OCT Assisted CI Electrode Insertion

Abstract

Implant electrode insertion system for inserting an implant electrode into the cochlea, comprising an oct device comprising an oct probe defining an optical axis and configured to provide an orientation signal representative for an orientation of the oct probe with respect to a cochlea measured using optical coherence tomography of light emitted along the optical axis; an implant electrode insertion module connected to the oct device, and configured to be arranged in an insertion position on the basis of the orientation signal; and an alignment unit configured to assist in positioning of the implant electrode insertion module in the insertion position on the basis of the orientation signal; and wherein the implant electrode insertion module comprises an electrode guide that defines a guide axis, and is configured to, in the insertion position, guide a cochlear implant electrode along the guide axis towards the cochlea, wherein the guide axis is coaxial with the optical axis of the oct device.

Description

P37052NL00 / MBA Title: OCT Assisted Cl Electrode Insertion Field ofthe invention The present invention relates to an implant electrode insertion system for inserting an implant electrode into the cochlea, to an implant electrode assembly, a method for guiding a cochlear implant electrode, a method for surgically implanting a cochlear implant electrode, and to a method for mapping electrode pads of a cochlear implant electrode to frequency bins on an auditory nerve. Background of the invention A cochlear implant (Cl) as known in the art is a surgically implantable medical device that directly stimulates the cochlear nerve by an electrode array in the cochlea. Their use in children with severe degree of hearing loss has brought substantial benefits to those implanted, and when accompanied by proper rehabilitation they lead to significant improvement in audiological status, overall functioning and speech perception skills. Children with cochlear implants have greater likelihood of acquiring oral language, integrating into regular schools and being able to experience sounds along with better speech skills. Cochlear implants can also have a beneficial impact on learning and educational outcomes as well as the overall quality of life, though many factors other than implantation influence these results. In recent years, the scope of implantation has been expanded to adults with severe to profound sensorineural hearing loss, who show improved speech perception and health-related quality of life with their use. A cochlear implant comprises both external and internal components. The external components generally comprise a microphone and a speech processor, which converts recorded sound into an electrical signal. The electric signal is transmitted to the internal components, usually comprising a decoder to generate electrical pulses and an electrode that is inserted into the spiral-shaped cochlea for stimulating the auditory nerve and bypassing the malfunctioning cochlea. The electrode array is generally inserted in the scala tympani of the cochlea. This can be done by inserting it through the round window or through a drilled entrance to the scala tympani (cochleostomy). It has been found that the known procedures may lead to damage of internal ear structures such as the basilar membrane, the osseous spiral lamina or the spiral ligament in the cochlea, which can lead to an inflammation reaction and the formation of fibrotic tissue, potentially inducing necrosis and / or apoptosis, causing loss of the preserved auditory hair cells responsible for residual hearing and / or increasing the impedance and affecting residual hearing. It has been demonstrated that patients with preserved postoperative residual hearing have improved speech perception with electro-acoustic or electro-vibrational stimulation, especially in speech perception in noise and music perception. Traditionally, an electrode is inserted using a mental representation of the cochlea, based on experience, a limited visual assessment and preoperative CT and / or MRI scans. However, it has been found that such scans have a relatively low resolution, do not visualize soft intraocular structures, and do not correlate to the orientation of the cochlea while inserting the implant electrode or to the actual position of the electrode inside the scala tympani. Further, such scans require relatively large and expensive machines and expose a patient to harmful radiation. Further, during insertion of the electrode, only the entrance to the scala tympany may be seen and heavy reliance is placed on tactile feedback, and an insertion axis of the electrode can be changed when increased tactile resistance is experienced. However, as a result, tactile feedback can only be perceived after the electrode has already touched the cochlear wall and possibly traumatized it. This is especially important as it has been found that electrode insertion trauma is often not accompanied by an increased resistance or mechanical forces, making it currently an unreliable parameter for insertion monitoring. It has been found that the ideal insertion angle of an implant electrode varies as much as 60 degrees among the subjects. As a result, Cl surgery poses a considerable risk for loss of residual hearing due to intraoperative trauma to the internal structures of the cochlea, occurring in up to 32% of implantations. Obiect ofthe invention It is therefore an object of the intention to provide an implant electrode insertion system that reduces the chances oftrauma to the cochlea, that allows to visualize the position of the implant electrode relatively precisely, which correlates to the orientation of the cochlea while inserting the implant electrode or to the actual position of the electrode inside the scala tympani, or at least to provide an alternative implant electrode insertion system, for example an implant electrode insertion system that allows to visualize the position of the implant electrode, that allows for relative precise positioning of the electrode in the cochlea, at a higher resolution, that is better able to visualize soft structures, requires a smaller machine, and / or that exposes the patient to less harmful radiation. Description of the invention The present invention provides an implant electrode insertion system according to claim 1. 