After six years of study, the Otolaryngology Department of PUMCH developed the world’s first device that describes facial dynamic indicators from multiple dimensions, which has passed accuracy test and was granted a patent. The project won the third prize of PUMCH 2018 Medical Achievement Award.
Facial paralysis is a common disease, its treatment, treatment assessment and prognosis prediction all relying on accurate evaluation of facial nerve functions. Present evaluation systems can be largely divided into being subjective and objective. A subjective system is easily affected by observers themselves and the difference between them, and therefore lacks stability, while the absence of objective systems has been hindering the treatment and study of the disease.
The Otolaryngology team led by Professor Gao Zhiqiang developed 3-D ASFM, a 3D dynamic quantitative analysis system based on facial movements. It can, in a short time, complete static and dynamic evaluation of a patient by obtaining a whole set of facial movement parameters. Its accuracy and stability have been proven in 50 cases. It not only breaks the limits of conventional subjective assessment, but is well related to such system. Novelty search showed no similar system in the world.
In developing the system, the team innovatively applied 3D anatomy and facial motion capture principles; it used the sides of partes occipitotemporalis and occipital as fixed reference points, established a stable reference system in relation to a patient’s head; it described space locations and moves on coronal, sagittal and horizontal planes and used distance parameters. The 3D anatomy principles used here were proposed for the first time.
Subjects study has preliminarily proven that the system can complete static measurement in a quick, convenient and accurate manner. It is the first time that researchers obtained 3D absolute values of facial motions’speed, acceleration, direction and other dynamic parameters, serving as an “infrastructural project” of quantitative assessment of facial expressions.
Through the analysis, researchers revealed the laws and features of facial movements after paralysis, and based on that, established models for more accurate prognosis prediction to guide clinical practice. They also unveiled the relationship between movement indicators and facial nerve functions, thus providing reference for diagnosis. It should be pointed out that in the acute phase, electrophysiological examination remains the best indicator for prognosis prediction; for a paralysis older than one month, a combination of subjective assessment and 3D analysis can provide the best prognosis evaluation.
The team also for the first time obtained a databank of facial movements of Han ethnic group, which will provide important reference for facial expression design in animations and robots, plastic surgery planning for facial paralysis and the development of prosthesis in the treatment of paralysis.
The project, due to its innovation and wide potential of application, has been supported by many funds from the National Natural Science Foundation, and was among the 2017 Top 10 Chinese Medical Assays. The system, as a quick evaluation means, helps doctors and patients to assess facial paralysis, and is of significant clinical and social value.