Endoscopic device and imaging method for intraoperative imaging of the cochlea and image-guided cochlear implant placement

Abstract

1. An endoscope system comprising: an optical imaging probe having a proximal end and a distal end, the optical imaging probe including a fiber connector, an optical probe position module, an optical fiber, and an optical probe head, the optical probe head configured to emit a focused light beam, and the optical probe position module controlling the axial position of the optical probe head; and a sheath having a proximal end and a distal end, the sheath including a flexible sheath, a tube adapter, and a stylet tube, the flexible sheath, the tube adapter, and the stylet tube forming a continuous channel and configured to surround at least a portion of the optical fiber.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No. 63 / 481,625, filed January 26, 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] STATEMENT REGARDING FEDERAL SUPPORT OF RESEARCH OR DEVELOPMENT This invention was made with government support under Contract No. W81XWH-20-1-0855 awarded by the US Army Medical Research Acquisition Activity. The government has certain rights in this invention. [Background technology]

[0003] Sensorineural hearing loss (SNHL) affects many patients worldwide. Currently, the most successful treatment for SNHL is cochlear implantation. The cochlear implant procedure carries the risk of damaging the delicate structures of the cochlea, potentially resulting in the patient losing any remaining hearing. The electrode array is the component of the cochlear implant that is inserted into the cochlea. Insertion of the electrode array is guided largely by the surgeon's experience, with little or no intraoperative imaging guidance. Furthermore, because there are currently no in vivo imaging techniques for diagnosing intracochlear pathology, it is difficult or impossible to correlate the results of the cochlear implant with the patient's cochlear pathology, making the prognosis unclear.

[0004] Manufacturers have improved their designs and introduced different approaches, including various insertion aids to reduce the risk of cochlear tissue damage. One example is the "advance off-stylet" technique, a cochlear implant electrode array insertion technique that involves pre-inserting a rigid metal stylet into a central channel in the body of the electrode array, improving assembly rigidity, allowing for easier insertion, and reducing insertion trauma. However, many challenges remain. Summary of the Invention

[0005] Methods and systems, including endoscopy systems, for intraoperative imaging of the cochlea and image-guided cochlear implant insertion are disclosed. In various embodiments, these methods and systems may include one or more of the following:

[0006] An endoscopic system is disclosed. The endoscopic device includes an optical imaging probe and a sheath. The optical imaging probe has a proximal end and a distal end. Similarly, the sheath also has a proximal end and a distal end. In some embodiments, the optical imaging probe includes a fiber connector, an optical probe position module, an optical fiber, and an optical probe head. The optical imaging probe is configured so that the optical probe head can irradiate a sample with a focused light beam. The optical probe position module controls the position of the optical imaging probe. The sheath includes a flexible sheath, a tube adapter, and a stylet tube. The flexible sheath, the tube adapter, and the stylet tube are configured to form a continuous channel and surround at least a portion of the optical fiber.

[0007] A method for imaging the human cochlea in vivo is also disclosed. The method includes providing an endoscopic device. The endoscope includes an optical imaging probe and a sheath. The endoscope is configured such that an optical probe head at the distal end of the optical imaging probe extends beyond the distal end of the sheath. The method further includes positioning the endoscopic device in a stylet channel of the electrode array and advancing the endoscope within the electrode array. The method further includes inserting the electrode array-endoscopic device into the cochlea. Inserting may further include illuminating the proximal end of the optical imaging probe and illuminating the light from the distal end of the optical probe head toward the interior of the cochlea to focus the light on cochlear tissue. Inserting the endoscopic device may also include rotating the optical imaging probe to focus the light on different portions of the cochlear tissue. Inserting the endoscope may also include receiving reflected light from the cochlea with the optical imaging probe and transmitting the reflected light toward the proximal end of the optical imaging probe. Inserting may further include generating a two-dimensional image of a portion of the cochlea surrounding the optical imaging probe based on reflected light received from the optical imaging probe. Essentially, inserting may include imaging the interior of the cochlea during insertion. The method may further include displaying a two-dimensional image of a portion of the cochlea surrounding the optical imaging probe. The two-dimensional image may indicate the distance between the outer surface of the optical imaging probe and the cochlear wall. The two-dimensional image may provide cross-sectional structural and functional information of tissues, including sensory cells, within the cochlea. The two-dimensional image may be used to provide diagnostic information for sensorineural hearing loss (SNHL) and correlate with the outcome of cochlear implantation.

