Patient Cooling Microclimate Structure with Dynamic Airflow Control

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Solution Overview

Problem

Patients in care facilities, such as hospitals, are at risk of developing bed sores due to heat and moisture accumulation when on bed mattresses, and existing microclimate structures often require a large volume of air for effective cooling and drying.

Innovation Solution

A patient support apparatus with a microclimate structure featuring a vapor and liquid permeable upper layer, an air permeable middle layer, and a liquid impermeable lower layer, along with perforations and a crease mechanism to control air flow, which directs pressurized air through a therapeutic region to cool and dry the skin with minimal air volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a microclimate structure supplies a large volume of air, then effective cooling and drying of the patient's skin is achieved, but air consumption and energy use increase

Engineering Contradiction:
Improveeffectiveness of cooling and dryingVSAvoidair volume required
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The microclimate structure is divided into three functional layers with distinct properties: an upper layer that is vapor and liquid permeable for targeted therapeutic regions, a middle layer that is air permeable for general ventilation, and a lower layer that is liquid impermeable for moisture protection. This segmentation allows each layer to perform its specific function efficiently, reducing the overall air volume needed while maintaining effective cooling and drying where most needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes phase change principles by allowing vapor to pass through the upper layer while condensing moisture on the lower layer. The structure changes the state of moisture from vapor to liquid through controlled condensation, enabling effective drying with minimal air volume. The crease mechanism also dynamically changes the airflow parameters by blocking perforations in response to head elevation.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the microclimate structure uses a simple single-layer design, then device complexity is reduced, but effectiveness in simultaneously managing vapor, liquid, and air is compromised

Engineering Contradiction:
Improvestructure layeringVSAvoidmicroclimate control effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The microclimate structure is divided into three independent functional layers: an upper layer for vapor and liquid management in therapeutic regions, a middle layer for air circulation, and a lower layer for liquid impermeability. This segmentation allows each layer to handle specific aspects of moisture and air management, achieving comprehensive microclimate control while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs a composite structure combining three different types of layers with distinct properties. The upper layer uses vapor and liquid permeable materials for targeted therapy, the middle layer uses air permeable materials for ventilation, and the lower layer uses liquid impermeable materials for protection. This composite approach enables the structure to simultaneously manage multiple forms of moisture and air with enhanced reliability.

Inventive Principle:
Principle #40Composite materials

3Temperature

If air flow is supplied to all perforations regardless of head position, then cooling coverage is maximized, but energy waste occurs when the head is elevated and does not need cooling

Engineering Contradiction:
Improveskin cooling coverageVSAvoidair flow energy waste
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The microclimate structure incorporates a dynamic response mechanism through the crease feature that automatically adjusts airflow distribution based on head position. When the head is elevated, the crease forms and blocks airflow to the upper perforations, redirecting air flow dynamically to match the patient's actual cooling needs. This eliminates energy waste on areas that no longer require cooling while maintaining effective temperature control where needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The structure uses passive feedback through the crease mechanism that responds to head elevation changes. The crease forms or unfolds based on the mechanical input from head position, automatically regulating airflow distribution without requiring external control systems. This feedback mechanism ensures energy is only consumed when and where cooling is actually needed, optimizing energy efficiency while maintaining therapeutic effectiveness.

Inventive Principle:
Principle #23Feedback

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

Effectively reduces the risk of bed sores by efficiently cooling and drying targeted therapeutic regions with reduced air flow requirements, promoting skin health and preventing moisture accumulation.

Implementation Method 1

The microclimate structure may conduct air along the interface of a patient with the surface to keep the patient's skin cool and dry

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

The microclimate structure may conduct air along the interface of a patient with the surface to keep the patient's skin cool and dry

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

At least a portion of the upper layer is vapor and liquid permeable

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3431066B1Patient cooling system responsive to head elevation
Publication Date: 2020.12.16 HILL ROM SERVICES INC
  • EP3431066B1 patent drawingFigure 1
  • EP3431066B1 patent drawingFigure 2
  • EP3431066B1 patent drawingFigure 3

AI summary

A patient support structure includes a cushion layer. A microclimate structure is integrated atop the cushion layer. The microclimate structure includes an upper layer having a vapor and liquid permeable therapeutic region, an air permeable middle layer, and a liquid impermeable lower layer. A first plurality of perforations extends through the upper layer of the microclimate structure in a seat section of the microclimate structure. A second plurality of perforations extends through the upper layer of the microclimate structure in a head section of the microclimate structure. When the microclimate structure is in a first position, air is supplied through the first plurality of perforations and the second plurality of perforations. When the microclimate structure is in a second position, air is supplied through the first plurality of perforations and air flow through the second plurality of perforations is limited.