Adaptive full-ejection point detection for automatic control of the electrohydraulic total artificial heart

Area of Science:

• Biomedical Engineering
• Artificial Organs
• Control Systems

Background:

• The electrohydraulic total artificial heart (EHTAH) requires precise control for effective function.
• Current methods for detecting ventricular full ejection may fail under variable afterload pressures.
• A fixed trigger level for ejection detection can compromise system stability, safety, and efficiency.

Purpose of the Study:

• To develop an adaptive algorithm for detecting full ejection points in the EHTAH.
• To enhance the stability, safety, and efficiency of EHTAH automatic control.
• To address the limitations of fixed-level triggering under variable afterload conditions.

Main Methods:

• Developed an adaptive algorithm to detect full ejection points for EHTAH automatic control.
• Implemented a variable full ejection trigger level based on estimated afterload from the previous beat's pressure waveform.
• Utilized an adaptive averaging window to improve the accuracy of afterload estimation from pressure waveforms.

Main Results:

• Mock circulation tests demonstrated that the enhanced control scheme accurately tracked actual afterload.
• The adaptive algorithm successfully controlled the EHTAH device in mock circulation.
• The control scheme was successfully applied to EHTAH devices implanted in three chronic calves.

Conclusions:

• The developed adaptive algorithm provides a more robust method for controlling the EHTAH.
• Varying the full ejection trigger level based on estimated afterload improves EHTAH performance.
• This adaptive control strategy shows promise for clinical application in patients requiring total artificial hearts.