scholarly journals Erratum: “Possible Sources of Discrepancy Between Sphygmomanometer Cuff Pressure and Blood Pressure Quantified in a Collapsible-Tube Analogue” (Journal of Biomechanical Engineering, 1992, 114, pp. 68–77)

1992 ◽  
Vol 114 (2) ◽  
pp. 201-201
Author(s):  
C. D. Bertram ◽  
K. S. A. Butcher
1992 ◽  
Vol 114 (1) ◽  
pp. 68-77 ◽  
Author(s):  
C. D. Bertram ◽  
K. S. A. Butcher

This paper examines the assumption that the audible events detected as Korotkov sounds in sphygmomanometry occur when blood pressure equals arm-cuff pressure. Several effects that contribute to discrepancy between these pressures are quantified using an idealised arm-and-cuff system consisting of a thick-walled collapsible tube subject to external compression along a central part of its length. The effects studied are (1) transverse pressure difference, resulting from tissues sustaining a part of the external compression through (a) circumferential bending stiffness and (b) longitudinal curvature of the tensed localised neck at the site of initial collapse, (2) longitudinal pressure difference between upstream pressure and pressure at the collapse point due to both (a) viscous and (b) inertial pressure drop. These effects are found to compensate partially for each other; the pressure within the vessel at the collapse point is less than the cuff pressure, but is also less than the blood pressure at the upstream end of the cuff. All four of the contributing terms increase proportionally to the flow-rate raised to a power greater than one, except the viscous pressure drop. Owing to a progressive shortening of the collapsed neck as flow-rate increases, the viscous term is almost independent of the flow-rate. The overall discrepancy displays less flow-rate dependency and is smaller than some of the terms which contribute to it. This means that considerable accuracy is needed if measurements of the effects are to be used to correct the raw data on cuff pressure at the time of Korotkov sound emission so as to obtain an improved estimate of the blood pressure.


2006 ◽  
Vol 128 (5) ◽  
pp. 680-687 ◽  
Author(s):  
Satoru Hayashi ◽  
Toshiyuki Hayase ◽  
Atsushi Shirai ◽  
Masaru Maruyama

In this paper, a simulation model based on the partially pressurized collapsible tube model for reproducing noninvasive blood pressure measurement is presented. The model consists of a collapsible tube, which models the pressurized part of the artery, rigid pipes connected to the collapsible tube, which model proximal and distal region far from the pressurized part, and the Windkessel model, which represents the capacitance and the resistance of the distal part of the circulation. The blood flow is simplified to a one-dimensional system. Collapse and expansion of the tube is represented by the change in the cross-sectional area of the tube considering the force balance acting on the tube membrane in the direction normal to the tube axis. They are solved using the Runge-Kutta method. This simple model can easily reproduce the oscillation of inner fluid and corresponding tube collapse typical for the Korotkoff sounds generated by the cuff pressure. The numerical result is compared with the experiment and shows good agreement.


Author(s):  
Enrique Alvarez Vazquez ◽  
Daniel Ewert ◽  
Dave Jorgenson ◽  
Michael Sand

Abstract This study describes a non-invasive medical device capable of measuring arterial blood pressure (BP) with a combination of inflationary and deflationary procedures. The device uses the pressure cuff pressure signal, arterial skin-surface acoustics, and photoplethysmography (PPG) to make a sensor-fusion estimation of blood pressure readings. We developed an apparatus composed of 1) a modified off-the-shelf oscillometric blood pressure system, 2) a contact microphone with an amplifier, 3) and high-sensitivity pulse oximeter, and its control electronics.


