Wearable Sensors for Sleep Monitoring in Free-Living Environments: A Scoping Review on Parkinson's Disease.

Parkinson's disease (PD) is a neurodegenerative disorder that affects multiple neural pathways, leading to a broad spectrum of motor and non-motor symptoms. Sleep disorders, such as insomnia and excessive daytime sleepiness, are prevalent among PD patients and significantly impact symptomatology and patients' quality of life. Wearable technology presents an opportunity to study these interactions in patients' daily life environments without the limitations of in-clinic sleep studies. Thus, this review aims to explore how wearable technology has been employed or developed for the sleep monitoring of PD patients in free-living environments. A comprehensive search was conducted across PubMed, Scopus, and IEEE Xplore to identify original research articles focusing on wearable sleep technology for the ambulatory monitoring of PD patients. Twenty-six studies fulfilled the inclusion criteria and underwent structured data extraction and quality assessment. Key aspects analysed included subject demographics, extracted sleep parameters, identified sleep disorders, and the application of machine-learning algorithms. Wearable devices could offer a practical solution for long-term sleep monitoring in PD, though further validation is needed. The absence of standardised protocols and the lack of device validation within PD populations remain significant challenges. The evidence gathered in this study remains insufficient to define a standardised protocol for sleep assessment of PD patients in free-living environments.