1.De-noising method research of ballistocardiogram signal.
Dan YANG ; Bin XU ; Linlin YE ; Jingjing JIN
Journal of Biomedical Engineering 2014;31(6):1368-1372
Ballistocardiogram (BCG) signal is a physiological signal, reflecting heart mechanical status. It can be measured without any electrodes touching subject's body surface and can realize physiological monitoring ubiquitously. However, BCG signal is so weak that it would often be interferred by superimposed noises. For measuring BCG signal effectively, we proposed an approach using joint time-frequency distribution and empirical mode decomposition (EMD) for BCG signal denoising. We set up an adaptive optimal kernel for BCG signal and extracted BCG signals components using it. Then we de-noised the BCG signal by combing empirical mode decomposition with it. Simulation results showed that the proposed method overcome the shortcomings of empirical mode decomposition for the signals with identical frequency content at different times, realized the filtering for BCG signal and also reconstructed the characteristics of BCG.
Algorithms
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Ballistocardiography
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methods
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Humans
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Monitoring, Physiologic
2.Measurement Error Analysis and Calibration Technique of NTC - Based Body Temperature Sensor.
Chi DENG ; Wei HU ; Shengxi DIAO ; Fujiang LIN ; Dahong QIAN
Chinese Journal of Medical Instrumentation 2015;39(6):395-399
A NTC thermistor-based wearable body temperature sensor was designed. This paper described the design principles and realization method of the NTC-based body temperature sensor. In this paper the temperature measurement error sources of the body temperature sensor were analyzed in detail. The automatic measurement and calibration method of ADC error was given. The results showed that the measurement accuracy of calibrated body temperature sensor is better than ± 0.04 degrees C. The temperature sensor has high accuracy, small size and low power consumption advantages.
Body Temperature
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Calibration
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Humans
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Monitoring, Physiologic
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methods
3.Progress of research on intracranial pressure monitoring.
Jun WU ; Wei HE ; Lian ZHU ; Zhifang PAN
Journal of Biomedical Engineering 2014;31(2):458-471
At present, the monitoring methods fwor intracranial pressure adopted in clinical practice are almost all invasive. The invasive monitoring methods for intracranial pressure were accurate, but they were harmful to the patient's body. Therefore, non-invasive methods for intracranial pressure monitoring must be developed. Since 1980, many non-invasive methods have been sprung out in succession, but they can not be used clinically. In this paper, research contents and progress of present non-invasive intracranial pressure monitoring are summarized. Advantages and disadvantages of various ways are analyzed. And finally, perspectives of development for intracranial pressure monitoring are presented.
Humans
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Intracranial Pressure
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Monitoring, Physiologic
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methods
4.The research and design of non-invasive cardiac output detector based on pulse graph theory.
Chinese Journal of Medical Instrumentation 2011;35(5):344-347
This cardiac output detector uses AT89C52 as the core MCU, carries the pulse signal sampling from pulse sensor into the SCM after A/D conversion, and then figures out the cardiac output value and displays it on the LED. Software analysis works out the cardiac output value through five-point difference threshold for feature location of the pulse graph method theory. Experiment results show that the normal measured cardiac output is 5.411 L/min, the standard deviation of 0.873, while the catheter method as the gold standard of the mean 5.51 L/min, the standard deviation of 1.09. This system can meet the testing requirements of normal cardiac output. It is a non-invasive, convenient and new cardiac output measurement instrument with continuous testing, easy operation and low cost.
Cardiac Output
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Monitoring, Physiologic
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instrumentation
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methods
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Pulse
5.A review of the application of electroencephalogram in detecting depth of anesthesia.
Journal of Biomedical Engineering 2005;22(3):645-648
Anesthesia as a necessary procedure in the process of surgical operation could restrain the response of patients to the damage stimulation; However, improper anesthesia could also result in severe misfortune for patients. At the present time, one kind of monitor technology assuring highly effectual anesthesia is exigently required in clinical practice and many researchers have actively undertaken investigations to seek the parameters predicting the depth of anesthesia (DOA). Electroencephalogram (EEG) assumes a dominant position in the current researches on detecting the depth of anesthesia. In this paper, the achievements of detecting the depth of anesthesia by means of EEG are systematically reviewed and the potentials are anticipated.
Anesthesia
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Anesthesiology
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methods
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Electroencephalography
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Humans
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Monitoring, Physiologic
6.Technical Difficulties in the Implementation of the Continuous Glucose Monitoring System.
Yacheng FU ; Changyun QUAN ; Lixia LIU ; Wei ZHANG
Chinese Journal of Medical Instrumentation 2022;46(4):422-427
The continuous glucose monitoring system (CGMS) has been clinically applied to monitor the dynamic change of the subcutaneous interstitial glucose concentration which is a function of the blood glucose level by glucose sensors. It can track blood glucose levels all day along, and thus provide comprehensive and reliable information about blood glucose dynamics. The clinical application of CGMS enables monitoring of blood glucose fluctuations and the discovery of hidden hyperglycemia and hypoglycemia that are difficult to be detected by traditional methods. As a CGMS needs to work subcutaneously for a long time, a series of factors such as biocompatibility, enzyme inactivation, oxygen deficiency, foreign body reaction, implant size, electrode flexibility, error correction, comfort, device toxicity, electrical safety, et al. should be considered beforehand. The study focused on the difficulties in the technology, and compared the products of Abbott, Medtronic and DexCom, then summarized their cutting-edge. Finally, this study expounded some key technologies in dynamic blood glucose monitoring and therefore can be utilized as a reference for the development of CGMS.
