scholarly journals A blood protein monitor for the continuous measurement of blood volume changes during hemodialysis

1990 ◽  
Vol 38 (2) ◽  
pp. 342-346 ◽  
Author(s):  
Daniel Schneditz ◽  
Helmuth Pogglitsch ◽  
Jörg Horina ◽  
Ulrich Binswanger
Keyword(s):  
Blood Volume ◽  
Continuous Measurement ◽  
Blood Protein ◽  
Volume Changes

Serial Blood Water Estimations and in-Line Blood Viscometry: The Continuous Measurement of Blood Volume during Dialysis Procedures

1984 ◽  
Vol 66 (5) ◽  
pp. 575-583 ◽  
Author(s):  
R. N. Greenwood ◽  
C. Aldridge ◽  
W. R. Cattell
Keyword(s):  
Blood Volume ◽  
Blood Viscosity ◽  
Packed Cell Volume ◽  
Continuous Measurement ◽  
Quantitative Measure ◽  
Capillary Viscometer ◽  
Extracorporeal Circuit ◽  
Volume Changes ◽  
Serial Measurements

1. It has been shown in vitro that serial measurements of blood water during ultrafiltration accurately reflect changing blood volume. 2. It has been shown that minute changes in blood hydration produce detectable changes in blood viscosity. 3. An ‘in-line’ capillary viscometer has been constructed which can be placed in parallel with an extracorporeal circuit to give a continuous semi-quantitative measure of blood viscosity during ultrafiltration or haemodialysis. By making serial measurements of blood water each ‘viscometer curve’ can be corrected to permit calculation of blood volume provided that the starting blood volume is known. 4. Blood volume changes of less than 1% can be detected in vitro and provided that blood volume changes solely as a result of the removal or influx of water it can be measured continuously to within an accuracy of 4% for volume changes up to 30% irrespective of starting packed cell volume or blood water.

Influence of volume changes on osmolality-vasopressin relationships in conscious dogs

1983 ◽  
Vol 244 (1) ◽  
pp. H73-H79 ◽  
Author(s):  
E. W. Quillen ◽  
A. W. Cowley
Keyword(s):  
Blood Volume ◽  
Left Atrial ◽  
Continuous Measurement ◽  
Plasma Osmolality ◽  
Conscious Dogs ◽  
Relative Importance ◽  
Volume Changes ◽  
Short Term ◽  
New Techniques ◽  
Plasma Vasopressin

The relative importance of plasma osmolality (Posm) and left atrial pressure (LAP) as controllers of plasma vasopressin concentration (PAVP) was investigated in conscious dogs (n = 8). New techniques for the continuous measurement of LAP and computerized data collection permitted monitoring of LAP and mean arterial pressure (MAP) while Posm was suppressed with intravenous distilled water and then elevated with hypertonic NaCl. PAVP was determined by radioimmunoassay. This relationship between Posm and PAVP was determined at low, normal, and high (-0.9 +/- 0.8, 1.8 +/- 0.8, and 7.7 +/- 1.1 cmH2O, respectively) levels of LAP produced by either hemorrhage or autotransfusion of whole blood. MAP was not altered by these maneuvers. The results of these short-term studies have demonstrated a significant modulation of the osmoregulation of PAVP by changes in blood volume as indexed by LAP. Because of this modulation, PAVP is regulated so that contraction or expansion of the blood volume is more expeditiously corrected than would occur if osmoreceptors alone regulated plasma vasopressin.

scholarly journals Development of Continuous Blood Pressure Measurement System Using Photoplethysmograph and Pulse Transit Time

2021 ◽  
Vol 3 ◽  
pp. 8-12
Author(s):  
Hong Long Pua ◽  
Kok Beng Gan
Keyword(s):  
Blood Pressure ◽  
Blood Volume ◽  
Transit Time ◽  
Pressure Measurement ◽  
Continuous Measurement ◽  
Blood Pressure Measurement ◽  
Pulse Transit Time ◽  
Volume Changes ◽  
Non Invasive

