METHODS AND APPARATUS FOR FITTING HEARING DEVICE TIPS

Abstract: A gauge tip (40) for fitting in-the-canal hearing device tips is formed to fit on an existing otoscope (30) and includes on its distal end (42) a fastening device to enable variously sized hearing device tips (50) to be attached. The otoscope assembly, including the gauge tip (40) and hearing device tip (50), is inserted into a person's ear canal and the physician or audiologist can make an assessment as to the proper fit of the hearing device tip. Larger or smaller hearing device tips or complete gauge tips can be readily interchanged until a proper fit is achieved.

Description: DESCRIPTION Methods And Apparatus For Fitting Hearing Device Tips Field Of The Invention The present invention pertains to hearing aids. More particularly, the present invention pertains to methods and apparatus for quickly and correctly sizing an in-the- canal hearing aid receiver tip within an ear canal. Background Of The Invention The modern trend in the design and implementation of hearing devices is focusing to a large extent on reducing the physical size of the hearing device. Miniaturization of hearing device components is becoming increasingly feasible with rapid technological advances in the fields of power supplies, sound processing electronics and micro- mechanics. The demand for smaller and less conspicuous hearing devices continues to increase as a larger portion of our population ages. Those who face hearing loss also encounter the accompanying desire to avoid the stigma and self consciousness associated with this condition. As a result, smaller hearing devices which are cosmetically less visible are increasingly sought after. Hearing device technology has progressed rapidly in recent years. First generation hearing devices were primarily of the Behind-The-Ear (BTE) type, where an externally mounted device was connected by an acoustic tube to a mold placed within the ear. With the advancement of component miniaturization, modern hearing devices rarely use a Behind-The-Ear technique, focusing mainly on one of several forms of an In-The-Canal hearing device. Three main types of In-The-Canal hearing devices are routinely offered by audiologists and physicians. In-The-Ear (ITE) devices rest primarily in the concha of the ear and have the disadvantage of being fairly visible to a bystander. Smaller In-The- Canal (ITC) devices fit partially in the concha and partially in the ear canal and are less visible but still leave some of the hearing device exposed. Recently, Completely-In-The- Canal (CIC) hearing devices have come into greater use. As the name implicates, these devices fit completely within the ear canal and are essentially hidden from view from the outside. In addition to the obvious cosmetic advantages these types of in-the-canal devices provide, they also have several acoustic advantages that larger, externally mounted devices do not offer. Placing the hearing device within the ear canal and proximate to the tympanic membrane (ear drum) improves the frequency response of the device, reduces distortion due to jaw extrusion, reduces the occurrence of the occlusion effect and improves overall sound fidelity. The shape and structure, or morphology, of the ear canal varies from person to person. However, certain characteristics are common to all individuals. When viewed in the transverse plane, the path of the ear canal is extremely irregular, having several sharp bends and curves. It is this structural characteristic which creates problems for the acoustic scientist and hearing device designer. For general discussion purposes, the ear canal can be broken into three main segments. The external and medial segments are both surrounded by a relatively soft cartilaginous tissue. The external segment is largely visible from the outside and represents the largest cavity of the ear canal. The innermost segment of the ear canal is surrounded by a denser bony material and is covered with only a thin layer of soft tissue. This bony material allows for little expansion to occur in this region compared with the cartilaginous regions of the external and medial segments of the ear canal. In addition to being surrounded by cartilage rather than bone, these areas are covered with a substantially thicker tissue layer. Pressure exerted on the bony region of the ear canal can lead to discomfort and/or pain to an individual, especially when an in-the-canal hearing device is inserted deep within the ear canal and is in contact with this bony region. Since the morphology of the ear canal varies so greatly from person to person, hearing aid manufacturers and audiologists have resorted to custom manufactured devices in order to fit the precise dimensions of the ear canal. This process necessitates impressions of