Implanted Blood Flow Measurement Using LVAD Motor Heat
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Solution Overview
Problem
Existing methods for determining total fluid volume flow in implanted vascular support systems, such as LVADs, require transcutaneous catheters and cannot provide continuous measurement outside of cardiac surgery, limiting clinical applicability.
Innovation Solution
A method utilizing thermally anemometric principles that leverage the thermal dissipation loss of the electric motor in the support system to determine total fluid volume flow without additional heating elements, incorporating sensors to measure reference and motor temperatures and current to calculate flow based on heat transfer principles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transcutaneous catheters are used for flow measurement, then measurement capability is provided, but continuous measurement outside of cardiac surgery cannot be achieved
Solution Approach 1:
The electric motor's thermal dissipation is utilized as the heat source for flow measurement, eliminating the need for separate heating elements. The motor's inherent thermal byproduct is converted into a useful measurement function, enabling self-service operation without additional components that would require external access or intervention.
Solution Approach 2:
The electric motor serves dual functions: driving the pump and providing thermal energy for flow measurement. This multi-functionality allows the same component to perform both mechanical work and thermal measurement, eliminating the need for separate systems and enabling continuous operation without additional transcutaneous access.
2Measurement precision
If additional heating elements are used for thermal flow measurement, then flow measurement accuracy is improved, but power consumption increases
Solution Approach 1:
The thermal dissipation from the electric motor, which is normally considered waste heat or energy loss, is converted into a useful resource for flow measurement. By utilizing this inherent thermal byproduct, the system achieves accurate flow measurement without requiring additional heating elements that would consume extra power.
Solution Approach 2:
The electric motor provides its own thermal energy for measurement purposes, eliminating the need for separate power-consuming heating elements. The motor's operational thermal output is repurposed to serve the measurement function, reducing overall system power requirements.
3Measurement precision
If transcutaneous catheters are used for measurement, then measurement data can be obtained, but the system cannot remain fully implanted
Solution Approach 1:
The measurement function is extracted from external transcutaneous systems and integrated into the implanted pump device itself. By incorporating temperature sensors and utilizing the motor's thermal output within the implanted device, the system eliminates the need for external catheters and transcutaneous access points.
Solution Approach 2:
The flow measurement functionality is merged with the pump system by using the same electric motor as the heat source. This integration combines the drive mechanism and measurement function into a single implanted unit, eliminating separate external measurement systems and simplifying the overall implantation.
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
Enables continuous, fully implanted measurement of total fluid volume flow with comparable quality to surgical methods, eliminating the need for additional heating elements and reducing power consumption, thus extending battery life in autonomous systems.
Implementation Method 1
determining the thermal dissipation loss of the electric motor
Implementation Method 2
determining a motor temperature of an electric motor of the support system
Data Source
AI summary
The invention relates to a method for determining a total fluid volume flow (1) in the region of an implanted vascular support system (2), comprising the following steps: a) determining a reference temperature (3) of the fluid, b) determining a motor temperature (4) of an electric motor (5) of the support system (2), c) determining the thermal dissipation loss (6) of the electric motor (5), d) ascertaining the total fluid volume flow (1) using the reference temperature (3), the motor temperature (4), and the thermal dissipation loss (6) of the electric motor (5).