2 The cochlear implant electrode insertion system comprises an oct device comprising an oct probe defining an optical axis. The oct device is configured to provide a cochlear orientation signal representative for an orientation of the oct probe with respect to a cochlea. The cochlear orientation signal is measured using optical coherence tomography of light emitted along the optical axis. The light may be emitted such that it can be reflected and / or backscattered by surfaces to be imaged, and can be received by the oct probe. A detector may be provided, configured to detect interference of the reflected and / or backscattered light with the emitted light to measure the cochlear orientation signal. The cochlear orientation signal may be representative for a distance and / or angle of the oct probe with respect to the cochlea. The oct device may be configured to emit infrared laser light to image through the round window membrane in the cochlea. The oct device may be configured to visualize the orientation of the basilar membrane up to the basal turn. As such, an implant electrode may be guided into the cochlea relatively precise, with lower chances oftouching the basilar membrane. The oct probe may be configured to be tilted manually in the correct position, e.g. such that the optimal insertion axis is aligned with the optical axis. The oct device may be configured to measure the distance between the round window niche and the probe to determine an axial distance therebetween. The advantage is that oct may determine the distance at relatively high accuracy (microns). The cochlear implant electrode insertion system comprises an implant electrode insertion module connected, e.g. rigidly, to the oct device, and configured to be arranged in an insertion position on the basis of the orientation signal. The cochlear implant electrode insertion system further comprises an alignment unit configured to assist in positioning of the implant electrode insertion module in the insertion position on the basis of the orientation signal. The alignment unit may be configured to assist passively, e.g. by providing feedback on the orientation of the oct probe with respect to the cochlea, for example such that a surgeon may position the implant electrode insertion module manually with respect to the cochlea, and / or actively, e.g. by altering the orientation of the oct probe with respect to the cochlea, for example through a drive system. The implant electrode insertion module comprises an electrode guide that defines a guide axis, and is configured to, in the insertion position, guide a cochlear implant electrode along the guide axis towards the cochlea. The guide axis may be the longitudinal axis of the electrode guide, in particular of the outer end thereof, and / or correspond to the longitudinal axis of an electrode arranged therein and protruding therefrom. The implant electrode insertion module may be connected to the oct device such that the orientation signal is 3 representative for an orientation of the electrode guide. The electrode guide may be configured to guide the electrode such that a tip axis of a guided electrode matches the optical axis of the oct probe. The electrode guide may comprise a housing to protect the electrode array. The guide axis is coaxial with the optical axis of the oct device. The guide axis and the optical axis may coincide. As such, the electrode may be guided and inserted into the cochlea along the precise axis thatwas measured with the oct probe. It has been found that larger difference between an ideal or optimal insertion axis of the electrode, and actual insertion axis is associated with more damage to the intracochlear structures. The ideal insertion axis correlates with the centerline of the first nearly straight part of the cochlea extending from the round window to the basal turn (first turn) of the cochlea. The insertion angle is defined with respect to the basal turn of the cochlea as the electrode enters through the round window. This ideal insertion angle varies as much as 60 degrees among the subjects. From an intraoperative perspective, this variability involves pushing the electrodes as near to the buttress or as near to the emergence of the corda tympani as possible, depending on the case. Since the human cochlea is entirely surrounded by bone it is impossible for a surgeon to determine the pathway of the ideal insertion axis with respect to the position of the round window. The oct probe allows to measure the optimal insertion axis very precisely, and due to the coaxial alignment of the guide axis with the optical axis of the oct probe, the electrode may be inserted while the oct probe is held in the same orientation, thereby reducing the chances of deviations. As a result, the invention advantageously allows the electrode to be guided very precisely and the invention provides an implant electrode insertion system that reduces the chances of trauma to the cochlea, that, by using oct, allows to visualize the position of the implant electrode relatively precisely, which due to the coaxial alignment correlates to the orientation of the insertion module while inserting the implant electrode or to the actual position of the electrode inside the scala tympani. Therewith, the chances of preservation of residual hearing are increased, the postoperative outcomes may be improved and the surgeon may perform the cochlear implant insertion with increased confidence. The combination of an oct probe and coaxial guide axis provides several advantages. Firstly, the oct probe may provide visualization of the cochlea at a relatively high resolution and that is relatively well able to visualize soft structures, compared to the prior art. In particular, pre-operative CT does not visualize soft intraocular structures and does not 4 correlate to the orientation of the cochlea while inserting the implant electrode or to the actual position of the electrode inside the scala tympani. The same disadvantages apply to MRI which cannot be used intraoperatively, i.e. during insertion of the implant electrode. Further, due to the use of oct , less exposure of the patient harmful radiation may be achieved compared to CT or MRI imaging. Finally, the use of oct enables to use machines with a smaller foodprint compared to CT or MRI imaging. Secondly, oct may enable measurement of speeds, for example via the doppler effect. As the guide axis is coaxial with the optical axis, the light emitted by the oct device may be backscattered and / or reflected by the implant electrode. As such, an insertion speed of the implant electrode during insertion of the implant electrode via the implant electrode insertion module may be measured, e.g. with