R波相关振动法血压测量

为了提高振地血压测量的准确性，提出了一咱基于心电Ｒ波与血压振动波之间相关性，识别振动信号的一种抗干扰方法＝－Ｒ波相关法，结合振动波形特征识别，该方法可有效地提取信号，消除干扰影响，该算法已在１６位８０９８单片机上实现，本文同时给出了程序的详细流程图。     

多气阀数字血压计的研制

本文研制的袖套式数字血压计，基于示波法原理，通过采用多通道、多气阀以及软件上的改进，改善了目前一般数字血压计的不足，与一般袖套式数字血压计相比，具有重复性好、测量范围大（成人和儿童都可测量）等优点。     

Pulse wave analyzed cardiovascular parameters in young first degree relatives of type 2 diabetics- a cross-sectional study

BackgroundFirst degree relatives (FDR) of type 2 diabetic (T2D) are predisposed for type 2 diabetes mellitus (T2DM) which accelerates cardiovascular aging. Pulse wave analysis (PWA) gives non-invasive measurement of central hemodynamics like central blood pressure (cBP), cardiac output (CO), stroke work (SW) and vascular stiffness like pulse wave velocity (PWV) and augmentation index at heart rate 75 (AIx@75).ObjectiveTo study PWA derived cardiovascular parameters in FDRs of T2D as compared to controls.Materials and methodsWe enrolled 117 FDRs of T2D and 117 matched controls for a cross-sectional study. We performed PWA using Mobil-o-Graph (IEM, Germany) by oscillometric method to derive cardiovascular parameters which were compared and correlated for significance. P value less than 0.05 was considered statistically significant.ResultsGender, age, height, weight, body mass index (BMI), physical activity were comparable between groups. FDRs of T2D had significantly higher blood pressure (brachial-systolic 125 vs 118, diastolic 80 vs 77, mean 100 vs 96 mmHg and central- systolic 113 vs 105, diastolic 82 vs 79, pulse pressure 31 vs 28 mmHg), SW (98 vs 90 g m/bt), rate pressure product (RPP- 113 vs 107), PWV (5.14 vs 4.89 m/s), AIx@75 (30 vs 27) than control. Dependant variables correlated with brachial BP more than age or anthropometric variables. Result did not differ by maternal or paternal inheritance in case group.ConclusionsYoung, sedentary, non-obese FDRs of T2D have adverse cardiovascular profile which is suggested to worsen before or with onset of T2DM and definitely need attention for life style modification as primary prevention.     

Clinical evaluation of the oscillometric blood pressure monitor in adults and children based on the 1992 AAMI SP-10 standards

Objective and Methods. A noninvasive blood pressure monitor (model BP8800MS, Colin Medical Instruments Corp., San Antonio, TX) that uses the oscillometric principle was evaluated against the manual auscultatory method in 85 adults and 85 children following the requirements of the 1992 AAMI SP-10 standard. This was the first evaluation study of the electronic sphygmomanometers according to the new AAMI standards.Results. In adult subjects, the mean difference and standard deviation of the differences between the oscillometric and auscultatory methods were 2.81 ± 5.35 mm Hg (mean ± SD) for systolic and 0.04 ± 4.90 mm Hg for diastolic; in children, they were 3.18 ± 5.96 mm Hg for systolic and –0.82 ± 5.24 mm Hg for diastolic. Excellent correlation between the oscillometric and auscultatory methods, particularly the diastolic pressure, is due to usage of the Phase V Korotkoff's sounds for auscultatory detection of the diastolic pressure, increased accuracy of the two observers' measurements, and proper selection of cuff sizes depending on the mid-arm circumference. Five different-sized cuffs were used in this study. The cuff-width-to-midarm circumference ratio was adjusted to be 0.4 or larger to minimize the measurement error associated with mismatch of cuff-size/arm-size relationship. The distribution of errors associated with each cuff was nearly the same.Conclusions. The 1992 AAMI SP-10 standards offer a thorough evaluation of the oscillometric sphygmomanometer by enforcing more stringent criteria on (1) agreement between two observers, (2) wide spectrum of blood pressure from hypertensive (above 180 mm Hg) to hypotensive, and (3) data analysis. The oscillometric blood pressure monitor evaluated in this study meets the specifications of the new AAMI SP-10 standards and can offer an accurate, automatic, and noninvasive measure of both systolic and diastolic blood pressure in adults and children. It can safely replace the manual or automatic auscultatory system in various clinical settings.This study was supported in part by a grant in aide from Nippon Colin (Komaki, Japan) and Colin Medical Instruments (San Antonio, TX). The authors acknowledge Dr. James Pool and Ms. Charlyne Allston-Wright of the Department of Medicine, Baylor College of Medicine, for providing hypertensive subjects. Technical assistance by Ms. Julie Glueck of the Department of Surgery, Baylor College of Medicine, is also acknowledged.     

