Inductance Plethysmography for Non-Invasive Aortic Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring aortic blood flow in small laboratory mammals are invasive or require cumbersome, constraining techniques, lacking non-invasive and non-binding solutions that adhere to regulatory constraints.
Innovation Solution
A device comprising adjustable, electrically conductive coils in an elastic garment for thoracic plethysmography by inductancemetry, along with a processor to calculate aortic flow, extracts the cardiac component of thoracic volume variations using a functional model of cardio-respiratory exchanges, allowing for non-invasive sub-diaphragmatic aortic flow measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If invasive measurement techniques (aortic band, electromagnetic flowmeter, implantable telemetry) are used to measure aortic blood flow, then measurement precision is improved, but animal constraint and invasiveness increase
Solution Approach 1:
The patent replaces direct mechanical contact with the aorta (aortic band, electromagnetic flowmeter) with an indirect electromagnetic field-based measurement system. The inductance plethysmography coils detect thoracic volume changes through electromagnetic induction without mechanical contact or surgical implantation, thereby maintaining measurement precision while eliminating invasiveness and animal constraint
Solution Approach 2:
The patent introduces thoracic volume changes as an intermediary parameter to indirectly measure aortic blood flow. Instead of directly measuring flow in the aorta, the system measures thoracic volume variations caused by cardiac pumping action and uses a functional model to derive aortic flow, thus avoiding direct contact with the animal's circulatory system
2Object-affected harmful factors
If non-invasive methods (PET, MRI, CT scan, Ultrasound) are used to explore cardiac function, then animal constraint is reduced, but device complexity and operational constraint increase
Solution Approach 1:
The patent employs simple, low-cost inductance coils and elastic garments that can be easily applied and removed, replacing complex, expensive, and cumbersome equipment like PET, MRI, and CT scanners. The measurement system is portable, requires no specialized facility, and can be used on awake animals without confinement
Solution Approach 2:
The patent extracts only the essential measurement function from complex medical imaging systems. By isolating the cardiac-related thoracic volume changes and using a functional model to derive aortic flow, the system eliminates the need for expensive, complex imaging equipment while maintaining the ability to assess cardiac function
3Measurement precision
If aortic band with wired connection is used for measurement, then measurement precision is improved, but animal mobility and operational ease deteriorate due to general anesthesia requirement
Solution Approach 1:
The patent replaces the wired mechanical connection system (aortic band connected to acquisition device by wires) with a wireless electromagnetic field-based system. The inductance coils detect thoracic volume changes without physical connection to the animal, enabling measurement in mobile, awake animals without anesthesia
Solution Approach 2:
The patent uses thoracic volume changes as an intermediary to measure aortic flow without requiring direct contact with the aorta. This indirect measurement approach eliminates the need for surgical implantation and wired connections, allowing free animal movement and eliminating anesthesia requirements
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, non-invasive, and non-binding measurement of aortic flow in small laboratory mammals, meeting metrological performance requirements with reduced animal constraint, suitable for awake animals.
Implementation Method 1
A device for plethysmography of the thorax by inductancemetry comprising two electrically conductive extensible coils secured to an elastic garment
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a device for non-invasive measurement of aortic flow in the subdiaphragmatic region in a small laboratory mammal, characterised in that it comprises: - a device for plethysmography of the thorax by inductance measurement, comprising two electrically conducting, extendible coils (2, 3) rigidly attached to an elastic garment (1) that is adjustable to the torso of said mammal (A), - a device (4) for acquiring the signal from variation in the cross-section of each coil, - a processor (6) configured to calculate the instantaneous subdiaphragmatic aortic flow of said mammal from said signals from the variation in cross-section of each coil and from a functional model of the cardiorespiratory system, according to which the exchanges of blood between the thorax and the rest of the body of said mammal consist of an output of blood via the abdominal aorta in the subdiaphragmatic region and an input of blood via the inferior vena cava.