2021 ◽  
Vol 1 (1) ◽  
pp. 12-16
Author(s):  
Pragati Poudyel ◽  
Seerina Adhikari

 Introduction: Growing incidence of hypertension and its significant association with diabetes mellitus are being observed in both developing and developed countries around globe. Scanty literature is available about the comparative study of inter-arm variation of blood pressure in normal individuals and diabetic among Nepalese population. This research was performed to determine extent of inter-arm variation in normal individuals and diabetics. Methods: A descriptive observational study was carried out from 2013 January to 2014 January in a tertiary level teaching hospital of Nepal. After taking the consent and giving necessary instructions, blood pressures were measured in both the arms one after another in sitting posture using mercurial sphygmomanometer and Littman cardiosonic stethoscope. Arterial blood pressure was measured by palpatory method followed by auscultatory method The cuff pressure at which the tap sound were first perceived was noted as systolic blood pressure (SBP). Similarly, diastolic blood pressure (DBP) was noted at the point where the sound disappeared. Results: A total of 120 volunteers between ages of 40-80 years were studied. Highly significant inter-arm variation of both SBP and DBP was found in diabetics as compared to normal (p<0.01). Highly significant inter-arm variation was found in diabetic male and female as compared to their normal counter parts (p<0.01). Conclusion: This study showed that there was significant inter-arm variation of SBP and DBP in diabetic and normal individual. So, this study encourages to measure blood pressure (BP) in both arms for proper treatment planning of an individuals.


1992 ◽  
Vol 73 (5) ◽  
pp. 1946-1957 ◽  
Author(s):  
J. H. Muntinga ◽  
K. R. Visser

In 13 healthy volunteers a computerized experimental set-up was used to measure the electrical impedance of the upper arm at changing cuff pressure, together with the finger arterial blood pressure in the contralateral arm. On the basis of a model for the admittance response, the arterial blood volume per centimeter length (1.4 +/- 0.3 ml/cm), the venous blood volume as a percentage of the total blood compartment (49.2 +/- 12.6%), and the total arterial compliance as a function of mean arterial transmural pressure were estimated. The effective physiological arterial compliance amounted to 2.0 +/- 1.3 microliters.mmHg-1.cm-1 and the maximum compliance to 33.4 +/- 12.0 microliters.mmHg-1.cm-1. Additionally, the extravascular fluid volume expelled by the occluding cuff (0.3 +/- 0.3 ml/cm) was estimated. These quantities are closely related to patient-dependent sources of an unreliable blood pressure measurement and vary with changes in cardiovascular function, such as those found in hypertension. Traditionally, a combination of several methods is needed to estimate them. Such methods, however, usually neglect the contribution of extravascular factors.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Fan Pan ◽  
Peiyu He ◽  
Xiaobo Pu ◽  
Hu Gao ◽  
Fei Chen ◽  
...  

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
V. P Lombardi ◽  
Patrick C Reichhold ◽  
Jennifer L Cramer ◽  
Hannah P Harkness ◽  
Natalie J DeBell ◽  
...  

Purpose: To compare the accuracy & level of agreement of Oscar 2 & Spacelabs 90207 ABPMs with 2 observers (O1O2) using an Hg column & ThinkLabs digital stethoscope. Methods: O1O2 measured simultaneous same arm Hg column BPs & ABPMs assessed simultaneous opposite arm BPs in triplicate in 17 seated subjects (7 ♀, 10 ♂). Supine, seated & standing BPs were measured using non-dominant relaxed arms in 12 subjects. Hypotheses: ABPM & O1O2 BPs would differ clinically & statistically with accuracy based on posture because ABPM proprietary equations are derived from seated BPs & use peak cuff pressure to estimate systolic (SBP) & diastolic (DBP) pressures. Results: For seated subjects, the Oscar overestimated O1O2 SBP by ~ 10 mm Hg (Δ = -9.8 ± 9.4 mm Hg, P < 0.001), but with extreme variability as 95% of Oscar SBPs were 9.0 mm Hg below to 28.7 mm Hg above O1O2. The Spacelabs overestimated O1O2 SBP by ~ 5 mm Hg (Δ = -5.2 ± 7.8 mm Hg, P < 0.001) with 95% of Spacelabs SBPs 10.5 mm Hg below to 20.9 mm Hg above O1O2. There was a stepwise increase in the Oscars’ SBP overestimation of Hg column BPs from supine (-3.1 mm Hg, P < 0.01), to seated (-5.3 mm Hg, P < 0.001) to standing (-6.6 mm Hg, P < 0.01). The Oscar overestimated supine (-7.0 mm Hg, P < 0.001), but underestimated standing (3.9 mm Hg, P < 0.05) DBPs. The Spacelabs also overestimated supine (-6.5 mm Hg, P < 0.001), but underestimated standing (4.8 mm Hg, P < 0.01) DBPs. Conclusions: Our results confirm that leading oscillometric ABPMs are prone to clinically & statistically significant errors even in a controlled lab setting. Given that ABPMs are motion intolerant & unable to assess & adjust for a patient’s posture, errors will be compounded during 24-hr field testing. Results will vary based on the ABPM & postural %s assumed by each patient. International & national ABPM testing protocols must be strengthened & require postural testing as an essential component of validation.


