Auto-Contour Patient Support Linkage for Head Elevation Stability

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Solution Overview

Problem

Existing patient support apparatuses, such as stretchers and hospital beds, face difficulties in maintaining patient stability when the head section is raised, as heavier patients tend to migrate towards the foot end, and existing auto contour mechanisms may not effectively manage thigh section movement in conjunction with head section elevation.

Innovation Solution

A patient support apparatus with a linkage system that allows the thigh section to remain parallel to the seat section as the head section is raised, featuring a cam mechanism and a spring clutch for adjustable operation, enabling the thigh section to be raised or lowered relative to the drop rail based on the head section's position, and includes handles for locking and releasing the spring clutch to control the movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the head section is raised to improve patient comfort and positioning, then patient comfort is improved, but the patient tends to migrate toward the foot end causing instability

Engineering Contradiction:
Improvepatient comfortVSAvoidpatient stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by making the thigh section movable relative to the seat section through a linkage mechanism. As the head section is raised, the linkage automatically adjusts the thigh section angle to raise the patient's knees, dynamically maintaining patient stability while allowing head elevation for comfort.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If an auto contour mechanism is used to raise the thigh section when the head section is raised, then patient stability is improved, but the caregiver loses the ability to independently position the thigh section

Engineering Contradiction:
Improvepatient stabilityVSAvoidpositioning flexibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The linkage mechanism is designed to be disengageable, allowing it to switch between an engaged state (providing automatic stability) and a disengaged state (allowing independent positioning). This dynamic capability enables the system to adapt between automatic and manual control modes as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The positioning system is segmented into independently controllable sections. The thigh section can be positioned independently of the head section when the linkage is disengaged, allowing caregivers to adjust each section separately for optimal patient comfort and positioning.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If gas springs are used to aid in lifting the head section, then ease of operation is improved, but the system complexity increases

Engineering Contradiction:
Improvehead section liftingVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent uses gas springs (pneumatic elements) to provide assisted lifting of the head section. The gas springs are integrated into the existing articulation mechanism, providing mechanical advantage without requiring complex additional systems, thus improving ease of operation with moderate complexity addition.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Data Source

PatentEP1810650B1Patient support apparatus having auto contour
Publication Date: 2011.10.19 HILL ROM SERVICES INC
  • EP1810650B1 patent drawingFigure 1
  • EP1810650B1 patent drawingFigure 2~3
  • EP1810650B1 patent drawingFigure 4

AI summary

A patient support apparatus (20) comprises a frame (26), at least one drop rail (66) coupled to the frame and tiltable relative to the frame (26), a seat section (44) supported by the at least one drop rail (66) to tilt therewith, a thigh section (46) coupled to the seat section (44), a head section (42) coupled to the frame (26) and coupled to the at least one drop rail (66), and a linkage (400) coupled to the head section (42) and coupled to the thigh section (46). Raising and lowering of the head section (42) results in tilting of the at least one drop rail (66) relative to the frame (26). The linkage (400) has a first mode of operation in which the seat (44) and thigh sections (46) remain substantially parallel as the at least one drop rail (66) tilts. The linkage (400) has a second mode of operation in which the thigh section (46) tilts relative to the seat section (44) as the at least one drop rail (66) tilts.