Innovative mobile app solution for facial nerve rehabilitation: a usability analysis

Abstract

Background: Facial palsy after vestibular schwannoma surgery is temporary in many cases but can significantly affect patients' quality of life. Physical training-initially guided and subsequently performed by the patient-is of paramount importance for recovery of facial nerve function. The introduction of medical application software (apps) might improve therapy by maintaining motivation for daily home-based training and surveilling patients' rehabilitation progress.

Methods: We developed a mobile app, "FACEsemper", for home-based facial nerve rehabilitation. This app guides patients through a daily training program comprising six variable exercises, each performed in three repetitions. The app allows the user to customize the exercise intensity for different facial areas and includes a reminder function for daily training. Additional features include photo documentation, a calendar function, training report generation, and the possibility of direct communication with the attending physician. The app's usability was prospectively investigated with 27 subjects, including 8 physicians, 9 patients with facial palsy and 10 healthy subjects, over a two-week period. Usability was assessed using various self-rating questionnaires (i.e., mHealth App Usability Questionnaire, MAUQ; System Usability Scale, SUS; Visual Aesthetics of Apps Inventory, VisAAI) and scores were compared across the groups.

Results: The participants reported an average smartphone use of 12.19 years and completed a mean number of 290 ± 163 facial exercises during the study period. Patients used the app significantly more frequently than the other two groups (p = 0.017). The average total scores of the questionnaires were: MAUQ 5.67/7, SUS 89.6/100, VisAAI 5.88/7 and specific rating 6.13/7. In particular, the simplicity of use and craftsmanship of the app were rated very highly. Usability scores did not significantly differ between groups. A primary limitation identified was malfunction of the daily reminder feature in some Android versions.

Conclusion: This usability study demonstrated a positive user experience and excellent usability of the FACEsemper app. However, some limitations and areas for improvement were identified. As a next step, the app should be evaluated in a large patient cohort with facial palsy to determine its potential medical benefits for facial rehabilitation compared to traditional training methods.

Keywords: APP; facial palsy; rehabilitation; smartphone; usability; vestibular schwannoma.

Figure 1

Structure of the FACEsemper app. (A) After initial setup, a welcome page is shown to the user. The app functionalities presented in B-I can be opened via specific buttons. (B) demonstrates one exercise of the daily training. In the large circle, the user's face is captured and displayed via the camera. Furthermore, video instructions for the exercise are displayed in the small circle. (C,D) show the specific and individual exercises. (E) Photo documentation is provided in a standardized form of 6 facial expressions. (F) Training reports can be sent for improved patient-therapist communication. (G) A calendrical summary showing the exercise units and photo documentation gives the user an overview of their training status. (H) demonstrates one of the information sides and (I) shows the functions of the training settings.

Figure 2

Usability evaluation by different rating scales. (A) FACEsemper specific questionnaire; (B) mHealth app Usability Questionnaire for standalone apps (MAUQ); (C) System Usability Scale (SUS) values are compared with SUS values of everyday products published by Kortum et al. (19); (D) Visual Aesthetics of Apps Inventory (VisAAI).