Design and Realization of a Wearable Hip-Airbag System for Fall Protection

Abstract

Nowadays falls are a serious problem for elderly people with the coming of aged society in the world. According to statistics,hip fracture accounts for the most of the deaths and costs of all the fall-induced injury. This paper presented an airbag system of hip protection, which included air source, sensors, microcontroller, gas circuit and airbags. A six-axial inertial sensor module that integrated an embedded three-axis MEMS accelerometer and three-axis MEMS gyroscope was used to collect human motion data, and a one-axis obliquity sensor was used to collect human angle data. The microcontroller was employed to recognize the activities of daily living (ADL) and falls based on fall detection algorithm and the collected data from sensors. The gas circuit was triggered once the event that the fall would be inevitable was confirmed by the microcontroller, then the compressed gas would fill into airbags through the gas circuit rapidly. Therefore, a buffer would appear between the human body and the ground before the body impacting the ground, which would reduce the impact of the human body. Compressed CO2 was selected as the air source after we tested several kinds of gas. A 16g CO2 pressurized cylinder could provide enough pressure and volume to inflate quickly the airbags. In order to improve the reliability of the gas circuit, a needle valve was optimized from the several designed structures by the experimental optimization methods. Finally, the airbag system was tested in various designed trials. The results indicated that the system gained the satisfaction for the design requirements and would be potential to apply to the protection of hip joint in the fall high-risk people in the future.

New coordination complexes-based gas-generating energetic composites

“…Recently, new applicative markets have emerged with the goal to prevent personal injuries during extreme sport (skiing, equitation, motorcycling), urban twowheelers or to protect the elderly from hips fracture when falling. For these new applicative domains, smart inflatable protection devices using compressed CO2 bottles are now available on the market [4][5][6]. When the sensors detect a fall, the integrated circuitry triggers the actuator, which then inflates the nylon airbag before the impact [7,8].…”

A Study on the Application of LSTM to Judge Bike Accidents for Inflating Wearable Airbags

“…It is 15 times the 50 ms, which was used as the sampling time of this system. Although 15 sets of data are inputted by axis based on 750 ms [ 33 ], in the bike accident, the falls may occur clearly at a faster speed [ 32 ], which can be confirmed from the collected data as well. In Figure 9 , an accident occurred in the 46T–48T section and did not exceed 100 ms.…”

Wearable Airbag System for Real-Time Bicycle Rider Accident Recognition by Orthogonal Convolutional Neural Network (O-CNN) Model

“…The overall composition is shown in Figure 2 It takes about 770 ms for a person to fall in the event of an accident. Since the case of a bicycle accident is faster, the airbag must be inflated in time [14,23]. Thus, the whole system process from the determination of an accident by artificial intelligence to completion of the airbag operation was designed to be shorter than 770 ms.…”

“…Because the artificial neural network must react within the time it takes a person to fall (770 ms), the time range for the input data was set at 750 ms [14,19,23]. The sampling interval was fixed at about 50 ms.…”