1.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
2.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
3.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
4.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
5.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
6.Accuracy of the daily dengue severity score in assessing disease severity in children
Mary Ann G. Abella ; Belle M. Ranile
Pediatric Infectious Disease Society of the Philippines Journal 2024;25(2):69-79
BACKGROUND
Dengue is a global health concern, particularly in tropical regions such as the Philippines. In 2019,Cebu City reported the highest number of dengue cases in Central Visayas with 3,290 cases and 20 deaths, an 11.8% increase compared to 20181 . To help predict disease outcomes and provide timely management, a scoring system, the Daily Dengue Severity Score (DDSS)² was utilized.
OBJECTIVETo determine the clinicodemographic profile of dengue patients, determine the accuracy of the DDSS in assessing disease severity, and determine a cut off score that suggests severe dengue.
METHODSPatients 1 month to 18 years admitted for dengue at Perpetual Succour Hospital from January 2018 to December 2020 were included. Cases were classified as Dengue without Warning Signs, Dengue with Warning Signs, and Severe Dengue, and scored using the DDSS. Statistical analysis used were Geometric mean and Area Under the Receiver Operating Characteristic (AUROC) curves to analyze the discriminative performance of the DDSS among the different disease severity states.
RESULTSOut of 327 cases, 34 were classified as Dengue without Warning Signs, 271 Dengue with Warning Signs, and 22 Severe Dengue. The highest mean DDSS was 17.7 ±14.0 at Day -4 among those with Severe Dengue, and the lowest mean DDSS was 1.1 ± 2.0 at Day +3 among those with Dengue without Warning Signs. A cut off point of 10 on Day -1 predicted subsequent Severe Dengue among patients with Dengue with Warning Signs. In 91.39% of cases, there was a significant relationship between the DDSS and dengue classification, and the higher the DDSS, the more severe the disease.
CONCLUSIONMajority of dengue patients were males, aged 8.1 to 9.2 years. DDSS showed 66.67% sensitivity, 92.86% specificity, a positive likelihood ratio of 9.3, and a cutoff of 10 is predictive of severe dengue among patients with dengue with warning signs.
Human ; Dengue ; Scoring Methods ; Research Design ; Patient Monitoring ; Monitoring, Physiologic
7.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
8.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
9.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
10.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