A novel blood pressure measurement system was designed which based on auscultatory method. And the electret sensor that embedded into the internal instrument can detect the Korotkoff-sound signal directly which is coupled by the cuff and transmitted in the cross connection. The BP values identification algorithm is based on combined detection of Korotkoff-sound and pulse signal, and the products of amplitudes and energies are calculated as the characteristic values of Korotkoff-sound, and the Korotkoff-sound phases are classified and detected by means of clustering of characteristic values, and then BP parameters are determined. The contrast test and statistical analysis showed good consistency and accuracy between the new BP detection method and conventional mercury sphygmomanometer.
Blood Pressure ; Blood Pressure Determination ; instrumentation ; methods ; Equipment Design

OBJECTIVETo assess mental fatigue by noninvasive monitoring of the physiological signals.

METHODSThe changes in the physiological parameters including the electrodermal activity, heart rate and heart rate variability were analyzed in 14 subjects performing the reaction-time tasks when fatigue and changes in the reaction time occurred.

RESULTSThe average skin conductance level, average heart rate, and heart rate variability parameters including the total power density, percentage of the very low power density, percentage of high power density all differed significantly between the sober state and the mental fatigue state.

CONCLUSIONMonitoring the physiological parameters including the electrodermal activity, heart rate and heart rate variability is a noninvasive, effective and practical approach to mental fatigue assessment.

Adult ; Galvanic Skin Response ; physiology ; Heart Rate ; physiology ; Humans ; Male ; Mental Fatigue ; physiopathology ; Reaction Time ; Young Adult

This paper is aimed to study the feasibility of myocardial infarction risk assessment by noninvasive multivariable trend analysis, including heart rate variability (HRV), deceleration capacity (DC) of heart rate and pulse wave velocity (PWV). Thirty five patients with cardiovascular diseases (11 Myocardial infarction (MI), 8 coronary artery disease (CAD), 6 artery atherosclerosis (AA) and 10 hypertension), and 31 healthy subjects were randomly selected into a control group for this research as comparison. 15 min ECG and 1 min pulse wave data were collected based on the analysis workbench developed by our Lab. HRV, DC and PWV between the cardiovascular group and the control group were analyzed and compared. The results showed that the HRV indices, DC and PWV were significantly higher than those in the control group. The DC and the HRV indices including NN50, PNN50 and TINN especially presented a decline trend that was consistent with the regularity of cardiovascular development process. This noninvasive multivariable trend analysis of HRV, DC and PWV can be a reference for the earlier risk prediction of MI.
Aged ; Electrocardiography ; Female ; Forecasting ; Heart Rate ; Humans ; Male ; Middle Aged ; Multivariate Analysis ; Myocardial Infarction ; physiopathology ; Pulse ; Risk Assessment

This article describes a design of physiological signal storage format and transfer protocol for the tele-medical system between home and community. The protocol is based on ASCII character, with frames as its basic structure. There are two kinds of frames: control frames and data frames. Control frames can start and stop data transfer, confirm the order, and ask for start. There are seven kinds of data frames, according to the different data types. Data is transferred in data frames. The protocol described in this article is simple and extensible. The design target has been accomplished in real system.
Community Health Services ; methods ; Medical Informatics Applications ; Software Design ; Telemedicine ; instrumentation ; methods

Physiology parameters measurement based on volume pulse wave is suitable for the monitoring blood pressure continuously. This paper described that the systolic blood pressure (SBP) and diastolic blood pressure (DBP) can be calibrated by measuring the pulse propagation time, just on one point of finger tip. The volume pulse wave was acquired by lighting the red and infrared LED alternately, and after signal processing, an accelerated pulse wave was obtained. Then by measuring the pulse wave propagation time between the progressive wave and reflected wave, we can find the relationship of the time and the blood pressure, and establish the related systolic blood pressure measurement equation. At the same time, based on the relationship between alternating current and direct current components in the volume pulse waveforms and through regression analysising, the relevant diastolic blood pressure measurement equation can be established. 33 clinical experimentation cases have been worked by dividing them into two groups: training group (18 cases) and control group (15 cases), by comparing with the measuring results of the OMRON electronic sphygmomanometer. The results indicated that the two methods had good coherence. The measurement described is simple and reliable, and may be served as a new method for noninvasively and continuously measurement of blood pressure.
Blood Pressure ; physiology ; Blood Pressure Determination ; instrumentation ; methods ; Humans ; Pulse ; Sphygmomanometers

