Locating nerves for a surgical procedure

Abstract

Presented herein are techniques for monitoring neuroactivity of a patient of a medical device, and using the neuroactivity to locate a chorda tympani of a patient. The location of the chorda tympani is then used to perform a surgical procedure.

Description

UOCATING NERVES FOR A SURGICAE PROCEDUREBACKGROUNDTechnical Field[oooi] The present disclosure relates generally to determining a location of a nerve of a patient, such as a chorda tympani nerve of a patient, to facilitate a surgical procedure.Related Art

[0002] Medical devices have provided a wide range of therapeutic benefits to patients over recent decades. Medical devices can include internal or implantable components / devices, external or wearable components / devices, or combinations thereof (e.g., a device having an external component communicating with an implantable component). Medical devices, such as traditional hearing aids, partially or fully-implantable hearing prostheses (e.g., bone conduction devices, mechanical stimulators, cochlear implants, etc.), pacemakers, defibrillators, functional electrical stimulation signals devices, and other medical devices have been successful in performing lifesaving and / or lifestyle enhancement functions and / or patient monitoring for a number of years.

[0003] The types of medical devices and the ranges of functions performed thereby have increased over the years. For example, many medical devices, sometimes referred to as “implantable medical devices,” now often include one or more instruments, apparatus, sensors, processors, controllers or other functional mechanical or electrical components that are permanently or temporarily implanted in a patient. These functional devices are typically used to diagnose, prevent, monitor, treat, or manage a disease / injury or symptom thereof, or to investigate, replace or modify the anatomy or a physiological process. Many of these functional devices utilize power and / or data received from external devices that are part of, or operate in conjunction with, implantable components.SUMMARY

[0004] In one aspect, a method is provided. The method comprises monitoring neuroactivity of a patient of a medical device, determining a location of a chorda tympani nerve of the patient based on the neuroactivity of the patient, and using the location of the chorda tympani nerve to perform a surgical procedure associated with the patient.

[0005] In another aspect, a system is provided. The system comprises at least one electrode configured to monitor neuroactivity of a patient of a medical device, a processor, and a memorycomprising instructions executable by the processor to cause the processor to receive signals from the at least one electrode, the signals indicating the neuroactivity of the patient monitored by the at least one electrode, and determine a location of a chorda tympani nerve of the patient based on the neuroactivity.

[0006] In yet another aspect, a method is provided. The method comprises providing an electrical stimulation signals to a patient, receiving neuroactivity resulting from the electrical stimulation, and determining a location of a chorda tympani nerve of the patient based on the neuroactivity.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Embodiments of the present disclosure are described herein in conjunction with the accompanying drawings, in which:

[0008] FIG. 1A is a schematic diagram illustrating a cochlear implant system with which aspects of the techniques presented herein can be implemented;

[0009] FIG. IB is a side view of a patient wearing a sound processing unit of the cochlear implant system of FIG. 1A;[ooio] FIG. 1C is a schematic view of components of the cochlear implant system of FIG. 1 A;[ooii] FIGs. 2 A and 2B each illustrate an ear of a patient with which aspects of the techniques presented herein can be implemented;

[0012] FIG. 3 is a schematic diagram of an anatomical structure of a mouth of a patient with which aspects of the techniques presented herein can be implemented;

[0013] FIG. 4 illustrates a surgical procedure being performed using aspects of the techniques presented herein;

[0014] FIG. 5 is a top view of a mouth of a patient with which aspects of the techniques presented herein can be implemented;

[0015] FIG. 6 is a rear view of a mouth of a patient with which aspects of the techniques presented herein can be implemented;

[0016] FIG. 7 is a three-dimensional (3D) map of neuroelectric fields that can be generated using aspects of the techniques presented herein;

[0017] FIG. 8 is another schematic diagram of an anatomical structure of a mouth of a patient with which aspects of the techniques presented herein can be implemented;

[0018] FIG. 9 is a flowchart of a method, in accordance with certain aspects presented herein;

[0019] FIG. 10 is a flowchart of another method, in accordance with certain aspects presented herein;

[0020] FIG. 11 is a flowchart of another method, in accordance with certain aspects presented herein;

[0021] FIG. 12 is a flowchart of another method, in accordance with certain aspects presented herein; and

[0022] FIG. 13 is a schematic diagram illustrating a computing device with which aspects of the techniques presented herein can be implemented.DETAILED DESCRIPTION

[0023] Presented herein are techniques for using neuroactivity to locate (e.g., determine a location of) one or more nerves of a patient or medical device recipient (collectively and generally referred to herein as a “patient” or “patients”) to facilitate performing a surgical procedure. In accordance with the techniques presented herein, the neuroactivity is measured / obtained through the use of at least one electrode positioned / disposed in the oral cavity (mouth) of the patient, where the at least one electrode is used to deliver or measure electrical signals. It is to be appreciated that the techniques presented herein can be used to locate a number of different nerves (e.g., the chorda tympani, the facial nerve, the vagus nerve, etc.) of a patient for a number of different reasons. However, merely for ease of description, the techniques presented herein are primarily described with reference to locating a chorda tympani nerve (chorda tympani) of a patient. Some examples presented herein also relate to locating the facial nerve and / or the vagus nerve.

[0024] The chorda tympani innervates a portion of the tongue, but passes close to the ears of a patient. More specifically, the chorda tympani arises from the mastoid segment of the facial nerve, carrying afferent special sensation from the anterior two-thirds of the tongue via the lingual nerve, as well as efferent parasympathetic secretomotor innervation to the submandibular and sublingual glands. After branching off from the facial nerve, the chorda tympani courses through the temporal bone before joining the lingual nerve. During certainsurgical procedures, such as procedure to implant a cochlear implant, the chorda tympani can become exposed and, as a result, vulnerable to injury (e.g., contact) that can reduce its functionality. For example, contact with the chorda tympani during a surgical procedure can cause hypogeusia (i.e., reduced sense of taste), ageusia (i.e., complete loss in taste), and / or loss of muscle control. As such, it is desirable to locate (determine the location of) the chorda tympani at a stage of a surgical procedure (e.g., before beginning the surgical procedure, before opening the patient, etc.) where there is the opportunity to avoid contacting the chorda tympani during the surgical procedure, thereby maintaining desirable functionality of the chorda tympani. Unfortunately, the chorda tympani is relatively small and can have a complex anatomical course that deviates in its trajectory between different patients. Therefore, the location of the chorda tympani can be difficult to determine using conventional techniques, such as those based on anatomical reference points of each patient.

[0025] As such, embodiments of the present disclosure are directed to using neuroactivity related to the chorda tympani to determine the location of the chorda tympani. For example, neuroactivity propagates along the chorda tympani between a lateral portion of a skull of the patient and the tongue. Thus, a location of increased neuroactivity can be used to ascertain a location of the chorda tympani. To generate such neuroactivity, electrical stimulation signals are provided to the patient, and the location of the chorda tympani is determined based on the generated neuroactivity. Consequently, the surgical procedure can proceed based on the determined location of the chorda tympani, namely with a surgical plan that can avoid contact with the chorda tympani.

[0026] It is to be appreciated that various nerves of a patient, such as the chorda tympani, follow complex anatomical courses / paths, and, as such, nerves have varying widths / thickness, lengths, turns, etc. As used herein, the terms “locating” a nerve or “determining a location of’ a selected nerve refer to determining the location of all, substantially all, or one or more parts of the nerve pathway (e.g., determining the width, length, turns, etc. of all or part of a selected nerve) within a particular patient. That is, as used herein, the “location” of the nerve is more than a general location, but instead specifically defines the precise placement / position of the selected nerve in the specific patient.

