Taking an ear impression is perhaps the most common non-diagnostic procedure performed by audiologists, and is one of the first technical skills that students learn in audiology training programs. While common, taking ear impressions is also a very technically challenging and invasive procedure. The skills and techniques necessary for taking proper ear impressions take many years to develop, and even when performed by an experienced clinician, the patient can experience significant discomfort or, rarely, injury. Nevertheless, accurate ear impressions are vital to the successful fitting of any custom in-ear product, including hearing aids, earmolds, custom headphone sleeves, and noise protection earplugs.
With the AURATM 3D Ear Scanner, Lantos Technologies is bringing the process of creating earmolds into the digital age. The first digital ear scanner of its kind (shown below), this device allows for quick, comfortable, and accurate digital impressions of the pinna and ear canal. The scanner captures the topology of the whole ear, from a complete concha to down the canal to within a few millimeters of the tympanic membrane. The AURATM 3D scanner provides a number of innovative and clinically relevant benefits that audiologists will appreciate. The AURATM 3D scanner consists of a hand-held scanner with retractable scope and proprietary LantosViewTM software. Housed within the scope is a high-resolution video camera with extremely wide field of view, allowing the scanner to also function as a high quality video otoscope, providing full visualization of the ear canal and the tympanic membrane.
When using the unit to obtain digital ear impressions, a small inflatable membrane is placed over the scope prior to insertion into the ear. The scope is placed into the ear canal in otoscope mode, which provides constant visualization of the ear canal and tympanic membrane, minimizing the risk of discomfort or injury, while allowing for precise placement of the scope into the ear canal. Once the scope is at the desired depth, the audiologist uses the scanner-mounted controls to inflate the membrane.
Housed within the scanner unit is a light-absorbing fluid medium, which flows into the membrane, inflating it gently but completely. As illustrated in the figure at the right, when inflated, the membrane conforms to the surface of the ear. Any hair in the ear canal is gently pushed out-of-the-way, as is modest amounts of cerumen, trapped between the ear canal wall and the external surface of the membrane. The scope, now within the inflated membrane and surrounded by the fluid medium, emits light which fluoresces the inside of the membrane. The LantosViewTM software compares the intensity of light in two different bandwidths to determine relative distances, which allows mapping of the surface of the ear with accuracy on the order of microns. This highly accurate digital image is stitched together in real-time, and is displayed in the user interface during scanning (click here for Lantos Technologies YouTube video). Once the scan is complete, the audiologist deflates the membrane and removes the scope from the patient’s ear.
Once completed, the digital ear impression (shown left) is a three-dimensional representation of the external ear and ear canal, visible within the LantosView TM software. The file generated is an “.stl” file, a standard file format in the realm of high-resolution 3D printing. This impression can be manipulated, measured, and dissected for use as a clinical counseling tool. Hearing aid options that are available to the patient can be discussed in the context of the digital ear impression. Similarly, hearing aid styles that may not be an option for a particular patient, due to limitations in a specific individual’s ear anatomy, can be reviewed and the patient counseled with real data to support the audiologist’s recommendations.
As we know, the traditional process of obtaining an earmold impression is relatively time-consuming. Once the impression material is injected into the ear canal, it must be allowed to cure for five to ten minutes. In some patients, they tolerate both ears being impressed simultaneously; others find the experience of being completely “blocked up” off-putting and request the impressions be done sequentially. Often this results in considerable “down time” for the audiologist; for instance, very little communication can occur with the patient during this time. Once the impressions come out, they must be packaged and the hearing aid or earmold order form must be completed. The order form may need to be copied, and then is folded and placed inside the box with the impressions. The box is placed into a shipping bag, which also needs a shipping label, and then a package “pick-up” must be scheduled. If it is too late in the day, the pick-up may not occur until the next day. In a busy practice, this time-intensive procedure may be undertaken many times each day. The scanning procedure is similar in some ways to taking ear impressions, but without the discomfort often experienced by patients. Many audiologists will find that the skills they have developed in taking ear impressions translate easily to the ear scanning procedure. The scan takes about 45-60 seconds per ear.
Digital ear scanning eliminates many of the time-consuming steps outlined above. The digital scan can be sent electronically to the hearing aid or earmold manufacturer, reaching them almost instantly, and possibly cut shipping costs in half. This can facilitate online ordering, and may be integrated directed into the manufacturers’ existing shell/earmold fabrication process.
Many audiologists remember the impact that digital signal processing had on the quality of hearing aid technology. The Lantos AURATM 3D Ear Scanner is the next generation of ear impressions. Ear impressions have gone digital, allowing for a more interactive patient experience and a more rapid transition from audiogram to hearing aid fitting. Visit Lantos Technologies at AudiologyNOW! March 26-28, 2014, at booth 1614 to see the AURATM 3D ear scanner in action!
Brian Fligor, Sc.D., is Chief Audiology Officer at Lantos Technologies, Inc., Wakefield, MA. Prior to joining Lantos, Dr. Fligor was Director of Diagnostic Audiology at Boston Children’s Hospital and Assistant Professor at Harvard Medical School. He is adjunct faculty at Northeastern University and Salus University, a member of the Children’s Oncology Group, and founder and past-chair of the Music-Induced Hearing Disorders Taskforce for the National Hearing Conservation Association. He was a member of the Board of Directors of the American Academy of Audiology 2009-2012. Dr. Fligor’s publications on hearing loss risk from music received considerable popular media attention, including being spoofed on the David Letterman Show in 2005. His publications on ototoxicity have helped shape the JCIH Position Statement (2007) and helped shape a new unified international chemotherapy ototoxicity grading scale. He holds a B.S. in Biomedical Engineering and Sc.D. in Audiology from Boston University.
Andrew P. McGrath, Au.D., is the Global Training Manager at Lantos Technologies, Inc. Prior to joining Lantos, Dr. McGrath was the Director of the Department of Audiology at Women & Infants Hospital in Providence, RI. He has held faculty appointments at the Yale University School of Medicine, the Brown University Alpert Medical School, and the University of Rhode Island. Dr. McGrath has extensive experience working both in private audiology practice and in hospital-based audiology practices, with expertise in electrophysiology, vestibular disorders, pediatric audiology, and adult and pediatric amplification.