Digitalisation of the Brief Visuospatial Memory Test-Revised and Evaluation with a Machine Learning Algorithm

摘要

The disease multiple sclerosis (MS) is characterized by various neurological symptoms. This paper deals with a novel tool to assess cognitive dysfunction. The Brief Visuospatial Memory Test-Revised (BVMT-R) is a recognized method to measure optical recognition deficits and their progression. Typically, the test is carried out on paper. We present a way to make this process more efficient, without losing quality by having the patients using a tablet App and having the drawings rated with the use of a machine learning (ML) algorithm. A dataset of 1 ’525 drawings were digitalized and then randomly split in a training dataset and in a test dataset. In addition to the training dataset the already trained drawings from a preliminary paper were added to the training dataset. The ratings done by two neuropsychologists matched for 81% of the test dataset. The ratings done automatically with the ML algorithm matched 72% with the ones of the first neuropsychologist and 79% of the ones of the second neuropsychologist. For a semiautomated rating we defined a threshold value for the reliability of the rating of 78.8%, under which the drawing is routed for manual rating. With this threshold value the ML algorithm matched 80.3% and 86.6% of the ratings of the first and second neuropsychologists. The neuropsychologists have in that case to manually check 17.4% of the drawings. With our results is it possible to execute the BVMT-R Test in a digital way. We found out, that our ML algorithms have with the semiautomated method the similar matching as the two professional raters.