the person's ear canal to be taken. The resulting mold is then used to fabricate a rigid hearing device shell. This process is both expensive and time consuming and the resulting rigid device shell does not perform well during the deformation of the ear canal shape that occurs during normal jaw movement. In order to receive a properly fit hearing device, the person typically has to make several trips to the audiologist for reshaping and resizing. Even after the best possible fit is obtained, the rigid shell rarely provides comfortable hearing enhancement at all times. The high labor costs associated with fabricating this type of hearing device are inevitably passed on to the consumer. Furthermore, since the resulting hearing aid device shell is typically formed from a hard acrylic material, discomfort to the user is typical when worn for extended periods of time. The inability of the hard shell to conform to the normal ear canal deformations can cause it to become easily dislodged from its proper position. Consequently, the quality of the hearing enhancement suffers from this improper positioning. Thus, it would be desirable to provide a hearing device that is at least partially formed from an off-the-shelf, or pre-formed component readily available to the audiologist or physician. Co-pending U.S. patent application Serial No. 09/161,344, entitled, "Conformal In The Canal Hearing Device," which is fully incorporated herein by reference for all that it teaches, discloses CIC hearing devices that employ a soft conformal tip that can be securely seated within the deep bony region of the ear canal without causing appreciable pain or discomfort to the wearer. In particular, use of a conformal tip can provide a custom fit to the inner region of the ear canal by employing a deformable material that accurately conforms to the contours of the inner bony region, even during normal periods of ear canal deformation. Preferably, an audiologist or physician would have on hand an assortment of standard sizes of conformal hearing aid device tips, which could be selectively inserted into a person's ear canal for proper size determination. However, in order to select a properly sized conformal tip, the dimensions of the ear canal must still be measured. Otoscopes and videoscopes are commonly used to visualize the ear canal, but there is still a need for a device which directly measures the dimensions and geometric properties of the ear canal. Currently used otoscopes and videoscopes do not measure dimensions, but simply provide a visual representation of the ear canal. CAT scans and MRI systems can be used to reconstruct three dimensional geometries of the ear canal, but due to the extremely high cost of these procedures, they are rarely used for such purposes. Thus, ear canal impressions remain the most widely used method of extracting geometric data from the ear canal, despite the problems discussed above that are associated with this type of fitting procedure, which continue to plague audiologists, physicians and wearers of hearing aid devices. Summary Of The Invention In accordance with a first aspect of the invention, a device for use in fitting an object in an ear canal is provided, which comprises a body having a distal end, a proximal end and a longitudinal axis, the body including an aperture defined along the longitudinal axis, wherein the body is adapted to engage with an otoscope. In accordance with a further aspect of the invention, a method employing an otoscope, of fitting a hearing device in an ear canal includes, selecting a gauge tip adapted to fit on the otoscope, the gauge tip having a distal end adapted to accept variously sized hearing device components; selecting a first hearing device component; attaching the first hearing device component to the gauge tip distal end; inserting the gauge tip into the ear canal; and verifying the adequacy of the fit of the first hearing device component within the ear canal. As will be apparent to those skilled in the art, other and further aspects and advantages of the invention will appear hereinafter. Brief Description Of The Drawings The drawings illustrate both the design and utility of the preferred embodiments of the present invention, with similar elements in different embodiments are referred to by the same reference numbers for purposes of ease in illustration, wherein: Fig. 1 is a cross sectional view of an ear canal in the coronal plane; Fig. 2 is a perspective view of an otoscope aligned to engage with a gauge tip constructed in accordance with the present invention; Fig. 3 is a perspective view of the gauge tip of Fig. 2; Fig. 4 depicts a first preferred fastening device used to secure a conformal hearing device tip to the gauge tip; Fig. 5 depicts a second preferred fastening device used