respect to the oct probe. It has been found that magnitude and variation in electrode insertion speed correlate with trauma, especiallywhen the electrode is inserted manually. By enabling measurement of insertion speed due to the advantageous combination of oct and coaxial alignment of the insertion axis and the guide axis, feedback on the speed and speed variation of the cochlear implant electrode may be provided to reduce the chances of trauma. Thirdly, the oct device may allow visualization of the scala tympani up to the basal turn to identify the ideal axis of an electrode array, during surgery, e.g. in real time. Therewith, due to the connection of the implant electrode insertion module to the oct probe, it may be guaranteed that the guide axis remains coaxial with the optical device of the oct device. Existing methodologies do not provide that, and scientific publications present devices do not demonstrate that. Finally, the use of an oct probe allows relatively convenient control of the area imaged and represented in the orientation signal, compared to a relative large CT and / or MRI machine. As such, the oct probe may allow control of more degrees of freedom of the guide axis thanwas possible in the prior art. The implant electrode insertion system may comprise a camera configured to receive light, e.g. parallel to the optical axis, wherein the cochlear implant insertion system is configured to provide the cochlear orientation signal in further dependence of camera footage. This way, the orientation signal may be representative for a relatively large number of degrees of freedom. The camera may be a full colour camera. The camera may be attached to, e.g. mounted on, the oct probe. The camera may be congured to capture at least two degrees of freedom (e.g. x, horizontal; y, vertical) of the orientation of the cochlea, e.g. of the round window, whereas the 5 oct probe may be configured to capture an additional three degrees of freedom (e,g, z, axial distance; Rx, rotation over x; Ry rotation over y) using optical coherence tomography. This way, in comparison to the prior art, more degrees of freedom (Rx, Ry) may be represented in the orientation signal that what would be possible in the prior art. When the oct probe is positioned in front of the ear, e.g. in front of the round window of the cochlea, a surgeons view on the ear may be obstructed. By having a camera positioned on the oct probe, improved view on the ear may be provided to the surgeon via camera footage. As a result, positioning and safety of the device may be increased. The camera may be configured to capture footage representative for lateral movement, e.g. movement in a direction transverse to the guide axis and / or transverse to the optical axis. It has been found that lateral shifts, e.g. shifts in the plane of the circular window, may be detected relatively well with a camera. The alignment unit may be configured to assist in positioning of the implant electrode insertion module in further dependence of the footage captured with the camera. In particular, a feedback device may be configured to provide feedback in dependence of the orientation signal and captured camera footage. The feedback may be provided to assist in alignment of the oct probe with respect to the ear, e.g. to the round window. In an embodiment, the alignment unit comprises a feedback device configured to provide feedback, e.g. visual, auditive and / or haptic feedback, in dependence the orientation signal. By providing feedback, an operator or surgeon may be assisted in manually positioning the electrode insertion system with respect to the ear, such that compared to the prior art, relatively less reliance is necessary on manual positioning, skill and blind eye view of the operator or surgeon. In an embodiment, the cochlear implant insertion system comprises a processing unit configured to determine, e.g. calculate, an optimal insertion axis for the implant electrode on the basis of the cochlear orientation signal, wherein the alignment unit is configured to assist in alignment of the implant electrode insertion module with respect to the determined optimal insertion axis. The processing unit may be configured to determine the optimal insertion axis on the basis of a determined ideal insertion axis. The ideal insertion axis may be determined by the centerline of the first nearly straight part of the cochlea extending from the round window to the basal turn of the cochlea. The processing unit may be configured to determine one or more dimensions, e.g. a length, a width and / or a volume of the first part of the cochlea. The ideal insertion axis may be 6 determined by computing a longitudinal center line through the first part of the cochlea using the one or more dimensions. The processing unit may be configured to determine a location of one or more obstructions, e.g. a location of the facial nerve and / or the chorda tympani nerve. The optimal insertion axis may be determined by adjusting the ideal insertion axis for the one or more obstructions, e.g. by selecting an optimal insertion axis having an angle with respect to the basal turn of the cochlea that is as close as possible to the angle of the ideal insertion axis, but wherein the optimal insertion axis does not intersect with the one or more obstructions. In an embodiment, the alignment unit comprises a feedback device configured to provide feedback, e.g. visual, auditive and / or haptic feedback, in dependence of a difference between the optical axis and the determined optimal insertion axis. This way, the feedback device may assist an operator and / or surgeon in finding the optimal insertion axis and / or positioning the implant electrode insertion system even more effectively. In an embodiment, the oct device is configured to, during insertion of an implant electrode via the implant electrode insertion module, provide an insertion speed signal representative for an insertion speed of the implant electrode, e.g. with respect to the oct probe; further comprising an insertion monitoring unit configured to, on the basis of the insertion speed signal, determine the insertion speed of the cochlear implant electrode during insertion, e.g. using the doppler effect. In an embodiment, the feedback device is a visual device configured to visualise the determined optimal insertion axis and to provide visual feedback in dependence of the difference between the optical axis and the determined optimal insertion axis. It has been found that by visually displaying the determine optimal insertion axis, positioning the implant electrode insertion system may be performed even more effectively. In an embodiment, the electrode guide extends at least partially cylindrical along the guide axis and delimits a hollow interior through which the implant electrode can pass. The hollow interior may have a substantially circular cross section. The inner dimensions of the hollow interior, e.g. a diameter thereof, may be substantially equal to the outer dimensions of an implant electrode. 