of electrical speech processing can improve the speech perception abilities and hearing in noise of cochlear implant users. Preservation of low frequency hearing requires an intact middle-ear conductive mechanism in addition to intact inner-ear mechanisms. Little is known about the effect of a cochlear implant electrode on middle-ear function.Methods:Stapes displacement was measured in seven patients undergoing cochlear implantation. Measurements were carried out intra-operatively before and after electrode insertion. Each patient acted as his or her own control. Sound was delivered into the external auditory canal via a speaker and calibrated via a probe microphone. The speaker and probe microphone were integrated into an individually custom-made ear mould. Ossicular displacement in response to a multisine stimulus at 80 dB SPL was measured at the incudostapedial joint via the posterior tympanotomy, using an operating microscope mounted laser Doppler vibrometry system.Results:Insertion of a cochlear implant electrode into the scala tympani had a variable effect on stapes displacement. In three patients, there was little change in stapes displacement following electrode insertion. In two patients, there was a significant increase, while in a further two there was a significant reduction in stapes displacement. This variability may reflect alteration of cochlear impedance, possibly due to differing loss of perilymph associated with the electrode insertion.Conclusion:Insertion of a cochlear implant electrode produces a change in stapes displacement at low frequencies, which may have an effect on residual low frequency hearing thresholds.

Comparison of Electrically Evoked Whole-Nerve Action Potential and Electrically Evoked Auditory Brainstem Response Thresholds in Nucleus CI24R Cochlear Implant Recipients

2002 ◽  
Vol 13 (08) ◽  
pp. 416-427 ◽  
Author(s):  
Marcia J. Hay-McCutcheon ◽  
Carolyn J. Brown ◽  
Kelly Schmidt Clay ◽  
Keely Seyle
Keyword(s):  
Action Potential ◽  
Cochlear Implant ◽  
Auditory Brainstem Response ◽  
Electrode Array ◽  
Auditory Brainstem ◽  
Electrode Arrays ◽  
Direct Stimulation ◽  
Nerve Action ◽  
Brainstem Response ◽  
Response Thresholds

In this study, differences between electrically evoked whole-nerve action potential (EAP) and electrically evoked auditory brainstem response (EABR) measurements within Nucleus CI24R cochlear implant recipients were evaluated. Precurved modiolus-hugging internal electrode arrays, such as the CI24R, are designed to provide more direct stimulation of neural elements of the modiolus. If the electrode array is closer to the modiolus, electrically evoked and behavioral levels might be lower than were previously recorded for the straight electrode array, the CI24M. EAP and EABR growth functions and behavioral levels were obtained for 10 postlingually deafened adults. Results revealed no significant differences between EAP and EABR threshold levels, and these levels were not significantly lower than those obtained using the CI24M.

Hearing Preservation with the Slim Modiolar Electrode Nucleus CI532® Cochlear Implant: A Preliminary Experience

2017 ◽  
Vol 22 (6) ◽  
pp. 317-325 ◽  
Author(s):  
Angel Ramos-Macías ◽  
S.A. Borkoski-Barreiro ◽  
J.C. Falcón-González ◽  
A. Ramos-de Miguel
Keyword(s):  
Cochlear Implant ◽  
Randomized Study ◽  
Electrode Array ◽  
Hearing Preservation ◽  
Residual Hearing ◽  
Flexible Electrode ◽  
And Performance ◽  
The Impact ◽  
Sydney Australia

As the indications for cochlear implant have expanded to include younger patients and individuals with greater degrees of residual hearing, increasing emphasis has been placed on atraumatic surgery and the preservation of the cochlear structure. Here, a descriptive prospective randomized study was performed. It was shown that residual hearing preservation is possible 12 months postoperatively with an atraumatic perimodiolar flexible electrode array CI532® (Cochlear Ltd, Sydney, Australia). Residual hearing preservation, considered as < 15 dB, was obtained in 70% of the cases. Better clinical outcomes and performance could be obtained compared with the previous perimodiolar CI512®, but further research and a longer follow-up are necessary to verify the impact of outcomes.

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