[0027] There are a number of different types of devices in / with which embodiments of the present disclosure may be implemented. Merely for ease of description, the techniques presented herein are primarily described with reference to implanting a specific device in the form of a cochlear implant system. However, it is to be appreciated that the techniquespresented herein may also be partially or fully implemented with respect to any of a number of different types of devices, including consumer electronic device (e.g., mobile phones), wearable devices (e.g., smartwatches), hearing devices, implantable medical devices, consumer electronic devices, etc. As used herein, the term “hearing device” is to be broadly construed as any device that acts on an acoustical perception of an individual, including to improve perception of sound signals, to reduce perception of sound signals, etc. In particular, a hearing device can deliver sound signals to a user in any form, including in the form of acoustical stimulation, mechanical stimulation, electrical stimulation, etc., and / or can operate to suppress all or some sound signals. As such, a hearing device can be a device for use by a hearing-impaired person (e.g., hearing aids, middle ear auditory prostheses, bone conduction devices, direct acoustic stimulators, electro-acoustic hearing prostheses, auditory brainstem stimulators, bimodal hearing prostheses, bilateral hearing prostheses, dedicated tinnitus therapy devices, tinnitus therapy device systems, combinations or variations thereof, etc.), a device for use by a person with normal hearing (e.g., consumer devices that provide audio streaming, consumer headphones, earphones, and other listening devices), a hearing protection device, etc. In other examples, the techniques presented herein can be implemented by, or used in conjunction with, various implantable medical devices, such as visual devices (i.e., bionic eyes), sensors, pacemakers, drug delivery systems, defibrillators, functional electrical stimulation devices, catheters, seizure devices (e.g., devices for monitoring and / or treating epileptic events), sleep apnea devices, electroporation devices, etc.

[0028] FIGs. 1A-1C illustrate an example cochlear implant system 102 with which aspects of the techniques presented herein can be implemented. The cochlear implant system 102 comprises an external component 104 that is configured to be directly or indirectly attached to the body of the user, and an intemal / implantable component 112 that is configured to be implanted in or worn on the head of the user. In the examples of FIGs. 1A-1C, the implantable component 112 is sometimes referred to as a “cochlear implant.” FIG. 1A illustrates the cochlear implant 112 implanted in the head 154 of a user, while FIG. IB is a schematic drawing of the external component 104 worn on the head 154 of the user. FIG. 1C is another schematic view of the cochlear implant system 102. For ease of description, FIGs. 1A-1C will generally be described together.

[0029] In the examples of FIGs. 1A-1C, the external component 104 comprises a sound processing unit 106, an external coil, and generally, a magnet fixed relative to the external coil. The cochlear implant 112 includes an implantable coil 114 and an elongate stimulatingassembly 116 configured to be implanted in the user’s cochlea. In one example, the sound processing unit 106 is an off-the-ear (OTE) sound processing unit, sometimes referred to herein as an OTE component, which is configured to send data and power to the implantable component 112. In general, an OTE sound processing unit is a component having a generally cylindrically shaped housing 111 and which is configured to be magnetically coupled to the user’s head 154 (e.g., includes an integrated external magnet 150 configured to be magnetically coupled to an intemal / implantable magnet 152 in the implantable component 112). The OTE sound processing unit 106 also includes an integrated external (headpiece) coil (the external coil) that is configured to be inductively coupled to the implantable coil 114.

[0030] It is to be appreciated that the OTE sound processing unit 106 is merely illustrative of the external devices that could operate with implantable component 112. For example, in alternative examples, the external component 104 may comprise a behind-the-ear (BTE) sound processing unit configured to be attached to, and worn adjacent to, the user’s ear. A BTE sound processing unit comprises a housing that is shaped to be worn on the outer ear of the user. In certain examples, the BTE is connected to a separate external coil assembly via a cable, where the external coil assembly is configured to be magnetically and inductively coupled to the implantable coil 114, while in other embodiments the BTE includes a coil disposed in or on the housing worn on the outer ear of the user. It is also to be appreciated that alternative external components could be located in the user’s ear canal, worn on the body, etc.

[0031] Although the cochlear implant system 102 includes the sound processing unit 106 and the cochlear implant 112, as described below, the cochlear implant 112 can operate independently from the sound processing unit 106, for at least a period, to stimulate the user. For example, the cochlear implant 112 can operate in a first general mode, sometimes referred to as an “external hearing mode,” in which the sound processing unit 106 captures sound signals that are then used as the basis for delivering stimulation signals to the user. The cochlear implant 112 can also operate in a second general mode, sometimes referred as an “invisible hearing” mode, in which the sound processing unit 106 is unable to provide sound signals to the cochlear implant 112 (e.g., the sound processing unit 106 is not present, the sound processing unit 106 is powered-off, the sound processing unit 106 is malfunctioning, etc.). As such, in the invisible hearing mode, the cochlear implant 112 captures sound signals itself via implantable sound sensors and then uses those sound signals as the basis for delivering stimulation signals to the user. Further details regarding operation of the cochlear implant 112 in the external hearing mode are provided below, followed by details regarding operation ofthe cochlear implant 112 in the invisible hearing mode. It is to be appreciated that reference to the external hearing mode and the invisible hearing mode is merely illustrative and that the cochlear implant 112 could also operate in alternative modes.

[0032] In FIGs. 1A and 1C, the cochlear implant system 102 is shown with an external device 110, configured to implement aspects of the techniques presented. The external device 110 is a computing device, such as a personal computer (e.g., laptop, desktop, tablet), a mobile phone (e.g., smartphone), a remote control unit, etc. The external device 110 and the cochlearimplant system 102 (e.g., sound processing unit 106 or the cochlear implant 112) wirelessly communicate via a bi-directional communication link 126. The bi-directional communication link 126 may comprise, for example, a short-range communication, such as Bluetooth link, Bluetooth Low Energy (BLE) link, a proprietary link, etc.

[0033] As noted, the cochlear implant system 102 includes the external coil and the implantable coil 114. The external magnet 150 is fixed relative to the external coil and the intemal / implantable magnet 152 is fixed relative to the implantable coil 114. The external magnet 150 and the intemal / implantable magnet 152 fixed relative to the external coil and the intemal / implantable coil 114, respectively, facilitate the operational alignment of the external coil with the implantable coil 114. This operational alignment of the coils enables the external component 104 to transmit data and power to the implantable component 112 via a closely- coupled wireless link formed between the external coil with the implantable coil 114. In certain examples, the closely-coupled wireless link is an RF link. However, various other types of energy transfer, such as infrared (IR), electromagnetic, capacitive, and inductive transfer, may be used to transfer the power and / or data from an external component to an implantable component.

[0034] The sound processing unit 106 is configured to process the received input audio signals (received at one or more of the input devices) and convert the received input audio signals into output control signals for use in stimulating a first ear of a patient or user (e.g., an external sound processing module is configured to perform sound processing on input signals received at the sound processing unit 106). One or more processors (e.g., processing element(s) implementing firmware, software, etc.) in the sound processing unit 106 are configured to execute sound processing logic in memory to convert the received input audio signals into output control signals (stimulation signals) that represent electrical stimulation for delivery to the user. According to an example embodiment, output control signals (stimulation signals) are transcutaneously transferred (e.g., in an encoded manner) to the implantable component112 via the external coil and the implantable coil 114. In an alternative embodiment, the sound processing unit 106 can send less processed information (e.g., audio data) to the implantable component 112, and the sound processing operations (e.g., conversion of input sounds to output control signals) can be performed by a processor within the implantable component 112. Regardless, the output control signals are provided to the stimulating assembly 116.

[0035] The stimulating assembly 116 extends through an opening in the user’s cochlea (e.g., cochleostomy, the round window, etc.) and includes a plurality of longitudinally spaced intra- cochlear electrical stimulating contacts (electrodes) that collectively form a contact array (electrode array) for delivery of electrical stimulation signals (current) to the user’s cochlea. In particular, the stimulating assembly is configured to utilize the output control signals to generate electrical stimulation signals (e.g., current signals) via the stimulating contacts. In this way, the cochlear implant system 102 electrically stimulates the user’s auditory nerve cells, bypassing absent or defective hair cells that normally transduce acoustic vibrations into neural activity, in a manner that causes the user to perceive one or more components of the input audio signals (the received sound signals).

[0036] As detailed above, in the external hearing mode, the cochlear implant 112 receives processed sound signals from the sound processing unit 106. However, in the invisible hearing mode, the cochlear implant 112 is configured to capture and process sound signals for use in electrically stimulating the user’s auditory nerve cells. To this end, the cochlear implant includes implantable sound sensors that detect / capture input sound signals for generating the output control signals that stimulate the ear of a user.

[0037] It is to be appreciated that the above description of the so-called external hearing mode and the so-called invisible hearing mode are merely illustrative and that the cochlear implant system 102 could operate differently in different embodiments. For example, in one alternative implementation of the external hearing mode, the cochlear implant 112 could use signals captured by external input devices and implantable sound sensors in generating stimulation signals for delivery to the user.