to secure a conformal hearing device to the gauge tip; Fig. 6 is a perspective view of a conformal tip being inserted into an ear canal (shown in cross-section) using the gauge tip of Fig. 2; Fig. 7 is a perspective view of an alternate preferred embodiment of a gauge tip constructed in accordance with the present invention, including a conformal tip; Fig. 8 is a perspective view of a further alternate preferred embodiment of a gauge tip constructed in accordance with the present invention, including a conformal tip; and Fig. 9 is a perspective view of an alternate preferred embodiment of an otoscope aligned to engage with a gauge tip constructed in accordance with the present invention. Detailed Description Of The Preferred Embodiments Fig. 1 shows a coronal cross section of an ear canal looking down from the top of the skull, and is included herein mainly for the purpose of illustrating the various regions of the ear canal and the differing types of tissue that make its structure. The ear canal, represented generally as 10, can be divided into three regions labeled in Fig. 1 as I, II and III. Region I is the most external portion of the ear canal and is surrounded primarily by cartilaginous material 12. Region II represents the main interior length of the ear canal 10 and is also surrounded by a similar cartilaginous material 12. Region III is the most internal portion of the ear canal and, unlike regions I or II, is surrounded by a dense bony material 14. As can be seen from Fig. 1, the overall width of the ear canal 10 gradually narrows as one progresses toward the inner regions II and III and the tympanic membrane 20. The entire wall of the ear canal 10 is covered with relatively soft tissue layers 16, 17 and 18, respectively. However, while the external region I and medial region II are covered with relatively thick layers of tissue 16 and 17, the internal region III is covered with substantially thinner tissue layer 18. The increased thickness of the respective tissue layers 16 and 17, combined with the underlying soft cartilaginous layer 12, allows for significant expansion to occur in regions I and II of the ear canal 10 when a solid object, such as a hearing device body, is inserted. In this manner, regions I and II are conducive to providing a pressure fit seal around the hearing device body, without causing discomfort to the individual. On the other hand, region III, with its relatively thin layer of tissue 18 and the underlying dense bony material 14, allows for little, if any expansion to occur when a solid object is inserted. As a result, a solid object inserted into the bony area of region III will eventually cause fatigue and discomfort to the individual. As previously noted, it is desirable to have a hearing device positioned as close as possible to the tympanic membrane 20 in order to reduce many of the acoustical problems normally associated with in-the-canal hearing devices. However, this necessarily involves placing the hearing device within the bony region III of the ear canal. Fig. 2 shows a standard otoscope 30 used by an audiologist or physician to examine the ear canal and tympanic membrane. The otoscope 30 includes a handle portion 32 and a scope portion 34 provided with a cone-shaped tip 38. The scope portion 34 includes a viewing window 36, which allows the physician or audiologist to observe the ear canal and tympanic membrane when the otoscope tip 38 is inserted into the ear canal. The otoscope 30 also includes magnification and illumination apparatus [not shown] to further assist the treating audiologist/physician in viewing the ear canal and tympanic membrane. In accordance with a first aspect of the present invention, a gauge tip 40 is formed into a shape that substantially matches the otoscope tip 38, but is slightly larger in each dimension so as to fit snuggly thereon. In most situations, the otoscope tip 38 is cone shaped and slightly tapered in order to easily insert the device into an ear canal. In such an arrangement, the gauge tip 40 would similarly be cone shaped and tapered. In particular, the gauge tip 40 has a wide proximal opening 44 and is configured for use as an extension or attachment to the otoscope tip 38. Several different gauge tip formats are therefore contemplated by the present invention in order to accommodate various otoscope models available on the market. The gauge tip 40 has a distal end 42, which includes a fastening device 46 adapted to secure a variously sized conformal hearing device tip 50 to the distal end 42. The fastening device 46 is preferably configured so that the conformal tip 50 can be easily removed and replaced by a treating physician or audiologist. The gauge tip 40 includes a distal end aperture 43 (best seen in Figs. 4 and 5), which is aligned with an aperture 