## 3 Development of a Video Otoscope with an Integrated Scanner: A Low-Cost Approach
### Video Otoscope Design  
The initial phase of the system development focused on defining the technical and functional requirements of the device, followed by detailed hardware design. Ergonomic aspects were considered, such as user comfort and ease of handling, as well as the integration of technologies to guarantee the effectiveness and precision of the system. The device architecture was designed to be modular and easily adjustable, which facilitates its adaptation to different application scenarios. All elements were designed to be quickly assembled and disassembled. To guarantee the adaptation of the system to different ear morphologies, strategically positioned screws were considered, which, in addition to guaranteeing the stability of the system, enable personalized adjustment and manual insertion of the video otoscope into the ear canal. The video otoscope is coupled to an actuator that allows its controlled retreat and advancement within the EEC. This feature aims to facilitate accurate image collection throughout the ear canal, ensuring a reliable and adaptable experience for healthcare professionals and patients. The configuration and adjustment of the video otoscope (Figures 1 and 2) are essential to guarantee an accurate and comfortable hearing examination. The vertical position of the video otoscope is adjusted through the support-headgear interface, see Figure 1. This system allows precise adjustment of the height of the video otoscope using a screw that secures the connection between the bracket and the headgear. The headgear can be repositioned and adjusted, providing a personalized adaptation to the user ensuring that the video otoscope is always at the desired height for the examination. Furthermore, the angular tuning of the video otoscope, both vertically and horizontally, is achieved through a spherical joint (Figure 2A). This joint is used to connect the part that supports the video otoscope fitting, which allows precise adjustments to the necessary angles. This configuration ensures that the video otoscope can be oriented in various directions, adapting to the specific anatomy of each patient's ear canal and ensuring that the examination is performed at the correct angle. As referred before, the system was designed to be versatile, allowing the use of video otoscopes with different dimensions. This way, the video otoscope support comprises a set of easily interchangeable parts. These interchangeable parts allow the device to be adapted to accommodate video otoscopes of various sizes without compromising the stability or accuracy of the equipment. Changing parts is simple, ensuring that the process of adapting to different video otoscopes is quick and effective. Additionally, to ensure that the video  
Figure 1: Video otoscope support components for height positioning. Figure 2: Video otoscope support components for angular positioning (**A**) and longitudinal axis fitting (**B**). otoscope is always placed in the same way on the equipment, the part where it is attached plays a crucial role. The geometry of this part was carefully designed to prevent any rotation of the video otoscope along its longitudinal axis (Figure 2B). This design, created in Solidworks 2023 SP2.1, ensures that the video otoscope is always positioned in the same way, maintaining consistency in placement and, consequently, in the examination quality. The device provides different and multiple adjustment points to adapt the system to different relative positions of the ear pinna. The headgear can be adjusted to allow the device to align correctly with the specific anatomy of the ear pinna of each patient. In addition, the ball joint, which includes a screw, allows for additional vertical adjustment, providing precise control over the positioning of the video otoscope in relation to the ear canal. These adjustment options ensure that the device can be adapted to a wide range of anatomical variations of the ear pinna. In addition, the headgear itself is fully adjustable.