Conductive Overlay for Patient Support Reducing Common-Mode Interference
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Solution Overview
Problem
Differential voltage measuring systems, such as those used for bioelectric signal measurement like ECG, face challenges in suppressing common-mode interference signals due to impedance differences between measuring paths, especially when electrodes are in contact with the patient's skin, making it difficult to maintain consistent conditions and reduce interference.
Innovation Solution
A patient support apparatus with a support plate and overlay, where the support plate or overlay has an electrically conductive layer connected to a contact-making apparatus via a transmission path, allowing the patient to be connected to a ground or mass with reduced impedance, utilizing a capacitively coupling section to minimize interference signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrodes are used to contact the patient's skin for measuring bioelectric signals, then the measuring capability is improved, but the impedance difference between measuring paths increases causing stronger common-mode interference signals
Solution Approach 1:
The patent introduces a conductive layer as an intermediary component between the patient's body and the measuring system. This conductive layer is connected to both measuring paths and provides a common reference potential, thereby reducing the impedance difference between the two measuring paths and suppressing common-mode interference signals while maintaining the ability to measure bioelectric signals through electrodes.
2Object-affected harmful factors
If the impedance conditions at electrode contact points are made consistent, then common-mode interference is reduced, but the complexity of maintaining consistent conditions throughout the measurement duration increases
Solution Approach 1:
The patent implements equipotentiality by connecting the conductive layer to both measuring paths, creating a common reference potential that equalizes the impedance conditions at different electrode contact points. This approach automatically maintains consistent impedance conditions without requiring complex active control mechanisms, thereby reducing common-mode interference while keeping the system relatively simple.
3Object-affected harmful factors
If a conductive layer is added to the patient support apparatus, then common-mode interference suppression is improved, but the device complexity increases
Solution Approach 1:
The conductive layer is designed to serve multiple functions: it acts as an electrode contact surface for bioelectric signal measurement, provides a common reference potential for reducing impedance differences, and serves as part of the patient support structure. By making the conductive layer multi-functional, the patent reduces common-mode interference without proportionally increasing device complexity.
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
This configuration effectively reduces common-mode interference signals by up to 20 dB to 30 dB, improving the accuracy of bioelectric signal measurements and reducing the susceptibility to errors while enhancing patient comfort and freedom of movement.
Implementation Method 1
utilizing a capacitively coupling section to minimize interference signals
Data Source
AI summary
An arrangement is disclosed including a patient support apparatus with a support plate and an overlay for the support plate. In an embodiment, the support plate or overlay includes an electrically conductive first layer. The first layer is connected and/or connectable to a contact-making apparatus via a first electric transmission path. The contact-making apparatus is connected and/or connectable to a ground or mass via a second electric transmission path. And, in an operating mode of the arrangement in which a patient is supported on the patient support apparatus, the first layer is connected and/or connectable to the patient via a third electric transmission path.