ABSTRACT
Objective To study the shadowing effect when using UWB bio-radar to detect multiple static human targets to solve the problem in multi-target detection.Methods With simulated breathing apparatus as detection targets,the UWB bioradar multi static targets respiration detection experiment was designed,and the influences of distance and angle between targets and its respiratory frequency and amplitude on the shadowing effect were studied.Result The shadowing effect was mainly affected by the relative position of the multiple targets,while the respiratory frequency and amplitude of the target had less influence on it.Conclusion When multi static human targets are detected the shadowing effect does exist,and the effect mainly derives from the block of electromagnetic wave by the front target,while the change of respiratory parameters of the front target has little influence on the effect.
ABSTRACT
Human gait involves a complex mechanism of muscular skeletal coordinated operation,which is specific and can be used as the basis of identity recognitions and clinical disease diagnoses.Human gaits have wide application value in the field of disaster rescue,battlefield ambulance,counter-terrorism,security,and medical and healthcare.The traditional contact-free gait detection technology mainly depends on optical images or ultrasound,which is susceptible to light,low visibility,obstacles,etc.In recent years,with the rapidly development of bio-radar technology,the bio-radar based contact-free human gait signal detection technology has shown more advantages.It can not be affected by light,can penetrate clothing,camouflage or even walls,and can operate in all-weathe,including low visibility weather conditions such as smog,smoke and fog.In this paper,the technical principles and methods of bio-radar based contact-free human gait detection technologies were discussed,the research status was summarized,and the development trendency was prospected.
ABSTRACT
Objective To explore the feasibility and applicable conditions of one-dimensional distance distinction combining pixel segmentation algorithm in multi-target recognition and identification of multi-channel ultra wide-band bioradar.Methods The signals the radar received were decomposed,reconstructed and filtered,and one-dimensional distance distinction algorithm was applied to achieving multi-target distance discrimination,then multi-target two-dimensional positioning was achieved based on the principle of angle determination applying pixel segmentation algorithm.Finally,a target positioning experiment was executed by collecting 10 volunteers using the method above.Results The experiment indicated that pixel segmentation algorithm gained advantages when used for positioning a single target while disadvantages for multi target.Concluslon It's proved that it's feasible to locate three or less targets with one-dimensional distance distinction as well as two-dimensional locating based on pixel segmentation algorithm.Positioning accuracies are different in case of numbers of targets.
ABSTRACT
Objective To explore the feasibility and applicable conditions of one-dimensional distance distinction combining pixel segmentation algorithm in multi-target recognition and identification of multi-channel ultra wide-band bioradar.Methods The signals the radar received were decomposed,reconstructed and filtered,and one-dimensional distance distinction algorithm was applied to achieving multi-target distance discrimination,then multi-target two-dimensional positioning was achieved based on the principle of angle determination applying pixel segmentation algorithm.Finally,a target positioning experiment was executed by collecting 10 volunteers using the method above.Results The experiment indicated that pixel segmentation algorithm gained advantages when used for positioning a single target while disadvantages for multi target.Concluslon It's proved that it's feasible to locate three or less targets with one-dimensional distance distinction as well as two-dimensional locating based on pixel segmentation algorithm.Positioning accuracies are different in case of numbers of targets.
ABSTRACT
To separate the biological radar echo signals in different breathing modes. Echo signals of bioradar-based vital signs monitoring system were acquired in different breathing modes, and an improved signal separa-tion algorithm was used to obtain respiratory and heartbeat signals as well as their parameters. Under two breath-ing modes, the center frequencies of the signals from the self-adaptive filter were kept consistent with those of heartbeat signals, and the signals with other frequencies were suppressed effectively. The algorithm can be used to sep-arate heartbeat signals while suppress other interference signals effectively. ZHANG Jing and LIU Qian are the first au-thors who contributed equally to the article.
ABSTRACT
To design a new method to simulate the micro-motion of human body surface due to respiration and heartbeat, and to provide detection object and calibration signal for the bio-radar technology. Precision lin-ear module was used to transform rotational movement to linear displacement, with AC servo motor to precisely control the module's rotation. Ultimately, ultralow-frequency micro-motion was produced with its displacement being quantitatively controlled. A system simulating the micro-motion of human body surface was newly built. Compared with the old system, the new one produced micro-motion with better constancy, and realized quantitative control of the motion's dis-placement. The method lays technological foundation for simulating the micro-motion of human body surface due to respiration and heartbeat and may promote the development of bio-radar technology towards intensive and compre-hensive levels.
ABSTRACT
Bioradar is based on the integration of theory of radar and bio-medical engineering,which can detect the life-parameters in farther distance.It is new concept radar presented by foreign experts.The technology can be widely used in detection of lifeform signal and non-contact clinical monitoring.Biomedical signal processing method is the premise that the technology can be realized.The signals can be interfered by the environmental factors,breath motion and so on,especially the influences of breath motion which can not be solved by average methods.A large number of signal processing methods are used in various aspects of the technology.This review introduces the progress of bioradar technology and the application of the current signal processing methods in the field.