The Study of Improving Detection Accuracy of Blood Pressure Meter Based on Oscillometric Method

INTRODUCTION　Noninvasive blood pressure meteris wide- used in clinical physiological monitor-ing system and home care instrument.There are two principal methods of noninva-sive detecting blood pressure.　　 Auscultatory technique is whereby sounds( known as Korotkoff sounds) areheard over an occluded artery as the occluding pressure is slowly released,the ap-pearance of sounds coinciding with systolic and the disappearance of sounds witdiastolic blood pressure.This method has some intrin…     

Theoretical analysis of non-invasive oscillometric maximum amplitude algorithm for estimating mean blood pressure

A theoretical analysis is performed to evaluate the effect of arterial mechanical and blood pressure pulse properties on the accuracy of non-invasive oscillometric maximum amplitude algorithm (MAA) estimates of the mean blood pressure obtained using air-filled occlusive cuffs. Invasively recorded blood pressure pulses, selected for their varied shapes, are scaled to simulate a wide range of blood pulse pressures (diastolic blood pressure minus systolic blood pressure). Each scaled blood pressure pulse is transformed through an exponential model of an artery to create a series of blood volume pulses from which a simulated oscillometric waveform is created and the corresponding MAA estimate of the mean blood pressure and error (mean blood pressure minus MAA estimate) are determined. The MAA estimates are found to depend on the arterial blood pressure. The errors are found to depend on the arterial mechanical properties, blood pressure pulse shape and blood pulse pressure. These results suggest that there is no direct relationship between the mean blood presure and MAA estimate, and that multiple variables may affect the accuracy of MAA estimates of the mean blood pressure obtained using air-filled occlusive cuffs.     

Comparison of arm and calf automatic noninvasive blood pressures in pediatric intensive care patients

The purpose of this study was to compare upper arm and calf automatic blood pressures (BPs) in a convenience sample of 221 children, ages 1 to 8 years, admitted to a pediatric intensive care unit of a 180-bed teaching hospital in the Mid-Atlantic region of the United States. Subjects were positioned in bed, with the head of bed elevated 30° and extremities resting on the bed. BP cuff size was based on arm and calf circumferences. BPs were measured simultaneously using bedside and portable Spacelabs monitors. Calf BPs were greater than arm BPs in approximately 73% of the sample. Paired t tests show statistically significant differences for systolic BPs and mean arterial pressures. Influence of demographics, agitation levels, medical diagnoses, and current medications was explored. Calf and arm BPs were not interchangeable in acutely ill children, ages 1 to 8 years.     

Non-invasive oscillometric measurement of systolic,mean and diastolic blood pressure in infants with congenital heart defects after operation. A comparison with direct blood pressure measurements

The accuracy of indirect oscillometric blood pressure measurements has been evaluated in 32 infants up to 11 months of age undergoing heart surgery. In a number of 1029 simultaneous measurements the indirect blood pressure was compared with the direct value obtained from a radial artery catheter. Cuffs of different sizes were applied. The main results were as follows: (1) Regarding the ratio of cuff width to arm circumference, the best correlation between oscillometric and direct blood pressure measurements was obtained with a ratio of 0.38–0.41. (2) The value of indirect blood pressure measurements depends on the absolute height of the blood pressure. In low blood pressure there is a tendency to underestimate and in high blood pressure there is a tendency to overestimate by the oscillometric blood pressure measurement.By applying an appropriate cuff size and by using our diagrams it should be possible to derive a direct value for the blood pressure on the basis of indirect oscillometric blood pressure measurements.Abbreviations BP blood pressure - BPM blood pressure measurements - CW/ArmC cuff width to arm circumference ratio - DAP diastolic arterial pressure - MAP mean arterial pressure - SAP systolic arterial pressure - ME mean error - SD standard deviation Research fellow supported by the A. v. Humboldt Stiftung