[0038] FIG. 2A provides an overview of an anatomy of an ear 200 of a patient. In particular, FIG. 2A illustrates that the ear 200 includes an outer ear 201, a middle ear 205, and an inner ear 207. The outer ear 201 comprises an auricle 210 and an ear canal 202. An acoustic pressure or sound wave 203 is collected by auricle 210 and channeled into and through the ear canal 202. Disposed across the distal end of the ear canal 202 is a tympanic membrane 204, whichvibrates in response to the sound wave 203. This vibration is coupled to oval window or fenestra ovalis 212, which is adj acent to a round window 221 , through the bones of the middle ear 205. The bones of the middle ear 205 comprise the malleus 208, the incus 209, and the stapes 211, collectively referred to as the ossicles 206. The ossicles 206 are positioned in a middle ear cavity 213 and serve to filter and amplify the sound wave 203, causing the oval window 212 to articulate (vibrate) in response to the vibration of the tympanic membrane 204. This vibration of the oval window 212 sets up waves of fluid motion of perilymph within a cochlea 230. Such fluid motion, in turn, activates tiny hair cells (not shown) inside of cochlea 230. Activation of the hair cells causes appropriate nerve impulses to be generated and transferred through the spiral ganglion cells (not shown) and an auditory nerve 214 to the brain (also not shown), where the nerve impulses are perceived as sound.

[0039] The human skull is formed from a number of different bones that support various anatomical features. Illustrated in FIG. 2A is the temporal bone 215, which is situated at the side and base of the patient’s skull 224 (covered by a portion of the patient’s skin / muscle / fat, collectively referred to herein as tissue 219). The temporal bone 215 has a superior portion 218 and a mastoid portion 220. The superior portion 218 comprises the section of the temporal bone 215 that extends superior to the auricle 210. That is, the superior portion 218 is the section of the temporal bone 215 that forms the side surface of the skull. The mastoid portion 220, referred to herein simply as the mastoid 220, is positioned inferior to the superior portion 218. The mastoid 220 is the section of the temporal bone 215 that surrounds the middle ear 205.

[0040] Various nerves also extend through the head adjacent to different parts of the ear 200 of the patient. For example, a chorda tympani 232 extends adjacent to the malleus 208 and the tympanic membrane 204. The chorda tympani 232 branches from a facial nerve 234 and innervates a portion (e.g., an anterior portion) of the tongue of the patient. Meanwhile, the facial nerve 234 innervates various muscles of the face of the patient. Moreover, a vagus nerve 236 extends at least partially within the outer ear 201 and innervates other portions (e.g., an external muscle) of the tongue.

[0041] The chorda tympani 232, the facial nerve 234, and / or the vagus nerve 236 can become exposed during a surgical procedure that is performed at or adjacent to the ear 200 of the patient. By way of example, during a surgical procedure to implement a cochlear implant in the patient, a surgical incision can be made near any of the nerves 232, 234, 236. To avoid undesirably contacting (e.g., cutting) the nerves 232, 234, 236, it is desirable to determine the location of the nerves 232, 234, 236. As further discussed herein, the location of one or moreof the nerves 232, 234, 236 can be determined based on neuroactivity of various body structures of the patient, such as the tongue innervated by the chorda tympani 232. The neuroactivity can be monitored in conjunction with other techniques, such as visual observation performed by an optical sensor 238 (e.g., a camera) to establish biomarkers used to infer, reference, or otherwise determine the location of the nerves 232, 234, 236.

[0042] FIG. 2B provides an overview of an anatomy of the ear 200 of the patient with a cochlear implant 300. The cochlear implant 300 includes an external component 302 and an intemal / implantable component 304. The external component 302 is directly or indirectly attached to the body of the patient and includes an external coil 306 and a magnet (not shown in FIG. 2B) fixed relative to the external coil 306.

[0043] The external component 302 includes a sound processing unit 312 with a sound input device 308 (e.g., microphones and / or telecoils positioned by the auricle) configured to capture / receive input signals. The implantable component 304 includes an implant body (main module) 314, a lead region 316, and an intra-cochlear stimulating assembly 318, all configured to be implanted underthe skin / tissue (tissue) ofthe patient. The implant body 314 also includes an intemal / implantable coil 322 that is configured to couple to the external coil 306 of the cochlear implant 300 (e.g., via a magnet). As an example, the coils 306, 322 are typically wire antenna coils, each comprised of multiple turns of electrically insulated single-strand or multistrand platinum or gold wire.

[0044] The stimulating assembly 318 includes stimulating contacts (electrodes) 326 that collectively form a contact or electrode array 328 for delivery of electrical stimulation signals (current) to the patient’s cochlea 330. The stimulating assembly 318 extends through an opening in the patient’s cochlea (e.g., cochleostomy, the round window, etc.) to position the contact array 328 within the cochlea. To implant the implantable component 304 within the patient, a surgical procedure is performed adjacent to the chorda tympani 232, the facial nerve 234, and the vagus nerve 236. For example, the implantable component 304 is inserted to extend the lead region 316 of the implantable component 304 proximate to the nerves 232, 234, 236.

[0045] Thus, it is desirable to determine the location of the nerves 232, 234, 236 to, as an example, avoid contacting the nerves 232, 234, 236 via the lead region 316, avoid making an incision that moves or deforms the nerves 232, 234, 236 (e.g., for positioning the lead region 316), or otherwise avoid affecting functionality of the nerves 232, 234, 236 (e.g., to causehypogeusia or ageusia of the ipsilateral side of the tongue, cause loss in control of facial movements). As discussed, the chorda tympani 232 innervates a portion of the tongue of the patient. For this reason, the tongue can be used to help determine the location of the chorda tympani nerve 232, such as based on neuroactivity related to innervation between the chorda tympani 232 and the tongue. A surgical device 332 can be used to help monitor such neuroactivity (e.g., via an electrode or sensor positioned in the surgical device 332). For instance, the surgical device 332 is a device that is already in use during the surgical procedure, such as for opening a facial recess, and the surgical device 332 can provide an additional function to help monitor the position of the nerves 232, 234, 236.

[0046] FIG. 3 is a schematic diagram illustrating a tongue 400 of a patient showing innervations between various portions of the tongue 400 and nerves of the patient. In particular, the chorda tympani 232 (e.g., along with a lingual nerve) innervates an anterior portion 402 (e.g., the anterior two-thirds) of the tongue 400. For this reason, an electrode 404 (e.g., operating as a stimulation device or as a sensing device) is positioned in contact with the anterior portion 402, such as using a ballooning mechanism to maintain contact of the electrode 404 with the anterior portion 402. In some embodiments, the electrode 404 is configured to monitor neuroactivity at the anterior portion 402. In particular, because the chorda tympani 232 innervates the anterior portion 402, neuroactivity at the anterior portion 402 indicates functionality of the chorda tympani 232 (e.g., to enable muscles at the anterior portion 402 to activate). In such embodiments, electrical stimulation signals are provided or delivered (e.g., via the surgical device 332) to the patient at another body structure of the patient adjacent to the location of the chorda tympani 232 to cause the chorda tympani 232 to generate neuroactivity, which is then inducted along the chorda tympani 232 to the anterior portion 402. An amplitude of the neuroactivity at the anterior portion 402 increases as the electrical stimulation signals are provided more closely to the chorda tympani 232. Therefore, the location of the chorda tympani 232 can be determined based on the amplitude of the neuroactivity inducted at the anterior portion 402 (e.g., when exceeding a threshold value, which indicates that the electrical stimulation signals are being provided at the location of the chorda tympani 232).

[0047] In additional or alternative embodiments, the electrode 404 is used to provide electrical stimulation signals to the anterior portion 402 of the tongue 400. The provided electrical stimulation signals generate neuroactivity that is then inducted along the chorda tympani 232 and can be measured (e.g., via the surgical device 332) at a location at or adjacent to the chordatympani 232. Therefore, neuroactivity of a body region / structure of the patient adjacent to the chorda tympani 232 (e.g., a lateral portion of the skull 224 near the tympanic membrane 204 and the malleus 208) can be monitored to determine the location of the chorda tympani 232. For example, the location of the chorda tympani 232 can be determined based on an amplitude of the neuroactivity exceeding a threshold value. In this manner, an anatomical analysis process to locate the chorda tympani 232 is performed by providing electrical stimulation signals at a first body region / structure (e.g., one of the anterior portion 402 of the lateral portion of the skull 224) and monitoring resulting neuroactivity inducted at a second body region / structure (e.g., the other of the anterior portion 402 of the lateral portion of the skull 224). For example, the anatomical analysis process is performed before, during, or as a part of a surgical procedure in which a cochlear implant is being implemented in the patient.

