Objective facial paralysis grading based onPface and eigenflow

To provide physicians with an objective and quantitative measurement of single-sided facial paralysis, the paper presents a computer-based approach that is different from the nine existing, subjective and hand-performed international scales, such as House-Brackman. For voluntary expressions of a patient, this approach used P_face, which stems from D_face, to measure the asymmetry between two sides of the face and used eigenflow to measure the expression variations between the patient and normal subjects. The results from P_face and eigenflow were then combined by the support vector machine produce to P_degree. A study of 25 subjects revealed that P_degree could differentiate paralysis states (P_degree≧0) and normal states (P_degree<0), with the ability to grade facial paralysis automatically. Moreover, the P_face of specific facial areas can be used in the supervision of the rehabilitation process.