7 In an embodiment, the electrode guide comprises a detachment device for detachment of the implant electrode from the electrode guide. The detachment device may comprise a wiring opening for releasing electrode wiring from the electrode guide. The wiring opening may extend substantially parallel to the guide axis. It has been found that by using a wiring opening, detachment of the electrode from the electrode guide may be facilitated and / or electrode wiring may remain connected to the electrode during insertion. In an additional and / or alternative embodiment, the detachment device may be releasably couplable with the cochlear implant electrode. In an embodiment, the electrode guide comprises a feed part that is not aligned coaxially with the optical axis and a guide part having at least one bend section that guides the implant electrode towards the optical axis. The feed part may for example extend a longitudinal axis, e.g. substantially parallel to the guide axis. The at least one bend section may be configured to locally bend the implant electrode to change the direction thereof. This way, the implant electrode may be provided away from the optical axis, e.g. to limit obstruction of the field of view for an operator or surgeon. In an embodiment, the guide part comprises a first bend section arranged on a first side of the optical axis, and a second bend section arranged on an opposite second side of the optical axis. The first bend section may be configured to direct the cochlear implant electrode from the feed part towards a first direction not coaxial with the optical axis and the second bend section may be configured to direct the cochlear implant electrode from the first direction towards the guide axis. The first bend section and the second bend section may be shaped oppositely to each other, e.g. be mirror symmetrical to each other. The at least one bend section may be provided such that the optical axis is unobstructed. In an embodiment, the first bend section and the second bend section are arranged separately and at a distance from each other. For example, the first bend section may be provided on a first side of the oct probe, e.g. on a top side thereof, and the second bend section may be provided on an opposite side of the oct probe, e.g. on a bottom side thereof. The camera may for example be provided on the oct probe, e.g. on a surface between the top side and the bottom side. In an embodiment, the electrode guide extends between the first bend section and the second bend section, wherein electrode guide comprises an oct opening aligned with the 8 optical axis to allow light emitted along an optical axis to reach the cochlea. As such, additional guidance may be provided to the implant electrode between the first bend section and the second bend section. In an embodiment, the electrode insertion module comprises a manipulation recess configured to receive a forceps for moving a cochlear implant electrode along the optical axis e.g. by pushing the cochlear implant electrode. The manipulation recess may be formed by the wiring opening and / or vice versa. The manipulation recess may comprise one or multiple slits that extend longitudinally along the electrode guide, e.g. parallel to the optical axis. The manipulation recess may be shaped such that the interior of the electrode guide may be reached from outside with a forceps. The skilled person will understand that forceps as used herein is meant to include similar and suitable tools for moving the implant electrode. In an embodiment, the implant electrode insertion system further comprises a forceps. In an embodiment, the electrode insertion module comprises a movement mechanism for moving the implant along the guide axis, wherein the movement mechanism comprises an input device for receiving a driving movement from an operator; and a transmission device configured to reduce and / or smoothen the movement received by the input device and to transmit the reduced and / or smoothened movement to the cochlear implant electrode for moving the cochlear implant electrode along the optical axis. The input device may comprise an input element, e.g. a handle, movable pin and / or rotatable wheel and a moving surface configured to engage the implant electrode. The transmission device may be provided with a transmission ratio to reduce and / or smoothen the movement. In an embodiment, the electrode insertion module comprises a movement mechanism for moving the implant along the guide axis, wherein the movement mechanism comprises an actuator configured to, upon activation, provide a driving movement for moving the cochlear implant electrode along the optical axis. The actuator may for example comprise an electric motor or linear actuator, pneumatic and / or hydraulic actuator. It has been found that this way, a relatively controlled, e.g. constant, insertion of the implant electrode may be achieved. The movement mechanism may comprise a controller configured to control the movement of the implant electrode through the electrode guide. For example, a movement sensormay be provided wherein the controller is configured to control movement on the basis of the sensor signal. 