Author(s):  
Zahra Ghasemi ◽  
Chang-Sei Kim ◽  
Eric Ginsberg ◽  
John Duell ◽  
Anuj Gupta ◽  
...  

This paper presents a model-based system identification approach to estimation of central aortic blood pressure waveform from non-invasive cuff pressure oscillation signals. First, we developed a mathematical model that can reproduce the relationship between central aortic blood pressure waveform and non-invasive cuff pressure oscillation signals at diametric locations by combining models to represent wave propagation in the artery, arterial pressure-volume relationship, and mechanics of the occlusive cuff. Second, we formulated the problem of estimating central aortic blood pressure waveform from non-invasive cuff pressure oscillation signals into a system identification problem. Third, we showed the proof-of-concept of the approach using simulated central aortic blood pressure waveform and cuff pressure oscillation signals. Finally, we illustrated the feasibility of the approach using central aortic blood pressure waveform and cuff pressure oscillation signals collected from a human subject. We showed that the proposed approach could estimate central aortic blood pressure waveform with accuracy: the root-mean-squared error associated with the central aortic blood pressure waveform was 1.7 mmHg (amounting to 1.6 % of the underlying mean blood pressure) while the errors associated with central aortic systolic and pulse pressures were −0.4 mmHg and −1.5 mmHg (amounting to −0.3 % and −1.4 % of the underlying mean blood pressure).


2003 ◽  
Vol 95 (1) ◽  
pp. 342-347 ◽  
Author(s):  
Jan T. Groothuis ◽  
Linda van Vliet ◽  
Miriam Kooijman ◽  
Maria T. E. Hopman

Venous occlusion strain gauge plethysmography (VOP) is based on the assumption that the veins are occluded and arterial inflow is undisturbed by the venous cuff pressure. Literature is not clear concerning the pressure that should be used. The purpose of this study was to determine the optimal venous occlusion pressure at which the highest arterial inflow is achieved in the forearm, calf, and leg by using VOP. We hypothesized that, for each limb segment, an optimal (range of) venous cuff pressure can be determined. Arterial inflow in each limb segment was measured in nine healthy individuals by VOP by using pressures ranging from 10 mmHg up to diastolic blood pressure. Arterial inflows were similar at cuff pressures between 30 and 60 mmHg for the forearm, leg, and calf. Arterial inflow in the forearm was significantly lower at 10 mmHg compared with the other cuff pressures. In addition, arterial inflows at 20 mmHg tended to be lower in each limb segment than flow at higher cuff pressures. In conclusion, no single optimum venous cuff pressure, at which a highest arterial inflow is achieved, exists, but rather a range of optimum cuff pressures leading to a similar arterial inflow. Venous cuff pressures ranging from 30 mmHg up to diastolic blood pressure are recommended to measure arterial inflow by VOP.


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