Wrist-Worn Pulsometer Matrix for Reliable Pulse Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing portable pulsometers on the wrist face reliability issues due to physiological differences in vascularization and poor positioning, leading to inconsistent pulse measurements.

Innovation Solution

A portable pulsometer with an electronic optical measurement device arranged in a matrix format, featuring multiple light sources and receivers, allowing for orthogonal and parallel orientations to compensate for varying physiological characteristics and detect incorrect positioning, along with an electronic circuit for signal processing and reliability index calculation to enhance measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single light source and four photodiodes are arranged symmetrically, then the device structure is simple, but measurement reliability is insufficient due to physiological differences and positioning errors

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The optical measurement device is segmented into multiple light sources and photodiodes arranged in a matrix pattern, with each row containing alternating light sources and receivers, and columns offset from each other. This segmentation allows independent optimization of each sensor's measurement path, improving reliability by capturing pulse signals from multiple anatomical locations simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent deliberately introduces asymmetry by offsetting the columns of light sources and receivers in a direction orthogonal to the wrist direction. This asymmetric arrangement ensures that at least one receiver receives light through a valid pulse path regardless of wrist orientation or positioning errors, directly addressing the reliability issue caused by poor positioning.

Inventive Principle:
Principle #4Asymmetry

2Adaptability or versatility

If receivers are distributed symmetrically around light sources, then the optical path is uniform, but the device cannot adapt to different vascularization patterns among wearers

Engineering Contradiction:
Improveadaptability to physiological differencesVSAvoidoptical path alignment
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Different receivers in the matrix are positioned to capture light through different local paths through the wrist tissue. The offset column arrangement ensures that receivers at different positions experience different optical paths, allowing the system to adapt to various vascularization patterns by selecting or weighting signals from receivers that work best for each individual wearer.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from a single-plane symmetric arrangement to a two-dimensional matrix with offset columns. This dimensional expansion creates multiple measurement planes and paths, enabling the device to capture pulse signals that are robust to variations in wrist anatomy and vascularization while maintaining manufacturable precision through standardized matrix positioning.

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

3Ease of operation

If the case is poorly positioned on the wrist, then ease of wear is improved, but measurement accuracy deteriorates

Engineering Contradiction:
Improveease of wearVSAvoidpulse measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The offset column matrix arrangement is pre-configured to anticipate potential positioning errors. By having columns offset in the orthogonal direction, the system proactively ensures that at least one receiver will maintain a valid optical path through the wrist regardless of how the case is positioned, eliminating the need for precise alignment during wear.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The multiple receivers in the matrix provide redundant measurement paths that act as feedback mechanisms. By comparing signals from multiple receivers, the system can identify which receivers are receiving valid pulse signals and weight or select those readings, effectively compensating for poor positioning through real-time signal quality assessment.

Inventive Principle:
Principle #23Feedback

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 matrix arrangement increases measurement reliability, detects incorrect positioning, and provides reliable pulse readings across diverse morphologies, while the electronic circuit ensures accurate pulse calculation and user feedback on measurement quality.

Implementation Method 1

an electronic device for optically measuring the pulse of the wearer... comprises at least one light source and several light receivers which are arranged in the bottom of the case and which are oriented towards the wrist

Methodology Applied
Scientific EffectLight absorption and transmission through tissue: Absorption (EM radiation)

Data Source

PatentEP1880666B1Method and wrist worn device for pulse rate detection
Publication Date: 2009.07.01 ETA SA MFG HORLOGERE SUISSE
  • EP1880666B1 patent drawingFigure 1
  • EP1880666B1 patent drawingFigure 2~3
  • EP1880666B1 patent drawingFigure 4

AI summary

The pulsometer (10) has an electronic optical measurement device (18) measuring a pulse of a wearer and comprising light sources (E1-E3) and receivers (R1-R3). The sources are formed by a diode emitting light in infrared range, and the receivers are formed by photodiodes. The sources and the receivers are arranged in the form of a matrix including rows and columns (C1-C3). The rows are oriented along a direction orthogonal to a direction of a wrist, and the columns are oriented parallel to the direction of the wrist. Each row and column alternately contains one light source and one receiver. An independent claim is also included for a method for controlling a pulsometer.