It is not only a problem for old age anyone. So, blood pressure is the one provides importance information with vital signs about cardiovascular health using oscillometric method. Unfortunately, this method required inflation and following deflation of the cuff. This method only gives instantaneous blood pressure and continuous measurement is not available. It is not available to the patients that required long term monitoring. To overcome this problem, the development of Continuous Non-Invasive Blood Pressure (NIBP) algorithm based on Pulse Transit Time (PTT) using two channel Photoplethysmograph (PPG) is proposed in this study. PPG is a non-invasive device for detecting blood volume changes can be affected by various physiological factors, analysis of the PPG signal can provide sufficient information on the human health condition; more specifically their cardio-vascular related performance. Literatures show that the PTT has linear relationship with blood pressure. Nevertheless, the determination of the model structure, order and real-time implementation to offer a continuous measurement of the PTT still remains challenging tasks in this area. PTT can be as index to monitor cardiovascular disease. In this project, dynamic model based on pulse transit time will be proposed to continuously monitor blood pressure by using PPG signals. Different kind of resolutions in microcontroller combined with PPG sensor will be used as well. MATLAB software is also been applied for PTT calculation based on two PPG sensors. PPG is method for detect blood volume changes with optical source transmitter send from one end and received the signal from another by receiver through body tissue as medium. MATLAB functions as Digital Signal Processing (DSP) for signals received in computer. Linear Regression technique and Fung's algorithm are applied to obtain the best fit line for all the points in order to systolic and diastolic blood pressure measurement. The results showed that the algorithm based on pulse transit time has been developed for the assessment of blood pressure and justify patient’ condition with 86.34% and 88.20% accuracy. Finally, this technique is a simple, user friendly and operator independent PPG system suitable for long term and wearable blood pressure monitor.

Early MRI blood volume changes in constrictor muscles correlate with post-radiation dysphagia

2020 ◽  
Author(s):  
Michelle L. Mierzwa ◽  
Laila A. Gharzai ◽  
Pin Li ◽  
Joel R. Wilkie ◽  
Peter G. Hawkins ◽  
...  
Keyword(s):  
Blood Volume ◽  
Volume Changes ◽  
Post Radiation

An Electronic Method of Detecting Blood Volume Changes

1965 ◽  
Vol 26 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Rex J. Underwood ◽  
David Gowing
Keyword(s):  
Blood Volume ◽  
Volume Changes ◽  
Electronic Method

scholarly journals Cerebral blood volume changes during the BOLD post-stimulus undershoot measured with a combined normoxia/hyperoxia method

NeuroImage ◽  
2019 ◽  
Vol 185 ◽  
pp. 154-163 ◽  
Author(s):  
Eulanca Y. Liu ◽  
Frank Haist ◽  
David J. Dubowitz ◽  
Richard B. Buxton
Keyword(s):  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Volume Changes

scholarly journals Artifact Elimination in Impedance Cardiography using Gradient based Adaptive Signal Enhancement Techniques

2019 ◽  
Vol 8 (2) ◽  
pp. 598-606
Keyword(s):  
Stroke Volume ◽  
Blood Volume ◽  
Impedance Cardiography ◽  
Signal Enhancement ◽  
The Body ◽  
Body Segment ◽  
Volume Changes ◽  
The Real ◽  
Adaptive Techniques ◽  
Adaptive Signal

Impedance Cardiography (ICG) is a noninvasive method for indirect measurement of stroke volume, monitoring the cardiac output and observing the other hemodynamic parameters by the blood volume changes in the body. The blood volume changes inside a certain body segment due to a number of physiological processes are extracted in the form of the impedance variations of the body segment. The ICG analysis provides the heart stroke volume in sudden cardiac arrest. In the clinical environment desired ICG signals are influenced by several physiological and non-physiological artifacts.As these artifacts are not stationary in nature, we proposed adaptive filtering techniques to eliminate the artifacts. In this paper we used Least Mean Square (LMS), Least Mean Fourth (LMF), Median LMS (MLMS), Leaky LMS (LLMS), and Dead Zone (DZLMS) adaptive techniques to eliminate artifacts from the desired signals. Several adaptive signal enhancement units (ASEUs) are developed based on these adaptive techniques, and evaluated on the real ICG signal components. The ability of these algorithms is evaluated by performing the experiments to eliminate the various artifacts such as sinusoidal artifacts (SA), respiration artifacts (RA), muscle artifacts (MA) and electrode artifacts (EA). Among these techniques, the DZLMS based ASEU performs better in the filtering process. The signal to noise ratio improvement (SNRI) for this algorithm is calculated as 11.9140 dB, 7.3657 dB, 10.4060 dB and 10.5125 dB respectively for SA, RA, MA and EA. Hence, the DZLMS based ASEUs are well suitable for ICG filtering in the real time health care monitoring systems.

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