Chronic performance control system for rotodynamic blood pumps
First Claim
1. A cardiac assist apparatus comprising:
- a blood pump;
a drive unit that drives the blood pump;
a power supply that supplies power to the drive unit;
a frequency sensor that senses a rotational speed of the blood pump;
a current sensor that senses an average direct current waveform of the drive unit;
a power supply voltage sensor that senses a power supply voltage; and
a blood pump controller that;
(i) receives data from the frequency sensor, current sensor, and the power supply voltage sensor;
(ii) passively determines, from said data, a physiologic status of a patient without affecting one or more of the following;
the pump'"'"'s performance and the patient'"'"'s physiology, the patient'"'"'s physiologic status comprising one or more of the following;
a drive unit input power for determination of pump flow rate;
a heart rate;
a pump flow rate; and
, a pressure differential; and
(iii) calculates a target flow based on the physiologic status; and
(iv) automatically adjusts the blood pump to the target flow.
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Accused Products
Abstract
In a left ventricular assist device (LVAD) a rotodynamic blood pump (10) is powered by a brushless DC motor (12). A power supply (14) supplies power to the motor (12). Three feedback channels, one for each of voltage, current, and motor speed lead to a microcontroller or microprocessor (18). The three feedback waveforms are analyzed, and from these waveforms, motor input power, patient heart rate, current pump flow rate, and systemic pressure are determined. The microprocessor (18) then calculates a desired flow rate proportional to the patient heart rate. The microprocessor communicates a new power output to a commutation circuit (16), which regulates power to the motor (12). The pump (10) also includes safety checks that are prioritized over desired pump flow. These include prevention of ventricular suction, low pulsatility, minimum and maximum pump speed, minimum speed-relative pump flow, minimum absolute pump flow, minimum and maximum motor input power.
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Citations
24 Claims
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1. A cardiac assist apparatus comprising:
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a blood pump; a drive unit that drives the blood pump; a power supply that supplies power to the drive unit; a frequency sensor that senses a rotational speed of the blood pump; a current sensor that senses an average direct current waveform of the drive unit; a power supply voltage sensor that senses a power supply voltage; and a blood pump controller that; (i) receives data from the frequency sensor, current sensor, and the power supply voltage sensor; (ii) passively determines, from said data, a physiologic status of a patient without affecting one or more of the following;
the pump'"'"'s performance and the patient'"'"'s physiology, the patient'"'"'s physiologic status comprising one or more of the following;
a drive unit input power for determination of pump flow rate;
a heart rate;
a pump flow rate; and
, a pressure differential; and(iii) calculates a target flow based on the physiologic status; and (iv) automatically adjusts the blood pump to the target flow. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of controlling blood flow with a blood pump comprising the steps of:
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sensing a current waveform of a drive motor of the blood pump; sensing an input voltage waveform to the drive motor; sensing a rotational frequency waveform of the drive motor; passively determining, at a blood pump controller, a physiologic status of a patient based on one or more of the sensed current waveform, input voltage waveform, and rotational frequency waveform, the patient'"'"'s physiologic status comprising one or more of the following;
a drive motor input power of pump flow rate;
a heart;
a pump flow rate; and
, a pressure differential whereinsaid step of determining is performed without affecting one or more of the following;
the pump'"'"'s performance and the patient'"'"'s physiology; andcalculating a target flow based on the physiologic status; and automatically adjusting the blood pump to the target flow. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification