Search

Dragonflies fly in flapping wing flight, bearing a variety of variable forces during flight. To comprehend and study from the biological system and then carry out technological innovation, the characteristic point cloud data of dragonfly wings were obtained and the 3D geometric models were reconstructed. The biomechanical characteristics of Costa, Radius and Postal veins of the wings were examined by a nanoindenter. It was shown that the reduced modulus and nanohardness of Radius of dragonfly forewings and hindwings are large. The maximum reduced modulus and nanohardness of Costa, Radius and Postal veins of hindwings appear at the place 0.7L of dragonfly wings. The biomechanical characteristics of dragonfly wings were researched and then the deformations and stresses of the bionic models under the uniform load were investigated. It was shown that the dragonfly wings are less deformed under the uniform load and the chief veins have stronger stability and bearing capacity. The combinations of the main veins and branch veins can improve the overall strength and load-bearing capacity of dragonfly wings. It tries to explore the structural models of imitating dragonfly wings with good load-bearing capacity and, then, were used to guide the plan and manufacturing of thin film and offer novel ideas and methods for the study of thin film. [ABSTRACT FROM AUTHOR]

Pulse oximetry saturation (SpO2) is a main parameter that reflects the condition of the human cardiovascular system. It is best to detect SpO2 non-destructively with photoplethysmography (PPG). The embedded technique was used to control the dual-wavelength LED illuminating the fingertips, photoelectric sensors to detect reflection data and, then, upload the data to computers, IIR filtering and S-G smoothing filtering on MatLab to process the collected data. The results is shown that the discreteness of the processed data was reduced by 2–6% and the high-frequency noise and motion artifact were removed effectively. It would provide some references for improving the accuracy of the pulse oxygen saturation monitoring system in a complex environment. [ABSTRACT FROM AUTHOR]