Validation of a Smartphone Application Measuring Motor Function in Parkinson's Disease

Area of Science:

• Neurology
• Digital Health
• Biomedical Engineering

Background:

• Accurate motor function measurement is crucial for Parkinson's disease (PD) management.
• Ambulatory assessment using mobile technology can provide insights into a patient's condition beyond clinical settings.
• A custom smartphone application was developed to quantitatively assess hand dexterity for PD motor function evaluation.

Purpose of the Study:

• Validate a novel smartphone application against the established MDS-UPDRS motor assessment (MDS-UPDRS-III) and a two-target tapping test.
• Develop a predictive model for MDS-UPDRS-III scores using smartphone-derived parameters.
• Evaluate the repeatability, compliance, and user satisfaction of the smartphone application in PD patients.

Main Methods:

• 103 Parkinson's disease patients were recruited from movement disorder clinics.
• The smartphone application was used by patients at home for three days, followed by a user experience survey.
• Repeatability was assessed by repeat testing under identical clinical conditions for a subset of patients.

Main Results:

• Significant correlations were found between smartphone application parameters and MDS-UPDRS-III scores (r=0.281-0.608, p<0.0001).
• A prediction model explained 52.3% of the variation in MDS-UPDRS-III (R²=0.523, p<0.0001).
• Repeatability of key parameters and predicted MDS-UPDRS-III was moderate to strong (ICC=0.584-0.763, p<0.0001), with high user comfort reported.

Conclusions:

• The developed smartphone application demonstrates satisfactory validity and repeatability when compared to the MDS-UPDRS-III.
• The application's performance is considered acceptable, particularly given its focus on hand dexterity.
• This mobile tool shows potential for objective, remote monitoring of motor function in Parkinson's disease.