Patent EA-003497-B1 (EA)
Title: Method of compression volume oscillometry for determining parameters of blood circulation system
IPC: A61B5/02
Filed: 2001-07-04
Abstract: 1. A method for determining parameters of the blood circulation system by volume compression oscillometry, comprising monitoring pulse curves of blood vessels in the process of pressure change in a pressure measuring cuff applied on a patient extremity with subsequent electric and graphic conversion, characterized in that a graph of linear increase of pressure being applied and venous and arterial oscillometric curve, is monitored initially in the process of pressure increase in the cuff within frequencies from about 0 to 50 Hz with straight horizontal amplitude-frequency characteristic and a linear amplitude characteristic along the path of converting and amplifying, then, continuing the cuff compression to 200-300 mm mercury oscillometric curve of the arterial pressure is monitored and according to the obtained pulse curves values of diastolic, mean, systolic and final systolic pressures res of venous and arterial pressures, a lamina of main arterial vessels in the systole and diastole phases in loaded by the cuff and unloaded state are monitored and at a certain time interval the pulse frequency is counted. 2. The method of claim 1, characterized in that the arterial pressure is monitored in both cases of the linear increase or the linear pressure drop in the pressure measuring cuff. 3. The method of claim 1, characterized in that the external points are marked out in the diastolic and systolic oscillometric curve and in the arterial pulse curve, the point are approximated by straight lines in the diastolic and systolic zones to intersecting said lines, then the intersection of said lines are projected on the graph of the linear change of pressure being applied, ordinates of said points correspond to the absolute values of the respective venous and arterial pressures. 4. The method of claim 1, characterized in that the systolic arterial pressure (Pc) is determined by the value of the amplitude and the rate of the pulse curve leading edge, for which the amplitude Y and the rate of the pulse wave leading edge (dY/dt) are measured on the section of oscillomertic curve monitored after mean arterial pressure, the maximum amplitude Ymax and the minimum value of rate of the leading edge dYdtmin are monitored on the measured section, the pulse wave with Ymax and dYdtmin is a sign Pc. Pc ( (Ymax, dYdtmin). 5. The method of claim 1, characterized in that Pc is determined by the amplitude ratio of impulse wave for which the amplitude ratio of Y and Ydw proportional to dP and dPdw pressure values respectively are measured on the section of oscillomertic curve, the pressure of dicrotic wave is measured by a bend in the zone of the dicrotic wave and according to the Y, Ydw and Pdw values Pc is calculated by the formula: Pc= Pd + (Y/Ydw)(Pdw-Pd), wherein: Pdw - the pressure of dicrotic wave, Pd - the diastolic pressure, Y - the maximum amplitude of selected pulse curve to the diastolic pressure, Ydw - the amplitude of the dicrotic wave of the same pulse curve. 6. The method of claim 1, characterized in that Pc is determined by the integral values of the pulse wave, for which the mean value of an amplitude of one pulse wave Z is determined on the section of oscillomertic curve monitored before the diastolic arterial pressure, the maximum value of the wave Y is measured, Pd and Pcp values are determined and Pc is calculated by the formula: Pc = Pd + (Y/Z)(Pcp - Pd), wherein: Pc - the mean pressure, Z - the mean amplitude pressure of the selected pulse wave before emergence of diastolic arterial pressure on the oscillometric curve, Y - the maximum amplitude of said pulse wave. 7. The method of claims 4 5, characterized in that for determining values of venous pressure and arterial pressure Pd, Pcp, Pc, laminae of main arterial vessel in systole and diastole phases the cuff is compressed till emergency of signs of the mean arterial pressure. 8. The method of claim 1, characterized in that the lamina value of an arterial vessel is determined by the difference of the maximum amplitude of the pulse wave monitored in the point of mean pressure and proportional to the sum of the vessel lamina in the systole and diastole phases and the amplitude of the pulse wave monitored in the point of the diastolic pressure in the cuff and proportional to the lamina increase in the vessel in the systole phase compressed by the cuff. 9. The method of claim 1, characterized in that the lamina value of an arterial vessel is determined by the difference of the maximum amplitude of the pulse wave monitored in the point of mean pressure and proportional to the sum of the vessel lamina in the systole and diastole phases and the amplitude of the pulse wave monitored in the range of low pressures in the cuff and proportional to the lamina increase in the point of the diastolic pressure in the cuff and proportional to the lamina increase in the vessel in the systole phase with practically no compression in the cuff. 10. The method of any one of claims 1 to 9, characterized in that the values of arterial pressure laminae in an arterial vessel in systole and diastole phases are used for graphical plotting and calculation of different parameters of the blood circulation system.