The widespread adoption of wearable health devices has created a data paradox: users generate vast amounts of valuable data but lack control and face privacy risks. While blockchain technology offers a path to restore data sovereignty, its complexity presents a significant barrier to mainstream adoption. This research confronts this challenge through a multi-faceted PhD study, developing and validating a user-centered framework for designing blockchain-enabled health wearables that are usable, acceptable, and trustworthy. Key contributions include a practical design toolkit for user acceptance, insights from building and testing the CipherPal device, validated guidelines for designing Web3 applications, and a comprehensive evaluation approach.