[0008] A method for implanting a cochlear implant using intraoperative image guidance is also disclosed. The method includes providing an endoscopic device. The endoscope includes an optical imaging probe and a sheath. The endoscope is configured such that an optical probe head at the distal end of the optical imaging probe extends beyond the distal end of the sheath. The method further includes positioning the endoscopic device in a stylet channel of the electrode array and advancing the endoscope within the electrode array. The method further includes inserting the electrode array-endoscopic device into the cochlea. Inserting may further include illuminating the proximal end of the optical imaging probe and illuminating the light from the distal end of the optical probe head toward the interior of the cochlea to focus the light on cochlear tissue. Inserting the endoscopic device may also include rotating the optical imaging probe to focus the light on different portions of the cochlear tissue. Inserting the endoscope may also include receiving reflected light from the cochlea with the optical imaging probe and transmitting the reflected light toward the proximal end of the optical imaging probe. Inserting may further include generating a two-dimensional image of a portion of the cochlea surrounding the optical imaging probe based on reflected light received from the optical imaging probe. Essentially, inserting may include imaging the interior of the cochlea during insertion. Inserting the electrode array-endoscopic device into the cochlea may also include determining an insertion depth based on the generated two-dimensional image of the cochlea. The method also includes continuing to rotate and image the optical imaging probe as the electrode array is advanced from the stylet tube, monitoring the position of the electrode array and the cochlea. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an endoscopic device according to one or more embodiments of the present disclosure, including an optical imaging probe (gray) and a sheath (black). [Figure 2] FIG. 2 is a schematic diagram of an optical imaging probe in accordance with one or more embodiments of the present disclosure. [Figure 3] FIG. 3 is a schematic diagram of a sheath assembly according to one or more embodiments of the present disclosure. [Figure 4]FIG. 4 is a schematic diagram of an assembly of an endoscopic device in accordance with one or more embodiments of the present disclosure. [Figure 5] FIG. 5 shows a schematic diagram of an electrode array-endoscopic device assembly in accordance with one or more embodiments of the present disclosure. [Figure 6] FIG. 6 shows a schematic diagram of an optical probe head having multiple optical surfaces to generate multiple optical propagation modes in accordance with one or more embodiments of the present disclosure. [Figure 7] FIG. 7 shows a schematic diagram of an optical probe head directing light from a second waveguide of a multimode fiber consisting of two segments with different core diameters in accordance with one or more embodiments of the present disclosure. [Figure 8] FIG. 8 is a schematic illustration of a sheath in accordance with one or more embodiments of the present disclosure. [Figure 9] FIG. 9 illustrates one embodiment of a tube adapter (top) and an assembly of a flexible sheath, tube adapter, and stylet (bottom) in accordance with one or more embodiments of the present disclosure. [Figure 10] FIG. 10 is a schematic diagram of an optical fiber interfacing to an optical probe head in accordance with one or more embodiments of the present disclosure. [Figure 11] FIG. 11 is a schematic illustration of a sheath with a stylet tube exposed from a tube adapter, in accordance with one or more embodiments of the present disclosure. [Figure 12] FIG. 12 shows a schematic view (top) and a cross-sectional view (bottom) of an optical positioning module in accordance with one or more embodiments of the present disclosure. [Figure 13] FIG. 13 shows a schematic diagram of an endoscopic device with a rotary joint and an OCT console in accordance with one or more embodiments of the present disclosure. [Figure 14] FIG. 14 shows a flowchart of a method for imaging the interior of the cochlea in accordance with one or more embodiments of the present disclosure. [Figure 15] FIG. 15 shows a flow chart of a method for intraoperative image-guided cochlear implantation. DETAILED DESCRIPTION OF THE INVENTION

[0010] According to some embodiments of the present disclosure, mechanisms (which may include, for example, systems and methods) are provided for intraoperative imaging of the cochlea and image-guided cochlear implantation.

[0011] In some embodiments, an endoscopic device is described that includes an optical imaging probe and a sheath used to image the interior of the cochlea. In some embodiments, the optical imaging probe is placed within the sheath before insertion into the cochlea. In some embodiments, the sheath protects the optical imaging probe from damage. In some embodiments, the optical imaging probe can rotate within the sheath without contacting the inside of the sheath. In some embodiments, the optical imaging probe can move axially within the sheath and be advanced beyond the tip of the sheath. In some embodiments, the endoscope is used with an electrode array of a cochlear implant. The endoscope is inserted into the channel of the electrode array before imaging. The stylet tube must be rigid enough to provide mechanical support for the electrode array for "advance off-stylet" insertion. Conventional stylets are made of metal to achieve this rigidity and are not transparent to OCT light. Therefore, to perform OCT imaging, the optical imaging probe must be able to extend beyond the tip of the stylet tube. This endoscopic device functions as a conventional stylet tube while simultaneously providing OCT imaging, which allows for insertion guidance and helps reduce the risk of cochlear damage during insertion.

[0012] In some embodiments, a method is described for obtaining cross-sectional OCT (optical coherence tomography) images of the interior of a human cochlea using an endoscopic device. OCT images of the cochlea can provide information about the morphology of the sensory epithelium and the interior of the cochlea.

[0013] In some embodiments, a method for implanting an electrode array of a cochlear implant system using an endoscopic device is described, aided by real-time image guidance provided by the optical imaging probe of the endoscopic device. In some embodiments, a stylet tube functions as a traditional electrode array stylet, supporting the electrode array and facilitating insertion into the straight portion of the scala tympani without bending the electrode array or damaging the tissue inside the cochlea. The endoscopic device is inserted into the electrode array before inserting the entire assembly. During insertion of the endoscopic device-electrode array assembly, the optical imaging probe is safely extended from the rigid stylet tube to prevent the optical probe head from contacting the electrode array. The optical imaging probe rotates within the sheath via a drive shaft assembly, acquiring optical coherence tomography (OCT) images through the electrode array and providing real-time feedback on the distance of the electrode array's end to the tissue within the scala tympani. This allows the insertion procedure to be guided by real-time OCT images.

[0014] In some embodiments, the systems and methods described herein allow visualization of the interior of the human cochlea at a cellular level, potentially providing diagnostic information for sensorineural hearing loss based on disease etiology and progression. Information obtained through OCT imaging can be used to correlate with cochlear implant treatment outcomes and aid in prognostic prediction of cochlear implant treatment. In some embodiments, the systems and methods described herein can aid in customizing future cochlear implant devices.