39 in the otoscope tip 38 when the gauge tip 40 is seated thereon. The gauge tip aperture 43 allows the treating physician or audiologist to view the conformal tip 50, as it is inserted into the ear canal. The audiologist/physician can thereby observe the clearances between the conformal tip 50 and a person's ear canal walls, the distance between the conformal tip 50 and the tympanic membrane, and the overall fit of the conformal tip 50 in the particular ear canal. Verbal feedback from the person during the fitting procedure can simultaneously be used to gauge the proper fit and comfort level of the conformal tip 50. In practice, an audiologist or physician would select a gauge tip 40 and attach it over the tip 38 of a standard otoscope 30. Several models of gauge tips 40 would be available and the physician/audiologist would preferably select one which is configured for the particular otoscope 30 being used. The gauge tip 40 is formed in essentially the same shape as the otoscope tip 38 and preferably snaps or locks into place thereon . One of an assortment of pre-manufactured sizes of conformal tips 50 is then selected by the physician/audiologist and attached to the distal end 42 of the gauge tip 40. The conformal tips 50 would preferably be available in an assortment of diameters as well as lengths. The physician/audiologist then gradually inserts the assembled otoscope 30, gauge tip 40 and conformal tip 50 into a person's ear canal in the same manner as he would while examining the ear canal with only the otoscope 30. As the conformal tip 50 is being inserted into the ear canal, the physician/audiologist can continuously monitor the positioning of the conformal tip 50 through the otoscope view finder. The gauge tip 40 thus allows the physician/audiologist to make a visual determination of whether the conformal tip 50 is properly sized and fitted securely within the ear canal. If the physician/audiologist determines that the conformal tip 50 selected for the person is too large, he can remove the otoscope assembly 30 and select a smaller conformal tip 50. Conversely, if the first conformal tip 50 is too small, a larger one can be selected. This process is then repeated until a properly sized conformal tip 50 is selected. Verbal feedback from the person being fit with the conformal tip 50 is also preferably used to judge comfort level. The gauge tip 40 may also include an integrated acoustic tube [not shown] which allows the physician/audiologist to measure the acoustic integrity of the particular conformal tip 50 at the same time he is fitting the tip 50 within the ear canal. This provides another level of assurance to the physician/audiologist that the tip 50 is properly fit. Additionally, the gauge tip 40 may include a disposable sterile cover [not shown]. Referring now to Fig. 3, a more detailed view of the gauge tip 40 is shown. The body 41 of the gauge tip 40 is generally in the shape of a tapered cone, and is designed to accurately mate over the tip 38 of the otoscope 30. In particular, the gauge tip 40 is meant to slip over the existing otoscope tip 38 and therefore an accurately matched shape is preferred. Gauge tips 40 are therefore contemplated to be manufactured to fit specific otoscope models. A tapered cone shape is also preferred for ease of insertion into the ear canal. Most otoscope tips 38 are so-configured for this purpose. The body 41 is formed from a rigid polycarbonate material or other medical grade plastic. In a preferred embodiment, this material can be sterilized and used repeatedly. With continuing attention to Fig. 3 and also referring to Fig. 4, the fastening mechanism 46 in one embodiment comprises a pair of inwardly biased extensions 47a and 47b located on the periphery of the distal end 42. The extensions 47a and 47b are preferably opposing each other, however, more than two extension can be utilized. In such a case, the extensions are preferably equally spaced around the periphery of the distal end 42 and are each essentially centrally facing. As the conformal tip 50 is engaged with the gauge tip 40, the extensions 47a and 47b clamp around a proximal extension 52 located on the end of conformal tip 50. The conformal tip effectively snaps into position on the distal end of the gauge tip 40. In an alternate embodiment, shown in Fig. 5, the fastening device comprises a tapered chamber 48, wherein the extension 52 is peg-shaped to appropriately mate with the chamber 48. Notably, Figs. 4 and 5 also depict the aperture 43 through which the treating physician/audiologist can observe the placement of the conformal tip into the ear canal. The magnification and illumination capabilities of the otoscope further aid in assessing the proper fit of the tip 50. Various other fastening mechanisms are contemplated by the