Air Mattress Pressure Phasing for Bed Articulation Shear Relief
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Solution Overview
Problem
Hospital beds with orientation adjustable components cause shear stress on occupants' skin due to friction at the mattress interface, leading to skin breakdown and tissue stretch when the head section is changed from a horizontal to a non-horizontal orientation, as the interior body parts translate but the skin and soft tissues do not, disrupting blood flow and lymphatic function.
Innovation Solution
The implementation of an air mattress with at least two classes of inflatable and deflatable bladders (A and B) that are coordinated to adjust their pressure phases in response to changes in the bed's orientation, providing a relatively lower occupant/support interface pressure at one location and a higher pressure at another to alleviate shear stress, allowing the tissue to return to a relaxed state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the head section is changed from horizontal to non-horizontal orientation, then the bed provides adjustable positioning for patient care, but shear stress and tissue stretch occur at the occupant/mattress interface
Solution Approach 1:
The mattress uses dynamically adjustable air bladders that can change their inflation state in response to bed orientation changes. When the head section is elevated, the system activates specific bladders to provide counteracting forces, transforming the static mattress into a dynamic support system that adapts to prevent shear stress while maintaining positioning versatility
Solution Approach 2:
The system changes the physical parameters of the mattress by adjusting air pressure in different bladder regions. By varying the inflation pressure of specific bladders based on bed orientation, the mattress modifies its support characteristics to counteract shear forces while preserving the ability to adjust bed orientation for different patient care needs
2Stability of the object's composition
If friction at the occupant/mattress interface is increased to prevent sliding, then patient positioning is maintained, but shear stress on skin and soft tissue increases
Solution Approach 1:
The mattress employs different bladder regions with locally optimized characteristics. Specific bladders are positioned to provide targeted support at the head, torso, and leg regions, creating non-uniform pressure distribution that maintains patient positioning stability while minimizing shear stress in critical areas through localized pressure adjustment
Solution Approach 2:
The air bladders act as an intermediary layer between the patient and the bed frame. By adjusting the inflation state of this intermediary system, the mattress can decouple the patient from direct contact with the moving bed frame, reducing shear stress transmission while maintaining positioning stability through controlled pressure distribution
3Object-affected harmful factors
If an air mattress with multiple bladders is used to relieve shear stress, then tissue stretch is reduced, but device complexity increases
Solution Approach 1:
The mattress is segmented into multiple independent bladder regions that can be controlled separately. This segmentation allows targeted pressure adjustment in specific areas to relieve shear stress and prevent tissue stretch, while the modular nature of the segmented design enables manageable system complexity through standardized, independently controllable units
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 solution effectively reduces and prevents tissue stretch and shear stress by dynamically adjusting the pressure distribution across the mattress, ensuring the skin and soft tissues can translate with the body's movement without sustaining harmful stress, thereby mitigating skin breakdown and improving comfort and health outcomes.
Implementation Method 1
providing a relatively lower occupant/support interface pressure at a location A and a relatively higher occupant/support interface pressure at a location B followed by providing a relatively higher occupant/support interface pressure at the location A and a relatively lower occupant/support interface pressure at the location B
Data Source
AI summary
A bed comprises a frame 34 with at least one orientation adjustable section (44, 46, 48), a mattress 58 supported by the frame and having at least one A bladder and at least one B bladder. The bladders are inflatable and deflatable out of phase with each other in coordination with at least one of a) issuance of a command for the frame section to change orientation and b) an actual change in orientation of the frame section. Also described is an associated method for operating an occupant support at least part of which is orientation adjustable relative to other parts of the occupant support. The method comprises providing, in response to a change of orientation of the orientation adjustable part, a relatively lower occupant/support interface pressure (OSIP) at a location A and a relatively higher OSIP at a location B followed by providing a relatively higher OSIP at the location A and a relatively lower OSIP at the location B.