Cardiovascular analysis, method and apparatus
First Claim
Patent Images
1. A method of obtaining LVEDP (left ventricular end diastolic pressure) in a mammalian body comprising:
- (a) measuring diastolic and systolic pressures;
(b) detecting the start of the electrocardiograph QRS complex;
(c) detecting the start of the first carotid pulse after the start of said QRS complex;
(d) detecting the start of the first heart sound after the start of said QRS complex;
(e) determining the carotid pulse slope by;
(1) sensing the carotid artery pressure by a transducer secured against the neck;
(2) converting the pressure variations sensed to electrical voltage signals;
(3) amplifying said voltage signals;
(4) adjusting the amount of said amplifying to calibrate the swing of said voltage signals to a predetermined level;
(5) processing said signals as amplified to obtain carotid pulse slope time by the time it takes said voltage signals to pass between two fixed reference levels;
(6) processing said carotid pulse slope time with said diastolic and systolic pressures to obtain carotid pulse slope; and
,(f) calculating LVEDP by processing the equation;
space="preserve" listing-type="equation">LVEDP=DIA-(T3-T2)CS Where;
DIA=diastolic pressure at a brachial arteryT3=Time from start of QRS complex to start of carotid pulseT2=Time from start of QRS complex to start of first heart soundCS=Carotid pulse slope.
0 Assignments
0 Petitions
Accused Products
Abstract
Left ventricular end diastolic pressure is determined by data processing analysis of EKG waveform, first heart sound and carotid pulse waveform. Electrical, sonic and pressure transducers obtain patient data noninvasively and provide it to a data processing system.
-
Citations
9 Claims
-
1. A method of obtaining LVEDP (left ventricular end diastolic pressure) in a mammalian body comprising:
-
(a) measuring diastolic and systolic pressures; (b) detecting the start of the electrocardiograph QRS complex; (c) detecting the start of the first carotid pulse after the start of said QRS complex; (d) detecting the start of the first heart sound after the start of said QRS complex; (e) determining the carotid pulse slope by; (1) sensing the carotid artery pressure by a transducer secured against the neck; (2) converting the pressure variations sensed to electrical voltage signals; (3) amplifying said voltage signals; (4) adjusting the amount of said amplifying to calibrate the swing of said voltage signals to a predetermined level; (5) processing said signals as amplified to obtain carotid pulse slope time by the time it takes said voltage signals to pass between two fixed reference levels; (6) processing said carotid pulse slope time with said diastolic and systolic pressures to obtain carotid pulse slope; and
,(f) calculating LVEDP by processing the equation;
space="preserve" listing-type="equation">LVEDP=DIA-(T3-T2)CSWhere; DIA=diastolic pressure at a brachial artery T3=Time from start of QRS complex to start of carotid pulse T2=Time from start of QRS complex to start of first heart sound CS=Carotid pulse slope. - View Dependent Claims (2, 3, 4, 5)
-
-
6. Apparatus for obtaining LVEDP (Left Ventricle End Diastolic Pressure) noninvasivety comprising:
-
(a) A sphygmomanometer; (b) at least two electrocardiograph transducers; (c) a heart sound transducer; (d) a carotid pressure transducer providing an electrical output signal and means for securing it against a mammalian neck; (e) a first electronic processor connected to said carotid pressure transducer and comprising; (1) an adjustable gain amplifier connected to receive said electrical ouput signal; (2) means to supply two predetermined reference voltages; (3) a comparator for comparing the output of said amplifier to said reference voltages; (4) electrical circuit means connected to said comparator and providing an output signal related to the time taken by a signal from said amplifier to change level by the difference between said two predetermined voltages in order to provide a carotid pulse slope time; (f) additional electronic processors connected to the output of said electrocardiograph transducers and said heart sound transducer; and
,(g) a data processor connected to receive data from each of said electronic processors and having a data entry terminal for receiving data obtained by said sphygmomanometer, said data processor being programmed to obtain LVEDP in accordance with the equation;
space="preserve" listing-type="equation">LVEDP=DIA-(T3-T2)CSWhere; DIA=Diastolic Pressure T3=Time from start of QRS complex to start of carotid pulse upstroke T2=Time from start of QRS complex to start of first heart sound CS=The pressure time slope of the carotid pulse at the beginning of the upstroke. - View Dependent Claims (7, 8, 9)
-
Specification