With the growing population with chronic disease in most developed countries, the amount and variety of interactive medical devices adopted in healthcare and wellbeing management is on the rise. Studies show that people with chronic conditions are facing many barriers to effective self-management, which leads to significant economic losses in many countries. The question as to how we can design personal medical devices that are able to facilitate an effective self-management by tackling these barriers presents a challenging research topic. We offer an overview of a controlled-experiment designed to evaluate an innovative tagging feature and a confidence of measurement feature in chronic disease management. This is a work-in-progress, which will finish by the end of June 2013.