Cardiovascular Biomechanics
Vahid Abouie; Farzad Towhidkhah; Vahid Reza Nafisi; Hani Sharifian
Volume 5, Issue 4 , June 2011, , Pages 305-311
Abstract
Today, Dialysis hypotension during hemodialysis process is the most common problems for about 20 to 30 percent of dialysis patients. In order to avoid this hypotension, blood pressure should be measured during dialysis process continuously and noninvasively But it is practically impossible and few devices ...
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Today, Dialysis hypotension during hemodialysis process is the most common problems for about 20 to 30 percent of dialysis patients. In order to avoid this hypotension, blood pressure should be measured during dialysis process continuously and noninvasively But it is practically impossible and few devices for noninvasive and continuous blood pressure measurement are very expensive. Considering this subject, the parameters related to blood pressure should be used to reach this goal. The blood concentrations and heart rate changes are associated with blood pressure in dialysis patients, so in this study, we determined a model by these two parameters in order to predict the blood pressure of hemodialysis patients. After measuring blood concentration, Heart rate and blood pressure from 14 dialysis patients, using neural network model, we determined a new model that can predict blood pressure in dialysis patient by using blood concentration and heart rate data with 3.8 percent error between the real pressure and the pressure that predicted by the model.
Mohammad Ali Ardakani; Vahid Reza Nafisi
Volume 2, Issue 4 , June 2008, , Pages 325-333
Abstract
Hot-wire anemometry (HWA) is a suitable method for pulmonary research and routine tests. This anemometry method has high frequency response, calibration stability, low pressure drop and desired precision over whole clinical range of human respiration. Nevertheless, flow direction detection in inspiratory ...
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Hot-wire anemometry (HWA) is a suitable method for pulmonary research and routine tests. This anemometry method has high frequency response, calibration stability, low pressure drop and desired precision over whole clinical range of human respiration. Nevertheless, flow direction detection in inspiratory and expiratory phases is one of the main problems in this method. We apply the obstacle-wake probe as a solution. In this probe, an obstacle is inserted between 2 bot-wire sensors; and the effects of the shape and relative position of the obstacle and hot-wire sensors are discussed. Finally the results are used in manufacturing a clinical spirometer. It satisfies common clinical/research demands along with inspiratory/expiratory flow direction detection.
