Extracorporeal Cardiac Support Weaning With Synchronized Flow Pulses
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Solution Overview
Problem
Existing cardiac support systems face challenges in weaning patients from extracorporeal support without causing hemodynamic energy surpluses or sudden changes that can stress the heart, leading to potential complications.
Innovation Solution
A cardiac assistance system with a control device that alternates between a support mode and a weaning mode, providing pulses synchronized to the heart cycle with reduced energy in the weaning mode to gradually reduce support, ensuring quasi-continuous cardiac assistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of pulses is reduced to support every other or every third heartbeat for weaning, then the heart can gradually recover from dependency on support, but overall mean flow decreases causing flow mismatch and related alarms
Solution Approach 1:
The system implements periodic pulsatile support where pulses are delivered at regular intervals synchronized to the patient's heart cycle. During weaning mode, the control device is configured to deliver pulses at a reduced frequency (e.g., every other or every third heartbeat) while maintaining synchronization with the patient's native heart rhythm, allowing gradual recovery while preventing flow mismatch alarms through periodic reinforcement of cardiac output.
Solution Approach 2:
The system dynamically adjusts the pulsatile support parameters based on the patient's recovery progress. The control device monitors hemodynamic parameters and automatically modifies pulse frequency, amplitude, and timing to optimize the balance between supporting cardiac output and allowing heart recovery. This dynamic adaptation prevents flow mismatch while facilitating gradual weaning.
2Power
If pulses are provided with higher hemodynamic energy surplus to support the heart, then cardiac support effectiveness is improved, but additional stress is generated on the heart and patient during unsupported heart cycles
Solution Approach 1:
The system changes the energy parameters of delivered pulses based on the support mode. During weaning mode, the control device reduces the hemodynamic energy surplus of each pulse compared to full support mode, delivering gentler pulses that provide necessary support without creating excessive stress on the heart during subsequent unsupported cycles. This parameter adjustment optimizes the balance between support effectiveness and heart stress reduction.
Solution Approach 2:
By delivering pulses periodically synchronized to the patient's heart cycle rather than continuously, the system allows natural heart recovery during unsupported intervals while providing rhythmic reinforcement when needed. This periodic delivery pattern reduces cumulative stress compared to continuous high-energy support while maintaining adequate cardiac output through timing-optimized pulse delivery.
3Productivity
If the pump output is increased to maintain sufficient mean flow during weaning, then flow mismatch alarms are prevented, but the heart remains dependent on high levels of support
Solution Approach 1:
The control device dynamically adjusts pump output parameters during weaning mode to gradually reduce dependency. The system monitors mean flow and automatically modulates pulse amplitude and frequency to maintain adequate cardiac output while progressively lowering support levels. This dynamic control allows the heart to adapt to decreasing support levels without triggering flow mismatch alarms, facilitating gradual independence.
Solution Approach 2:
The system uses periodic pulsatile delivery rather than continuous flow to maintain mean flow during weaning. By timing pulses to coincide with the patient's cardiac cycle and delivering concentrated flow at optimal moments, the system maintains adequate mean flow with lower overall pump output levels, allowing heart independence while preventing flow mismatch conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system allows for a smooth transition from cardiac support to physiological heart function by minimizing hemodynamic energy surpluses and reducing stress, ensuring consistent oxygen supply and cardiac support during the weaning process.
Implementation Method 1
at least one pump fluidically connected to the suction line and the pressure line, the pump being configured to pump a fluid, in particular blood, to create a fluid flow from the suction line to the pressure line
Data Source
Figure 1
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AI summary
The present invention relates to an extracorporeal cardiac assistance system (10), comprising a pump (18) being configured to create a fluid flow from a suction line (12) to a pressure line (14) of the system; further comprising a control device (22) configured to control the pump (18) and/or an adjustable flow limiter (20) to provide an adjustable flow rate and/or a pressure, wherein the control device (22) is configured to execute a support mode with a plurality of consecutive support flow rate pulses and/or support pressure pulses interposed on the fluid flow and to execute a weaning mode with a plurality of such pulses, wherein an amount of energy provided to the fluid flow with each pulse is lower in the weaning mode than in the support mode. The invention further relates to a method for operating the system (10) and to a treatment method.