Patient Support Power Transfer for Continuous Device Charging

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Solution Overview

Problem

Conventional patient transport apparatuses, such as cots and stair chairs, often require separate devices for transporting patients up or down stairs, leading to complications in patient care due to battery depletion of powered devices and inefficient power management.

Innovation Solution

A patient support system with a base and litter that includes a control system for power transfer between energy storage units, allowing seamless charging and operation of powered devices across different components, ensuring continuous power supply during patient transport.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate powered devices are used for patient transport apparatuses (cot and stair chair), then each device can perform its specific function independently, but battery depletion occurs and requires separate charging management

Engineering Contradiction:
Improvefunctional independenceVSAvoidcontinuous power supply
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a universal power management system where the cot apparatus includes a power transfer architecture that can charge both the cot's own battery and the stair chair's battery. The control system detects which device needs charging and transfers power accordingly, allowing one device to serve multiple power-related functions and eliminating the need for separate charging operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple separate powered devices are employed, then each device can be optimized for its specific transport function, but the overall system complexity increases and requires multiple battery management protocols

Engineering Contradiction:
Improvedevice specializationVSAvoidpower management system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the power management functions of multiple devices into a single integrated system. The cot's control system is enhanced to manage power for both the cot and stair chair, combining what would otherwise be separate battery monitoring, charging control, and power transfer functions into one unified management architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control system is designed with universal power management capabilities that can handle multiple devices. It detects which device requires charging and executes appropriate power transfer protocols, allowing a single control system to perform multiple power management functions across different transport devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If battery charging is handled separately for each powered device, then each device can maintain its own power supply, but time is lost during charging operations and patient care is interrupted

Engineering Contradiction:
Improveindividual power supplyVSAvoidcharging time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary power transfer actions by automatically detecting when a device's battery charge level falls below a threshold and initiating charging before complete depletion occurs. The control system proactively manages power distribution to prevent battery exhaustion, ensuring continuous operation without interrupting patient care.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The powered devices engage in self-service power management where the system automatically monitors battery levels and executes power transfer operations without external intervention. When the stair chair or cot battery requires charging, the control system autonomously initiates the power transfer process, eliminating the need for manual charging operations.

Inventive Principle:
Principle #25Self-service

4Reliability

If separate charging operations are performed for each device, then power can be managed independently, but the operational efficiency decreases and requires additional manual intervention

Engineering Contradiction:
Improveindependent power managementVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system implements self-service power management where the control automatically monitors battery charge levels and initiates power transfer operations without manual intervention. When either the cot or stair chair battery requires charging, the system autonomously detects the need and executes the charging process, maintaining independent power management while eliminating manual operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control system is designed with universal power management capabilities that can handle multiple devices through a single interface. It performs multiple functions including monitoring both batteries, determining which device needs charging, and executing the appropriate power transfer protocol, thereby improving operational efficiency while maintaining independent power management.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4391982B1Patient support systems with power transfer architecture
Publication Date: 2025.07.02 STRYKER CORP
  • EP4391982B1 patent drawingFigure 1A
  • EP4391982B1 patent drawingFigure 1B
  • EP4391982B1 patent drawingFigure 2

AI summary

A patient transport apparatus including a base frame, an intermediate frame to provide support to a patient, an apparatus energy storage unit, an apparatus user interface, and an apparatus controller. The patient transport apparatus also includes a powered device having a module to perform a powered function, a device energy storage unit, a device user interface, a device interface adapted to cooperate with the apparatus interface to facilitate power transfer from the apparatus energy storage unit to the device energy storage unit, and a device controller. The device controller includes a power module configured to determine a charging level for the device energy storage unit based on a current state of the apparatus energy storage unit, and to draw power from the apparatus energy storage unit via the apparatus interface and across the device interface to charge the device energy storage unit at the charging level.