Human Lower Limb Motion Capture and Recognition Based on Smartphones

Abstract

Human motion recognition based on wearable devices plays a vital role in pervasive computing. Smartphones have built-in motion sensors that measure the motion of the device with high precision. In this paper, we propose a human lower limb motion capture and recognition approach based on a Smartphone. We design a motion logger to record five categories of limb activities (standing up, sitting down, walking, going upstairs, and going downstairs) using two motion sensors (tri-axial accelerometer, tri-axial gyroscope). We extract the motion features and select a subset of features as a feature vector from the frequency domain of the sensing data using Fast Fourier Transform (FFT). We classify and predict human lower limb motion using three supervised learning algorithms: Naïve Bayes (NB), K-Nearest Neighbor (KNN), and Artificial Neural Networks (ANNs). We use 670 lower limb motion samples to train and verify these classifiers using the 10-folder cross-validation technique. Finally, we design and implement a live detection system to validate our motion detection approach. The experimental results show that our low-cost approach can recognize human lower limb activities with acceptable accuracy. On average, the recognition rate of NB, KNN, and ANNs are 97.01%, 96.12%, and 98.21%, respectively.

Facile Preparation of a Self-Adhesive Conductive Hydrogel with Long-Term Usability

“…Flexible wearable sensors have attracted much attention because of their similar function with human skin. , These sensors play a crucial role in converting external stimuli into bioelectronic signals, thereby finding widespread applications in areas such as electronic skin, − bionic robot, , and artificial limb . However, the design of wearable strain sensors needs a holistic approach that takes into account a range of integrated requirements.…”

“…1,2 These sensors play a crucial role in converting external stimuli into bioelectronic signals, thereby finding widespread applications in areas such as electronic skin, 3−5 bionic robot, 6,7 and artificial limb. 8 However, the design of wearable strain sensors needs a holistic approach that takes into account a range of integrated requirements. These essential considerations encompass the attainment of flexible-tough mechanical characteristics, effective skin adhesive properties, biocompatibility, and antidrying effects for long-term usability.…”