[0048] FIG. 4 illustrates an example arrangement for performing a surgical procedure 450, such as for implanting a cochlear implant in a patient 452. During the surgical procedure 450, an intubation tube 454 (e.g., an endotracheal tube) is inserted into a mouth 456 of the patient 452 and extends into a trachea 458. The intubation tube 454 is used to provide air to the patient 452 and / or to administer a chemical substance (e.g., an anesthetic to inhibit contraction of certain muscles) into the patient 452 during the surgical procedure 450. While inserted into the patient 452, the intubation tube 454 is in contact with a portion (e.g., the anterior portion) of a tongue 460 innervated by the chorda tympani. For this reason, the electrode 404 is positioned on the intubation tube 454 to monitor neuroactivity at and / or provide electrical stimulation signals to the portion of the tongue 460 for determining the location of the chorda tympani.

[0049] In some embodiments, the intubation tube 454 includes a cuff 461 that can be used to facilitate contact with the tongue 460. For example, the cuff 461 can be inflated and / or moved to press the electrode 404 against the tongue 460, thereby enabling the electrode 404 to maintain contact with the tongue 460 for monitoring neuroactivity at and / or providing electrical stimulation signals to the tongue 460. Although the cuff 461 in the illustrated embodiment is shown as being at a distal end of the intubation tube 454, the cuff 461 can be positioned adjacent to the electrode 404 in an additional or alternative embodiment to help move the electrode 404 toward the tongue 460. As an example, a user can utilize a cuff inflating tube 463 to adjust the inflation and / or position of the cuff 461.

[0050] The surgical device 332 is positioned to monitor neuroactivity at and / or provide electrical stimulation signals at a lateral portion of a skull of the patient 452. For example,positioning the surgical device 332 at the lateral portion of the skull completes an electrical circuit formed between the surgical device 332, the chorda tympani, the tongue 460 innervated by the chorda tympani, and the electrode 404. Thus, the surgical device 332, the intubation tube 454, and the electrode 404 form a neuromonitoring system 462 in the illustrated embodiment for monitoring neuroactivity related to the chorda tympani.

[0051] FIG. 5 is a top view of a mouth 500 of a patient illustrating another arrangement for determining the location of the chorda tympani. In particular, a first electrode 404A can be attached to a tooth 502 configured to be in contact with the anterior portion of a tongue 504 innervated by the chorda tympani to enable the first electrode 404A to determine the neuroactivity of and / or provide electrical stimulation signals to the anterior portion of the tongue 504. For example, the first electrode 404A can be an electrically conductive material that is configured to be temporarily adhered (e.g., an electrically conductive sticker) to the tooth 502 at a position that maintains contact of the first electrode 404A with the anterior portion of the tongue 504 to form the neuromonitoring system 462 used for monitoring neuroactivity related to the chorda tympani. Additionally or alternatively, a second electrode 404B can be attached to a wearable component 506, such as a mouthguard, worn by the patient to position the second electrode 404B in contact with the anterior portion of the tongue 504. By way of example, the wearable component 506 captures and secures to one or more teeth of the mouth 500 to maintain contact of the second electrode 404B with the anterior portion of the tongue 504. In some embodiments, multiple electrodes 404 are positioned on the wearable component 506. Therefore, a single wearable component 506 can be used to position multiple electrodes 404 in contact with the anterior portion of the tongue 504. Additionally, in certain embodiments, an additional tongue depressing element 508 can be pressed against the tongue 504 to maintain the tongue 504 in a position that contacts the electrodes 404.

[0052] FIG. 6 is a rear view of a mouth 550 of a patient illustrating another arrangement for determining the location of the chorda tympani. The mouth 550 includes an orthodontic device 552 (e.g., a retainer) that extends along teeth 554 positioned adjacent to the anterior portion of a tongue (not shown) of the patient. The electrode 404, such as a lingual wire electrode, is disposed on (e.g., adhered to) the orthodontic device 552 to position the electrode 404 in contact with the anterior portion of the tongue to form the neuromonitoring system 462 for monitoring neuroactivity of the chorda tympani.

[0053] It should be noted that any other suitable device / component can be used to position the electrode 404 (or multiple electrodes) in contact with an anterior portion of a tongue. By wayof example, the electrode 404 can be secured directly onto the tongue, such as using a sleeve that encloses the anterior portion. In any case, the electrode 404 is used to monitor neuroactivity of the anterior portion and / or to provide electrical stimulation signals to the anterior portion as part of the neuromonitoring system 462 to help determine the location of the chorda tympani.

[0054] In certain embodiments, a map (e.g., a three-dimensional (3D) map) of neuroelectric fields can be generated to indicate the location of the chorda tympani. For example, neuroactivity for different portions of a body region are monitored, and attributes (e.g., a magnitude) of each neuroactivity is determined and compared to one another. The differences in attributes of neuroactivity at different portions of the body region indicate the location of the chorda tympani with respect to the body region.

[0055] FIG. 7 is an example 3D map 600 (e.g., a heat map) of neuroelectric fields indicating neuroactivity at different portions of a body region, such as a lateral portion of a skull, of a patient. The 3D map 600 includes multiple datapoints 602, each corresponding to a different portion of a body region. Each datapoint 602 also includes a value indicative of neuroactivity monitored at the portion of the body region corresponding to the datapoint 602, such as by providing stimulations to the anterior portion of the tongue and monitoring resulting neuroactivity that would be generated around the chorda tympani. The datapoints 602 of neuroactivity at different portions of the body region collectively form the neuroelectric fields to provide the 3D map 600. The 3D map 600 includes multiple layers 604 of datapoints 602, indicating that neuroactivity at multiple layers of the body region are monitored. By way of example, a first datapoint 602A indicates neuroactivity monitored at a first portion of a first layer (e.g., a relatively superficial layer) of the body region, a second datapoint 602B indicates neuroactivity monitored at a second portion of the first layer of the body region, and a third datapoint 602C indicates neuroactivity monitored at a portion of a second layer (e.g., a relatively deeper layer) of the body region. For instance, to ascertain datapoints 602 at multiple layers, neuroactivity at different portions of one of the layers (e.g., skin) is initially monitored while such a layer is exposed to provide datapoints 602 corresponding to the different portions of the layer. Next, the layer is moved (e.g., by making a surgical incision to remove a flap of skin) to expose a subsequent layer, and neuroactivity at different portions of the subsequent layer is monitored while the subsequent layer is exposed to provide datapoints 602 corresponding to the different portions of the subsequent layer. In this manner, neuroactivity at different layers is sequentially monitored to provide datapoints 602 of neuroelectric fieldslayer by layer. In some embodiments, neuroactivity at a certain layer can be extrapolated or interpolated (e.g., predicted) using a model based on trends of localized neuroactivity strength. For example, the neuroactivity indicating the location of the chorda tympani at a subsequent layer can be predicted before a surgical incision is made (e.g., while avoiding contact with the chorda tympani at the predicted location) to expose the subsequent layer. Upon exposure of the subsequent layer, neuroactivity at the subsequent layer can be monitored to determine or verify the location of the chorda tympani.

[0056] In certain embodiments, neuroactivity at each different portion of the body region (e.g., at the same layer) is individually monitored using the same device (e.g., the surgical device 332). For example, the device is positioned at a first portion of the body region, electrical stimulation signals are provided, and resulting neuroactivity is monitored by the device at the first portion of the body region. The device is then moved to a second portion of the body region, additional electrical stimulation signals are provided, and resulting neuroactivity is monitored by the device at the second portion of the body region. Thus, the device is moved each time neuroactivity at a different portion of the body region is monitored, and a different electrical stimulation signals are provided to monitor neuroactivity at each different portion of the body region. In additional or alternative embodiments, neuroactivity at multiple datapoints 602 (e.g., across the same layer) is concurrently monitored. As an example, a device (e.g., the surgical device 332 or multiple surgical devices 332) includes an array of electrodes and positioning the device on the body region arranges each electrode at a different portion of the body region at the same time. Consequently, providing electrical stimulation signals causes each electrode to simultaneously monitor resulting neuroactivity at a corresponding portion of the body region. In this manner, the datapoints 602 can be acquired more efficiently, such as without having to position the same device at each individual portion of a body region and provide separate electrical stimulation signals for each individual portion of a body region.

