Inflatable Mattress Cell Phasing to Reduce Patient Movement and Noise
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Solution Overview
Problem
Traditional alternating pressure support systems, such as the '1 of 2' system, compromise between reducing patient movement and providing effective pressure relief, as they often result in a large proportion of the mattress surface changing pressure simultaneously, leading to discomfort and movement sensations, while '1 of 3' or '1 of 4' systems offer less frequent pressure relief.
Innovation Solution
The implementation of a control unit that allows for time-offset inflation and deflation of different sets of inflatable cells, creating a phased crossover effect where each set changes pressure at a unique time, ensuring a stable surface for a larger proportion of the cycle and maintaining the same pressure relief rate as traditional systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If all A cells are connected together and all B cells are connected together in traditional alternating systems, then the pump design is simplified using a single rotary valve, but a large proportion of the mattress surface changes pressure simultaneously causing patient movement and discomfort
Solution Approach 1:
The patent divides the mattress surface into multiple independent cell groups (first group, second group, third group, fourth group) that can be controlled separately. Each group can be inflated or deflated independently, allowing the pressure changes to be distributed across different regions rather than affecting the entire surface simultaneously. This segmentation enables the system to maintain pump design simplicity while reducing patient discomfort by localizing pressure changes.
2Object-affected harmful factors
If '1 of 3' or '1 of 4' systems are used to reduce patient movement sensation, then a larger proportion of cells remain inflated at fixed pressure, but pressure relief from patient areas occurs less frequently
Solution Approach 1:
The patent segments the mattress into multiple independently controllable cell groups, allowing different regions to be in different phases of the pressure cycle simultaneously. This enables the system to provide frequent pressure relief to specific areas while maintaining support in other areas, thus achieving both reduced patient movement sensation and maintained pressure relief frequency.
Solution Approach 2:
The patent implements periodic inflation and deflation cycles for different cell groups in a coordinated sequence. By alternating the pressure cycles between different groups with appropriate timing, the system ensures that pressure relief is delivered frequently to all areas over time while at any given moment only a portion of the surface is changing pressure, reducing patient movement sensation.
3Device complexity
If a single rotary valve is used to distribute air to all cells, then the device complexity is reduced, but the ability to provide phased pressure changes across different cell groups is limited
Solution Approach 1:
The patent segments the air distribution system into multiple valve circuits, each controlling a specific group of cells. This segmentation allows independent control of different cell groups with relatively simple valve mechanisms, achieving phased pressure control without requiring a single complex valve system. Each valve group can be designed to be relatively simple while the overall system achieves sophisticated control capability.
Data Source
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AI summary
Inflatable mattress apparatus includes a mattress provided with a plurality of inflatable cells (A, B); a manifold unit (V1-V4) connected to the plurality of cells, wherein the manifold (V1-V4) couples the cells into a plurality of individual sets of cells; and a control unit connected to the manifold, the control unit being operable to provide substantially simultaneous inflation and deflation of cells (A, B) in each set of cells over a period, and time offset inflation and deflation of cells in different sets of cells. The apparatus can provide the same benefits of a 1 of 2' system with reduced movement of the entire surface at any point in the cycle, less air moving at any given time and thus a reduction in the audible noise produced in any pump supplying the air and the associated airflow in the mattress. The arrangement provide other benefits too.