Physiological Control for Mechanical Circulatory Devices

Pilot Study for the Evaluation of Control Algorithms for Mechanical Circulatory Support Devices Based on Physiological Demand

Aim of this clinical study is to compare our newly developed control algorithms for mechanical circulatory support devices based on physiological demand with the standard manual LVAD speed operation. Specifically it shall be demonstrated that:

• Suction is properly detected by the pre-trained pump flow estimation algorithm
• Suction events (due to changes in physiological demand) can be reduced by control algorithms compared to continuous speed
• If suction is encountered, it can be detected and cleared
• The pump reacts adequately to changes in patient demand due to physical activity
• Physicians pump setpoints (of requested speed for a certain heartrate) can be achieved safely.

Patients complete a set of tests in constant speed setting and repeat the same tests with physiological control algorithms turned on. Order is randomized.

Inclusion Criteria:

All patients with a Medtronic HVAD system implanted at the Medical University of Vienna, Division of Cardiac Surgery, which are able and willing to understand and sign the informed consent form, and which do not meet any exclusion criteria will be included.

Exclusion Criteria:

• Inability to provide informed consent
• Patients with known intraventricular or aortic root thrombus formation confirmed by transthoracic ultrasound diagnostic
• Known pathology of the coagulatory system
• Supra or sub-therapeutic anticoagulation (aPTT or INR)
• Suspected or confirmed pump thrombus (based on lab parameters, abnormal high pump power consumption or acoustic spectral analysis)
• History of ischemic or hemorrhagic stroke (<2 months)
• Hypertension at rest (mean arterial pressure > 120mmHg)
• Cerebrovascular or musculoskeletal disease preventing the performance of daily life activities or exercise training
• Severe arrhythmia (e.g. long QT syndrome), ventricular fibrillation or required defibrillation - excluding the LVAD implantation - in the previous 2 months
• All contraindications applicable to the HVAS are applicable to this study.

The System is contraindicated:

• In patients with a body surface area (BSA) less than 1.2 m²
• In patients who cannot tolerate anticoagulation therapy
• During pregnancy