[0057] As discussed, the varying attributes of neuroactivity at different datapoints 602 indicates the positioning of each portion of the body region corresponding to the datapoints 602 with respect to the chorda tympani. By way of example, more elevated levels of amplitude of neuroactivity indicate greater proximity to the chorda tympani. In the illustrated embodiment, the neuroactivity at the first datapoint 602A indicates the first portion of the first layer of the body region is at or very near (e.g., within a low threshold distance of) the chorda tympani. For example, an amplitude of the neuroactivity at the first datapoint 602A is above a high threshold amplitude. The neuroactivity at the second datapoint 602B indicates the secondportion of the first layer of the body region is far from (e.g., above a high threshold distance of) the chorda tympani. For instance, an amplitude of the neuroactivity at the second datapoint 602B is below a low threshold amplitude. The neuroactivity at the third datapoint 602C indicates the portion of the second layer of the body region is at an intermediate distance from (e.g., between the low threshold distance and the high threshold distance) of the chorda tympani. As an example, an amplitude of the neuroactivity at the third datapoint 602C is between the high threshold amplitude and the low threshold amplitude. The datapoints 602 therefore can indicate the positioning of each portion of the body region relative to the chorda tympani, thereby providing greater indication of the location of the chorda tympani (e.g., a direction of extension of the chorda tympani). For example, the 3D map 600 indicates that a direction from the first portion of the first layer of the body region corresponding to the first datapoint 602A to the second portion of the second layer of the body region corresponding to the second datapoint 602B moves away from the chorda tympani.

[0058] The 3D map 600 can be used in conjunction with biomarkers to help determine the location of the chorda tympani. As an example, the first datapoint 602A is determined to be adjacent to a first body structure (e.g., tissue adjacent to the tympanic membrane). As another example, the first body portion of the first layer of the body region corresponding to the first datapoint 602A is marked as a reference point. In either case, the first body structure and / or the reference point can then be referenced as the location of the chorda tympani.

[0059] It should be noted that any other suitable nerve that innervates a portion (e.g., a muscle) of a tongues can be located using the techniques discussed herein. For example, FIG. 8 is a schematic diagram of a mouth 650 of the patient having the tongue 400 showing innervations between various portions of the tongue 400 and nerves of the patient, and an electrode 652 is positioned to monitor neuroactivity related to a different nerve than the chorda tympani, such as for determining the position of the different nerve. Specifically, the electrode 652 is positioned at or adjacent to a palatoglossus muscle 654 of the patient. The palatoglossus muscle 654 is innervated by a vagus nerve. Therefore, the electrode 652 can be used to monitor a location of the vagus nerve. As an example, electrical stimulation signals are provided to a body region (e.g., via the surgical device 332), and neuroactivity is monitored by the electrode 652 to determine whether the body region corresponds to the location of the vagus nerve based on, for instance, a magnitude of the neuroactivity (e.g., indicating the electrical stimulation signals are transmitted along the vagus nerve to generate the neuroactivity). As another example, electrical stimulation signals are provided to the palatoglossus muscle 654 via theelectrode 652, and resulting neuroactivity is monitored at a body region (e.g., via the surgical device 332) to determine whether the body region corresponds to the location of the vagus nerve. The electrode 652 can be disposed at or adjacent to the palatoglossus muscle 654 using any suitable technique (e.g., positioning the electrode 652 on the intubation tube 454) discussed above to enable the electrode 652 to readily monitor neuroactivity for determining the location of the vagus nerve (e.g., to avoid contacting the vagus nerve during the surgical procedure) and / or for verifying that a vagus nerve stimulation device (e.g., an auricular vagus nerve stimulation device) has been implemented properly.

[0060] Each of FIGs. 9-12 illustrates a respective method related to monitoring neuroactivity for performing a surgical procedure. It should be noted that operations of the methods can be performed by the same device, such as a computing device, or by different devices, such as different computing devices. Additionally, operations of any of the methods can be performed differently than depicted. For example, a depicted operation can be performed differently, an additional operation can be performed, operations can be performed in a different order, and / or an operation may not be performed. Moreover, the methods can be performed in any suitable manner with respect to one another, such as concurrently and / or sequentially (e.g., in response to one another).

[0061] FIG. 9 is a flowchart of a method 700 for performing a surgical procedure based on monitored neuroactivity. At block 702, neuroactivity of a body region of a patient is monitored. At block 704, a location of a chorda tympani is determined based on the neuroactivity. The chorda tympani is located at a middle ear of the patient and innervates a portion of a tongue. Therefore, in some embodiments, electrical stimulation signals are delivered to a first body region, such as to one of the tongue or a lateral portion of a skull, and resulting neuroactivity is monitored at a second body region, such as the other of the tongue or the lateral portion of the skull. An attribute, such as an amplitude, of the monitored neuroactivity indicates the proximity of the lateral portion of the skull being analyzed with respect to the chorda tympani. For example, the amplitude exceeding a threshold amplitude indicates the chorda tympani nerve is located at or very near (e.g., within a threshold distance of) the lateral portion of the skull being analyzed.

[0062] At block 706, a surgical procedure is performed based on the location of the chorda tympani. For instance, the surgical procedure includes modifying (e.g., making an incision into, moving, removing) a body structure or planning to modify (e.g., programming a robotic surgical device to make an incision into, move, remove) the body structure of the patient, andthe chorda tympani is to be avoided during modification of the body structure. By avoiding contact with the chorda tympani, functionality of the chorda tympani is maintained while the body structure is modified. By way of example, the surgical procedure includes implanting a cochlear implant or other medical device within the patient.

[0063] In certain embodiments, the location of the chorda tympani is determined via the monitored neuroactivity as a part of the surgical procedure or in parallel with the surgical procedure. That is, for example, as the body structure is being modified or planned to be modified, the location of the chorda tympani is tracked. In additional or alternative embodiments, the location of the chorda tympani is initially determined (e.g., and marked, such as using a biomarker or other visually observable indication), and the surgical procedure is performed based on the initial determination (e.g., to avoid the biomarker or visually observable indication). In either case, functionality of the chorda tympani can be preserved using the monitored neuroactivity.

[0064] As discussed herein, the chorda tympani branches from the facial nerve. Therefore, the location of the chorda tympani is adjacent to the location of the facial nerve. As such, it is desirable to distinguish / differentiate the location of the chorda tympani nerve from the location of the facial nerve. To this end, electrical stimulation signals can be provided in different manners between a body region corresponding to the chorda tympani and a body region corresponding to the facial nerve for generating neuroactivity having different attributes. Thus, neuroactivity corresponding to the chorda tympani can be distinguished from neuroactivity corresponding to the facial nerve based on their different attributes. In some implementations, distinguishing the location of the chorda tympani from the location of the facial nerve can help accurately identify the location of the facial nerve. For instance, during the surgical procedure, techniques for monitoring the location of the facial nerve alone using muscle activity can be inhibited because of anesthetics administered to the patient to reduce such muscle activity. Therefore, using neuroactivity to distinguish between the location of the chorda tympani and the location of the facial nerve can help identify the location of the facial nerve even when muscle activity effectuated by the facial nerve is suppressed.

[0065] FIG. 10 is a flowchart of a method 750 for distinguishing a first location of a chorda tympani from a second location of a facial nerve based on neuroactivity, such as that generated by providing electrical stimulation signals to different body regions / structures (e.g., at the tongue using an electrode on an intubation tube, at a facial muscle using a transcutaneous electrode) corresponding to the chorda tympani or the facial nerve. At block 752, a firstatribute of a first portion of neuroactivity and a second atribute of a second portion of the neuroactivity are identified. By way of example, neuroactivity resulting from electrical stimulation signals are received as signals that produce a graph (e.g., with signals of neuron firing amplitudes or rates over time) of a particularly shaped curve, and two distinct curves respectively corresponding to the nerves are identified. The atributes are then identified from the distinct curves.

