Design and Usability of an Open-Source, Low-Cost Flexible Laryngoscope for Resource-Limited Settings.

Importance: Endoscopes are paramount to the practice of otolaryngology. To provide physicians in low-middle-income countries with adequate tools to treat otolaryngologic problems, it is necessary to create a low-cost sustainable option. Objective: To describe the design and usability of an open-source, low-cost flexible laryngoscope that addresses the lack of affordable and accessible methods for otolaryngologic visualization in resource-limited settings. Design, Setting, and Participants: This quality improvement study used a mixed-methods approach, including a technical description of device design as well as quantitative and qualitative survey evaluation of device usability. Engineering involved device design, sourcing or manufacturing individual components, fabricating a prototype, and iterative testing. Key assumptions and needs for the device were identified in collaboration with otolaryngologists in Zimbabwe, and designed and simulated by biomedical engineers in a US university laboratory. Board-certified otolaryngologists at a single US university hospital trialed a completed prototype on simulated airways between May 2023 and June 2023. Main Outcomes and Measures: Technical details on the design of the device are provided. Otolaryngologist gave feedback on device characteristics, maneuverability, and visualization using the System Usability Scale, a customized Likert-scale questionnaire (5-point scale), and semistructured interviews. Results: A functional prototype meeting requirements was completed consisting of a distal-chip camera, spring bending tip, handle housing the control mechanism and electronics, and flexible polyether block amide-coated silicone sheath housing the camera and control wires; an external monitor provided real-time visualization and ability to store data. A total of 14 otolaryngologists participated in the device review. The mean (SD) System Usability Scale score was 88.93 (10.08), suggesting excellent usability. The device was rated highly for ease of set up, physical attributes, image quality, and functionality. Conclusions and Relevance: This quality improvement study described the design of a novel open-source low-cost flexible laryngoscope that external review with otolaryngologists suggests was usable and feasible in various resource-limited environments. Future work is needed to translate the model into a clinical setting.

Prevalence and causes of paediatric hearing loss in a rural province of Zimbabwe: A cross-sectional study.

BACKGROUND: Hearing loss (HL) in childhood is a significant disability with severe consequences for educational, cognitive, and social-emotional success. Nevertheless, prevalence estimates for HL in Sub-Saharan Africa (SSA) are based on scarce data. Therefore, we aimed to estimate the prevalence of HL in a sample of primary school children from a rural province of Zimbabwe. METHODS: A cross-sectional study was performed on primary school children aged 4-13 years from a rural Zimbabwean province. In the quietest room available, participants underwent audiometry, video otoscopy, and tympanometry. Hearing loss was defined as a pure-tone average > 25 dB. Risk factors of hearing loss were evaluated via a questionnaire. Furthermore, to enable comparison with similar studies, HL prevalence was calculated according to two other commonly used definitions. RESULTS: A total of 451 pupils were included, of which 10.6% (95% CI 7.8-13.5) met the study criteria for HL. Conductive HL (95.1%) was nineteen times more prevalent than sensorineural HL (4.9%). Otitis media was the underlying cause in 40% of all cases of HL. The prevalence of clinically significant HL varied depending on the definition applied, i.e., 0.4% (95% CI -0.2-1.0) in the worst World Health Organisation category as opposed to 4.2% (95% CI 2.4-4.1) in the worst American Speech-Hearing Association category. CONCLUSIONS: Hearing loss was common in this sample of primary school children from a rural province in Zimbabwe.