[0015] In some embodiments, the systems and methods described herein help minimize the risk of damaging certain cochlear structures during cochlear implant insertion, avoiding damage to a subject's residual hearing, and in some embodiments, the systems and methods can improve the accuracy of cochlear implant placement.

[0016] An endoscopic system refers to a system or device used to image the interior of a body cavity or organ. As used herein, the terms "endoscopic system" and "endoscopic device" are used interchangeably. In some embodiments, an endoscopic system can be used to image the interior of the human cochlea.

[0017] OCT imaging refers to optical coherence tomography, a procedure for obtaining high-resolution cross-sectional images of a sample. Micro-OCT (μOCT) refers to an OCT imaging procedure that improves the image resolution of a sample. Herein, the terms "OCT" and "micro-OCT" are used interchangeably. OCT imaging is suitable for obtaining images of the interior of the human cochlea. Micro-OCT imaging has high lateral resolution (e.g., less than 5 μm) and maintains a long imaging range (e.g., greater than 300 μm).

[0018] A "sample" refers to an object or tissue imaged by an endoscopic device. For example, a sample may refer to the scala tympani of a human cochlea. A sample may also be taken from a subject, such as a human. In some embodiments, a subject refers to a human diagnosed with sensorineural hearing loss. In some embodiments, a subject refers to a human undergoing cochlear implant insertion. In some embodiments, a subject refers to a human experiencing symptoms of sensorineural hearing loss.

[0019] 1 illustrates an example endoscopic system 100 for optical coherence tomography (OCT) of the cochlea in accordance with one embodiment of the present disclosure. As shown in FIG. 1, the endoscopic device 100 includes an optical imaging probe 200 and a sheath 300.

[0020] 2 illustrates an example optical imaging probe 200 according to some embodiments of the present disclosure. The optical imaging probe 200 is capable of performing optical coherence tomography (OCT), an imaging method capable of producing high-resolution cross-sectional images. It is particularly suited for imaging the interior of the cochlea. Several optical configurations are applicable to this imaging method. Some suitable optical systems and methods are described in U.S. Patent Application Publication No. 2019 / 0029570 A1, which is incorporated herein by reference in its entirety.

[0021] As shown in FIG. 2 , the optical imaging probe 200 includes a fiber connector 202 that delivers imaging light to an optical fiber and ultimately delivers a focused light beam from the distal end of the optical imaging probe 200 to a sample (e.g., tissue inside the cochlea) for imaging. An optical fiber can refer to a single waveguide or a combination of multiple waveguides. The optical probe positioning module 204 connects the fiber connector 202 at the proximal end of the optical probe positioning module to a sheath 300 via a lockable sheath connector 302 at the distal end of the optical probe positioning module. The optical probe positioning module 204 houses a drive shaft assembly 206. The optical probe positioning module 204 holds the sheath 300 while the drive shaft assembly 206 rotates. The optical probe positioning module 204 controls the axial position of the optical probe head 212. As used herein, the term "axial position" refers to a position along an axis parallel to the length of the endoscopic device 100, and the optical probe positioning module 204 controls the position of the optical probe head 212 along the length of the probe, and in particular serves to extend and retract the optical probe head 212 at the end of the probe.

[0022] A proximal end segment of the drive shaft assembly 206 is housed within the optical probe positioning module 204. The drive shaft assembly 206 connects to a fiber connector 202 at the proximal end of the drive shaft assembly 206. The drive shaft assembly 206 houses a first waveguide 208. The first waveguide 208 is housed inside the fiber connector 202 and the drive shaft assembly 206. The distal end of the first waveguide 208 extends a fixed distance beyond the distal end of the drive shaft assembly 206. In some embodiments, the fixed distance is equal to or less than (e.g., less than) the length of the channel in the electrode array endoscopic device 100. A second waveguide 210 can be connected to the first waveguide 208. In some embodiments, the combination of the first waveguide 208 and the second waveguide 210 is referred to as an optical fiber. An optical probe head 212 can be fabricated at the distal end of the second waveguide 210. The optical probe head 212 reflects and focuses the imaging light beam onto a sample (e.g., a portion of the scala tympani in the cochlea of ​​a human subject) and can function as the focusing element in an optical imaging probe.

[0023] The optical imaging probe 200 is suitable for micro-optical coherence tomography (micro-OCT). The optical imaging probe 200 can be configured to receive light from a light source and reflect a portion of the light toward a proximal end of a first waveguide 208. In some embodiments, the first waveguide 208 and the second waveguide 210 can be configured to transmit the light source light from the proximal end of the first waveguide 208 to the distal end of the second waveguide 210. The second waveguide 210 is connected to an optical probe head 212 and is positioned to project the light source light from the optical probe head 212. The optical probe head 212 can be configured to reflect the light source light emitted from the distal ends of the first waveguide 208 and the second waveguide 210 toward a sample.

