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OwnerStephen Nicholas Hunyor, Serguei Michael Plekhanov +1inventors
InventorsStephen Nicholas Hunyor, Serguei Michael Plekhanov, Yifei Huang
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A method and system measure the instantaneous volume of blood contained within a chamber of a heart, irrespective of its shape, whereby stroke volume and cardiac output volume can be continuously monitored and feedback to a non-blood contacting cardiac assist device. In a preferred form the device uses the distances between the sensors which are implanted in a biomaterial that integrates with a heart surface to determine changes in heart volume. Sonomicrometry crystal measurements are disclosed as a preferred mode of obtaining distance readings. A computer readable medium carries instructions to convert data from dimension sensors into sensor positions within a predetermined coordinate system. Ventricular volume is based on the sensor positions.
A method of determining the ventricular volume(s) of a heart using dimension sensors attached to or placed about the heart, wherein at least one of the dimension sensors is embedded in at least one cardiac assist device which is attached to or placed about the surface of the heart, the ventricular volume(s) being calculated based on measured distances between selected dimension sensors and the shape of the at least one cardiac assist device.
The method as claimed in any one of the preceding claims, wherein eight, nine or ten dimension sensors are used for the volume calculation(s).
The method as claimed in any one of the preceding claims, wherein for each ventricle of the heart, geometrical shapes are fitted to the measured positions of selected dimension sensors, and the volume of each of the fitted geometrical shapes is used to calculate the ventricular volume(s) of the heart.
The method as claimed in any one of the preceding claims, wherein at least one additional dimension sensor is used to obtain a thickness measurement of the left ventricle and/or right ventricle heart wall, the wall thickness measurement being factored into heart volume calculations.
The method as claimed in any one of the preceding claims, wherein the dimension sensors are piezoelectric devices.
The method as claimed in any one of the preceding claims, wherein the dimension sensors are piezoelectric sonomicrometry crystals.
The method as claimed in any one of the preceding claims, wherein the measured distances and volume calculations are performed in real-time.
A method of assisting the function of a heart, the method including calculating heart stroke blood volume and cardiac output blood volume in real-time using crystals attached to or placed about the heart, wherein at least one of the crystals is embedded in at least one cardiac assist device which is attached to or placed about the surface of the heart, the heart stroke blood volume and cardiac output blood volume being calculated based on measured distances between selected crystals and the shape of the at least one cardiac assist device, which is known when distance measurements are obtained, and operation of the cardiac assist device being controlled as a function of the calculated heart stroke blood volume and cardiac output blood volume.
A method of determining the interior volume of a heart, the method including the steps of:
The method as claimed in any one of the preceding claims, wherein dimension sensor positions are located at or near the:
A method of determining the wall shape of a heart using dimension sensors attached to or placed about the heart, wherein at least one of the dimension sensors is embedded in at least one cardiac assist device which is attached to or placed about the surface of the heart, the wall shape being calculated based on measured distances between selected dimension sensors and the shape of the at least one cardiac assist device, which is known when distance measurements were obtained.
A method of determining the wall shape of a heart, the method including the steps of:
A system for assisting the function of a heart, the system including:
A computer readable medium of instructions for determining the ventricular volume of a heart using dimension sensors attached to or placed about the heart, wherein at least one of the dimension sensors is embedded in at least one cardiac assist device which is attached to or placed about the surface of the heart, the instructions including procedures to:
Dependencies are inferred from the claim text.