Elderly Fall Analysis And Detection And Hip Bone Research On Protection System Characteristics

Falls have become the leading cause of death among the elderly in China^[1].According to the world health reported,the most serious injury in the process of falling is the hip bone.which is a major cause of disability and death in older people because of their low bone strength.Therefore,it has great significance to study the protection of hip bone for the elderly.The fall mechanism is studied aiming at the problem of fall protection combined with biomechanics.This paper mainly study the forward and lateral fall,fall in the human body multi-rigid-body model is established through simplify,Then,Kane method is used to establish the multi-body model equations of human body for forward fall and lateral fall respectively.Finally,combined with the relationship between the main joint torque and the angle determined by Ali Erkan engin experiment,Kane equation is solved to get the relationship between the main joint torque and the angle during the fall Change of angle and angular velocity of simplified joints.According to the results of Kane equation,the theoretical impact stress on the hip is 2.439MPa when the human body falls.This paper design a kind of active passive hybrid vibration isolation fall buffer scheme,that is,inflatable airbag and rubber vibration isolation double buffered generalized spring,which is tied on both sides of the waist of human body in the way of belt.The buffered generalized spring is composed of hyperelastic rubber model and inflatable airbag mathematical model based on CV method.In order to analyze the buffering efficiency of the vibration isolation generalized spring,the single body model and the hip model are used to simulate the fall impact with or without buffer and isolation respectively.The pressure and velocity responses after the composite vibration isolation are obtained.The buffer capacity of the composite vibration isolation system is evaluated by analyzing the simulation results.The results show that the maximum impact stress is 1.611MPa and the buffer efficiency is 35.13%after the airbag rubber vibration isolation.The maximum impact stress value of the hip model is 1.549MPa and the cushioning efficiency is 40.22%.Therefore,in the process of human fall,rubber and air bag hybrid vibration isolation can effectively reduce the impact of fall impact,and also can reduce the injury of the elderly due to fall.In addition,regarding the problem of fall detection and control,a modular fall detection and control system is designed,which use STM32F103ZET6 as the main control chip,and integrates MPU6050 acceleration and gyroscope sensor module,NEO-6MGPS positioning module,SIM800C communication alarm module,buzzer,indicator light and other auxiliary components.This paper design from four aspects:hardware system,software program,function realization and experiment verification.The analysis results show that the accuracy rate of the fall detection control system is 94.5%,which verify the reliability and effectiveness of the fall detection control system.