Background
At present, measurements of Parkinson's disease symptoms are almost all performed in a clinical setting, which may not reflect daily life situations. The most widely used assessment scale for PD symptoms is the Unified Parkinson's Disease Rating Scale (MDS - UPDRS) which includes interviews asking the patient for historical information referring to the previous week, and a clinical rating scale which includes semi-quantitative assessment of motor (dys) function. However, there is broad agreement in the scientific field that new assessment strategies are needed, in particular those which have high ecological validity, multiple time points of evaluation and are effective.
Quantitative assessments using wearable technology may allow for continuous, objective and ecologically valid data collection and can be applied frequently at short intervals outside of the physician's office, allowing real-time monitoring of symptom changes. This approach may also improve patient-doctor interaction, influence therapeutic decisions and ultimately ameliorate patients' global health status. In addition, such measures have the potential to be used as outcome parameters in clinical trials, allowing for frequent assessments (e.g., in the home setting). These wearable sensors are of particular interest as they can be worn unobtrusively, so they do not relevantly influence the person who wears the sensor during a test, or during daily life. In addition, they can measure movements, and can be attached to almost every part of the body where symptoms of interest can occur.
The first studies with such sensors were performed more than 10 years ago and focused on the assessment of tremor and dyskinesia. Feeding the information obtained by such sensors back to the individual user, so that he or she can learn more about the individual disease presentations and how to counteract disease-associated symptoms, may provide additional motivation for users.
Within the framework of an EU-funded project (www-sense-park.eu), a device consisting of four components: software, a smartphone app, a Wii balance board and a set of sensors, was developed. This paper focuses on the results of this study with regard to feasibility and usability of the SENSE-PARK System over a prolonged time frame in the home environment of the users.