Menstrual Cycle Coaching via Wearable HRV Monitoring

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Solution Overview

Problem

Existing fitness monitors are bulky and inconvenient for continuous wear, hindering continuous physiological data collection, and there is a need for devices that can detect hormonal cycles to provide phase-specific coaching recommendations for exercise, recovery, and sleep.

Innovation Solution

A lightweight wearable system that continuously monitors heart rate and other physiological parameters without a chest strap, using light emitters and detectors to determine heart rate variability, and adjusts recommendations based on identified hormonal cycle phases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a chest strap is used to monitor heart rate, then measurement precision is improved, but ease of operation and comfort are worsened

Engineering Contradiction:
Improveheart rate measurement precisionVSAvoidease of continuous wear
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical chest strap system with an optical monitoring system using light emitters and detectors positioned on the wrist or finger. This substitution maintains measurement capability while eliminating the mechanical constraint that prevented continuous comfortable wear.

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

Solution Approach 2:

The patent uses light as an intermediary to measure heart rate indirectly through photoplethysmography. Instead of direct mechanical contact with the heart, light emitters detect blood volume changes in peripheral vessels, providing accurate heart rate data without requiring a chest strap.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If continuous physiological monitoring is implemented, then productivity and health management are improved, but device complexity increases

Engineering Contradiction:
Improvehealth management efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a multi-functional wearable device that simultaneously monitors heart rate, respiratory rate, and hormonal cycle phases. By combining multiple monitoring functions in one device, it improves health management efficiency without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system automatically detects hormonal cycle phases and generates coaching recommendations without user intervention. The device self-calibrates and adapts to individual physiological patterns, reducing the complexity burden on the user while maintaining high productivity in health management.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If hormonal cycle detection is added to the monitoring system, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvephase-specific coaching adaptabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system performs preliminary detection of hormonal cycle phases using physiological markers before providing phase-specific coaching recommendations. By pre-identifying the cycle phase, the system can adapt exercise, recovery, and nutrition guidance without requiring complex real-time analysis during each intervention.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic adaptation of coaching recommendations based on detected hormonal cycle phases. The system continuously adjusts exercise intensity, recovery timing, and nutritional guidance to match the user's physiological state, improving adaptability while using efficient algorithms to manage complexity.

Inventive Principle:
Principle #15Dynamics

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 continuous, comfortable monitoring of heart rate and other parameters, allowing for phase-specific coaching adjustments in exercise, recovery, and sleep, enhancing user health and fitness management.

Implementation Method 1

using light emitters and detectors to determine heart rate variability

Methodology Applied
Scientific EffectPhotoplethysmography: Absorption (EM radiation)

Data Source

PatentEP4278361B1Coaching based on menstrual cycle
Publication Date: 2026.04.15 WHOOP INC
  • EP4278361B1 patent drawingFigure 1
  • EP4278361B1 patent drawingFigure 2~3
  • EP4278361B1 patent drawingFigure 4~5

AI summary

Physiological parameters such as respiratory rate and/or heart rate variability can be measured over time for a user and correlated to physiological and/or hormonal cycles such as the menstrual cycle. By determining the phase of such a cycle in this manner, an automatic coach for the user can recommend phase-specific adjustments to activities such as sleep and exercise.