Suction detection for the MicroMed DeBakey Left Ventricular Assist Device.

Area of Science:

• Biomedical Engineering
• Medical Devices
• Cardiovascular Support

Background:

• The MicroMed DeBakey Ventricular Assist Device (VAD) is a continuous axial flow pump for long-term circulatory support, approved for bridge-to-transplantation and as a transplant alternative.
• Ventricular collapse due to excessive suction (low left ventricular volume or immoderate pump speed) can decrease flow and cause patient discomfort, necessitating reliable detection and adaptive control.

Purpose of the Study:

• To evaluate and validate system parameters for reliable detection of suction in VADs.
• To explore the use of electronic motor signals (current consumption and rotor speed) as a redundant method for suction detection.

Main Methods:

• In vitro studies using a mock loop with pulsatile and nonpulsatile flow.
• Analysis of motor current consumption and rotor/impeller speed signals influenced by suction.
• Comparison with flow waveform data from an implanted ultrasonic flow probe as the reference signal.
• Optimization of a suction-detection algorithm using amplified differentiated current and speed signals.

Main Results:

• Motor speed and current signals reliably indicate suction under both pulsatile and nonpulsatile conditions.
• Concurrent use of motor speed and current provides high reliability for suction detection.
• An optimized algorithm using these parameters has been proven safe in vitro across various operating conditions.

Conclusions:

• Motor speed and current signals offer a reliable, redundant method for detecting suction in VADs.
• The developed algorithm enhances VAD safety and performance by providing an alternative to flow-based detection.
• This approach can improve patient outcomes by enabling timely adaptive control of the device.