scholarly journals A Capacitive Cochlear Implant Electrode Array Sensing System to Discriminate Fold-Over Pattern

Author(s):  
Lei Hou ◽  
Xinli Du ◽  
Nikolaos V. Boulgouris ◽  
Nauman Hafeez ◽  
Chris Coulson ◽  
...  

Purpose During insertion of the cochlear implant electrode array, the tip of the array may fold back on itself and can cause serious complications to patients. This article presents a sensing system for cochlear implantation in a cochlear model. The electrode array fold-over behaviors can be detected by analyzing capacitive information from the array tip. Method Depending on the angle of the array tip against the cochlear inner wall when it enters the cochlear model, different insertion patterns of the electrode array could occur, including smooth insertion, buckling, and fold-over. The insertion force simulating the haptic feedback for surgeons and bipolar capacitance signals during the insertion progress were collected and compared. The Pearson correlation coefficient (PCC) was applied to the collected capacitive signals to discriminate the fold-over pattern. Results Forty-six electrode array insertions were conducted and the deviation of the measured insertion force varies between a range of 20% and 30%. The capacitance values from electrode pair (1, 2) were recorded for analyzing. A threshold for the PCC is set to be 0.94 that can successfully discriminate the fold over insertions from the other two types of insertions, with a success rate of 97.83%. Conclusions Capacitive measurement is an effective method for the detection of faulty insertions and the maximization of the outcome of cochlear implantation. The proposed capacitive sensing system can be used in other tissue implants in vessels, spinal cord, or heart.

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Lei Hou ◽  
Xinli Du ◽  
Nikolaos Boulgouris ◽  
Chris Coulson ◽  
Richard Irving ◽  
...  

2015 ◽  
Vol 20 (5) ◽  
pp. 339-348 ◽  
Author(s):  
Adrian Dalbert ◽  
Flurin Pfiffner ◽  
Christof Röösli ◽  
Konrad Thoele ◽  
Jae Hoon Sim ◽  
...  

Objective: To monitor cochlear function by extra- and intracochlear electrocochleography (ECoG) during and after cochlear implantation and thereby to enhance the understanding of changes in cochlear function following cochlear implantation surgery. Methods: ECoG responses to acoustic stimuli of 250, 500 and 1,000 Hz were recorded in 9 cochlear implant recipients with presurgical residual hearing. During surgery extracochlear ECoG recordings were performed before and after insertion of the cochlear implant electrode array. After insertion of the electrode array, intracochlear ECoG recordings were conducted using intracochlear electrode contacts as recording electrodes. Intracochlear ECoG recordings were performed up to 6 months after implantation. ECoG findings were correlated with findings from audiometric tests. Results: Extra- and intracochlear ECoG responses could be recorded in all subjects. Extracochlear ECoG recordings during surgery showed moderate changes. Loss or reduction of the ECoG signal at all three frequencies did not occur during cochlear implantation. During the first week following surgery, conductive hearing loss, due to middle ear effusion, led to a decrease in intracochlear ECoG signal amplitudes. This was not attributable to changes of cochlear function. All persistent reductions in ECoG response magnitude after normalization of the tympanogram occurred during the first week following implantation. Thresholds of ECoG signals were at or below hearing thresholds in all cases. Conclusion: Gross intracochlear trauma during surgery appears to be rare. In the early postoperative phase the ability to assess cochlear status by ECoG recordings was limited due to the regular occurrence of middle ear effusion. Still, intracochlear ECoG along with tympanogram recordings suggests that any changes of low-frequency cochlear function occur mainly during the first week after cochlear implantation. ECoG seems to be a promising tool to objectively assess changes in cochlear function in cochlear implant recipients and may allow further insight into the mechanisms underlying the loss of residual hearing.


2021 ◽  
Vol 11 (11) ◽  
pp. 5162
Author(s):  
Dana Dohr ◽  
Nicklas Fiedler ◽  
Wolfram Schmidt ◽  
Niels Grabow ◽  
Robert Mlynski ◽  
...  

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.


2018 ◽  
Vol 01 (01) ◽  
pp. 007-010
Author(s):  
Milind Kirtane ◽  
Kashmira Chavan

Abstract Introduction Different surgical approaches have been adopted for cochlear implantation, with cortical mastoidectomy–posterior tympanotomy being the most commonly followed technique. Method In this article, we describe the surgical technique for cochlear implant followed at our center, which has been successfully implemented in more than 2,500 cochlear implant surgeries. Cochlear implant surgery using the cortical mastoidectomy–posterior tympanotomy technique has been performed in more than 2,500 cases with some modifications to the original technique over a period of time. Results In spite of not using tie-down holes and securing down the receiver–stimulator with sutures, no cases of receiver–stimulator displacement or outward electrode migration have been noted with the current technique of creating a snug-fitting subperiosteal pocket along with a hook for the electrode array. Conclusion Adhering to a strict intraoperative surgical protocol plays an extremely important role in carrying out successful cochlear implant surgeries with minimal complications.


