Optical Bed Exit Warning System Using Physiological Monitoring

Solution Overview

Problem

Conventional bed exit detection systems using pressure switches or mats are uncomfortable for users, prone to material fatigue, and often trigger false alarms, being intrusive and unreliable in monitoring vital signs.

Innovation Solution

A bed exit warning system that monitors physiological characteristics such as heart rate, breathing rate, and temperature using sensors and a processor to predict when a user is likely to get out of bed, issuing an alarm while minimizing false positives through a bed exit prediction algorithm and adaptive learning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure switches or pressure sensing mats are installed on top of the mattress to detect bed exits, then the detection function is achieved, but the devices become stiff causing discomfort and physical irritation to the patient

Engineering Contradiction:

Improvebed exit detection reliabilityVSAvoidphysical and psychological irritation to patient

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical pressure sensing system with an optical sensing system. The pressure mat is replaced by optical sensors (such as cameras or depth sensors) that detect the patient's presence and movements optically, eliminating the need for stiff mechanical components on the mattress while maintaining bed exit detection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary processing system that analyzes optical data to infer bed exit events. Instead of direct mechanical pressure detection, the system uses intermediate optical measurements and algorithmic processing to determine when a patient has left the bed, thereby avoiding direct contact with stiff sensing elements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If pressure switches or pressure sensing mats are placed on the flexible mattress to detect bed exits, then the detection function works, but the devices rapidly suffer material fatigue and fail under normal use

Engineering Contradiction:

Improvebed exit detection reliabilityVSAvoiddevice lifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the mechanical pressure sensing system with an optical sensing system. The pressure mat is replaced by optical sensors (such as cameras or depth sensors) that detect the patient's presence and movements optically, eliminating the need for stiff mechanical components on the mattress while maintaining bed exit detection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts the sensing function from the mechanical pressure mat and relocates it to optical sensors positioned elsewhere (such as overhead cameras or integrated bed frame sensors). This separates the detection function from the mattress surface, eliminating material fatigue issues while preserving detection reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If large pressure sensitive mats are used to detect bed exits with spatial resolution, then bed exit prediction is achieved, but the devices become intrusive to the user

Engineering Contradiction:

Improvebed exit prediction accuracyVSAvoidintrusiveness to user

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical pressure sensing system with an optical sensing system. The pressure mat is replaced by optical sensors (such as cameras or depth sensors) that detect the patient's presence and movements optically, eliminating the need for stiff mechanical components on the mattress while maintaining bed exit detection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from two-dimensional pressure mat sensing to three-dimensional optical sensing. By using optical cameras or depth sensors that capture spatial information from above or at a distance, the system achieves precise movement detection without requiring a large physical mat on the bed surface, thereby reducing intrusiveness.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Provides a reliable, unobtrusive, and comfortable monitoring solution that adapts to individual user characteristics, reducing false alarms and ensuring timely alerts for bed exit events.

Implementation Method 1

the sensor comprises a pressure sensor or strain gauge

Methodology Applied

Scientific EffectPressure sensing: Pressure Increase

Data Source

PatentUS9179863B2Bed exit warning system

Publication Date: 2015.11.10 KONINKLIJKE PHILIPS NV

AI summary

A bed exit warning system is used in monitoring a user on a bed that include one or more sensors for measuring one or more physiological characteristics of the user and for producing corresponding signals indicative of the one more physiological characteristics. A processor is configured to monitor the corresponding signals and to determine the likelihood that the user is about to get out of the bed from changes in the one or more physiological characteristics.