Study On The Dynamic Characteristics Of Airbags For Flexible Nursing Beds For Turning Assistance

Aggravating population aging has become a social problem facing China and the world,and daily care and disease prevention for middle-aged and elderly people are complicated and necessary medical work.According to the main causes of respiratory system and the nursing needs of bed paralysis,a flexible nursing mattress for assisted turning over was designed.The mattress uses an airbag as a key force member,and combined with a flexible pressure-sensitive sensor to achieve the function of monitoring the breathing state during sleep and adjusting the sleeping position,and can prevent bed sores from occurring in bed through pressure equalization and massage functions.However,the model equation of the dynamics of the airbag used in the nursing bed is not clear.In order to effectively realize the sleeping position adjustment function of the mattress,it is necessary to design and verify the relationship between the inflation height,the internal pressure of the airbag,and the external bearing pressure.Based on the different loading conditions of different airbags,accurate control of the inflation height of airbag mattresses is achieved.The main contents of this paper are as follows:First,the design parameters,overall layout,and control methods of the multifunctional airbag care mattress are introduced,including the structure and size of the airbag,and the actual airway connection method of a single airbag.Secondly,because the airbag is the key active part of the flexible nursing mattress,in order to reasonably control the inflation of the airbag,it is necessary to explore the relevant dynamic characteristics of the airbag.Therefore,the key content of this article is to explore the relationship between the airbag pressure and the inflation height under different external loads,and to provide a control basis for effective control of the airbag.The finite element simulation software HYPERMESH is used to geometrically model the airbag,and the model boundary conditions are defined in HYPERCRASH,and submitted to the RADIOSS solver for solution.The airbag film material is subjected to a quasi-static uniaxial tensile test.The test data is processed and input into the existing material model of HYPERCRASH for superelastomers to obtain the airbag film material model needed to establish the airbag boundary conditions.An airbag parameter measurement platform is designed to measure the real-time inflation height and inflation pressure under a certain load,providing a basis for subsequent data analysis and comparison.Based on the no-load airbag model,a loaded airbag model is established to analyze the situation of the airbag on the mattress when it is under pressure from different parts of the human body.The airbag inflation height and internal pressure in the no-load state of modeling and simulation are compared with the airbag inflation height and internal pressure obtained from actual measurement experiments to verify the correctness of the no-load airbag model.The same method was used to verify the correctness of the airbag model with different loads.Finally,through the method of numerical fitting,the mathematical relationship between the inflation height of the airbag under different loads and the change in internal pressure is obtained,and a comparative analysis of how the inflation height of the airbag should be determined by the internal pressure of the airbag when different parts of the human body press the airbag It provides an important basis for the accurate control of flexible nursing bed airbags.