Bed Load Sensors Detect Body Axis Orientation

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Solution Overview

Problem

Current systems for monitoring patients in beds cannot accurately determine the body state, such as orientation, posture, and head placement, which is crucial for conditions like sleep apnea syndrome without using video-recording devices.

Innovation Solution

A body state detecting apparatus using load sensors under the bed to detect load variations and determine the extending direction of the body axis and head placement based on temporal variations of the center of gravity position, allowing for detailed monitoring of a subject's body state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If load sensors are used to detect body state, then patient comfort is improved and imaging devices are eliminated, but measurement precision of body orientation and posture is insufficient

Engineering Contradiction:
Improvepatient discomfortVSAvoidbody orientation detection accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The bed surface is divided into multiple detection zones with load sensors positioned at specific locations (head, middle, foot sections on both left and right sides). Each sensor detects load information from a specific body region, and the control unit integrates these segmented measurements to calculate comprehensive body state parameters including orientation, posture, and head placement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from traditional single-point or single-plane pressure detection to a multi-dimensional detection approach by placing sensors at multiple locations across the bed surface. This spatial distribution enables the system to detect not only vertical load but also lateral and longitudinal position variations, thereby achieving three-dimensional body state characterization without visual imaging.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If video-recording devices are used to detect body state, then measurement precision of body orientation and posture is improved, but device complexity and patient discomfort increase

Engineering Contradiction:
Improvebody state detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system replaces optical/mechanical video-recording devices with electrical load sensing technology. Instead of using cameras or visual systems to capture body position, the invention uses load sensors that electrically detect weight distribution and center of gravity position. This substitution simplifies the system by eliminating complex imaging hardware, video processing units, and associated software while achieving equivalent or superior measurement precision through electrical signal processing.

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

3Device complexity

If load sensors are placed under bed feet, then device complexity is reduced, but measurement precision of body state is insufficient

Engineering Contradiction:
Improvesensor arrangement simplicityVSAvoidbody state detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The detection system is segmented into multiple independent load sensor units positioned at strategically selected locations beneath the bed. Rather than using a single complex sensor array, the invention divides the detection function across five separate sensors (left head, left middle, left foot, right head, right middle, right foot), each contributing specific spatial information that collectively enables precise body state determination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the bed are equipped with load sensors according to the specific quality requirements of each detection zone. The head section sensors detect head placement and upper body orientation, middle sensors detect torso position, and foot sensors detect lower body and leg positioning. This localized sensor deployment optimizes measurement precision for each body region while maintaining overall system simplicity.

Inventive Principle:
Principle #3Local quality

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

Enables accurate detection of body state without imaging devices, improving the monitoring of symptoms like sleep apnea syndrome and reducing patient discomfort.

Implementation Method 1

a plurality of load detectors which are placed in the bed or under feet of the bed and which detect a load variation depending on a respiration of the subject

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3329891B1Physical condition detecting device, physical condition detecting method and bed system
Publication Date: 2020.09.09 MINEBEAMITSUMI INC
  • EP3329891B1 patent drawingFigure 1
  • EP3329891B1 patent drawingFigure 2~3
  • EP3329891B1 patent drawingFigure 4~5

AI summary

There is provided a body state detecting apparatus (100) for detecting a body state of a subject on a bed. The body state detecting apparatus (100) includes a plurality of load detectors (11, 12, 13, 14) which are placed in the bed or under feet of the bed and which detect a load variation depending on a respiration of the subject; and a body state detecting unit (32, 33) which determines an extending direction of a body axis of the subject and/or a head placement of the subject based on the detected load variation.