9 In an embodiment, the implant electrode insertion system comprises a support arm connected to the implant electrode insertion module for supporting the electrode guide in the insertion position. It has been found that the support arm may enhance stable holding of the implant electrode insertion system and may thereby further lower the chances of cochlear damage. The invention further relates to a robotic implant electrode insertion system, comprising the implant electrode insertion system according to any of the embodiments as disclosed herein. It has been found that robotic systems of the prior art have disadvantages that are similar to manual surgery methods, such that the chances of trauma are still significant. In particular, the insertion axis needs to be determined manually on the basis of preoperative CT scans and limited visibility. If an insertion axis would be determined automatically, such CT scans miss information about the soft tissues in the cochlea, such that a calculated ideal insertion axis on the basis ofCT scans is not necessarily correct. Further, if haptic feedback is present, the disadvantage is similar as described herein for manual procedures. The cochlear implant insertion system according to the present invention may be provided on a robotic arm. In particular, the electrode may be moved into the cochlea upon determining the optimal insertion axis and arranging the implant insertion module in the insertion position. The invention further relates to a cochlear implant electrode assembly, comprising a cochlear implant electrode and an implant electrode insertion system and / or a robotic implant electrode insertion system according to any of the preceding claims, wherein the cochlear implant electrode is arranged in the electrode guide. The invention further relates to a method for implanting a cochlear implant electrode, e.g. using a cochlear implant insertion system according to any of the preceding claims, comprising the steps of: providing an orientation signal with an oct device using optical coherence tomography of light emitted along an optical axis; aligning a cochlear insertion module connected to the oct probe in an insertion position on the basis of the orientation signal; and while the cochlear insertion module is arranged in the insertion position, guiding a cochlear implant electrode with an electrode guide of the cochlear insertion module along a guide axis towards the cochlea. 10 In an embodiment, the method further comprises the step of determining an optimal insertion axis on the basis of the cochlear orientation signal, wherein the step of aligning the cochlear insertion module comprises aligning the electrode guide with respect to the determined optimal insertion axis. In an embodiment, the method further comprises the step of determining, e.g. calculating, during insertion of an implant electrode via the implant electrode insertion module, an insertion speed of the cochlear implant electrode, for example using the doppler effect using optical coherence tomography of light emitted along the optical axis. The invention further relates to a method for mapping electrode pads of a cochlear implant electrode to frequency bins on an auditory nerve, e.g. the cochlear implant electrode guided according to the method of any of the embodiments as disclosed herein, comprising the steps of: providing an orientation signal with the oct device using optical coherence tomography of light emitted along an optical axis; determining a position of at least one electrode pad of the implant electrode with respect to the cochlea on the basis of the orientation signal; and comparing the determined position with predetermined frequency data of the auditory nerve representative for the positions of respective frequency bins to map the at least one electrode pad to at least one corresponding frequency bin. The robotic implant electrode insertion system, the implant electrode assembly, the method for guiding a cochlear implant electrode, the method for surgically implanting a cochlear implant electrode, and the method for mapping electrode pads of a cochlear implant electrode to frequency bins on an auditory nerve may be provided in or performed with different embodiments as disclosed herein for the implant electrode insertion system and similar advantages may be achieved as described for the respective embodiment of the implant electrode insertion system. Brief description of drawings Further characteristics of the invention will be explained below, with reference to embodiments, which are displayed in the appended drawings, in which: Figure 1A schematically depicts an implant electrode insertion system according to an embodiment of the invention, in perspective; Figure 1B schematically depicts a top view of the insertion system of Fig. 1A; Figure 1C schematically depicts a detailed partial view of the electrode guide of Fig. 1B; 11 Figure 2A schematically depicts an electrode guide according to an embodiment; Figure 2B schematically depicts the electrode guide of Fig. 2A, provided with an implant electrode; Figure 3A schematically depicts an electrode guide according to an embodiment; Figure 3B schematically depicts the electrode guide of Fig. 3A, provided with an implant electrode; Figure 4A schematically depicts the electrode guide of Figs. 2A-2B; and Figure 4B schematically depicts the electrode guide of Figs. 3A-3B. Figure 5A schematically depicts the optimal and ideal insertion axis in an ear; Figure 5B schematically depicts the optimal and ideal insertion axis in another ear; Figure 6A schematically depicts an ear of a patient; Figure 6B schematically depicts another ear of a patient; and Figure 7 schematically depicts an implant electrode insertion system according to an embodiment, arranged in the insertion position. Throughout the figures, the same reference numerals are used to refer to corresponding components or to components that have a corresponding function. Detailed description of embodiments Figure 1A schematically depicts an implant electrode insertion system 1 for inserting an implant electrode into the cochlea, comprising an oct device 2 comprising an oct probe 3 defining an optical axisA and configured to provide an orientation signal representative for an orientation of the oct probe 3 with respect to a cochlea 99, measured using optical coherence tomography of light emitted along the optical axis A. The system 1 comprises an implant electrode insertion module 4 connected to the oct device 2, and configured to be arranged in an insertion position on the basis of the orientation signal; and an alignment unit 5 configured to assist in positioning of the implant electrode insertion module in the insertion position on the basis of the orientation signal. The implant electrode insertion module 4 comprises an electrode guide that defines a guide axis G, and is configured to, in the insertion position, guide a cochlear implant electrode 98 along the guide axis towards the cochlea 99. The guide axis G is coaxial with the optical axis A of the oct device 2. In use, the light is emitted along the optical axisA such that it can be reflected and / or backscattered by surfaces to be imaged, and can be received by the oct probe 3. 