## 5 Conclusions and Suggestions  
### Conclusions  
To cater to the challenges of diverse user needs, this study made conclusions based on the research objectives as follows:  
(1) In the design of wearable devices, health and home monitoring functions are the primary focus. To achieve enhanced functionality while contributing to sustainability, three major aspects of product design must be considered: providing a pleasant and successful user experience, integrating sensing components with data application, and utilizing human-centered sensing technology. Sustainable design can be achieved by using eco-friendly materials, optimizing energy consumption, and extending the product's lifecycle, which reduces electronic waste and conserves natural resources. While wearable devices have the potential to influence health behaviors, these changes are not driven solely by the devices themselves. Their successful user experiences and potential health benefits depend largely on the design. In addition to meeting users' needs for comfort, protection, durability, weight, ease of movement, and aftercare, a human-centered design approach also promotes sustainability by focusing on user retention, reducing the need for frequent replacements.  
(2) Experts highlighted the importance of several design indicators, including \"Compatibility\", \"Foresight\", \"Integration\", \"Comfort\", \"Appearance\", \"Customization\", and \"Intelligence\". To increase consumers' willingness to continue using these devices and support sustainable practices, wearable devices should offer a high compatibility with other existing technologies. This allows for seamless upgrades or brand transitions, extending the product's lifecycle and reducing electronic waste. Moreover, enabling future integration with Internet of Things (IoT) applications can improve resource efficiency by optimizing how devices interact with each other, thereby reducing the environmental impact of manufacturing and disposal. For example, integrating data from multiple devices can create a unified user interface, ensuring that wearable devices continue to meet user needs while minimizing their environmental footprint.  
(3) In analyzing the cause-and-effect relationships and correlations between criteria and indicators, the criteria \"Function Enhancement\", \"Future Outlook\", and \"Quality Appearance\" were found to significantly impact key indicators such as \"Intelligence\", \"Foresight\", \"Integration\", \"Customization\", \"Connectivity\", \"Energy Consumption\", \"Compatibility\", and \"Appearance\". These indicators should be prioritized in product design to increase consumer willingness to use wearable devices. In terms of sustainability, reducing energy consumption and enhancing connectivity will decrease the devices' environmental footprint, making them more eco-friendly while improving user experience.  
(4) The integration of the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method with the Analytic Network Process (ANP) revealed that while all indicators are important, \"Energy Consumption\" and \"Connectivity\" stand out as top priorities for improvement. These indicators not only promote sustainability by optimizing energy use but also enhance the devices' overall efficiency, allowing wearers to experience the convenience and benefits of smart devices. Although \"Comfort\" is ranked highly due to its importance in product design, its status as an affected factor suggests that its improvement is tied to the overall sustainability of the product. Thus, reducing energy consumption while maintaining comfort will contribute to the sustainability of wearable devices by promoting user satisfaction and reducing the need for frequent product replacements.