ENT- VR/AR, 3D Printing, Digital tools and Wearables

Author: Pardise Elmi and Abhishek Achunair

TLDR

VR/AR - transforming otolaryngology by improving surgery, education, and rehabilitation

3D Printing - custom surgical tools, educational models, and realistic prosthetics, improving efficiency, accuracy, and patient outcomes.

Digital Tools and Wearables - DizzyFix, Shoebox Audiometry, and LearnENT are improving treatment, accessibility, and education for hearing and balance disorders

Virtual and Augmented Reality

Virtual reality (VR) and augmented reality (AR) are rapidly advancing the field of otolaryngology by transforming both surgical planning and patient rehabilitation. These technologies enable immersive 3D simulations that improve surgical precision and patient outcomes. Head and neck surgeon Dr. Eitan Prisman and his colleagues from the Vancouver Coastal Health Research Institute developed a customizable in-house software and 3-D surgical cutting guide called Real Time Reconstruction. This low-cost software maximizes perioperative planning, creating precise 3D virtual surgical models through visualization of CT data via the Amira v5 software bridged with an automation algorithm that incorporates the Ramer–Douglas–Peucker contour simplification method to optimize alignment of bone segments. Real Time Reconstruction features an interactive interface, allowing surgeons to delineate resection margins and plan reconstructions using three-dimensional virtual planes. Once surgical planning of the resection and reconstruction are complete, the software displays the reconstructed mandible using optimized fibular segments for review by the surgical team. The final plan is subsequently used to create 3D printed models which are sterilized for use in the operating room. This will be further discussed in the 3-D printing section below.

VR is a powerful educational tool especially in surgery, providing realistic experiences for trainees while minimizing patient risk. The SurgiSim is a VR simulation designed to simulate complex procedures using patient-specific anatomy, realistic stereoscopic visuals, and haptic feedback. SurgiSim is powered by CardinalSim, a VR temporal bone surgical simulator, developed at Stanford University and further refined at the University of Calgary and Western University. The SurgiSim tool aims to provide learners with an interactive interface, exposing them to virtual environments designed to effectively teach, plan, and practice otolaryngology. Specifically, trainees are subjected to the intricacies of temporal bone surgery. The face and content validity of CardinalSim was assessed through a national study via evaluation by otolaryngologists and residents from across Canada. Attitudes towards use of CardinalSim were nationally positive and the platform achieved acceptable criteria for both face and content validity. Traditional teaching with cadaveric models does not allow for repetition and opportunities for residents to perform otologic procedures during training are insufficient. VR is a promising avenue for optimizing resident teaching for these complex procedures.

VR has also shown to have significant potential for its use in vestibular rehabilitation. Dr. Heffernan and colleagues from the University of British Columbia (UBC) evaluated the congruency of commercially available VR video games and vestibular rehabilitation therapy as evaluated by vestibular physiotherapists. Video games, including VR Tunnel Race (VRTR) and VR Real World Bike Racing (VRWBR), demonstrated great potential for aiding vestibular rehabilitation. These video games were found to nearly replicate physiotherapy-prescribed exercises. VR has the potential to provide a low-cost, accessible, and enjoyable form of rehabilitation for individuals experiencing dizziness. A study assessed a VR-based VRT program utilizing Sony Playstation®4 VR Head Mounted Display in 25 patients diagnosed with peripheral vestibular hypofunction for 8 sessions. In this study, movement velocity and direction control significantly improved after VRT (p< 0.000). Oscillation averages in ‘toes up’ and ‘toes down’ positions also reduced significantly post VRT (p< 0.000). These findings demonstrate VR's potential in effectively retraining balance and alleviating symptoms in patients with vestibular dysfunction, ultimately enhancing their functional capacity and hopefully improving their quality of life.

3D Printing

3D printing technology is gaining traction in health care, especially in reconstructive surgeries, for creating custom equipment, and in educating learners. PolyUnity is a Canadian-based business founded by Dr. Travis Pickett, Dr. Michael Bartellas, and Dr. Stephen Ryan. Their company offers 3D-printing production equipment, design services, and access to an online database of 3D printable parts, allowing health-care professionals to quickly design, access, and produce necessary equipment on demand. Dr. Leung and colleagues conducted a systematic review assessing the use of 3D-printed anatomical models in both otolaryngology education and surgical practice. In general, medical students, residents, and attending physicians in otolaryngology demonstrated positive attitudes towards the use of 3D-printed models for surgical skill utility, anatomical similarity, and educational value. Of the studies that reported educational value, 100% suggested that the 3D-printed models offer utility for future training and surgical simulation. The most common surgeries evaluated were temporal bone or mastoidectomy procedures and endoscopic sinus surgeries. 3D-printing interventions, such as those provided by PolyUnity, offer significant potential for enhancing early exposure to otolaryngology for students and residents by allowing hands-on practice with realistic models. These technologies also benefit healthcare networks by enabling on-demand production of surgical tools and hospital equipment, thus improving accessibility and reducing procurement costs.