12 A detector is provided, configured to detect interference of the reflected and / or backscattered light with the emitted light to measure the cochlear orientation signal. The cochlear orientation signal is for a distance and / or angle of the oct probe 3 with respect to the cochlea 99. The oct device 2 is configured to emit infrared laser light to image through the round window membrane in the cochlea. The oct device 1 is configured to visualize the orientation of the basilar membrane up to the basal turn. In the shown embodiment, the oct probe 3 is configured to be tilted manually to align the insertion module 4 in the insertion position, e.g. such that the optimal insertion axis 0 for the specific cochlea 99 of the patient is aligned with the optical axis A. The oct device 2, e.g. via the processing unit, is configured to measure the distance between the round window niche and the probe 3 to determine an axial distance therebetween. The cochlear implant electrode insertion system comprises an implant electrode insertion module 4 rigidly connected to the oct device 2 and configured to be arranged in an insertion position on the basis of the orientation signal. The cochlear implant electrode insertion system 1 further comprises an alignment unit 5 configured to assist in positioning of the implant electrode insertion module in the insertion position on the basis of the orientation signal. The alignment unit 5 may be configured to assist passively and / or actively. The implant electrode insertion module 4 comprises an electrode guide that defines a guide axis G, and is configured to, in the insertion position, guide a cochlear implant electrode 98 along the guide axis G towards the cochlea 99. The guide axis G is formed by the longitudinal axis of the electrode guide, in particular of the outer end thereof, and corresponds to the longitudinal axis L of an electrode 98 arranged therein. The implant electrode insertion module 4 is connected to the oct device 2 such that the orientation signal is representative for an orientation of the electrode guide. The electrode guide comprises a housing and is configured to guide the electrode 98 such that a tip axis of a guided electrode matches the optical axis A of the oct probe 3. The electrode guide may comprise a housing to protect the electrode array. The implant electrode insertion system 1 comprises a full colour camera (not shown) mounted on the oct probe 3 and configured to receive light parallel to the optical axis A and the cochlear orientation signal is provided in further dependence of camera footage. The camera is configured to capture at least two degrees of freedom (Le. x, horizontal; y, vertical) of the orientation of the cochlea, e.g. of the round window, whereas the oct probe 3 is configured to capture an additional three degrees of freedom (i.e., z, axial distance; Rx, 13 rotation over x; Ry rotation over y) using optical coherence tomography. The camera is configured to capture footage representative for lateral movement, e.g. movement in a direction transverse to the guide axis G and / or transverse to the optical axis A. The alignment unit 5 is configured to assist in positioning of the implant electrode insertion module in further dependence of the footage captured with the camera. The cochlear implant insertion system 1 comprises a processing unit configured to determine, e.g. calculate, an optimal insertion axis 0 for the implant electrode on the basis of a determined ideal insertion axis I determined, e.g. calculated, on the basis of the cochlear orientation signal. The alignment unit 5 is configured to assist in alignment of the implant electrode insertion module with respect to the determined optimal insertion axis 0. The ideal insertion axis, as shown in Figs. 5A-5B, may be determined by the centerline of the first nearly straight part of the cochlea extending from the round window to the basal turn of the cochlea 99. The processing unit is configured to determine one or more dimensions, e.g. a length, a width and / or a volume of the first part of the cochlea 99 and the ideal insertion axis l is determined by computing a longitudinal center line through the first part of the cochlea 99 using the one or more dimensions. The processing unit is configured to determine a location of one or more obstructions, e.g. a location of the facial nerve 97 and / or the chorda tympani 96 nerve. The optimal insertion axis 0 may be determined by adjusting the ideal insertion axis I for the one or more obstructions 96, 97, e.g. by selecting an optimal insertion axis having an angle with respect to the basal turn of the cochlea that is as close as possible to the angle of the ideal insertion axis, but wherein the optimal insertion axis does not intersect with the one or more obstructions. The alignment unit 5 comprises a feedback device configured to provide feedback, in particular visual, auditive and / or haptic feedback, in dependence the orientation signal and captured camera footage, in dependence of a difference between the optical axisA and the determined optimal insertion axis 0. The oct device 2 is configured to, during insertion of an implant electrode 98 via the implant electrode insertion module 4, provide an insertion speed signal representative for an insertion speed of the implant electrode, e.g. with respect to the oct probe. The system 1 further comprises an insertion monitoring unit configured to, on the basis of the insertion speed signal, determine the insertion speed of the cochlear implant electrode 98 during insertion, e.g. using the doppler effect. The feedback device 5 is a visual device configured to visualise the determined optimal insertion axis 0 and to provide visual feedback in dependence of the difference 14 between the optical axis A and the determined optimal insertion axis 0, e.g. by showing diagrams according to Figs. 5A-7 in the display. The electrode guide 4 extends at least partially cylindrical along the guide axis G and delimits a hollow interior 40 having a substantially circular cross section, through which the implant electrode 98 can pass. The inner dimensions of the hollow interior 40, e.g. a diameter thereof, are substantially equal to the outer dimensions of an implant electrode 98. The electrode guide 4 comprises a detachment device 41 for detachment of the implant electrode 98 from the electrode guide 4, formed by a wiring opening for releasing electrode wiring from the electrode guide 4, which extends substantially parallel to the guide axis G. In an additional and / or alternative embodiment, the detachment device may be releasably couplable with the cochlear implant electrode. The electrode guide 4 may be provided in various embodiments, as