Will Smart Ring be Next Wave of Wearables?

Wearables provide a promising solution for proactive health by monitoring real-time vital signs long-term. However, wrist-worn devices, like smartwatches, have faced issues with inaccuracy and information loss. This is primarily due to two factors: motion artifacts, which interfere with recorded signals due to relative movement, and the anatomical complexity of the wrist, complicating sensor placement, especially for optical sensors that require optimal positioning of light sources and receivers. Photoplethysmography (PPG) is a critical signal recorded by wearables. The Finger is a more suitable measurement site for PPG signals due to its high vascular density and few static tissues. Additionally, fingerworn devices adhere more securely to the skin than wrist-worn devices, reducing sensitivity to external interference and improving PPG signal quality. Advances in electronic devices have led to significant progress in smart rings, making them a promising next-generation wearable. This paper discusses the development, potential, and challenges of smart ring technologies. With accelerating research, we believe smart rings are poised to become a main player in the wearable market.