Accelerometer-Based Motion Artifact Suppression in Wearable Vital Sign Monitoring

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing vital sign monitoring devices face challenges with accuracy, comfort, and reliability, particularly in athletic activities, due to noise, light, and motion-related issues, and often require user input for accurate calorie burn calculations.

Innovation Solution

A wearable monitoring device combining an optical sensor and a multiple-axis accelerometer to generate real-time signals, with a processor that suppresses motion-related harmonics and calculates heart rate, allowing for accurate and comfortable extended use, while enabling user input and output control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pulse oximetry devices are used for continuous monitoring, then real-time vital sign detection is improved, but motion artifacts and noise interfere with measurement accuracy

Engineering Contradiction:

Improvecontinuous monitoring capabilityVSAvoidvital sign measurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces an accelerometer as an intermediary device to detect motion artifacts. The accelerometer measures motion separately from the optical sensor, allowing the system to identify and compensate for motion-induced noise in the pulse oximetry signal, thereby maintaining measurement accuracy during continuous monitoring.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical filtering methods with signal processing techniques that use accelerometer data. Instead of physically isolating the optical sensor from motion effects, the system uses digital signal processing to separate the pulse signal from motion artifacts based on accelerometer measurements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the device monitors vital signs during athletic activities, then exercise monitoring is improved, but noise and light interference increase measurement errors

Engineering Contradiction:

Improveexercise monitoring capabilityVSAvoidvital sign measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The accelerometer serves as an intermediary that detects motion during athletic activities. By measuring motion separately, the system can identify periods of high movement and apply appropriate signal processing to compensate for noise and light interference, enabling accurate monitoring during exercise.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses accelerometer feedback to dynamically adjust signal processing parameters. When motion is detected, the system modifies its filtering and processing algorithms in real-time to account for the increased noise and light interference during athletic activities.

Inventive Principle:

Principle #23Feedback

3Productivity

If the device provides real-time monitoring during high-intensity exercise, then exercise intensity tracking is improved, but motion-related noise increases

Engineering Contradiction:

Improvereal-time monitoring rateVSAvoidmotion-related noise

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The accelerometer acts as an intermediary that captures motion information during high-intensity exercise. This separate motion measurement allows the system to maintain high real-time monitoring rates while using the accelerometer data to identify and compensate for motion-related noise in the vital sign signals.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The device provides accurate, real-time vital sign monitoring, including heart rate and calorie expenditure, with improved reliability and user interaction, overcoming previous limitations in noise and motion interference.

Implementation Method 1

Oxyhemoglobin absorbs infrared light while deoxyhemoglobin absorbs visible red light. Pulse oximeter devices also contain sensors that detect the ratio of red/infrared absorption

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

The accelerometer generates real-time accelerometer data comprising an X-axis signal, a Y-axis signal and a Z-axis signal based on a movement of the user

Methodology Applied

Scientific EffectAcceleration detection: Accelerometer

Data Source

PatentUS9039627B2Monitoring device with an accelerometer, method and system

Publication Date: 2015.05.26 YUKKA MAGIC LLC

AI summary

A monitoring device for monitoring the vital signs of a user is disclosed herein. The monitoring device is preferably comprises an article, an optical sensor, an accelerometer and processor. The optical sensor preferably comprises a photodetector and a plurality of light emitting diodes. A sensor signal from the optical sensor is processed with a filtered accelerometer output signal from the accelerometer to create a filtered vital sign signal used to generate a real-time vital sign for a user.