illustrated in Figs. 2A-4B. In an embodiment, the electrode guide 4 comprises a feed part 42 extending along a longitudinal axis parallel to the guide axis G, that is not aligned coaxially with the optical axis A and a guide part 43 having at least one bend 44 section that guides the implant electrode 98 and changes its direction towards the optical axis A. The guide part comprises a first bend 44 section arranged on a first side of the optical axis A, and a second bend section 45 arranged on an opposite second side of the optical axis A. The first bend section 44 is configured to direct the cochlear implant electrode 98 from the feed part 42 towards a first direction not coaxial with the optical axis and the oppositely shaped second bend section 43 is configured to direct the cochlear implant electrode 98 from the first direction towards the guide axis G. In an embodiment, the first bend section and the second bend section may be mirror symmetrical to each other. In Figs. 2A-4B, the first bend section 44 and the second bend section 45 are arranged separately and at a distance from each other. The first bend section 44 is provided on a first top side of the oct probe 3, and the second bend section 45 is provided on an opposite bottom side of the oct probe 3. In Figs 1A-1C and Fig. 7, the electrode guide 4 extends between the first bend section 44 and the second bend section 45. The electrode guide comprises an oct opening 46 aligned with the optical axis A to allow light emitted along an optical axis to reach the cochlea. ln Figs. 1A-ZB, the electrode insertion module 4 comprises a manipulation recess 41 formed by the wiring opening and configured to receive a forceps for moving a cochlear implant electrode along the optical axisA e.g. by pushing the cochlear implant electrode 98. Alternatively, the manipulation recess may comprise one or multiple slits that extend longitudinally along the electrode guide, e.g. parallel to the optical axis A. 15 In the embodiment of Figs. 1A-1C, the electrode insertion module 4 comprises a movement mechanism for moving the implant along the guide axis, wherein the movement mechanism comprises an input device 47 for receiving a driving movement from an operator. The movement mechanism comprises a transmission device configured to reduce and / or smoothen the movement received by the input device 47 and to transmit the reduced and / or smoothened movement to the cochlear implant electrode 98 and / or an actuator configured to, upon activation by pressing input device 47, provide a driving movement for moving the cochlear implant electrode along the optical axis. The actuator may for example comprise an electric motor or linear actuator, pneumatic and / or hydraulic actuator. The movement mechanism may comprise a controller configured to control the movement of the implant electrode through the electrode guide. For example, a movement sensor may be provided wherein the controller is configured to control movement on the basis of the sensor signal. The implant electrode insertion system 1 may comprise a support arm connected to the implant electrode insertion module for supporting the electrode guide in the insertion position, and / or may be provided on a robotic implant electrode insertion system. Figures 5A-5B schematically depict an ideal insertion axis I. Unfortunately, the ideal insertion axis can often not be reached due to blockage of the facial nerve 97 and chorda tympani nerve 96. Therefore, herein a differentiation is made between the ideal insertion axis I and the optimal insertion axis 0, wherein the optimal insertion axis 0 is defined as the axis closest to the ideal insertion axis I that extends through the surgical opening and can be used for inserting the implant electrode. The ideal insertion axis I correlates with the centerline of the first nearly straight part of the cochlea 99 extending from the round window 95 to the basal turn (first turn) of the cochlea 99. The insertion angle of the insertion axis is defined with respect to the basal turn of the cochlea as the electrode enters through the round window 95. This ideal insertion angle I varies as much as 60 degrees among subjects, due to varying ear geometry as for example depicted in Figs. 6A-6B. Since the human cochlea is entirely surrounded by bone, itwas impossible for a skilled person to determine the pathway of the ideal insertion axis I with respect to the position of the round window 95 using the prior art. 16 CONCLUSION 1. Implant electrode insertion system (1) for inserting a implant electrode in the cochlea (99), comprising: an octal device (2) comprising an octal probe (3) which an optical axis (A) determines and is designed to provide an orientation signal that is representative of an orientation of the OCT probe relative to the cochlea, measured by optical coherence tomography along a the optical axis (A) emitted light; an implant electrode insertion module (4) connected to the oct- structure and is structured to be placed in a contribution position on the basis of the orientation signal; and an alignment unit (5) equipped to assist in positioning the implant electrode insertion module (4) in the insertion position based on the orientation signal; and where the implant electrode insertion module (4) includes an electrode guide which determines a guide axis (G) and is configured to, in the insertion position, a to guide the cochlear implant electrode along the conduction axis to the cochlea, where the conduction axis (G) is coaxial with the optical axis of the OCT device. 2. Implant electrode insertion system in accordance with the preceding claim, where the alignment unit (5) includes a feedback device designed to provide feedback, e.g. visual, auditory and / or haptic feedback, depending on the orientation signal. 3. Implant electrode insertion system within the meaning of claim 1 or 2, further comprising a venNerking unit designed to an optimal input axis (0) for the to determine implant electrode, e.g. to calculate, based on the cochlear orientation signal; where the alignment unit is configured to assist in aligning the implant electrode insertion module (4) relative to the determined optimal input shaft 4. Implant electrode insertion system in accordance with the preceding claim, where the feedback setup is a visual setup that is designed to the specific to visualize the optimal input axis and to provide visual feedback in dependence on a difference between the optical axis and the specific optimal input shaft 17 5. Implant electrode insertion system in accordance with one of the preceding claims, where the oct device (2) is configured to, during the insertion of a implant electrode via the implant electrode insertion module (4) a to provide an input rate signal that is representative of in a insertion speed of the implant electrode, e.g. relative to the octagonal probe (3); further comprising a input monitoring unit set up to, on the basis of the insertion rate signal, the insertion rate of the cochlear- to determine implant electrode during insertion, e.g. by means of the Doppler effect. 