[0066] At block 754, the first atribute is determined to correspond to the chorda tympani. At block 756, the second atribute is determined to correspond to the facial nerve. As a result, the first location of the chorda tympani is determined via the first portion of the neuroactivity having the first atribute (e.g., based on an amplitude of the first portion of the neuroactivity being above a threshold amplitude to indicate the chorda tympani is at a body region at where the first portion of the neuroactivity is inducted), and the second location of the facial nerve is determined via the second portion of the neuroactivity having the second atribute (e.g., based on an amplitude of the second portion of the neuroactivity being above a threshold amplitude to indicate the facial nerve is at a body region at where the second portion of the neuroactivity is inducted).

[0067] In some embodiments, the atributes include a signal timing. For example, there is a time difference between providing electrical stimulation signals to generate the first portion of the neuroactivity corresponding to the chorda tympani and providing electrical stimulation signals to generate the second portion of the neuroactivity corresponding to the facial nerve. As such, there is also a time difference between receiving signals of the resulting first portion of the neuroactivity corresponding to the chorda tympani and receiving signals of the resulting second portion of the neuroactivity corresponding to the facial nerve. The time difference between the received signals indicates whether a received signal corresponds to chorda tympani neuroactivity or to facial nerve neuroactivity. In a specific instance, first electrical stimulation signals are initially provided at a first provision time to generate the first portion of the neuroactivity corresponding to the chorda tympani and second electrical stimulation signals are subsequently provided at a second provision time to generate the second portion of the neuroactivity corresponding to the facial nerve. Thus, the first portion of the neuroactivity corresponding to the chorda tympani is received at a first receiving time before the second portion of the neuroactivity corresponding to the facial nerve is received at a second receiving time. As such, the respective times at which signals corresponding to different neuroactivity (e.g., different neuroactivity curves) are received can be used as the atributes to distinguishthe location of the chorda tympani and the location of the facial nerve from one another, such as based on a difference between the first receiving time and the second receiving time corresponding to a difference between the first provision time and the second provision time.

[0068] In additional or alternative embodiments, the attributes include a signal amplitude (e.g., a peak amplitude). For instance, electrical stimulation signals corresponding to the chorda tympani and corresponding to the facial nerve are provided at different amplitudes. Therefore, the neuroactivities corresponding to the chorda tympani and corresponding to the facial nerve having different amplitudes (e.g., different maximum possible amplitudes). As an example, first electrical stimulation signals provided to generate the first portion of the neuroactivity corresponding to the chorda tympani have a relatively greater peak amplitude and second electrical stimulation signals provided to generate the second portion of the neuroactivity corresponding to the facial nerve have a relatively lower peak amplitude. Therefore, the resulting first portion of the neuroactivity corresponding to the chorda tympani has a relatively greater maximum possible amplitude caused by the relatively greater peak amplitude of the first electrical stimulation signals, whereas the resulting second portion of the neuroactivity corresponding to the facial nerve has a relatively lower maximum possible amplitude caused by the relatively lower peak amplitude of the second electrical stimulation signals. For this reason, the respective maximum possible amplitudes of the neuroactivity can be used as the attributes to distinguish the location of the chorda tympani and the location of the facial nerve from one another. In further embodiments, the attributes can include any other suitable parameter, such as a signal or pulse frequency, that changes based on the electrical stimulation signals being provided for distinguishing the location of the chorda tympani and the location of the facial nerve from one another.

[0069] The method 750 can be performed in conjunction with biomarkers to help track the chorda tympani and the facial nerve. By way of example, distinguishing the location of the chorda tympani and the location of the facial nerve from one another can include determining a first body region corresponding to the chorda tympani and a second body region corresponding to the facial nerve. The first body region and the second body region can then be identified (e.g., via artificial intelligence based image recognition of biomarkers corresponding to the body regions) using live camera feedback, body imaging (e.g., a computing tomography scan, an x-ray scan), or other available image data of the patient. Upon identifying the body regions, images of the chorda tympani and the facial nerve are overlaid and presented (e.g., through surgical optics). For instance, the live camera feedback is modifiedto indicate the location of the chorda tympani and the facial nerve, thereby communicating in real-time to a user where the nerves are located (e.g., whether the nerves are about to be exposed).

[0070] FIG. 11 is a flowchart of a method 800 for generating a three-dimensional (3D) map of neuroelectric fields indicating a location of a chorda tympani. At block 802, first neuroactivities at a first plurality of positions on a patient at a first layer (e.g., of a lateral portion of a skull) are determined. As a result, a first subset of datapoints, each datapoint indicating neuroactivity of a position of the first plurality of positions on the first layer, is received. At block 804, second neuroactivities at a second plurality of positions on the patient at a second layer (e.g., of the lateral portion of the skull) are determined. Thus, a second subset of datapoints, each datapoint indicating neuroactivity of a position of the second plurality of positions on the second layer, is received. In one example, the first layer (e.g., a transcutaneous layer) is more superficial than the second layer (e.g., a subcutaneous layer).

[0071] In certain embodiments, the first neuroactivities and / or the second neuroactivities are determined by using the same electrode arranged at each position of the first plurality of positions and of the second plurality of positions. That is, the electrode is moved across the first layer at the first plurality of positions and across the second layer at the second plurality of positions to determine the neuroactivities. In additional or alternative embodiments, an electrode array is used to collectively determine the first neuroactivities at the first plurality of positions and the electrode array is also used to collectively determine the second neuroactivities at the second plurality of positions. By way of example, the electrode array includes multiple electrodes that are simultaneously arranged at each respective position of the first plurality of positions to concurrently measure first neuroactivities at the first plurality of positions, and the electrodes are simultaneously arranged at each respective position of the second plurality of positions to concurrently measure second neuroactivities at the second plurality of positions. In either case, neuroactivity at each different position is determined. In certain embodiments, neuroactivities at one of the layers is determined using a model (e.g., an artificial intelligence model, a statistical model) based on localized neuroelectric field strength trends, such as without having to measure the neuroactivities using at least one electrode.

[0072] At block 806, a 3D map of neuroelectric fields is generated based on the neuroactivities. That is, the 3D map includes the first subset of datapoints at the first layer and the second subset of datapoints at the second layer. The positioning of the datapoints across each layer and also between layers indicates neuroactivity in three dimensions, such as at different depths withinthe patient. For instance, the first layer is a skin layer and the second layer is a tissue layer such that the 3D map extends into (e.g., transcutaneously, subcutaneously) a body portion of the patient. The 3D map can provide valuable information regarding a location of the chorda tympani, such as a direction (e.g., a 3D vector) in which the chorda tympani is located. Accordingly, contact with the chorda tympani can be more readily avoided.

[0073] FIG. 12 is a flowchart of one specific example surgical procedure (e.g., incorporating a particular anatomical analysis process) in which the location of a chorda tympani of a patient is determined and utilized. At block 852, the surgical procedure initiates for the patient. For example, the surgical procedure initiates after an intubation tube is inserted through a mouth of the patient and into contact with a tongue of the patient, and the surgical procedure includes modifying or planning to modify a body structure of the patient (e.g., for implanting a medical device within the patient). At block 854, electrical stimulation signals are delivered to areas of the tongue of the patient via an electrode positioned on the intubation tube that is placed in contact with the areas (e.g., an anterior portion) of the tongue innervated by the chorda tympani. At block 856, electroneural activity or any other suitable neuroactivity generated via the provided electrical stimulation signals are monitored using a surgical device, such as a conductive surgical drill / probe. The surgical device is used to help modify the body structure of the patient and is therefore placed in contact with the patient for receiving the electroneural activity generated via the provided electrical stimulation. By using the same surgical device for modifying the body structure of the patient and for monitoring electroneural activity, an ease of performing the surgical procedure can be facilitated (e.g., in comparison with having to use separate, dedicated devices for monitoring electroneural activity and for providing electrical stimulation).

[0074] At block 858, electroneural activity corresponding to the chorda tympani is delineated apart from electromonitoring of a facial nerve using temporal / phase shifted monitoring. For example, electrical stimulation signals that generates the electroneural activity corresponding to the chorda tympani is provided before electrical stimulation signals that generates electroneural activity corresponding to the facial nerve. As a result, inducted neuroactivity signals 860 are received in which signals corresponding to neuroactivity of the chorda tympani are received before signals corresponding to neuroactivity of the facial nerve are received. Therefore, the timing of the receipt of the neuroactivity signals 860 corresponding to the timing of the provision of electrical stimulation signals helps distinguish the chorda tympani electroneural activity from the facial nerve electroneural activity. Blocks 858 and 856 can berepeated to determine electroneural activity at different positions on the patient (e.g., across a layer, across multiple layers).