[0024] In some embodiments, the first and second waveguides 208 and 210 can be positioned to receive reflected light from the sample via a reflective surface. The reflected light is then transmitted along the first and second waveguides 208 and 210 from the distal end to the proximal end. The light reflected from the sample and transmitted to the proximal end can then be transmitted to an OCT imaging console that includes an interferometer and a photodetector. Photodetectors include camera sensors, such as spectrometer-based CCD image sensors or CMOS image sensors for spectral-domain OCT, and high-speed photodiodes (e.g., made of silicon, germanium, InGaAx, lead sulfide, or other materials, including balanced photodiodes) for swept-source OCT. The OCT imaging console can be configured to receive both light from a reference light source and reflected light from the sample, allowing signals from different depths to be distinguished using any suitable coherence tomography technique.

[0025] FIG. 3 illustrates an example of a sheath 300. The sheath 300 includes a lockable sheath connector 302 for connecting the sheath to the optical probe positioning module 204. The sheath 300 may also include a flexible sheath 304. The flexible sheath 304 may be made of a relatively low-friction material and may include a Teflon-coated drive shaft (e.g., high-density polyethylene (HDPE)). In some embodiments, the sheath 300 may include a tube adapter 306. The proximal end of the tube adapter 306 is connected to the flexible sheath 304. The distal end of the tube adapter 306 is connected to a stylet tube 308. The tube adapter 306 is made of a high-strength material (e.g., stainless steel, ABS, PLA) to hold the stylet tube 308 and to withstand reasonable forces applied during insertion of the stylet tube 308 (e.g., into the cochlea) without breaking. In some embodiments, the stylet tube 308 may support an electrode array. The stylet tube 308 may be made of metal (e.g., stainless steel) and may be rigid. The length of the stylet tube 308 may be at least 20 millimeters.

[0026] The flexible sheath 304, the tube adapter 306, and the stylet tube 308 may form a continuous channel and enclose at least a portion of the optical imaging probe 200. The flexible sheath 304 protects the drive shaft assembly 206 while allowing it to rotate freely. The stylet tube 308 may enclose and protect elements such as the distal end of the first waveguide 208, the second waveguide 210, and the optical probe head 212. The stylet tube 308 is particularly important for preventing damage to the optical probe head 212 during insertion of the endoscopic device 100 into the cochlea.

[0027] FIG. 4 shows a detailed block diagram of the endoscopic device 100. The component arrangements of the optical imaging probe 200 and sheath 300 according to one or more embodiments of the device are shown. A lockable sheath connector 302 is attached to the distal end of the optical probe positioning module 204. The flexible sheath 304 houses and protects the drive shaft assembly 206, which can rotate within the flexible sheath 304. The extended first waveguide 208 passes through a tube adapter 306 and a stylet tube 308. The axial distance of the optical imaging probe 200 is controlled by the optical probe positioning module 204. The optical probe positioning module 204 controls the axial position of the optical probe 200 by moving the sheath 300 relative to the optical probe 200 (e.g., the optical imaging probe 200 remains stationary and only the sheath 300 moves).

[0028] In some embodiments, the endoscopic device 100 is used in combination with a cochlear implant electrode array. FIG. 5 illustrates an example of an electrode array-endoscopic device 500 assembly in accordance with one or more embodiments of the present disclosure. Prior to an imaging session, the endoscopic device 100 is inserted into the channel of the cochlear implant electrode array 502. During this procedure, the optical probe head 212 is secured and protected within the stylet tube 308 to prevent damage during insertion. The optical imaging probe 200 is then advanced forward within the sheath 300. The tip of the optical imaging probe 200, specifically the optical probe head 212, protrudes from the stylet tube 308. Once the optical probe head 212 reaches the ideal position, the optical imaging probe 200 is secured. The optical imaging probe 200 is then able to rotate within the central channel of the electrode array without contacting the inner walls of the electrode array.

[0029] In some embodiments, the stylet tube 308 is transparent to the OCT light. After the endoscopic device 100 is inserted into the ideal position within the electrode array 502, the optical imaging probe 200, and in particular the optical probe head 212, does not protrude beyond the stylet tube 308. The optical probe head 212 rotates within the stylet tube 308. The axial position of the optical probe head 212 is controlled by the optical probe positioning module 204. In some embodiments, the optical probe positioning module 204 slowly pulls back the optical probe head 212 during imaging, allowing the OCT light to perform a helical scan over the tissue within the cochlea to acquire a three-dimensional OCT image of the interior of the cochlea.

[0030] Various embodiments of the optical imaging probe 200 can produce different imaging modalities. In some embodiments, the first waveguide 208 can be a single-mode fiber. In some embodiments, the second waveguide 210 can be a multimode fiber. In some embodiments, the second waveguide 210 has a larger core diameter (e.g., larger than the core diameter of the first waveguide 208) than the core diameter of the first waveguide 208, allowing the light beam emitted from the first waveguide 208 to expand before reaching the optical probe head 212. In some embodiments, the second waveguide 210 can also modulate the mode of the light beam to create multiple focal points after the optical probe head 212, thereby extending the depth of focus and allowing the depth of focus to be longer than the Rayleigh length of a typical focusing element.

[0031] The optical probe head 212 can include an optical assembly made up of miniature optical components, including, but not limited to, those shown above and in various embodiments, multimode fiber, GRIN fiber, coreless fiber, ball lens, C lens, and / or microprism. The optical probe head 212 can also be made from 3D printed parts to focus and reflect a light beam onto tissue to enable the generation of OCT images.

