Title: Parkinson's Disease Classification Program, Classification Device, and Classification Method using Handwriting.

(Accepted At 17/Jan/2024) 分類プログラム、分類装置及び分類方法 特許No. 7421603, (特願2020-028085)

Abstract [1]:
Parkinson’s disease is a movement disorder. It affects the nervous system, and symptoms become worse over time. If an individual can be diagnosed at an early stage in the development of Parkinson's disease, the treatment is more likely to be effective. In this context, we focus on the differential diagnosis of PD based on the handwriting. Handwriting consists of continuous, discontinuous, and Japanese characters depending on one or more strokes, i.e. tracing of the Archimedes spiral and sign curves, three-circle imitation, three-line marking, and free character writing. We have explored new features and investigated the discriminated between PD patient and healthy individuals using machine learning techniques. As the contribution of patent, in addition to the Spiral, Continuous tasks, Discontinuous tasks, and Katakana (character) tasks are compared. We use the following feature; (1) Time Series Features (kinematic feature) such as Writing Velocity, Acceleration, and Jerk, Pressure 1st and 2nd derivative, Azimuth 1st and 2nd derivative, Altitude 1st and 2nd derivative, Angle in Stroke (around 1 / 3 / 5 mm) (2) We use statistical representative value, such as Average, Standard Deviation, (3) We use DP Matching for each feature. We achieved around 95% recognition rate.

Abstract [2]:
Parkinson's disease (PD) is generally taken into consideration as a disease that involves the movement, it can also be accompanied by motor symptoms, such as slowness of movement, tremors, and stiffness, and non-motor symptoms like depression, sleep problems and loss of smell. However, if an individual can be diagnosed at an early stage in the development of Parkinson's disease, the treatment is more likely to be effective. In this context, this paper demonstrates the different kinematics of handwriting, angle of stroke and dynamic programming (DP) features that can be used for differential diagnosis of PD. The database contains handwritten records of 19 patients and 17 healthy individuals who performed six different tasks. The tasks consisted of continuous, discontinuous, and Japanese characters depending on one or more strokes. These include tracing of the Archimedes spiral and sign curves, three-circle imitation, three-line marking, and free character writing. As for feature extraction, kinematic features are extracted from dynamic handwriting, we have explored new features based on the properties obtained by the first and second derivatives of the pen angle, the angle of stroke and the DP matching. Therefore, important features were investigated by the t-test and discriminated between PD patient and healthy individuals by comparing LSTM and SVM classifications.