As previously mentioned, Real Time Reconstruction is an in-house software and 3D virtual surgical cutting guide developed by Dr. Prisman and his colleagues. It works in conjunction with 3D-printing technology to create customized surgical cutting guides, which are used in the operating room for head and neck reconstruction. Once the virtual models are finalized through the software, the surgical guides and diseased mandible are 3D printed. The 3D-printed models physically snap onto the mandible and fibula during surgery and contain slots that direct the surgeon’s cuts, replicating the preoperative plan. These guides are designed to ensure optimal bone alignment and guide cutting planes that minimize gap volume and allow for improved bony apposition and mandibular contour. Ten otolaryngology residents from the UBC were divided into two groups, one completing mandibular reconstructions using traditional free-hand methods and the other using the Real-Time Reconstruction model as explained. The guided group showed significant improvements in gap volume, overlap, and projection. Further, the guided group demonstrated a lower average time to completion, though this was not significant. Real-Time Reconstruction offers improved accuracy, efficiency, and cost-effectiveness compared to freehand methods, revolutionizing the approach to head and neck reconstruction.

Complex head and neck oncology cases often require the removal of key facial structures, such as the eye, nose, mouth, and ear, which can significantly impact a patient's quality of life. These physical changes can lead to isolation, anxiety, and a lowered sense of self-esteem. At Sunnybrook Hospital in Toronto, the craniofacial prosthetics unit (CPU) is addressing these challenges by creating highly realistic prosthetics. This allows patients who have undergone complex head and neck reconstructive procedures to navigate their daily lives with greater confidence and less anxiety about their appearance. By utilizing 3D printing technology, the CPU team has greatly improved efficiency, enabling them to assist more patients. For example, what once took 4-5 hours to sculpt an ear from wax is now achieved more efficiently with the help of a 3D printer. The team scans the patient’s contralateral ear (if available), mirrors and adjusts the image as needed, and utilizes the data to create a 3D-printed model with liquid resin. From this model, they construct a mold, followed by a wax copy, to improve flexibility and texture. While this innovative approach has transformed ear prosthetics, it is not yet used for nasal or ocular prosthetics.

Digital Tools and Wearables

Wearable technologies and digital applications are transforming the management of hearing and balance disorders. The DizzyFix device, developed by Dr. Matthew Bromwich, a pediatric otolaryngologist in Ottawa, offers a portable solution for patients suffering from benign paroxysmal positional vertigo (BPPV). The DizzyFix device is a clinically proven wearable technology, providing real-time visual feedback to guide patients with BPPV through the Epley maneuver. A recent randomized control trial assessed the effectiveness of combining the Epley maneuver with the DizzyFix device. Fifty patients with BPPV were divided into two groups: one receiving the Epley maneuver supplemented with the DizzyFix device and the other, receiving the traditional Epley maneuver alone. Supplementation with the DizzyFix device during the Epley maneuver was associated with significantly higher symptom resolution rates (90% vs. 60%) and patient satisfaction scores, lower recurrence rates (10% vs. 40%) and a considerable decrease in their Dizziness Handicap Inventory scores. The DizzyFix not only improves treatment outcomes but also enhances accessibility by offering a cost-effective, at-home solution that empowers patients to manage their condition with greater ease and independence.

Dr. Bromwich also founded Shoebox Audiometry, the first clinically validated automated hearing assessment tool available on an iPad. This software integrates advanced algorithms with an interactive interface to enable clinicians to perform accurate audiometric evaluations of patients. This capability extends access to quality hearing care, even outside of traditional sound booths, particularly useful in remote areas. Further, Shoebox Audiometry helps direct patients to the services they may need depending on their hearing test results. Reaching over 350,000 people globally, Shoebox Audiometry has revolutionized audiology, surpassing geographical and socioeconomic boundaries and increasing access to quality hearing care. Furthermore, a multi-centre comparative clinical study reported no significant difference in air and bone conduction thresholds when measured using the online digital audiometer versus a conventional audiometer. Shoebox Audiometry has improved access to hearing care by offering portable and accurate assessments, enabling timely evaluations and referrals, especially for patients in remote areas.

LearnENT is a mobile application that was first developed by a group from the University of Ottawa and has since gained traction internationally, becoming the official app of the Canadian Society of Otolaryngology and Head and Neck Surgery. LearnENT offers a free, innovative, and interactive approach to learning the fundamentals of otolaryngology. It includes peer-reviewed modules, with videos, case-based learning, flashcards, and question banks to enhance the learner experience. The application also offers additional features such as built-in point-of-care resources, note-taking abilities, and offline functionality. The application aims to standardize otolaryngology-related medical education, improving access to accurate resources for students and practitioners, globally.