[0075] At block 862, electroneural mapping, such as for a handheld or other manual surgical process and / or for a robotically driven surgical process, is performed using fiducial marking for referencing the location of the chorda tympani and / or of the facial nerve. In particular, at block 864, maps of neuroelectric fields at each subcutaneous level or layer are generated. That is, for each level, electroneural activity is monitored at different positions by using the same electrode and / or an electrode array with an electrode positioning matrix, such as by using a robotic surgical device / robotic assembly that programs the positioning of the electrode(s) and / or using position and motion tracking (e.g., with an inertial measurement unit) to provide desirable and consistent positioning of the electrode(s) at each level. The electroneural activity (e.g., an amplitude of generated neuroactivity signals) indicates the location of the chorda tympani and the location of the facial nerve extending across each level. In certain embodiments, a map of neuroelectric fields at the transcutaneous level can also be provided at a transcutaneous level with an electrode positioning matrix at different positions on skin of the patient. Blocks 862 and 864 can be repeated to generate a 3D map 866 that includes slices of levels at different depths, each slice indicating the location of the chorda tympani and the location of the facial nerve extending along and through each level of a plurality of levels to provide a 3D topography of the body region indicating the location of the chorda tympani and the location of the facial nerve.

[0076] At block 868, a feedback process is initiated to help proceed with the surgical procedure to modify the body structure of the patient in view of the location of the chorda tympani and / or the location of the facial nerve, such as to avoid contacting the chorda tympani and / or the facial nerve. As an example, movement of a surgeon (e.g., of a surgical device used by the surgeon) is monitored, and an alert is provided to the surgeon in response to a determination that the surgeon is within a threshold distance of the chorda tympani and / or of the facial nerve to prompt the surgeon to limit movement closer toward the chorda tympani and / or toward the facial nerve. As another example, a robotic surgical device performing the surgery is programmed to modify the body structure (e.g., to provide surgical incisions) based on the location of the chorda tympani nerve and / or of the facial nerve, such as at each slice of the 3D topography.

[0077] Any operations of the method 850 can be repeated during the surgical procedure. As an example, the location of the chorda tympani and / or of the facial nerve can be updated after a duration of time has elapsed since initiation of the surgical procedure (e.g., at block 852) toaccurately track the location of the chorda tympani and / or of the facial nerve. As another example, the location of the chorda tympani and / or of the facial nerve can be repeatedly determined to verify the accuracy of the determined locations. In either case, repeating the operations of the method 850 can help perform the surgical procedure while avoiding contact with the chorda tympani and / or with the facial nerve.

[0078] FIG. 13 is a block diagram illustrating one example arrangement for a computing device 1000 configured to perform one or more operations in accordance with certain embodiments presented herein. As shown in FIG. 13, the computing device 1000 includes at least one processing unit 183 and amemory 184. The processing unit 183 includes one ormore hardware or software processors (e.g., Central Processing Units) that can obtain and execute instructions. The processing unit 183 can communicate with and control the performance of other components of the computing device 1000. The memory 184 is one or more software or hardware -based computer-readable storage media operable to store information accessible by the processing unit 183. The memory 184 can store, among other things, instructions executable by the processing unit 183 to implement applications or cause performance of operations described herein, as well as other data. The memory 184 can be volatile memory (e.g., RAM), non-volatile memory (e.g., ROM), or combinations thereof. The memory 184 can include transitory memory or non-transitory memory. The memory 184 can also include one or more removable or non-removable storage devices. In examples, the memory 184 can include RAM, ROM) EEPROM (Electronically-Erasable Programmable Read-Only Memory), flash memory, optical disc storage, magnetic storage, solid state storage, or any other memory media usable to store information for later access. By way of example, and not limitation, the memory 184 can include wired media, such as a wired network or direct-wired connection, and wireless media, such as acoustic, RF, infrared, other wireless media, or combinations thereof. In certain embodiments, the memory 184 comprises logic 195 that, when executed, enables the processing unit 183 to perform aspects of the techniques presented.

[0079] In the illustrated example of FIG. 13, the computing device 1000 further includes a network adapter 186, one or more input devices 187, and one or more output devices 188. The computing device 1000 can include other components, such as a system bus, component interfaces, a graphics system, a power source (e.g., a battery), among other components. The network adapter 186 is a component of the computing device 1000 that provides network access (e.g., access to at least one network 189). The network adapter 186 can provide wired or wireless network access and can support one or more of a variety of communicationtechnologies and protocols, such as Ethernet, cellular, Bluetooth, near-field communication, and RF, among others. The network adapter 186 can include one or more antennas and associated components configured for wireless communication according to one or more wireless communication technologies and protocols. The one or more input devices 187 are devices over which the computing device 1000 receives input from a user. The one or more input devices 187 can include physically-actuatable user-interface elements (e.g., buttons, switches, or dials), a keypad, keyboard, mouse, touchscreen, and voice input devices, among other input devices that can accept user input. The one or more output devices 188 are devices by which the computing device 1000 is able to provide output to a user. The output devices 188 can include a display 190 (e.g., a liquid crystal display (LCD)) and one or more speakers 191, among other output devices for presentation of visual or audible information to the patient, a clinician, an audiologist, or other user.

[0080] It is to be appreciated that the arrangement for the computing device 1000 shown in FIG. 13 is merely illustrative and that aspects of the techniques presented herein can be implemented at a number of different types of systems / devices including any combination of hardware, software, and / or firmware configured to perform the functions described herein. For example, the computing device 1000 can be a personal computer (e.g., a desktop or laptop computer), a hand-held device (e.g., a tablet computer), a mobile device (e.g., a smartphone), a surgical system, and / or any other electronic device having the capabilities to perform the associated operations described elsewhere herein.

[0081] As should be appreciated, while particular uses of the technology have been illustrated and discussed above, the disclosed technology can be used with a variety of devices in accordance with many examples of the technology. The above discussion is not meant to suggest that the disclosed technology is only suitable for implementation within systems akin to that illustrated in the figures. In general, additional configurations can be used to practice the processes and systems herein and / or some aspects described can be excluded without departing from the processes and systems disclosed herein.

[0082] This disclosure described some aspects of the present technology with reference to the accompanying drawings, in which only some of the possible aspects were shown. Other aspects can, however, be embodied in many different forms and should not be construed as limited to the aspects set forth herein. Rather, these aspects were provided so that this disclosure was thorough and complete and fully conveyed the scope of the possible aspects to those skilled in the art.

[0083] As should be appreciated, the various aspects (e.g., portions, components, etc.) described with respect to the figures herein are not intended to limit the systems and processes to the particular aspects described. Accordingly, additional configurations can be used to practice the methods and systems herein and / or some aspects described can be excluded without departing from the methods and systems disclosed herein.

[0084] According to certain aspects, systems and non-transitory computer readable storage media are provided. The systems are configured with hardware configured to execute operations analogous to the methods of the present disclosure. The one or more non-transitory computer readable storage media comprise instructions that, when executed by one or more processors, cause the one or more processors to execute operations analogous to the methods of the present disclosure.

[0085] Similarly, where steps of a process are disclosed, those steps are described for purposes of illustrating the present methods and systems and are not intended to limit the disclosure to a particular sequence of steps. For example, the steps can be performed in differing order, two or more steps can be performed concurrently, additional steps can be performed, and disclosed steps can be excluded without departing from the present disclosure. Further, the disclosed processes can be repeated.

[0086] Although specific aspects were described herein, the scope of the technology is not limited to those specific aspects. One skilled in the art will recognize other aspects or improvements that are within the scope of the present technology. Therefore, the specific structure, acts, or media are disclosed only as illustrative aspects. The scope of the technology is defined by the following claims and any equivalents therein.

[0087] It is also to be appreciated that the embodiments presented herein are not mutually exclusive and that the various embodiments may be combined with another in any of a number of different manners.

