Physiological Information Transmission And Fusion For Assessing The Status Of Warfighter

The warfighter sign monitoring system can send soldiers'health,temperature load,injuries,and fatigue status to the medics or commanders over the wireless network in real time for the classification,assessment,treatment,and evacuation of vital signs during warfighters'health status.It is of great significance to combat deployment and soldier rescue.The thesis focuses on the monitoring requirements of individual soldiers under complex electromagnetic environment and usage conditions,and conducts the research on multi-sensor anti-jamming wireless body area network transmission for physical signs monitoring,data fusion and status classification based on body area network transmission.The main research contents of this thesis include:The data transmission scheme based on human body quasi-electrostatic field wireless body area communication was researched,and the body area communication transmission model under different positions of transceiver,human body and bulletproof vest was established;Based on the body area communication transmission model,the characteristics of body area communication interference under dynamic conditions are studied,which provides a theoretical basis for the optimization of communication links between distributed sensor nodes and individual soldier computers.The non-contact high-sensitivity quasi-electrostatic field signal communication transmission technology compatible with the individual protective equipment was studied.Combined with the subjective fatigue evaluation table,the trend of physiological characteristics under different fatigue levels was studied and a multi-source physiological parameter feature set was constructed.A multi-sensor physiological feature fusion algorithm of deep recurrent neural network was studied.The main innovative work of this article are:(1)Based on the quasi-steady-field theory and mirror image method,the gain and multi-path transmission model of the single-body body area communication transmission channel considering the individual soldier's protective equipment is established.The influence laws of transmitter position changes on the excitation characteristics and electric field distribution characteristics of the body area communication electric field are studied,which provides a theoretical basis for the research on the interference characteristics of wireless body area communication under dynamic conditions and the optimal design of transceivers.By using the finite element method to study the distribution law of human body electric field in a semi-enclosed environment,a body area communication transmission model under wearable soldier equipment was established.The effect of metal bulletproof vest on body area communication channel gain was obtained,which provides a theoretical basis for distributed sensor body area communication.(2)The interference characteristics of the wireless body area network transmission channel under dynamic conditions such as individual combat training were studied.Based on the principle of capacitive coupling,the electrostatic variation model of the body's electrification-discharge during exercise was established.It was revealed that the static changes of the human body during movement will produce an exponentially decaying spike at the receiving end.The spike width is related to the capacitance of the coupling capacitor at the receiving end and the cycle is the same as the step frequency.(3)The non-contact high-sensitivity wireless body area communication physical layer implementation technology that supports the integration of individual physical sign and protective equipment was studied.A method for optimizing the coupling efficiency of the electric field at the transmitting end based on isolated electrodes is proposed to realize the enhancement of human induced electric field.(4)An information fusion method based on deep recurrent neural network was proposed to evaluate the fatigue status of individual soldiers.Multi-source physiological information was used for feature-level information fusion,which reduced the error between predicted fatigue level and subjective fatigue level.The assessment of fatigue level is subjective and objective.Based on the theory and simulation analysis,the thesis completes the design and debugging of the prototype of Warfighter sign monitoring system based on the wireless body area communication networking,and validates the relevant theory through experiments.The human body communication error rate under different environments,different motion states and electromagnetic sweep frequency interference was tested.The results show that the optimized wireless body area communication prototype can adapt to different environments and has anti-motion interference and anti-electromagnetic interference stable transmission capability.The error rate during the test is lower than E^-5.The fatigue level recognition accuracy of different groups and different exercise loads were tested.The results showed that the fusion algorithm based on deep recurrent neural network has high robustness.It can accurately identify 5 levels of fatigue with an accuracy rate of more than 90%.It was superior to shallow recurrent neural network(RNN),back propagation neural network and multiple linear regression model(MLR)and other algorithms.