BACKGROUND: Researches on the diagnosis and detection methods of diabetic autonomic neuropathy(DAN) is very weak at present.OBJECTIVE: To get the data about the degree of autonomic neuropathy by using the nonlinear heart rate variability(HRV) so as to provide clinical evidence for the early diagnosis of DAN.DESIGN: A single sample study.SETTINGS: Computer department in a university; Staff room of medical physics of department of biomedical engineering in a university.PARTICIPANTS: The experiment was completed in the Staff Room of Medical Physics, Department of Biomedical Engineering in the First Military Medical University of Chinese PLA from March to May 2002. Thirty-four diabetic patients, including 22 with DAN complications, were selected from the inpatients of Department of Endocrinology in the Affiliated Nanfang Hospital of the First Military Medical University of PLA, and other 40 normal subjects, who were from the faculty in the First Military Medical University of Chinese PLA and students in the Department of Physical Education, Chinese PLA Institute of Physical Education, were taken as the controls. The R wave to R wave intervals(RRI) time series is sampled and corrected to 512 points for analysis.INTERVENTIONS: Based on the virtual instrumental workbench-LabVIEW, 74 standard adjacent RRI signals were selected from 34 diabetic patients and 40 normal cases, and then analyzed with the method of nonlinear predictability.MAIN OUTCOME MEASURES: Collective and analytical results of the 74 standard adjacent RRI signals.RESULTS: There was no significant difference between the diabetic patients without DAN and the controls by the analysis with normalized mean square error(NMSE) NMSE ( P = 0. 075 ), but the significant difference between the DAN patients and the controls( P = 0. 001) . While significant analysis between the diabetic patients without DAN complications and the controls was significant by the analysis of mean absolute error(MAE) (P = 0. 007 and P = 0. 000), there was also significant difference between the diabetic patients with and without DAN ( P = 0. 001 ).CONCLUSION: Different impaired degree of autonomic nerve system in diabetic patients can result in nonlinear reduction in HRV analysis, but nonlinear predictability analysis can prove the nonlinear model of HRV,. and can also provide important state information of sympathetic and parasympathetic systems so that it can provide reliable evidence for the earlier diagnosis and the prognosis evaluation of DAN.

In this paper a new technique, Empirical Mode Decomposition(EMD), for use in non-stationary and non-linear data processing, was introduced. Some simulated signal, real ECG and RRI signals combined with Hilbert Transform method were analyzed. The authors also put emphasis on the differences between EMD and Wavelet Transform.
Algorithms ; Computer Simulation ; Diagnosis, Computer-Assisted ; methods ; Electrocardiography ; Heart Rate

Lives are maintained by enough oxygen.Blood oxygen saturation is one of the important parameters which reflects oxygen concentration in blood.The accurate monitoring of blood oxygen saturation is very important to both physiological research and medical application.At present,dual-wavelength method is widely adopted in noninvasive detection of blood oxygen saturation.Therefore,accurate recognition of peak-to-peak value of pulse waveform is a key process in monitoring blood oxygen saturation.In the paper,LMS self-adaptive arithmetic is applied to processing pulse waveform signal.The ratio of corrective detection is improved by the method.

In allusion to the defects of traditional electronic sphygmomanometer in deflation process,this paper puts forward an innovative way which accomplishes the measure of blood pressure during charge process based on oscillometric method.It is proved to be more energy-saving,more subminiature,less measuring time and more stable for individual.

Objective To study non-invasive measurement of reflectance oxygen saturation.Methods Diffusion theory was used to explain the action of light in tissue and deduce reflectance oxygen saturation formula.Then,Reflectance Oxygen Saturation Detection System based on MSP430 was developed and calibrated.Result The calibration result and calibration curve was ascertained and analyzed.Conclusion The formula for detection and measurement of oxygen saturation is put forward by using Reflectance Oxygen Saturation Detection System.