Parkinson's disease (PD) affects more than 10 million people around the world, yet it has no specific diagnostic test, and is often misdiagnosed as other disorders such as essential tremor (ET). Thus, the purpose of this study is to evaluate how well a smartphone can detect, quantify, and distinguish between motor symptoms in PD and ET. To accomplish this, participants are instructed to complete a series of 10-second activities while sensors (e.g. accelerometer, gyroscope) collect de-identified data to ensure security. Participants who wish to withdraw from the study can do so at any time by exiting or deleting the app before finishing a study session and their data will be immediately destroyed.

Ultimately, the data collected from this study may help health professionals better understand how PD and ET differ and could advance the development of detection tools for PD and ET.