2008 ◽  
Vol 122 (4) ◽  
Author(s):  
M Viccaro ◽  
E De Seta ◽  
E Covelli ◽  
V Marvaso ◽  
R Filipo

AbstractObjective:We report a case of a rare cochlear implant complication: the introduction of the electrode array into the superior semicircular canal, with intra-operative measurements of neural response reactions suggesting reasonable functioning of the implant.Case report:A two-year old patient affected by congenital, profound, sensorineural deafness underwent bilateral cochlear implantation at the ENT clinic of the ‘La Sapienza’ University of Rome. Two Clarion 90k devices were implanted, and electrophysiological and radiological checks were performed. After the introduction of the array in the right side, neural response imaging was performed, and a neural potential was found only on two apical electrodes, at a stimulation intensity of 431 clinical units. The situation differed on the left side, where neural response imaging was present at a stimulation intensity of 300 clinical units on the two electrodes tested (one apical electrode (number three), and one middle electrode (number nine)). Intra-operative radiological assessment with a transorbital plain films was performed as usual in order to assess the position of the electrodes inside the cochlea. This radiography showed the electrode array to be in the superior semicircular canal in the right ear.Conclusion:Intra-operative monitoring tests during cochlear implant surgery play different roles; measurement of impedances and neural response imaging can evaluate the integrity of implant electrodes and the status of the electrode–cochlea interface, but it must not be the sole way in which correct positioning of the array is confirmed. In our opinion, intra-operative radiological assessment is mandatory during cochlear implant surgery.


2000 ◽  
Vol 114 (10) ◽  
pp. 746-749 ◽  
Author(s):  
S. J. Watts ◽  
P. Lindsey ◽  
M. Hawthorne

In the last few years, the main thrust of research into cochlear implantation has centred around the development of advanced multi-channel implants. A new area of development is now concentrating on maximizing the potential of each individual electrode in order to improve the quality of hearing. This study involved the medialization of the cochlear implant electrode array using a silastic positioner in five patients. Two parameters were measured, namely current units needed to produce a stapedial reflex, and impedance levels between the electrode and modiolus. On insertion of the cochlear implant, readings were taken before the insertion of the positioner, immediately afterwards and at two months.


2015 ◽  
Vol 20 (6) ◽  
pp. 349-353 ◽  
Author(s):  
Philipp Mittmann ◽  
Grit Rademacher ◽  
Sven Mutze ◽  
Arneborg Ernst ◽  
Ingo Todt

Migration of a cochlear implant electrode is a hitherto uncommon complication. So far, array migration has only been observed in lateral wall electrodes. Between 1999 and 2014, a total of 27 patients received bilateral perimodiolar electrode arrays at our institution. The insertion depth angle was estimated on the initial postoperative scans and compared with the insertion depth angle of the postoperative scans performed after contralateral cochlear implantation. Seven (25.93%) patients were found to have an electrode array migration of more than 15°. Electrode migration in perimodiolar electrodes seems to be less frequent and to occur to a lower extent than in lateral wall electrodes. Electrode migration was clinically asymptomatic in all cases.


2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Jian Zhang ◽  
J. Thomas Roland ◽  
Spiros Manolidis ◽  
Nabil Simaan

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.


2007 ◽  
Vol 122 (3) ◽  
pp. 246-252 ◽  
Author(s):  
S Berrettini ◽  
F Forli ◽  
S Passetti

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.


2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Daniel Schurzig ◽  
Zachariah W. Smith ◽  
D. Caleb Rucker ◽  
Robert F. Labadie ◽  
Robert J. Webster

Percutaneous cochlear implantation (PCI) is a recently developed minimally invasive technique that utilizes image guidance and a custom-made microstereotactic frame to guide a drill directly to the cochlea. It enables cochlear access through a single drill port, reducing invasiveness in comparison to mastoidectomy. With the reduction in invasiveness, PCI enables a corresponding reduction in visualization and space in which to work at the cochlear entry point. This precludes standard cochlear implant deployment techniques and necessitates a new insertion tool that can deploy a cochlear implant into the cochlea while working down a deep, narrow channel. In this paper, we describe a manual insertion tool that we have developed for this purpose. The tool is capable of inserting an electrode array into the cochlea using the advance off-stylet technique, using simple manual controls on its handle.


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