Ultrasonic Transducer Pair for Wearable State Detection

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Solution Overview

Problem

Existing wearable devices lack an efficient method to determine whether they are being worn by a user, which hinders optimized operation and energy management.

Innovation Solution

A wearable device equipped with a pair of ultrasonic transducers, positioned to be in line-of-sight when not worn and out of line-of-sight when worn, alternately emits ultrasonic pulses and evaluates the returned signals to classify the device's state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a wearable device uses ultrasonic transducers to determine wearing state, then the device can achieve refined operation and energy conservation, but the device complexity increases due to requiring multiple transducers and signal processing

Engineering Contradiction:

Improveenergy conservationVSAvoiddevice complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system divides the detection task into multiple ultrasonic transducers positioned at specific locations on the wearable device. Each transducer independently emits and receives ultrasonic signals, allowing the system to segment the wearing state detection into multiple measurement points that collectively provide comprehensive state classification

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces ultrasonic transducers as intermediary sensing elements between the wearable device and the user's body. These transducers serve as mediators that detect the presence or absence of the user's body through ultrasonic wave transmission and reflection patterns, enabling indirect detection of wearing state without direct contact sensors

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the wearable device uses multiple ultrasonic transducers in line-of-sight configuration, then the state classification accuracy improves, but the manufacturing precision requirements increase for positioning the transducers

Engineering Contradiction:

Improvestate classification accuracyVSAvoidtransducer positioning precision

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The system employs dynamic signal processing and evaluation algorithms that can adapt to variations in transducer positioning. The processor evaluates returned signals with flexibility to accommodate manufacturing tolerances, using signal characteristics rather than absolute position measurements to determine wearing state, thereby reducing the impact of positioning variations on classification accuracy

Inventive Principle:

Principle #15Dynamics

3Reliability

If the wearable device continuously monitors ultrasonic signals to determine wearing state, then the reliability of state detection improves, but the energy consumption increases

Engineering Contradiction:

Improvestate detection reliabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The ultrasonic transducers operate by emitting pulses at periodic intervals rather than continuously. The processor evaluates returned signals from these periodic pulses to determine wearing state, achieving reliable detection through sampled measurements while consuming significantly less energy compared to continuous monitoring. The periodic pulsed operation allows the system to balance reliability with energy efficiency

Inventive Principle:

Principle #19Periodic action

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

This solution enables accurate classification of the wearable device's state, allowing for refined operation and energy conservation by determining whether the device is worn or not.

Implementation Method 1

a pair of ultrasonic transducers, each transducer configured to emit ultrasonic pulses and receive returned signals corresponding to the emitted ultrasonic pulses

Methodology Applied

Scientific EffectUltrasonic pulse transmission and reception: Ultrasound

Implementation Method 2

receive returned signals corresponding to the emitted ultrasonic pulses

Methodology Applied

Scientific EffectEcho detection: Echo

Data Source

PatentUS20250189665A1Method and system for classifying state of a wearable device

Publication Date: 2025.06.12 INVENSENSE INC

AI summary

Methods and systems are disclosed for employing an ultrasonic sensor to classify the state of a wearable device. Ultrasonic pulses are emitted from a pair of ultrasonic transducers. The pair of ultrasonic transducers are in a line of sight relationship when the user is in a first state with respect to the wearable device and are not in a line of sight relationship when the user is in a second state with respect to the wearable device. The returned signals are evaluated and the state of the wearable device is classified as being one of the first state and the second state based at least in part on the evaluation.