6. Implant electrode insertion system in accordance with one of the preceding claims, where the electrode conduction is at least partially cylindrical along the guide shaft (G) extends and delineates a hollow interior space (40) whereby the can pass through the implant electrode. 7. Implant electrode insertion system under one of the preceding claims, where the electrode conduction includes a decoupling device for decoupling of the implant electrode of the electrode conduction, e.g. where the disconnecting device a wiring opening (41) which is mainly located extends parallel to the guide axis. 8. Implant electrode insertion system in accordance with one of the preceding claims, where the electrode conduction includes a non-coaxial feed part (42) aligned with the optical axis (A) and a guide part (43) that at least a curved part (44) that the implant electrode towards the optical axis conducts. 9. Implant electrode insertion system in accordance with the preceding conclusion, whereby the guide part (43) comprises a first curved part (44) that is fitted on a first side of the optical axis, and a second curved part (450 that is mounted on an opposite second side of the optical axis. 10. Implant electrode insertion system in accordance with the preceding conclusion, whereby the first curved part (44) and the second curved part (45) separately and are placed at a distance from each other. 11. Implant electrode insertion system under one of the preceding claims, where the electrode conduction (4) extends between a first curved part (44) and a second curved section (45), where the electrode conduction is an octa- 18 opening (46) which is aligned with the optical axis to pass through the octagonal device (2) to allow light emitted along the optical axis to reach the cochlea. 12. Implant electrode insertion system under one of the preceding claims, where the electrode insertion module (4) is equipped with a manipulation recess to receive forceps for moving the cochlear implant electrode along the optical axis, e.g. by pushing the cochlear- implant electrode. 13. Implant electrode insertion system under one of the preceding claims, where the electrode insertion module (4) includes a movement mechanism for the movement of the implant along the guidance axis, whereby the movement mechanism includes: an input device (47) for receiving a drive movement from an operator; and a transmission device designed to receive the input device to reduce and / or make movement smoother, and to the reduced and / or smoother movement of the cochlear implant electrode to transfer for moving the cochlear implant electrode along the optical axis. 14. Implant electrode insertion system under one of the preceding claims, where the electrode insertion module includes a movement mechanism for the move along the guide axis, where the movement mechanism is an actuator includes designed to provide a drive movement for the upon activation driving the cochlear implant electrode along the optical axis. 15. Implant electrode insertion system under one of the preceding claims, further comprising a support arm connected to the implant electrode- insertion module for supporting electrode conduction in the contribution position. 16. Robotic implant electrode insertion system, comprising the implant electrode insertion system according to one of the preceding conclusions. 17. Implant electrode assembly, comprising: a cochlear implant electrode; and 19 an implant electrode insertion system and / or a robotic implant electrode insertion system according to one of the preceding conclusions; where the cochlear implant electrode is placed in the electrode lead. 18. Procedure for guiding a cochlear implant electrode, e.g. by means of a cochlear implant electrode insertion system according to one of the previous conclusions, comprising the steps of: providing an orientation signal with the OCT device (2) by means of optical coherence tomography of light along an optical axis broadcast; aligning a cochlear implant electrode insertion module (4) connected with the oct device (2) in a contribution position based on the orientation signal; and it, while the cochlear implant electrode insertion module in the insertion position is provided, along a guiding axis towards the cochlea (99) guiding the cochlear implant electrode with electrode guidance of the cochlear implant electrode insertion module. 19. Procedure for guiding a cochlear implant electrode according to the previous conclusion, further comprising the step of determining a optimal input axis (O) based on the cochlear orientation signal, where the step of aligning the cochlear implant electrode- insertion module (4) aligning the electrode guide with respect to the includes certain optimal input axis (O). 20. Procedure for the surgical implantation of a cochlear- implant electrode, comprising the steps of: exposing an access to the cochlea (99); and carrying out the procedure under claim 18 or 19; whereby the step of guiding the cochlear implant electrode in such a way is performed so that the cochlear implant electrode is along the conduction axis (G) guided, through the entrance and into the cochlea. 21. Procedure for mapping, e.g. linking, electrode pads of a cochlear implant electrode to frequency bands of an auditory nerve, e.g. the cochlear implant electrode guided according to the method of one of the conclusions 18-20, comprising the steps of: 20 providing an orientation signal with the OCT device (2) by means of optical coherence tomography of light along an optical axis (A) broadcast; determining the position of at least one electrode pad of the implant electrode (98) relative to the cochlea (99) based on the orientation signal; and comparing the determined position with predetermined frequency data of the auditory nerve that is representative of positions of respective frequency bands, to map at least one electrode pad, e.g. to connect to at least a corresponding frequency band. 21

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