Time-Based Medical Bed Pairing with Wall Unit Plug Detection

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Solution Overview

Problem

Existing wireless patient beds in healthcare facilities face challenges in accurate pairing with wall units due to RF signal interference and multiple receptions, leading to potential damage from abrupt cable removal and incorrect location identification.

Innovation Solution

A system utilizing timers and AC plug sensors for precise pairing by comparing uptime measurements and detecting power cord insertion to ensure accurate wireless communication between medical devices and wall units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If wireless RF transmission is used for bed ID communication, then wired connection is eliminated and ease of operation is improved, but signal interference and multiple receptions occur leading to pairing reliability deterioration

Engineering Contradiction:
Improveease of operationVSAvoidpairing reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary verification mechanism using AC plug sensors and uptime comparison. The wall unit and bed each independently measure uptime since power connection, and pairing is confirmed only when both uptime values match within a threshold. This intermediary verification step prevents false pairings caused by RF signal interference and multiple receptions, resolving the reliability issue while maintaining wireless operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If RF signals are transmitted at high power to ensure coverage, then signal strength is improved, but signal passes through walls and causes incorrect location identification

Engineering Contradiction:
Improvesignal strengthVSAvoidlocation identification precision
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the wall unit receives bed ID transmissions and compares the reported uptime against its own independently measured uptime. Additionally, the system uses AC plug sensor feedback to verify physical connection status. This feedback loop ensures that even if high-power RF signals are received from distant locations, pairing only occurs when both uptime values and power connection status match, preventing incorrect location identification.

Inventive Principle:
Principle #23Feedback

3Reliability

If wired nurse call cable connection is used, then reliable communication is established, but abrupt cable removal can cause damage

Engineering Contradiction:
Improvecommunication reliabilityVSAvoiddamage from cable removal
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical wired nurse call cable connection with a wireless RF communication system. The bed transmits nurse call signals and bed ID information wirelessly to the wall unit, eliminating the physical cable that could cause damage when abruptly removed. The wireless system maintains communication reliability through the uptime comparison verification mechanism, ensuring that only properly paired devices communicate while removing the mechanical connection hazard.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4033793B1Time-based wireless pairing between a medical device and a wall unit
Publication Date: 2025.09.17 HILL ROM SERVICES INC
  • EP4033793B1 patent drawingFigure 1
  • EP4033793B1 patent drawingFigure 2
  • EP4033793B1 patent drawingFigure 3

AI summary

A time-based wireless pairing operation between a medical device, such as a patient bed, and a wall module in a patient room is initiated in response to a power plug of the medical device being plugged into a power receptacle carried by the wall module. Times determined by timers of the medical device and the wall module are compared by the wall module or by the medical device so that wireless pairing occurs only with the medical device that was plugged into the wall module. Different types of plug detectors used in the wall module to detect connection of the power plug include optical detectors, mechanical switches, and current sensors.