Auto-Contour Bed Linkage for Patient Stability During Head Raise
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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 independently of the head section.
Innovation Solution
A patient support apparatus with a linkage system that allows the thigh section to remain parallel or tilt relative to the seat section as the head section is raised, utilizing a cam and roller assembly with a spring clutch mechanism to control the movement, enabling independent adjustment of the thigh section's position relative to the drop rail.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the head section is raised to improve patient comfort and accessibility, then patient stability deteriorates as the patient tends to migrate toward the foot end
Solution Approach 1:
The deck is divided into separate articulating sections (head section, seat section, thigh section, foot section) that can move independently relative to each other. This segmentation allows the head section to be raised for accessibility while the thigh section remains stationary to maintain patient stability, preventing migration toward the foot end.
Solution Approach 2:
The linkage system provides dynamic control over the relationship between deck sections. The thigh section can be locked in place while the head section moves, or the thigh section can be raised automatically with the head section depending on the desired configuration. This dynamic adjustability resolves the contradiction between improving accessibility and maintaining stability.
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 improves, but the ability to independently control thigh section position deteriorates
Solution Approach 1:
The linkage system transitions from a fixed auto-contour mechanism to a dynamic system where the relationship between head section and thigh section can be changed. The thigh section may be locked to prevent movement relative to the seat section, or unlocked to allow automatic raising/lowering with the head section. This dynamic control provides both stability when needed and independent positioning capability when needed.
Solution Approach 2:
The system provides self-service through automatic thigh section adjustment when the head section is raised, eliminating the need for manual intervention. The linkage automatically raises or lowers the thigh section based on head section position, while still allowing manual override when independent control is required.
3Ease of operation
If gas springs are used to aid in lifting the head section, then ease of operation improves, but the complexity of the mechanism deteriorates
Solution Approach 1:
Gas springs are integrated into the linkage system to provide pneumatic assistance for raising and lowering the head section. The gas springs counterbalance the weight of the head section and patient, making the lifting operation easier and more controlled. This pneumatic assistance reduces the manual force required while adding minimal complexity to the overall mechanism.
Data Source
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AI summary
A patient support apparatus (20) comprising a frame (26), at least one drop rail (66) coupled to the frame for tilting movement between a first position generally parallel to the frame (26) and a lowered second position, 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) for tilting movement between a first position generally parallel to the at least one drop rail (66) and a second position raised with respect to the at least one drop rail, a head section (42) coupled to the frame (26) and coupled to the at least one drop rail (66), tilting movement of the head section from a lowered position generally parallel to the frame to a raised position resulting in downward tilting movement of the at least one drop rail (66) from the first position to the second position, and a linkage (400) coupled to the head section (42) and coupled to the thigh section (46) to initially raise and then lower the thigh section (46) as the head section (42) is raised.