Heart Failure
Conditions
Keywords
LVAD, Physiological Control
Brief summary
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.
Detailed description
Patients complete a set of tests in constant speed setting and repeat the same tests with physiological control algorithms turned on. Order is randomized.
Interventions
DEVICEPhysiological Control Module for the Medtronic -HVAD Left Ventricular Assist Device
Software, which sets the device speed according to physiological demand, is activated for the duration of the tests (up to 4 hours). Every patient provides his/her own control, because sequences with active control and with standard pump operation are subsequently performed in randomized order (determined by permutated blocks).
Sponsors
Heinrich Schima
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DEVICE_FEASIBILITY
Masking
SINGLE (Subject)
Masking description
Patients are blinded to their current control mode.
Intervention model description
Patients undergo testings in constant speed mode and physiologically controlled mode on the same day. the sequence is randomized. The number of patients was chosen due to the fact (experience in clinical care of the patients) the anatomical situation, the pump position due to surgical implant and the patient condition can vary to a high extent.
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Device Feasibility | duration of the testing (up to 4 hours) | Feasibility of the Control algorithm to safely adapt pump speed within provided limits, quantified by the number of necessary switchovers to manual mode |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Quantification of overpumping by number of suction events / minute during lying, standing and sitting and comparison with constant speed mode. | Duration of the testing (up to 4 hours) | Overpumping leads to occlusion of the pump inflow by the ventricular septum and sudden temporary decrease of flow. The number of such events can be counted by analysis of the flow pattern in the pump. The automatic control should lead to a reduction of such events per minute compared to the condition in constant speed. |
| Quantification of overpumping by number of suction events / minute due to change of position from lying sitting and sitting to standing compared to the situation in constant speed mode. | Duration of the testing (up to 4 hours) | Due to decreased venous return at changes of orthostasis the number of suctions increases in constant speed mode. The control should lead to a reduction of suction events due to intermittent reduction of pump speed. The quantification shall be done by comparing the number of suction events/minute immedeately after such changes in controlled and constant speed mode. |
Countries
Austria
Outcome results
None listed