How do we protect a device's artistic design?

Hi, we have designed a wearable device which links to a mobile app. The device measures and collects health data from the user, which our software then processes and displays on the app's interface, with additional recommendations, consultations, fitness-related feedback etc. One way in which the device is completely different from anything on the market is its innovative design, which blends functionality with art. We would like to protect the design, but how do we do this best? (As a startup, what degree of protection can we reasonably afford?)