Abstract:The loss of bone calcium caused in the weightlessness environment, which will lead to a significant decline in bone condition. Therefore, it is necessary to detect bone regularly. In view of the fact that most of the traditional bone detection devices are based on metal and semiconductor materials,which have poor flexibility and wearability,with the detection parts are incomplete, a human bone condition detection system based on portable flexible ultrasonic sensors is proposed.The proposed system adopts quantitative ultrasound and axial detection theory,composed of ultrasonic sensor, control circuit by FPGA (Field Programmable Gate Array) and mobile APP. The sensor package is changed to a flexible substrate, which could comprehensively detect all parts of the body.Experimental measurement is carried out at the tibia of 30 volunteers.The experimental results show that the energy transfer efficiency of the flexible ultrasonic bone data acquisition system is as high as 35%.The detection and real-time display of the detection results can be completed within 0.2s,with the error less than 0.3%. This system has an important application prospect in the field of lightweight bone detection system, which is expected to replace traditional bone detection equipment and provide technical support for the application of wearable devices.