Interpretation of venous occlusion plethysmographic measurements using a simple model

Interpretation of venous occlusion plethysmography using a nonlinear model

“…Whereas changes in calf volume can be determined using noninvasive techniques, including strain gauge (SGP) and impedance plethysmography (IPG), the blood pressure in the deep veins of the leg is not so easily determined. Previous investigators have relied on tilt-table methods (LuDBROOK, 1966) or cannulation of a superficial vein (HESSE, 1970;SEAGAR et al, 1984). Data for the present study were obtained from a tilt-table experiment on a normal leg.…”

“…This value is a function of the width of the thigh cuff employed. It is equal to 90 per cent of applied pressure when a 16 or 20cm wide cuff is employed (HESSE, 1970;ANDERSON, 1984), and 50 per cent when a 7 or 10cm cuffis used (HESSE, 1970;SEAGAR et al, 1984). If a standard cuff and occlusion pressure are employed, the distal venous pressure will be nearly constant at maximum venous filling (VC).…”

“…1), commonly referred to as the venous capacitance (VC), and a single exponential time constant (STRANDNESS and SUMNER, 1975;KAY et al, 1975;JAFERIN, 1976;SEAGAR et al, 1984). The validity of a linear V O P model is supported by the good fit of venous outflow curves to a single time constant in 90 normal limbs and in 33 limbs with deep-vein thrombosis (KAY et al, 1975).…”

Mathematical model of venous occlusion plethysmography for diagnosing deep vein thrombosis

“…While invasive methods for DVT detection such as venography are most accurate, they could cause some risk to the patient. As a result there has been many studies on non-invasive techniques, including venous occlusion plethysmography(VOP), to screen patients for the presence of DVT [1][2][3].…”

“…While invasive methods for DVT detection such as venography are most accurate, they could cause some risk to the patient. As a result there has been many studies on non-invasive techniques, including venous occlusion plethysmography(VOP), to screen patients for the presence of DVT [1][2][3].Although the results of VOP are helpful to detect DVT, being an indirect measure, there are difficulties in quantitative comparison of results that come from different degrees of thrombosis. So, there has been a study which estimates the effects of thrombosis size on patient's venous outflow with a numerical model [4].…”