Impedance-Based Chest Compression Depth Measurement for CPR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CPR assist technologies face inaccuracies in determining chest compression depth, particularly on compressible surfaces, and cause rescuer discomfort due to the use of pucks or require excessive force, necessitating improved methods for accurate and comfortable depth determination.
Innovation Solution
A system using impedance measurements between anterior and posterior electrode assemblies on the patient's chest and back to determine compression depth as a proportion of chest height, employing processors to analyze impedance signals and provide real-time feedback to rescuers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a puck is placed on the sternum to provide feedback, then chest compression depth measurement accuracy is improved, but rescuer hand pain increases
Solution Approach 1:
The patent introduces an intermediary system using electrode assemblies and impedance measurements to indirectly determine chest compression depth without requiring direct contact with the sternum. The electrode assemblies placed on the chest and back measure impedance changes that correlate with compression depth, eliminating the need for a puck on the sternum and thus preventing rescuer hand pain while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces the mechanical contact-based measurement system (puck on sternum) with an electrical measurement system (impedance measurement between electrode assemblies). This substitution eliminates the need for direct mechanical contact with the compression site, thereby preventing rescuer hand pain while providing accurate depth feedback through electrical signal analysis.
2Ease of operation
If accelerometer-based devices are used to avoid puck on sternum, then rescuer comfort is improved, but measurement accuracy deteriorates on compressible surfaces
Solution Approach 1:
The patent replaces accelerometer-based mechanical sensing with electrical impedance measurement. The electrode assemblies measure changes in electrical impedance through the chest tissue, which directly correlates with compression depth. This electrical measurement method is not affected by the compressibility of the underlying surface (bed or stretcher), providing accurate measurements while maintaining rescuer comfort through non-contact measurement.
Solution Approach 2:
The patent changes the measurement parameter from mechanical acceleration (accelerometer) to electrical impedance. By measuring impedance changes between electrode assemblies placed on the chest and back, the system can accurately detect compression depth regardless of the surface compressibility, overcoming the limitation of accelerometer-based systems on soft surfaces.
3Measurement precision
If force-based devices are used to measure compression depth, then measurement capability is provided, but excessive force requirements (200-600 Newtons) make the system impractical
Solution Approach 1:
The patent replaces force-based measurement with electrical impedance measurement. Instead of requiring force sensors to detect compression depth, the system uses electrode assemblies that measure electrical impedance changes through the chest tissue. This substitution eliminates the need for excessive force (200-600 Newtons) and makes the measurement system practical for real-time CPR feedback.
Solution Approach 2:
The patent introduces electrical impedance as an intermediary parameter to indirectly measure compression depth. The impedance changes between electrode assemblies serve as a mediator that correlates with compression depth without requiring direct force measurement, thereby reducing the force requirement from 200-600 Newtons to minimal measurement force.
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
Accurately determines chest compression depth as a proportion of chest height, providing real-time feedback to rescuers, enhancing CPR effectiveness while minimizing discomfort and force requirements.
Implementation Method 1
determining a chest compression depth based on impedance measurements
Data Source
AI summary
A medical device for indicating a chest compression depth, including a first electrode assembly structured to be disposed on a chest of a patient, a second electrode assembly structured to be disposed on a back of the patient, and a processor configured to determine a chest compression depth as a proportion of chest height based on a first impedance measurement between the first electrode assembly and the second electrode assembly when the chest is not compressed and a second impedance measurement between the first electrode assembly and the second electrode assembly when the chest is compressed.