Cardiac Pump Optical Fiber Flow Sensing for Accurate Output Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mechanical circulatory support systems face challenges in accurately and reliably measuring cardiac output, as current methods like motor current draw and ultrasound or thermal techniques are indirect or prone to signal degradation due to proximity with power conductors.
Innovation Solution
Incorporation of optical fibers for laser Doppler velocimetry (LDV) to directly measure blood flow velocity, using laser beams to detect Doppler shifts and interference, allowing precise volumetric flow rate measurement through mechanical circulatory support devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If motor current draw or power consumption is used to measure pump volume flow, then the measurement can be obtained from operating parameters, but the measurement is indirect and affected by multiple parameters such as viscosity, pressure head, wear, and suction events
Solution Approach 1:
The patent replaces electrical/mechanical measurement methods (motor current draw, power consumption) with optical measurement methods (laser Doppler velocimetry). The optical fiber-based LDV system directly measures blood flow velocity through laser light scattering, eliminating the indirect nature of electrical measurements and their dependence on multiple confounding parameters like viscosity, pressure head, and mechanical wear.
Solution Approach 2:
The patent introduces optical fibers as an intermediary medium to transmit laser light through the blood flow path. This optical intermediary allows non-contact measurement of flow velocity through Doppler shift detection, avoiding the need for electrical conductors that are susceptible to interference from power conductors and other electrical noise in the system.
2Measurement precision
If ultrasound or thermal techniques are integrated into the support system, then pump volume flow can be measured, but signal degradation occurs due to proximity with power conductors
Solution Approach 1:
The patent substitutes electrical and acoustic measurement systems (ultrasound, thermal techniques that require electrical conductors) with an optical measurement system. The laser Doppler velocimetry uses light instead of electrical signals or acoustic waves, eliminating signal degradation caused by proximity to power conductors and electrical interference.
Solution Approach 2:
The patent employs optical fibers as an intermediary to transmit laser light through the blood flow path. This optical intermediary is immune to electrical interference and does not suffer from signal degradation near power conductors, providing a reliable measurement channel that maintains signal integrity throughout the system.
3Ease of operation
If electrical conductors are used to transmit measurement signals, then signals can be transmitted to external devices, but signal degradation or measurement prevention occurs due to proximity with power conductors
Solution Approach 1:
The patent introduces optical fibers as an intermediary medium to replace electrical conductors for signal transmission. Optical fibers transmit light-based measurement signals (laser Doppler signals) that are immune to electrical interference, eliminating signal degradation and measurement prevention issues that occur with electrical conductors near power conductors.
Solution Approach 2:
The patent replaces the electrical signal transmission system with an optical signal transmission system. By substituting electrical conductors with optical fibers, the system eliminates electromagnetic interference and signal degradation, maintaining reliable signal transmission from the measurement point to external processing devices.
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
Provides accurate and reliable measurement of cardiac output by minimizing signal distortion from environmental influences, enabling precise control of pump speed and improving the functionality of mechanical circulatory support systems.
Implementation Method 1
using laser beams to detect Doppler shifts
Implementation Method 2
optical fibers for laser Doppler velocimetry (LDV) to directly measure blood flow velocity
Implementation Method 3
using laser beams to detect Doppler shifts and interference
Data Source
AI summary
A cardiac assist system having a pumping device for moving blood, wherein a pumping capacity of the pumping device is adjustable using an adjustment signal based on laser doppler with an optical fiber. A measuring device measures a flow rate of the body fluid, the measuring device comprising at least one light source for outputting a light beam and at least one sensor element for detecting a reflected partial beam of the light beam. The measuring device is adapted to measure the body fluid using the reflected partial beam of the light beam. A determination device is adapted to determine the adjustment signal using the measurement signal. The device may include a bore opening to a blood flow channel, with an optical fiber extending through the bore.