present invention and the previous example is not meant to be limiting. For example, the conformal tip can include a threaded screw with the gauge tip including a corresponding threaded socket. A removable medical grade adhesive can alternately be used to secure the conformal tip to the gauge tip. Other equivalent fastening means are also contemplated by the present invention. Turning now to Fig. 6, a gauge tip 40 of the present invention is shown attached to an otoscope 30 and inserted into an ear canal 10. A conformal hearing device tip 50 is attached to the distal end of the gauge tip 40. By this arrangement, an audiologist or physician can observe the position of the conformal tip 50 within the ear canal 10. As shown in Fig. 6, the conformal tip 50 is positioned proximate the tympanic membrane 20 deep within the ear canal 10, at a position where the surrounding material 14 is dense bone. Only a thin layer of tissue 18 covers the walls of the ear canal at this point and therefore, there is no compression of the ear canal when a solid object is inserted into this area. In this preferred embodiment, the conformal tip 50 includes a surrounding membrane 54 filled with a compliant material such as a gel, foam or liquid. This gel filled membrane allows the conformal tip to securely seat within the bony inner region of the ear canal without causing excessive pressure and resulting discomfort for the wearer. Further details of this conformal tip 50 are disclosed in co-pending U.S. Patent Application No. [not-yet-assigned, Lyon & Lyon docket no. 236/024], filed on the same date herewith, and which is fully incorporated herein by reference for all it discloses. The conformal tip 50 can be rapidly and easily exchanged with other (i.e., differently sized) conformal tips allowing the audiologist or physician to try different size conformal tips until one that properly fits within the ear canal 50 is found. Once the proper size is determined, the conformal tip 50 can be attached to a hearing device body and the fitting process is essentially complete. All steps to the process of fitting a hearing device can thus be accomplished at the audiologist or physician's office. The line of sight 60 of the treating physician/audiologist is maintained, while inserting the respective gauge tip 40 and conformal tip 50 into the ear canal 10. Therefore the physician/audiologist can simultaneously place the conformal tip 50 while examining its position. Referring now to Fig. 7, an alternate preferred gauge tip 140 is designed to allow the physician/audiologist to not only size a conformal hearing aid tip but to allow the physician/audiologist to size a hearing device shell as well. The gauge tip 140 is similarly designed to fit over an existing otoscope tip, but is additionally configured to represent the shape of an entire hearing device body rather than simply providing a way to size a conformal tip. More particularly, the gauge tip 140 includes a body 141 made of a similar polycarbonate material as the gauge tip 40 of Fig. 3. Like the conical gauge tip 40, gauge tip 140 includes a wide proximal opening 144 configured to fit over an otoscope tip 38. However, gauge tip 140 is not in the same conical shape as the previously described gauge tip 40, but instead has a distal end 142 formed into the shape of a fully assembled hearing device shell. Toward this end, distal end 142 is formed from two components 148 and 150, which together simulate the shape of a standard hearing device shell. Portion 148 is in the shape of a standard hearing device outer housing and portion 150 simulates the remaining body core portion of a hearing device. The portion 150 includes on its distal end a fastening device 146 similar to fastener 46 of tip 40. The fastening device 146 similarly allows a conformal tip 50 to be attached to the distal end of the gauge tip 140. The combination of portions 148 and 150, along with the conformal tip 50 attached to the distal end 142, creates an accurate model of the size and shape of a complete in-the- canal hearing device. Additionally, an accurate insertion distance can be more accurately maintained when sizing the conformal tip 50, thus further ensuring a proper sizing. Referring now to Fig. 8, a further alternate preferred gauge tip 240 is also designed to allow the physician/audiologist to simultaneously size both a hearing device shell, as well as a conformal hearing aid tip. The gauge tip 240 is preferably designed to fit over an existing otoscope tip and is also configured to represent the shape of an entire hearing device body. The gauge tip 240 includes an integrated conformal tip 250 permanently formed onto its distal end 242. In this manner, a physician/audiologist can interchange the entire gauge tip 240, rather than just the conformal tip