Cardiovascular assist system that quantifies heart function and facilitates heart recovery
The systems, devices, and methods presented herein use a heart pump to obtain measurements of cardiovascular function. The heart pumps described herein can operate in parallel with and unload the heart. The system can quantify the functioning of the native heart by measuring certain parameters/signals such as pressure or motor current, then calculate and display one or more metrics of cardiovascular function. These metrics, such as left ventricular end diastolic pressure (LVEDP), left ventricular pressure, and contractility, provide valuable information to a user regarding a patient's state of heart function and recovery.
1 . A method of using a heart pump system to determine cardiac function of a patient, the method comprising:
measuring, by a pressure sensor, an aortic pressure over time;
measuring, by a controller, a motor parameter over time;
receiving, from the pressure sensor, the aortic pressure over time;
generating, by the controller, a relationship between the motor parameter and the aortic pressure;
determining, by the controller, at least one heart metric indicative of cardiac function based on the generated relationship between the measured aortic pressure and the measured motor parameter;
displaying the at least one heart metric; and
dynamically adjusting, by the controller, operation of the heart pump system to change driving of a rotor of the heart pump system based on the at least one heart metric.
2 . The method of claim 1 , wherein the motor parameter is current delivered to a motor operatively coupled to the rotor, power delivered to the motor, or motor speed.
3 . The method of claim 1 , wherein the controller is configured to detect the motor parameter and the pressure sensor is configured to detect the aortic pressure over a portion of a cardiac cycle.
4 . The method of claim 1 , wherein the controller is configured to detect the motor parameter and the pressure sensor is configured to detect the aortic pressure over one or more cardiac cycles.
5 . The method of claim 1 , wherein the controller is further configured to store the at least one cardiovascular metric in a memory with a previously determined at least one cardiovascular metric.
6 . The method of claim 1 , wherein the controller is further configured to store the relationship between the motor parameter and the aortic pressure in a memory.
7 . The method of claim 6 , wherein the controller is further configured to determine from the stored relationship the at least one heart metric.
8 . The method of claim 7 , wherein the at least one heart metric is at least one of contractility, stroke volume, ejection fraction, chamber pressure, stroke work, cardiac output, cardiac power output, left ventricular end diastolic pressure (LVEDP), preload state, afterload state, heart rate, heart recovery, flow load state, variable volume load state, cardiac cycle volume load state, or cardiac cycle flow state.
9 . The method of claim 8 , wherein the at least one cardiovascular metric is the LVEDP.
10 . The method of claim 1 , wherein a motor operatively coupled to the rotor is configured to maintain a substantially constant speed of the rotor during actuation of the rotor.
11 . The method of claim 10 , wherein the motor is an integrated motor sized and configured for insertion into a patient's vasculature by a catheter.