[0032] FIG. 6 illustrates one embodiment of the optical probe head 212. The optical probe head 212 may be a 3D-printed optical component 602. The 3D-printed optical component 602 may be a monolithic structure with multiple optical surfaces 604. The 3D-printed optical component 602 may also include freeform surfaces 606 (e.g., surfaces that can be digitally designed for a particular probe or application and custom-manufactured, e.g., by 3D printing, and do not necessarily need to be based on mathematical functions such as polynomials, spherical functions, or elliptical functions) that can be customized to direct light in various directions based on the desired output beam, including generating multiple propagation modes. A single multi-curvature surface can generate multiple optical propagation modes 608, and the light beam is focused to form multiple focal points 610 within the cochlear tissue, thereby achieving an extended imaging depth of focus, as opposed to a conventional single optical element, which generates only one focal point and has a limited depth of focus defined by the Rayleigh length.

[0033] FIG. 7 shows another embodiment of an optical probe head 212. In this embodiment, the second waveguide 210 includes two multimode fiber segments with different core diameters. The first segment has a smaller core diameter, causing the light beam to undergo multiple internal reflections. The second segment allows the light beam to expand before reaching the focusing element. The optical probe head is comprised of a 3D-printed monolithic structure 702 with two optical surfaces that reflect and focus multiple light beams 704 toward tissue. These light beams are focused to multiple focal points 706, allowing for an extended depth of focus compared to traditional single-lens optics.

[0034] In some embodiments, the 3D printed optical probe head has an overall diameter smaller than that of an optical fiber (e.g., less than 80 μm) so that it does not contact the walls of the electrode array when the optical imaging probe 200 is rotated within the stylet tube 308.

[0035] In some embodiments of the sheath 300, the continuous channel is wider at the proximal end and narrows toward the distal end. In some embodiments, the diameter reduction occurs within the tube adapter. In some embodiments, the outer diameter of the distal end of the tube adapter is smaller than the outer diameter of the proximal end of the tube adapter.

[0036] In one embodiment of the sheath 300, the tube adapter 306 is a 3D-printed part with a hollow channel within its body. The proximal end of the tube adapter 306 can be fitted and assembled to the end of the flexible sheath 304, and the distal end can be assembled to hold the stylet tube 308. At the middle of the tube adapter 306, the internal channel tapers with a smooth transition from a larger diameter to a smaller diameter. Figure 8 shows a schematic diagram of the assembly of the flexible sheath 304, tube adapter 306, and stylet tube 308. Figure 9 shows a photograph of one embodiment of the tube adapter 306 (top) and a photograph of the assembly of the flexible sheath 304, tube adapter 306, and stylet tube 308 (bottom). In some embodiments, the tube adapter 306 includes a clear lumen to facilitate smooth insertion of an optical fiber.

[0037] The endoscopic system 100 has several parameters that are important for its application. The outer diameter of the stylet tube 308 is 150 μm or less, which is comparable to or smaller than the typical cavity size of currently commercially available cochlear implant electrode arrays. This allows the endoscopic system 100 to be used in combination with commercially available cochlear implant electrode arrays. The inner diameter of the stylet tube 308 is also less than 85 μm, ensuring rigidity while leaving sufficient space for the optical imaging probe 200. The optical fibers within the sheath 300 (e.g., the first waveguide 208 and the second waveguide 210) have outer diameters smaller than the inner diameter of the sheath 300, particularly the stylet tube 308. The optical probe head 212 has an outer diameter smaller than the inner diameter of the stylet tube 308. The length of the stylet tube 308 is greater than 20 mm. In some embodiments, the endoscopic system 100 functions in combination with an electrode array during insertion of a cochlear implant. In these embodiments, the length of the stylet tube 308 is important to ensure a deep insertion distance of the electrode array.

[0038] 10 shows a schematic diagram of one embodiment of the sheath 300. In this embodiment of the sheath 300, the stylet tube 308 is exposed 24 mm (±2 mm) from the tube adapter 306 and has an outer diameter of 150 μm (±5 μm) and an inner diameter of 83 μm (±1 μm). The first waveguide 208 is longer than the drive shaft assembly 206 to allow the optical probe head 212 to extend beyond the distal end of the stylet tube 308.

[0039] An important feature of the endoscopic device 100 is that the axial position of the optical imaging probe 200, and particularly the optical probe head 212, relative to the sheath 300 can be precisely controlled and adjusted by the optical probe positioning module 204. Even as the optical imaging probe 200 rotates within the sheath 300, the optical probe head 212 does not come into contact with potentially damaging surfaces (e.g., the walls of a cochlear implant electrode array). The smooth transition surface of the tube adapter 306 allows the optical imaging probe 200 to pass smoothly through the adapter (e.g., without catching on rough or uneven edges) during insertion and advancement. FIG. 11 shows a schematic diagram of the optical imaging probe 200 moving within the sheath 300. The optical imaging probe 200 is capable of axial movement (axial movement 1102) and rotation about its central axis (rotational movement 1104). The optical probe head 212 can be located within the stylet tube 308 or can protrude beyond the distal end of the stylet tube 308.

