The expansion of nursing-care assistant robots in smart infrastructure has provided more applications for homecare services. which has raised new demands for smart and natural interaction between humans and robots. This article proposed an innovative hand motion trajectory (HMT) gesture recognition system based on background velocity features. Here. https://www.spidertattooz.com/Metabo-HPT-NT1865DMASTM-18V-MV-15-Gauge-Brushless-Cordless-Angled-Finish-Nailer/