Wearables

Wearables are devices worn on the human body that are able to measure various health parameters, such as physical activity, energy expenditure, and gait. ^[1] Smart and medical wearable devices actively record physiological parameters and track metabolic status, providing a continuous stream of health-care data for disease diagnosis and treatment. ^[2]

Wearable medical devices have been designed for use on all parts of the human body, including the head, limbs, and torso, and can be classified into four application areas: health and safety monitoring, chronic disease management, disease diagnosis and treatment, and rehabilitation. ^[2] Wearable technology is a promising alternative to laboratory systems for movement and posture analysis. ^[1] Wearable device data is one of the layers of longitudinal big biological data, alongside multi-omics, clinical, and imaging data, used with AI and systems-biology approaches for precision health. ^[3]

A meta-analysis of 56 studies found that the Apple Watch generally provides accurate heart-rate and step-count measurements, whereas its accuracy for energy expenditure is limited. ^[4] In that meta-analysis, all energy-expenditure subgroups exceeded the 10% mean-absolute-percentage-error validity threshold, while none of the heart-rate subgroups exceeded it, with accuracy varying across user characteristics and measurement conditions. ^[4] The wearable medical device industry faces important limitations that constrain clinical use, including security and privacy concerns, the lack of industry standards, and various technical bottlenecks. ^[2]

Wearable sensor-based movement assessment is paving the way for more objective and systematic diagnosis of Parkinson's disease in everyday-life conditions, supporting personalized therapy and remote monitoring of disease progression. ^[5] In sport and health science, integration of wearable technology and real-time analytics enables more personalized precision athletic monitoring, while raising central ethical considerations around data privacy and accessibility. ^[6] A narrative systematic review of wearable devices in health care synthesized 82 relevant papers spanning daily health and safety monitoring through clinical practice. ^[2]