[0040] In one embodiment, the optical probe adjustment module 204 further includes a connecting sleeve 1202, a moving nut 1204, a locking nut 1206, a moving rod 1208, a sheath hypotube 1210, and a sheath adapter 1212. Figure 12 shows a schematic and cross-sectional view of one embodiment of the optical probe position adjustment module 204, where the moving nut 1204 may further include a bearing 1214 (Figure 12, bottom panel). The connecting sleeve 1202 connects the fiber connector 202 to the inner ring of the bearing 1214 of the moving nut 1204. The connecting sleeve 1202 is also secured to the drive shaft assembly 206. The moving nut 1204 is secured to the outer ring of the bearing 1214 and engages with the fine threads of the moving rod 1208. As the travel nut 1204 rotates along the travel rod 1208, the optical imaging probe 200 moves back and forth, allowing the optical probe head 212 to extend out of and retract into the distal end of the stylet tube 308. A lock nut 1206 prevents the travel nut 1204 from rotating and prevents the optical imaging probe 200 from being pushed forward.

[0041] In one embodiment, the drive shaft assembly 206 includes a stainless steel hypotube at its proximal end and a braided torque coil at its distal end, with the hypotube and torque coil bonded together. The proximal hypotube is secured to the fiber connector 202, the connecting sleeve 1102, and the sheath hypotube 1110. The torque coil is secured within the flexible sheath 304 and terminates short of the tubing adapter 306. The drive shaft assembly 206 carries the first waveguide 208 therein and transmits torque from the rotary joint to the optical probe head 212 at a 1:1 ratio.

[0042] In some embodiments, the optical probe positioning module 1200 is inserted into the electrode array. In some embodiments, the optical imaging probe 200 is advanced by manually rotating the travel nut 1104. In some embodiments, the position of the optical imaging probe 200 can be fixed within the sheath 300 by tightening the lock nut 1106 toward the travel nut 1104.

[0043] In some embodiments, the endoscopic device 100 or the electrode array-endoscopic device 500 operates in conjunction with an OCT imaging console and a rotary joint. FIG. 13 shows a schematic diagram of this configuration according to one or more embodiments of the present disclosure. In some embodiments, the optical imaging probe 200 is connected to a rotary joint 1302 via a fiber connector 202. The rotary joint 1302 is further connected to an OCT imaging console 1304. In some embodiments, an imaging laser from the OCT console 1304 is sent to the endoscopic device 100 via the rotary joint 1302. The rotary joint 1302 rotates the optical imaging probe 100, illuminating a focused light beam around a sample (e.g., the scala tympani of the human cochlea). Reflected light information is collected by the OCT imaging console 1304, and OCT images are processed and displayed in real time.

[0044] FIG. 14 illustrates an example process 1400 for micro-optical coherence tomography imaging of the cochlea according to some embodiments of the present disclosure. In some embodiments, the method includes providing 1402 an endoscopic device. In some embodiments, the provided endoscopic device corresponds to one or more embodiments of the endoscopic device 100 described herein. In some embodiments, the endoscopic device provided in 1402 includes an optical imaging probe and a sheath. In some embodiments, the optical imaging probe extends beyond the distal end of the sheath. In some embodiments, the method further includes positioning 1404 the endoscopic device within a channel of the electrode array. In some embodiments, the method further includes inserting 1406 the electrode array-endoscopic device obtained in 1404 into the cochlea. In some embodiments, inserting 1406 further includes shining light from the proximal end of the optical imaging probe, shining the light toward the interior of the cochlea and focusing the light on the cochlear tissue. In some embodiments, inserting 1406 further includes rotating the optical probe to focus the light at different portions of the cochlea. In some embodiments, inserting 1406 further includes causing the optical imaging probe to receive reflected light from the cochlea. In some embodiments, inserting 1406 further includes generating a two-dimensional image of a portion of the cochlea. In some embodiments, the method further includes displaying 1408 an image of the interior of the cochlea. In some embodiments, the generated image shows the distance between the outer surface of the optical imaging probe and the wall of the cochlea.

[0045] In some embodiments, the endoscopic device 100 operates within the electrode array of the cochlear implant system 502 using "advance off-stylet" technology. "Advance off-stylet" is a cochlear implant electrode array insertion technique that creates a channel in the center of the body of the electrode array and pre-inserts a rigid metal stylet into the channel, improving the rigidity of the assembly, allowing for easier insertion, and reducing insertion trauma. The described endoscopic device replaces the traditional solid stylet and can perform high-resolution OCT imaging through the electrode array body while acting as a traditional stylet for insertion.

[0046] Before imaging begins, the endoscopic device 200 is inserted into the channel of the cochlear implant electrode array 502, thereby forming the electrode array-endoscopic device 500. During this procedure, the optical probe head 212 is secured and protected within the stylet tube 300 to prevent damage. After the cochlear implant electrode array is inserted, the optical imaging probe 200 is advanced within the sheath 300. The tip of the optical imaging probe 200, specifically the optical probe head 212, extends from the stylet tube 308, which maintains a gap between the optical probe head 212 and the inner wall of the electrode array 502, allowing it to rotate within the central channel of the electrode array without touching the inner wall (see FIG. 11 ). Imaging is performed as the electrode array-endoscopic device assembly 500 is inserted into the scala tympani either manually by an otolaryngologist or by a robotic insertion system. As the optical imaging probe 200 rotates within the sheath 300, a light beam is focused on the cochlear tissue through the wall of the electrode array. During and after manual and / or robotic insertion of the cochlear implant, embodiments of the procedures disclosed herein allow visualization of the cochlear lumen and the organ of Corti; Visualization may be used to ensure minimal (or no) damage to the basement membrane during insertion. Visualization may also be used to confirm that the cochlear implant is correctly positioned; and / or The insertion process may be assisted or automated by adding image guidance (e.g., machine vision), which may increase the speed of insertion and / or reduce the risk of injury during the procedure. Additionally, the disclosed procedures may be used to visualize spiral ganglion neurons (SGNs) before, during, and / or after implantation to further optimize the performance of the cochlear implant.

