Title
Supervised Classification Of Bradykinesia In Parkinson'S Disease From Smartphone Videos
Abstract
Background: Slowness of movement, known as bradykinesia, is the core clinical sign of Parkinson's and fundamental to its diagnosis. Clinicians commonly assess bradykinesia by making a visual judgement of the patient tapping finger and thumb together repetitively. However, inter-rater agreement of expert assessments has been shown to be only moderate, at best.Aim: We propose a low-cost, contactless system using smartphone videos to automatically determine the presence of bradykinesia.Methods: We collected 70 videos of finger-tap assessments in a clinical setting (40 Parkinson's hands, 30 control hands). Two clinical experts in Parkinson's, blinded to the diagnosis, evaluated the videos to give a grade of bradykinesia severity between 0 and 4 using the Unified Pakinson's Disease Rating Scale (UPDRS). We developed a computer vision approach that identifies regions related to hand motion and extracts clinically-relevant features. Dimensionality reduction was undertaken using principal component analysis before input to classification models (Naive Bayes, Logistic Regression, Support Vector Machine) to predict no/slight bradykinesia (UPDRS = 0-1) or mild/moderate/severe bradykinesia (UPDRS = 2-4), and presence or absence of Parkinson's diagnosis.Results: A Support Vector Machine with radial basis function kernels predicted presence of mild/moderate/severe bradykinesia with an estimated test accuracy of 0.8. A Naive Bayes model predicted the presence of Parkinson's disease with estimated test accuracy 0.67.Conclusion: The method described here presents an approach for predicting bradykinesia from videos of finger tapping tests. The method is robust to lighting conditions and camera positioning. On a set of pilot data, accuracy of bradykinesia prediction is comparable to that recorded by blinded human experts.
Year
DOI
Venue
2020
10.1016/j.artmed.2020.101966
ARTIFICIAL INTELLIGENCE IN MEDICINE
Keywords
DocType
Volume
Classification, Parkinson's, Bradykinesia, Video, Computer vision, Diagnosis, Support vector machine
Journal
110
ISSN
Citations 
PageRank 
0933-3657
0
0.34
References 
Authors
0
7
Name
Order
Citations
PageRank
Stefan B. Williams166570.78
Samuel D. Relton2385.42
Hui Fang311414.47
Jane E. Alty4377.58
Rami Qahwaji512021.05
Christopher D Graham600.34
David C Wong700.34