Wrist-Worn Pulse Sensor Timing for Wrist Orientation Detection

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Solution Overview

Problem

Existing methods for determining whether a wrist-worn device is on the right or left wrist are cumbersome, easily forgotten, or complicated, and methods using angle sensors or face recognition face challenges such as difficulty in accurate determination due to hand movement or camera capture issues.

Innovation Solution

An electronic apparatus equipped with two pulse sensors positioned differently on the wrist and a processor that determines the wrist orientation based on the timing difference between pulse detections by these sensors, allowing for easy switching of button functions and screen orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a user operates buttons or menus to switch between right wrist mode and left wrist mode, then the device can adapt to different wearing positions, but the operation becomes cumbersome and easily forgotten

Engineering Contradiction:

Improveadaptability to different wearing positionsVSAvoidease of operation

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The device automatically determines the wearing position by detecting pulse signals from the first and second pulse sensors and calculating the time difference, eliminating the need for manual operation by the user. The system serves itself by autonomously detecting whether the device is worn on the right or left wrist and automatically adjusting button functions accordingly.

Inventive Principle:

Principle #25Self-service

2Extent of automation

If the device uses angle sensors to automatically determine wrist orientation, then automation is improved, but the determination becomes difficult due to continuous hand movement

Engineering Contradiction:

Improveautomation of wrist orientation detectionVSAvoidprecision of wrist orientation determination

Core Design Contradiction:

Extent of automationVSMeasurement precision

Solution Approach 1:

The patent replaces angle sensors with pulse sensors that detect blood flow pulses. Instead of measuring angular position which is affected by hand movement, the system measures the time difference of pulse arrival at two different positions on the wrist, providing a more reliable indicator of wearing position that is not influenced by continuous hand motion.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Extent of automation

If the device uses face recognition to automatically determine wrist orientation, then automation is improved, but the determination cannot be made unless the camera captures the face

Engineering Contradiction:

Improveautomation of wrist orientation detectionVSAvoidease of operation

Core Design Contradiction:

Extent of automationVSEase of operation

Solution Approach 1:

The patent replaces camera-based face recognition with pulse signal detection. Instead of requiring optical capture of the user's face, the system uses physiological signals (pulse waves) detected through the wrist to determine wearing position, making the determination continuous and independent of user actions or environmental conditions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Extent of automation

If two pulse sensors are positioned at different locations to detect pulse timing differences, then automatic wrist orientation determination is achieved, but the device complexity increases

Engineering Contradiction:

Improveautomation of wrist orientation determinationVSAvoidcomplexity of sensor arrangement

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The patent divides the pulse detection function into two separate pulse sensors positioned at different locations on the wrist. Each sensor independently detects pulse signals, and the processor calculates the time difference between the two detections. This segmentation allows for simple implementation while achieving automatic wearing position determination.

Inventive Principle:

Principle #1Segmentation

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 straightforward determination of wrist orientation, simplifying user interactions and improving usability by automatically adjusting button functions and screen layout.

Implementation Method 1

a first pulse sensor; a second pulse sensor that is arranged to be provided at a different position from the first pulse sensor in a direction from an arm to a fingertip in a case in which the user wears the electronic apparatus; and a processor that determines whether the electronic apparatus is worn on a right wrist or on a left wrist based on a difference between a timing at which the first pulse sensor detects a predetermined pulse and a timing at which the second pulse sensor detects the pulse

Methodology Applied

Scientific EffectPulse detection:

Data Source

PatentUS11960649B2Electronic apparatus configured to determine a current worn position among plural wearable positions, and storage medium

Publication Date: 2024.04.16 CASIO COMPUTER CO LTD

AI summary

An electronic apparatus to be worn on a wrist of a user includes a first pulse sensor, a second pulse sensor, and a processor. The second pulse sensor is provided at a different position from the first pulse sensor in a direction from an arm to a fingertip when the user wears the electronic apparatus. The processor determines whether the electronic apparatus is worn on a right wrist or on a left wrist based on a difference between a timing at which the first pulse sensor detects a predetermined pulse and a timing at which the second pulse sensor detects the pulse.