Methods and apparatus for controlling heart assist devices
First Claim
1. An apparatus for controlling a heart assist device, comprising a processing unit for computing the blood flow rate (q(t)) from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein the processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein the processing unit is adapted to determine said period by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, and wherein said threshold value is greater than q(t)=0.
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Abstract
An apparatus for a heart assist device, comprising a processing unit for computing the blood flow rate from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate. The processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of the said heart assist device are taken into account in determining the period. The apparatus adapts itself to changes in a patient'"'"'s heart frequency and aortic pressure.
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Citations
14 Claims
- 1. An apparatus for controlling a heart assist device, comprising a processing unit for computing the blood flow rate (q(t)) from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein the processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein the processing unit is adapted to determine said period by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, and wherein said threshold value is greater than q(t)=0.
- 5. A method for controlling a heart assist device, comprising computing the blood flow rate (q(t)) from the arterial pressure curve and predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein a signal for controlling a heart assist device is delivered at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein said period is determined by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, and wherein said threshold value is greater than q(t)=0.
- 9. An apparatus for controlling a heart assist device, comprising a processing unit for computing the blood flow rate from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein the processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein the processing unit is adapted to determine said period by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, wherein said heart assist device is an intra-aortic balloon pump having a balloon, wherein said signal initiates the inflation of the balloon, and wherein said signal to inflate said intra-aortic balloon pump is delivered about 40 msec ahead of the closing time of the heart valve.
- 12. A method for controlling a heart assist device, comprising computing the blood flow rate from the arterial pressure curve and predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein a signal for controlling a heart assist device is delivered at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein said period is determined by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, wherein said heart assist device is an intra-aortic balloon pump having a balloon, wherein said signal initiates the inflation of the balloon, and wherein said signal to inflate said intra-aortic balloon pump is delivered about 40 msec ahead of the closing time of the heart valve.
Specification