portion, when sizing a patient's ear canal. More particularly, the gauge tip 240 includes a body 241 made of a similar polycarbonate material as the gauge tips 40 and 140 of Figs. 3 and 7. Gauge tip 240 includes a wide proximal opening 244 configured to fit over an otoscope tip 38. The distal end 242 is formed from two components 248 and 250, which together simulate the shape of a standard hearing device employing a conformal tip. Portion 248 is in the shape of a standard hearing device shell and portion 250 simulates the conformal tip portion of an assembled hearing device. Fig. 9 shows an alternate preferred embodiment of an otoscope 130. Similar to the otoscope 30 described in conjunction with Fig. 2, the otoscope 130 includes a handle portion 132 and a scope portion 134. The scope portion 134 includes a viewing window 136, which allows the physician or audiologist to observe the ear canal and tympanic membrane when the otoscope is inserted into the ear canal. The otoscope 130 does not include its own tip portion as does the otoscope 30 of Fig. 2 (reference number 38). Instead, the otoscope 130 includes a mounting ring 138, which is adapted to allow the gauge tip 240 to be secured directly on the scope portion 134. Rather than sliding the gauge tip 240 over an existing otoscope tip, the otoscope 130 and gauge tip 240 are adapted to connect directly to one another. Although the invention has been described and illustrated in the above description and drawings, it is understood that this description is by example only and that numerous changes and modifications can be made by those skilled in the art without departing from the true spirit and scope of the invention. The invention therefore should not be restricted, except by the following claims and their equivalents.

Claims: Claims 1. A device for use in fitting an object in an ear canal, comprising: a body having a distal end, a proximal end and a longitudinal axis, the body including an aperture defined along the longitudinal axis; wherein the body is adapted to engage with an otoscope. 2. The device of claim 1 , wherein the distal end includes a fastening device. 3. The device of claim 2, wherein the fastening device comprises at least two inwardly biased extensions. 4. The device of claim 3, wherein the fastening device comprises a tapered aperture. 5. The device of claim 1, further comprising an acoustic measuring system integrated into the body. 6. The device of claim 5, wherein the acoustic measuring system comprises a lumen extending from the distal end to the proximal end. 7. The device of claim 1, wherein the body is at least partially formed into a shape resembling an in-the-canal hearing device body. The device of claim 1 , wherein the body is formed into a shape resembling an in- the-canal hearing device body and conformal tip. 9. The device of claim 1, wherein the distal end is adapted to engage a hearing device component. 10. The device of claim 1, wherein the device is adapted to fit over an existing otoscope tip. 11. A method employing an otoscope for fitting a hearing device in an ear canal of a patient, comprising: selecting a gauge tip adapted to fit on the otoscope, the gauge tip having a distal end adapted to accept variously sized hearing device components; selecting a first hearing device component; attaching the first hearing device component to the gauge tip distal end; inserting the gauge tip into the ear canal; and verifying the adequacy of the fit of the first hearing device component within the ear canal. 12. The method of claim 11, wherein verifying the adequacy of the hearing device fit comprises at least one of measuring the acoustic integrity of the first hearing device component; measuring the distance between the tympanic membrane and the first hearing device component; measuring the force required to remove the first hearing device component; and assessing the comfort level of the patient. 13. The method of claim 11 , further comprising: selecting a second hearing device component if the first selected hearing device component does not adequately fit in the patient's ear canal; and verifying the adequacy of the fit of the second hearing device component within the ear canal. 14. The method of claim 12, wherein measuring the acoustic integrity of the hearing device component includes utilizing an electronic acoustic measuring device in conjunction with the gauge tip. 15. The method of claim 12, wherein measuring the distance between the tympanic membrane and the hearing device component includes visually observing the distance through an aperture in the gauge tip.

Inventors: BRIMHALL OWEN D, KOSKOWICH GREGORY N, BRIMHALL, OWEN, D., KOSKOWICH, GREGORY, N.
Applicants: SONIC INNOVATIONS
Application year: 2000
Main classification: H04R25
IPC codes: A61B1, H04R25