Claims

CLAIMSWhat is claimed is:

1. A method, comprising: monitoring neuroactivity of a patient of a medical device; determining a location of a chorda tympani of the patient based on the neuroactivity of the patient; and using the location of the chorda tympani to perform a surgical procedure associated with the patient.

2. The method of claim 1, wherein using the location of the chorda tympani to perform the surgical procedure associated with the patient comprises: making an incision in the patient to avoid the chorda tympani based on the location of the chorda tympani.

3. The method of claim 1, wherein using the location of the chorda tympani to perform the surgical procedure associated with the patient comprises: programming a robotic surgical device to make an incision in the patient to avoid the chorda tympani based on the location of the chorda tympani.

4. The method of claim 1, 2, or 3, wherein monitoring the neuroactivity of the patient of the medical device comprises: delivering electrical stimulation signals to a first body region of the patient; and monitoring neuroactivity inducted at a second body region by the electrical stimulation signals delivered to the first body region.

5. The method of claim 4, wherein the first body region comprises an anterior portion of a tongue of the patient, and wherein the second body region comprises a lateral portion of a skull of the patient.

6. The method of claim 5, wherein delivering the electrical stimulation signals to the first body region of the patient comprises: delivering the electrical stimulation signals via at least one electrode positioned in a mouth of the patient in contact with the anterior portion of the tongue of the patient.

7. The method of claim 6. wherein delivering the electrical stimulation signals via the at least one electrode positioned in the mouth of the patient comprises: delivering the electrical stimulation signals via the at least one electrode positioned on an endotracheal tube placed in contact with the anterior portion of the tongue of the patient.

8. The method of claim 7, further comprising providing an anesthetic via the endotracheal tube.

9. The method of claim 6, wherein delivering the electrical stimulation signals via the at least one electrode positioned in the mouth of the patient comprises: delivering the electrical stimulation signals via the at least one electrode coupled to at least one tooth of the patient and in contact with the anterior portion of the tongue of the patient.

10. The method of claim 4, wherein the first body region comprises a lateral portion of a skull of the patient, and wherein the second body region comprises an anterior portion of a tongue of the patient.

11. The method of claim 1, 2, or 3, further comprising: generating, based on the neuroactivity, a map of neuroelectric fields at a lateral portion of a skull of the patient.

12. The method of claim 11, wherein generating the map of neuroelectric fields at the lateral portion of the skull of the patient comprises: generating a three-dimensional (3D) map of neuroelectric fields at the lateral portion of the skull of the patient.

13. The method of claim 12, wherein monitoring the neuroactivity of the patient of the medical device comprises: positioning an electrode at a plurality of positions; and determining neuroactivity at each position of the plurality of positions via the electrode to generate the 3D map of neuroelectric fields indicating the neuroactivity at each position.

14. The method of claim 12, further comprising: positioning an array of electrodes on the lateral portion of the skull of the patient, each electrode of the array of electrodes being arranged at a different position of a plurality of positions; and determining neuroactivity at each different position of the plurality of positions via the array of electrodes to generate the 3D map of neuroelectric fields indicating the neuroactivity at each different position.

15. The method of claim 12, wherein monitoring the neuroactivity of the patient of the medical device comprises: determining the neuroactivity as first neuroactivity at a first layer of the lateral portion of the skull; and determining the neuroactivity as second neuroactivity at a second layer of the lateral portion of the skull, the second layer being at a different depth than that of the first layer such that the 3D map of neuroelectric fields extends through the lateral portion of the skull.

16. The method of claim 15, wherein the first layer comprises a superficial layer at a skin of the patient, the second layer comprises a subcutaneous layer of the patient, and the method further comprises: removing a flap of the skin of the patient to expose the subcutaneous layer; and determining the second neuroactivity at the subcutaneous layer after removing the flap of the skin.

17. The method of claim 1, 2, or 3, further comprising differentiating a first portion of the neuroactivity corresponding to the chorda tympani from a second portion of the neuroactivity corresponding to a facial nerve of the patient.

18. The method of claim 17, wherein differentiating the first portion of the neuroactivity from the second portion of the neuroactivity comprises: identifying a first attribute of the first portion of the neuroactivity; determining the first attribute of the first portion of the neuroactivity corresponds to the chorda tympani; identifying a second attribute of the second portion of the neuroactivity; anddetermining the second attribute of the second portion of the neuroactivity corresponds to the facial nerve.

19. The method of claim 18, wherein the first attribute and the second attribute comprise at least one of: a signal timing, a signal amplitude, or a signal frequency.

20. A system, comprising: at least one electrode configured to monitor neuroactivity of a patient of a medical device; a processor; and a memory comprising instructions executable by the processor to cause the processor to: receive signals from the at least one electrode, the signals indicating the neuroactivity of the patient monitored by the at least one electrode; and determine a location of a chorda tympani of the patient based on the neuroactivity.

21. The system of claim 20, further comprising a stimulation device configured to provide an electrical stimulation signals to a body structure of the patient, wherein the at least one electrode is configured to monitor the neuroactivity in response to the electrical stimulation signals provided to the body structure.

22. The system of claim 20, comprising an intubation tube configured to extend into a mouth of the patient, wherein the at least one electrode is secured to the intubation tube in contact with an anterior portion of a tongue of the patient.

23. The system of claim 20, wherein the at least one electrode is configured to couple to a tooth of the patient in contact with an anterior portion of a tongue of the patient.

24. The system of claim 20, wherein the at least one electrode is coupled to a surgical device configured to be positioned at a lateral portion of a skull of the patient.

25. The system of claim 20, 21, 22, 23, or 24, wherein the instructions are executable by the processor to cause the processor to:generate a three-dimensional (3D) map of neuroelectric fields at a plurality of positions of the patient based on the neuroactivity; and determine the location of the chorda tympani based on the 3D map.

26. The system of claim 20, 21, 22, 23, or 24, wherein the at least one electrode is of a plurality of electrodes arranged at a different position of a plurality of positions, and the instructions are executable by the processor to cause the processor to: receive signals from each electrode of the plurality of electrodes, the signals indicating the neuroactivity of the patient monitored by each electrode of the plurality of electrodes arranged at the different position of the plurality of positions; generate a three-dimensional (3D) map of neuroelectric fields at the plurality of positions of the patient based on the neuroactivity; and determine the location of the chorda tympani based on the 3D map.

27. The system of claim 20, 21, 22, 23, or 24, wherein the instructions are executable by the processor to cause the processor to: differentiate the location of the chorda tympani from a location of a facial nerve of the patient.

28. The system of claim 27, wherein the instructions are executable by the processor to cause the processor to differentiate the location of the chorda tympani from the location of the facial nerve by: identifying a first attribute of the neuroactivity; distinguishing the first attribute of the neuroactivity from a second attribute of additional neuroactivity corresponding to the facial nerve; and determining a location of the facial nerve based on the additional neuroactivity.

29. A method, comprising: providing electrical stimulation signals to a patient; receiving neuroactivity resulting from the electrical stimulation signals; and. determining a location of a chorda tympani of the patient based on the neuroactivity.

30. The method of claim 29, further comprising:performing a surgical procedure associated with the patient based on the location of the chorda tympani.

31. The method of claim 29 or 30, further comprising: differentiating a first portion of the neuroactivity corresponding to the chorda tympani from a second portion of the neuroactivity corresponding to a facial nerve of the patient.

32. The method of claim 31, further comprising: providing the electrical stimulation signals to the patient as a first electrical stimulation signals to a first body structure corresponding to the chorda tympani; receiving the first portion of the neuroactivity in response to providing the first electrical stimulation signals to the first body structure; providing a second electrical stimulation signals to a second body structure corresponding to the facial nerve; and receiving the second portion of the neuroactivity in response to providing the second electrical stimulation signals to the second body structure.

33. The method of claim 32, wherein the first electrical stimulation signals are provided to the first body structure at a first provision time such that the first portion of the neuroactivity is received at a first receiving time, and the second electrical stimulation signals are provided to the second body structure at a second provision time, different from the first provision time, such that the second portion of the neuroactivity is received at a second receiving time, different from the first receiving time.

34. The method of claim 33, wherein the first portion of the neuroactivity is differentiated from the second portion of the neuroactivity based on a difference between the first receiving time of the first portion of the neuroactivity and the second receiving time of the second portion of the neuroactivity.

35. The method of claim 30, wherein performing the surgical procedure comprises: implanting an implantable device in the patient.

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