Blood Glucose
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Blood Glucose Self-Monitoring/methods*
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Humans
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Hyperglycemia
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Hypoglycemia
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Monitoring, Ambulatory/methods*
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Monitoring, Physiologic
7.Functional hemodynamic monitoring.
Jun XU ; Hou-Li WANG ; Zhong WANG ; Xue-Zhong YU
Acta Academiae Medicinae Sinicae 2008;30(2):214-217
Hemodynamic monitoring is important for critically ill patients in emergency medicine. While the conventional static hemodynamic monitoring may not accurately reflect the hemodynamic status, functional hemodynamic monitoring can dynamicly and individually monitor the hemodynamic status, and thus becomes a valuable supplementation for conventional static hemodynamic monitoring. This article reviews the limitations of conventional hemodynamic monitoring and introduces the methodology of functional hemodynamic monitoring.
Emergency Medicine
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methods
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Hemodynamics
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physiology
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Humans
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Monitoring, Physiologic
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methods
8.Investigating the fractal characteristic of heart rate variability during anesthesia.
Xiaofang LIU ; Wenlong XU ; Wu CHEN ; Zhiqian YE
Journal of Biomedical Engineering 2006;23(3):492-495
By use of fractal analysis indexes-correlation dimension, fractal dimension and scaling exponent, the heart rate variability signals obtained from 38 subjects' ECG during anesthesia are analyzed. The results show that there is an obvious change of fractal characteristic of heart rate variability during anesthesia. The correlation dimension (P < 0.000001) during anesthesia is evidently less than that during consciousness, while the short-range scaling exponent a (P < 0.0001) during consciousness is evidently less than that during anesthesia. These illustrate that the difference in fractal characteristic between anesthesia and well-balanced state can be detected by the fractal analysis of heart rate variability. In the end, the paper poses that the analysis of heart rate variability is fit for monitoring the depth of anesthesia by detrended fluctuation analysis.
Anesthesia
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Electrocardiography
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Heart Rate
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physiology
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Humans
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Monitoring, Physiologic
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methods
9.Development of cardiac output monitoring system based on thermodilution method.
Jilun YE ; Yun JIANG ; Sai LUO ; Fan WANG ; Xu ZHANG
Chinese Journal of Medical Instrumentation 2014;38(5):337-340
Cardiac output (CO) monitoring is a crucial part of the hemodynamic status monitoring. So far, thermodilution method, which is clinically recognized as the gold standard method to monitor cardiac output, still has irreplaceable advantages. This paper mainly introduces the use of platform for cardiac output measurement based on thermodilution method, mainly including three parts: the hardware platform, software design and algorithm process. A large amount of test data of this system has been got by CO simulator testing in the laboratory and preliminary clinical tests in the hospital. The testing result showed that using the proposed system can achieve good accuracy and repeatability.
Algorithms
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Cardiac Output
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Hemodynamics
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Humans
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Monitoring, Physiologic
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instrumentation
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methods
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Thermodilution
10.Wearable devices: Perspectives on assessing and monitoring human physiological status.
Chung-Kang PENG ; Xingran CUI ; Zhengbo ZHANG ; Mengsun YU
Journal of Biomedical Engineering 2023;40(6):1045-1052
This review article aims to explore the major challenges that the healthcare system is currently facing and propose a new paradigm shift that harnesses the potential of wearable devices and novel theoretical frameworks on health and disease. Lifestyle-induced diseases currently account for a significant portion of all healthcare spending, with this proportion projected to increase with population aging. Wearable devices have emerged as a key technology for implementing large-scale healthcare systems focused on disease prevention and management. Advancements in miniaturized sensors, system integration, the Internet of Things, artificial intelligence, 5G, and other technologies have enabled wearable devices to perform high-quality measurements comparable to medical devices. Through various physical, chemical, and biological sensors, wearable devices can continuously monitor physiological status information in a non-invasive or minimally invasive way, including electrocardiography, electroencephalography, respiration, blood oxygen, blood pressure, blood glucose, activity, and more. Furthermore, by combining concepts and methods from complex systems and nonlinear dynamics, we developed a novel theory of continuous dynamic physiological signal analysis-dynamical complexity. The results of dynamic signal analyses can provide crucial information for disease prevention, diagnosis, treatment, and management. Wearable devices can also serve as an important bridge connecting doctors and patients by tracking, storing, and sharing patient data with medical institutions, enabling remote or real-time health assessments of patients, and providing a basis for precision medicine and personalized treatment. Wearable devices have a promising future in the healthcare field and will be an important driving force for the transformation of the healthcare system, while also improving the health experience for individuals.
Humans
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Artificial Intelligence
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Wearable Electronic Devices
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Monitoring, Physiologic/methods*