Ventricular Assist Device Control Stabilization
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Solution Overview
Problem
Ventricular assist devices (VADs) face instability in speed control due to physiologically caused fluctuations in measured vascular and/or intracardiac pressures, which can affect the detection of events like suction.
Innovation Solution
A control device for VADs that processes measuring signals to derive refined actual values of heart characteristic parameters, eliminating or reducing physiologically caused fluctuations, thereby stabilizing VAD speed control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If VAD speed control is based on measured vascular and/or intracardiac pressures, then the VAD can assist heart function, but physiologically caused fluctuations in these pressure measurements lead to instability in VAD speed control
Solution Approach 1:
The patent introduces an intermediary processing stage between pressure measurement and VAD speed control. A control device processes the raw pressure measurements through algorithms that distinguish between physiologically caused fluctuations (noise) and true pressure changes (signal). This intermediary processing filters out respiratory-induced and other physiological variations while preserving clinically relevant pressure information for stable VAD speed control.
Solution Approach 2:
The system implements feedback control where the processed pressure measurements continuously inform VAD speed adjustments. The control device monitors pressure variations, processes them to eliminate physiological noise, and uses the refined pressure information to adjust VAD speed in real-time, creating a stable closed-loop control system that compensates for measurement fluctuations.
2Adaptability or versatility
If VAD speed is adjusted based on fluctuating pressure measurements, then heart assistance can be adapted to patient condition, but the detection of events such as suction is disturbed by these fluctuations
Solution Approach 1:
The control device acts as an intermediary that processes raw pressure signals before they are used for event detection. By applying signal processing algorithms, the system distinguishes between physiological noise and true event signatures (such as suction events). This intermediary processing enhances the detectability of clinically relevant events while filtering out confounding physiological variations.
Solution Approach 2:
The system extracts the essential signal components related to heart assistance needs and event detection from the complex pressure measurements. By separating the useful information (true pressure trends and event signatures) from the harmful physiological fluctuations, the system enables accurate event detection and appropriate heart assistance adaptation.
Data Source
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AI summary
A control device (100) for a ventricular assist device, VAD (50), with settable speed levels, the control device (100) comprising an input (101) configured to receive at least one measuring signal (LVPmeas) related to a physiological condition of the circulatory system of a patient (P) receiving heart assistance by the VAD (50), wherein the control device (100) is configured to derive an actual value (EDLVP; FG) of at least one characteristic parameter of the heart (H) from one or more of the at least one measuring signal (LVPmeas) and to provide a refined actual value (EDLVP*; FG*) of the at least one characteristic parameter in which effects of physiologically caused fluctuations are eliminated or reduced; and an output (105) configured to output an updated setting value (nVADset) for the speed level, wherein the control device (100) is configured to produce the updated setting value (nVADset) based on the refined actual value (EDLVP*; FG*) and a predeterminable set-point value (EDLVPset; FGset). A VAD (50) for assistance of a heart, comprising the control device (100), wherein the VAD (50) is preferably a non-pulsatile rotational blood pump, wherein further preferably the blood pump is catheter-based. A method for obtaining a refined actual value of at least one characteristic parameter of the heart (H), the method comprising receiving at least one measuring signal (LVPmeas) related to a physiological condition of the circulatory system of a patient (P); deriving an actual value (EDLVP; FG) of at least one characteristic parameter of the heart (H) from one or more of the at least one measuring signal (LVPmeas); processing the actual value (EDLVP; FG) or the one or more of the at least one measuring signal (LVPmeas) to provide the refined actual value (EDLVP*; FG*) in which physiologically caused fluctuations are eliminated or reduced. A method for controlling the speed level of a ventricular assist device, VAD (50), with settable speed levels, the method comprising obtaining the refined actual value of at least one characteristic parameter of the heart (H); and producing an updated setting value (nVADset) for the speed level based on the refined actual value (EDLVP*; FG*) and a predeterminable set-point value (EDLVPset).