[0047] FIG. 15 illustrates an example process 1500 for image-guided cochlear implantation. In some embodiments, process 1500 includes providing an endoscopic device. In some embodiments, the provided endoscopic device corresponds to one or more embodiments of endoscopic device 100 described herein. In some embodiments, the provided endoscopic device includes an optical imaging probe and a sheath. In some embodiments, the optical imaging probe is movable within and extendable from the sheath. In some embodiments, process 1500 includes positioning 1504 the provided endoscopic device in an electrode array. In some embodiments, the provided endoscopic device in 1502 is configured such that the optical imaging probe is fully contained within the sheath during positioning 1504. In some embodiments, the process further includes inserting 1506 the electrode array-endoscopic device from positioning 1502 into the cochlea. In some embodiments, the cochlea is a human cochlea. In some embodiments, inserting 1506 further includes shining light onto the proximal end of the optical imaging probe, such that the optical imaging probe can shine light into the interior of the cochlea and focus on the cochlear tissue. In some embodiments, inserting 1506 further includes rotating the optical imaging probe to focus on different portions of the cochlear tissue. In some embodiments, inserting further includes the optical imaging probe receiving reflected light from the cochlea and transmitting the reflected light toward the optical imaging probe. In some embodiments, inserting further includes generating a two-dimensional image of a portion of the cochlea. In some embodiments, inserting 1506 further includes identifying an ideal insertion depth based on the generated two-dimensional image of the cochlea. In some embodiments, process 1500 further includes advancing 1508 the electrode array from positioning 1504 forward out of the distal end of the endoscopic device. In some embodiments, the advancing includes continuing to rotate the optical imaging probe and generate images to monitor the position of the electrode array and the cochlea.

[0048] Once the electrode array-endoscopic device assembly 500 reaches the desired insertion depth, the electrode array 502 is advanced out of the stylet tube 308. In some embodiments, the stylet tube 308 continues to rotate and image to monitor the position of the electrode array 502 as the electrode array 502 is advanced out of the stylet tube 308. In some embodiments, the electrode array 502 is "pushed" out of the stylet 308. In some embodiments, the electrode array 502 is pushed out by the surgeon using forceps. After the electrode array 502 is fully inserted, the endoscopic device 100 is withdrawn from the electrode array and the cochlea. In some embodiments, the endoscopic device 100 continues to acquire images during withdrawal from the cochlea. This reduces the risk of damaging the cochlea during withdrawal of the endoscopic device.

[0049] The endoscopic device allows real-time imaging and can distinguish between the outer wall of the electrode array and the surface of the scala tympani cavity, thereby confirming proper insertion of the electrode-endoscopic assembly. The endoscopic device 100 allows insertion of the electrode array 502 while avoiding contact with and damaging the sensory tissue within the cochlea. Real-time imaging also allows cross-sectional images of the scala tympani, including the internal morphology of the cochlea, to be obtained.

[0050] By combining the endoscopic device 100 with commercially available cochlear implant electrode arrays, this OCT imaging can provide intraoperative guidance for electrode array placement and can also obtain cochlear morphology information to diagnose the etiology and / or predict the prognosis of a patient's hearing loss.

[0051] While the disclosed subject matter has been described above with reference to particular embodiments and examples, those skilled in the art will recognize that the present invention is not necessarily limited thereto, and that numerous other embodiments, examples, applications, modifications, and departures from the embodiments, examples, and applications are encompassed within the scope of the claims appended hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference herein as if each such patent or publication were individually incorporated by reference.

[0052] Various features and advantages of the invention are set forth in the following claims.

Claims

1. an optical imaging probe having a proximal end and a distal end, the optical imaging probe including a fiber connector, an optical probe position module, an optical fiber, and an optical probe head, the optical probe head configured to project a focused light beam, the optical probe position module controlling an axial position of the optical probe head; a sheath having a proximal end and a distal end, the sheath including a flexible sheath, a tube adapter, and a stylet tube, the flexible sheath, the tube adapter, and the stylet tube forming a continuous channel and configured to surround at least a portion of the optical fiber; An endoscope system comprising:

2. the optical fiber includes a first waveguide and a second waveguide; the first waveguide is located at the proximal end of the optical fiber; the second waveguide is located at the distal end of the optical fiber The system of claim 1 .

3. the first waveguide is a single mode fiber; The system of claim 2 .

4. The second waveguide is a multimode fiber. The system of claim 2 .

5. the optical probe head has a 3D printed unitary structure including a plurality of optical surfaces; The optical probe head is configured to generate multiple light propagation modes and multiple focal points. The system of claim 1 .

6. the second waveguide includes a multimode fiber consisting of two segments with different core diameters; The light beam is configured to expand before reaching the focusing element. The system of claim 3.

7. The stylet tube is made of metal and has a length of at least 20 millimeters. The system of claim 1 .

8. the stylet tube is constructed from a high strength material; Transparent to optical coherence tomography light The system of claim 1 .

