Apparatus for the diagnosis of heart conditions
First Claim
1. An apparatus for analysing the biomechanical behaviour of a subject'"'"'s cardiac muscle and for diagnosing its pathological conditions which comprises:
- pressure sensitive means shaped and dimensioned to monitor the variation of blood pressure in one part of the subject'"'"'s cardio-vascular system, and for generating electrical signals proportional to said blood pressure;
means responsive to said electrical signals for recording a plurality of values corresponding to successive blood pressure measurements during at least one cycle of the subject'"'"'s systolic or diastolic pressure phase in relation to time;
electrical means for analysing said values and for mathematically deriving at least one critical parameter from the shape of the curve representing the plotting of said values versus time during said cycle and for interpreting said curve as a theoretical pressure-function (P) varying in time (t) with changes of ventricular volume (V) according to the phenomenological model equation;
space="preserve" listing-type="equation">P(V,t)=B(V)t.sup.y e.sup.-xtwherein B is a factor corresponding to the influence of the cardiac muscle size, y represents a first parameter, indicative of the excitation-contraction delay, and x represents the second parameter indicative of the inotropic characteristic of the muscle; and
means for computing the x and y parameters which most closely fit the curve.
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Abstract
An apparatus for analyzing the biomechanical behaviour of the cardiac muscle and for diagnosing pathological conditions of the heart. The apparatus measures and records the rise and fall of intra-ventricular pressure monitored by a transducer installed in a cardiac catheter or in an arterial probe. The pressure versus time recordings during both the systolic and diastolic phases are mathematically analyzed, and two parameters indicative of the biomechanical conditions of the muscle are derived. The parameters are then plotted against each other on a map in which diagnostic zones of various normal and pathological heart conditions are delineated.
33 Citations
12 Claims
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1. An apparatus for analysing the biomechanical behaviour of a subject'"'"'s cardiac muscle and for diagnosing its pathological conditions which comprises:
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pressure sensitive means shaped and dimensioned to monitor the variation of blood pressure in one part of the subject'"'"'s cardio-vascular system, and for generating electrical signals proportional to said blood pressure; means responsive to said electrical signals for recording a plurality of values corresponding to successive blood pressure measurements during at least one cycle of the subject'"'"'s systolic or diastolic pressure phase in relation to time; electrical means for analysing said values and for mathematically deriving at least one critical parameter from the shape of the curve representing the plotting of said values versus time during said cycle and for interpreting said curve as a theoretical pressure-function (P) varying in time (t) with changes of ventricular volume (V) according to the phenomenological model equation;
space="preserve" listing-type="equation">P(V,t)=B(V)t.sup.y e.sup.-xtwherein B is a factor corresponding to the influence of the cardiac muscle size, y represents a first parameter, indicative of the excitation-contraction delay, and x represents the second parameter indicative of the inotropic characteristic of the muscle; and
means for computing the x and y parameters which most closely fit the curve. - View Dependent Claims (2, 3, 4, 5)
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6. A method for analysing the biomechanical behaviour of a subject'"'"'s cardiac muscle and for diagnosing its pathological conditions which comprises:
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measuring by means of at least one pressure sensor the variation of blood pressure in at least one part of the subject'"'"'s cardio-vascular system during at least one cycle of systolic or diastolic pressure; recording a plurality of values corresponding to successive blood pressure measurements taken during said cycle; plotting said value in relation to time; mathematically analysing said plotted values and deriving at least one parameter from the shape of the curve representing the variation of said signals during said cycle;
interpreting said curve as a theoretical pressure-function (P) varying in time (t) with changes of ventricular volume (V) according to the phenomenological model equation;
space="preserve" listing-type="equation">P(V,t)=B(V)t.sup.y e.sup.-xtwherein B is a factor corresponding to the influence of the cardiac muscle size, y represents a first parameter indicative of the excitation-contraction delay, and x represents a second parameter indicative of the inotropic characteristic of the muscle; and
computing the x and y parameters which most closely fit the curve. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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Specification