LVAD Pump Speed Synchronization Using Motor Signals to Reduce Suction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing left ventricular assist devices (LVADs) operate with a constant pumping speed, which is detrimental to patients due to the mismatch between the non-constant natural cardiac cycle, leading to potential adverse events such as ventricular load fluctuation and suction.
Innovation Solution
Implementing a system to synchronize the LVAD speed with the patient's cardiac cycle by modulating the pump speed during systole and diastole, using motor drive current or power signal processing to identify synchronization points and adjust the pump speed accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the LVAD operates with a constant pumping speed, then the device structure and control system are simple, but the hemodynamic conditions become unstable and organ perfusion becomes uneven
Solution Approach 1:
The LVAD pump speed is changed from constant to dynamic operation, where the motor speed is continuously adjusted based on real-time detection of cardiac cycle phases. The controller modulates the pump speed to increase during diastole and decrease during systole, making the device adaptive to the patient's natural cardiac rhythm and improving hemodynamic stability.
Solution Approach 2:
The system implements a feedback mechanism where the controller continuously monitors motor current or power consumption signals to detect cardiac cycle characteristics. Based on this feedback, the controller automatically adjusts the pump speed in response to detected systolic and diastolic phases, creating a closed-loop control system that maintains stable hemodynamic conditions.
2Reliability
If the LVAD operates with a constant pumping speed, then the device is easy to operate, but the risk of ventricular suction and overload increases
Solution Approach 1:
The pump operates dynamically by adjusting its speed in real-time according to the detected cardiac cycle phase. During systole, when the heart contracts and ventricular volume decreases, the pump speed is reduced to prevent suction. During diastole, when the heart relaxes and ventricular volume increases, the pump speed is increased to prevent overload, thereby improving reliability.
Solution Approach 2:
The device uses its own motor current or power consumption signals as the sensing mechanism to detect cardiac cycle phases, eliminating the need for external sensors or complex monitoring equipment. The controller processes these intrinsic signals to automatically adjust pump speed, making the system self-sufficient and maintaining ease of operation.
3Stability of the object's composition
If the LVAD speed is synchronized with the cardiac cycle, then hemodynamic stability is improved, but the device complexity increases due to signal processing requirements
Solution Approach 1:
The system utilizes the motor's own current or power consumption signals as the sensing input for detecting cardiac cycle phases. This self-service approach eliminates the need for separate sensors, external monitoring equipment, or complex signal acquisition systems, thereby reducing device complexity while enabling cardiac cycle synchronization.
Solution Approach 2:
The motor serves dual functions: it acts as both the pump driver and the sensing element for detecting cardiac cycle phases. The same motor that drives the pump also generates the electrical signals (current or power consumption variations) that contain information about the cardiac cycle, allowing the system to perform both pumping and sensing functions with a single component.
4Stability of the object's composition
If the LVAD speed is synchronized with the cardiac cycle, then organ perfusion becomes even, but the control system complexity increases
Solution Approach 1:
The control system uses the motor's own operational signals (current or power consumption) as the basis for detecting cardiac cycle phases and triggering speed adjustments. This self-service mechanism eliminates the need for external sensors, additional signal processing hardware, or complex monitoring systems, thereby maintaining relatively simple control system architecture while achieving even organ perfusion through cardiac-synchronized pumping.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle includes obtaining a signal from a motor of a heart assist pump device and filtering the signal to remove noise. The method also includes determining a speed synchronization start point at which time the motor of the heart assist pump device will begin a change in speed of operation based on the filtered signal. The method further includes modulating a speed of the motor of the heart assist pump device to a target speed at the speed synchronization start point, thereby synchronizing the change in speed of operation with a patient's cardiac cycle.