9. the proximal end of the continuous channel is wider than the distal end; The tube adapter has a configuration in which the diameter decreases from the proximal end to the distal end. The system of claim 1 .

10. the tube adapter provides a transition in outer diameter from the flexible sheath to the stylet tube; The outer diameter of the distal end of the tube adapter is smaller than the outer diameter of the proximal end of the tube adapter. The system of claim 1 .

11. the optical probe head is disposed within the stylet tube; configured to be protrudable away from the distal end of the stylet tube The system of claim 1 .

12. The fiber connector is connected to a rotary joint. The system of claim 1 .

13. The optical probe position module houses a drive shaft assembly rotatable within the continuous channel, the drive shaft assembly configured to redirect the focused light beam. The system of claim 1 .

14. A pre-curved or non-pre-curved electrode array disposed on the sheath. The system of claim 1 further comprising:

15. The stylet tube supports the pre-curved electrode array and holds the pre-curved electrode array in a straight configuration. The system of claim 14.

16. 1. A method for imaging a cochlea, comprising: providing an endoscopic device; placing the endoscopic device within a channel of an electrode array; inserting the endoscopic device into the cochlea and advancing the endoscopic device; A method comprising: The endoscope device includes: an optical imaging probe having a proximal end and a distal end, the optical imaging probe including a fiber connector, an optical probe position module, an optical fiber, and an optical probe head, the optical probe head configured to project a focused light beam, the optical probe position module controlling an axial position of the optical probe head; a sheath having a proximal end and a distal end, the sheath including a flexible sheath, a tube adapter, and a stylet tube, the flexible sheath, the tube adapter, and the stylet tube forming a continuous channel and configured to surround at least a portion of the optical fiber; Equipped with Inserting the endoscopic device into the cochlea includes: illuminating the proximal end of the optical imaging probe so that the optical probe head illuminates the interior of the cochlea and focuses the light on tissue of the cochlea; rotating the optical imaging probe to focus light onto different regions of the cochlea; receiving reflected light from the cochlea with the optical imaging probe and transmitting the reflected light toward the proximal end of the optical imaging probe; generating a two-dimensional image of a portion of the cochlea surrounding the optical imaging probe based on the reflected light received from the optical imaging probe; displaying the two-dimensional image of the portion of the cochlea surrounding the optical probe, the two-dimensional image showing the distance between an outer surface of the optical imaging probe and a wall of the cochlea; A method comprising:

17. The generated two-dimensional image provides a cross-sectional image of at least one of the scala tympani, the basilar membrane, and / or the basilar membrane structure.

17. The method of claim 16.

18. obtaining information about the morphology of the cochlea based on the generated two-dimensional image to aid in diagnosing or predicting the prognosis of hearing loss.

17. The method of claim 16 further comprising:

19. performing a pullback operation to withdraw the endoscopic device from the cochlea, and generating additional two-dimensional images during the pullback operation.

17. The method of claim 16 further comprising:

20. The optical probe head is retracted into the stylet tube, causing the light to helically scan the cochlea and generate a three-dimensional image of the interior of the cochlea.

17. The method of claim 16.

21. 1. A method for image-guided cochlear implantation, comprising: providing an endoscopic device; placing the endoscopic device within a channel of an electrode array; inserting the electrode array-endoscopic device into the cochlea and advancing the electrode array and the endoscope; A method comprising: The endoscope device includes: an optical imaging probe having a proximal end and a distal end, the optical imaging probe including a fiber connector, an optical probe position module, an optical fiber, and an optical probe head, the optical probe head configured to project a focused light beam, the optical probe position module controlling an axial position of the optical probe head; a sheath having a proximal end and a distal end, the sheath including a flexible sheath, a tube adapter, and a stylet tube, the flexible sheath, the tube adapter, and the stylet tube forming a continuous channel and configured to surround at least a portion of the optical fiber; Equipped with Inserting the endoscopic device into the cochlea includes: illuminating the proximal end of the optical imaging probe so that the optical probe head illuminates the interior of the cochlea and focuses the light on tissue of the cochlea; rotating the optical imaging probe to focus light onto different portions of the cochlear tissue; receiving reflected light from the cochlea with the optical imaging probe and transmitting the reflected light toward the proximal end of the optical imaging probe; generating a two-dimensional image of a portion of the cochlea surrounding the optical imaging probe based on the reflected light received from the optical imaging probe; determining an insertion depth based on the generated two-dimensional image of the cochlea; while advancing the electrode array from the stylet tube, the optical imaging probe continues to rotate and image to monitor the position of the electrode array and the cochlea; A method comprising:

22. The insertion is performed by a human operator 22. The method of claim 21.

23. The insertion is performed by a robotic insertion system 22. The method of claim 21.

24. identifying the outer wall of the electrode array and the surface of the scala tympani cavity based on the generated two-dimensional image to guide insertion of the electrode array; 22. The method of claim 21 further comprising:

25. providing a cross-sectional image of the morphology of the cochlea based on the generated two-dimensional image.

22. The method of claim 21 further comprising:

26. performing a pullback operation to withdraw the endoscopic device from the cochlea, and generating additional two-dimensional images during the pullback operation.

22. The method of claim 21 further comprising:

27. The optical probe head is retracted into the stylet tube, causing the light to helically scan the cochlea and generate a three-dimensional image of the interior of the cochlea.

22. The method of claim 21.

Images