Millimeter-Wave Radar Signal Processing for Robust Heart Rate Detection

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Solution Overview

Problem

Existing technologies struggle to detect the heart rate of a human body with high precision and robustness using radio waves, particularly in challenging environments.

Innovation Solution

An electronic device employing millimeter-wave radar with advanced signal processing techniques, including Fourier transform, envelope processing, and multiple window functions, to extract and analyze heart sound vibrations, enabling precise detection of heart rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radio wave transmission and reception is used to detect heart rate, then non-contact measurement is achieved, but measurement precision is insufficient in noisy environments

Engineering Contradiction:
Improveheart rate detection precisionVSAvoidenvironmental noise interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts heart sound vibration components from the complex radar signal by applying multiple window functions and envelope processing. The signal processing unit identifies and separates the微弱 heart sound signals from background noise and other interference, achieving precise heart rate measurement even in noisy environments through selective extraction of relevant signal components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a composite signal processing approach combining multiple techniques: Fourier transform, envelope processing, and multiple window functions (Hamming, Hanning, Blackman). This composite processing methodology integrates the strengths of each technique to achieve superior noise filtering and signal extraction compared to any single method alone.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If simple radar signal processing is used, then device complexity is low, but measurement precision deteriorates

Engineering Contradiction:
Improveheart rate detection precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the signal processing into distinct functional stages: transmission wave generation, reflected wave reception, beat signal formation, Fourier transform conversion, envelope processing, and heart sound extraction using multiple window functions. This segmentation allows each processing stage to be optimized independently while working together to achieve high measurement precision through coordinated complexity.

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

The device achieves accurate and robust heart rate detection, even in noisy environments, by filtering and analyzing heart sound vibrations with high precision.

Implementation Method 1

radio detection and ranging (RADAR) technology, which measures values such as the distance to an obstacle or other object by transmitting radio waves, such as millimeter waves, and receiving reflected waves back from the object

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

receiving reflected waves of transmitted radio waves reflecting off the object

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

envelope processing on the beat signal of the transmission wave and the received wave

Methodology Applied
Scientific EffectEnvelope processing:

Implementation Method 4

taking the Fourier transform of a beat signal of the transmission wave and the received wave

Methodology Applied
Scientific EffectFourier transform:

Data Source

PatentEP4589337A1Electronic apparatus, method for controlling electronic apparatus, and program
Publication Date: 2025.07.23 KYOCERA CORP
  • EP4589337A1 patent drawingFigure 1
  • EP4589337A1 patent drawingFigure 2
  • EP4589337A1 patent drawingFigure 3

AI summary

An electronic device includes a transmission unit, a reception unit, and a signal processing unit. The transmission unit is configured to transmit a transmission wave. The reception unit is configured to receive a reflected wave of the transmission wave from a target. The signal processing unit is configured to detect a distance, direction, and velocity of the target on the basis of a converted signal obtained by taking the Fourier transform of a beat signal of the transmission wave and the received wave. The signal processing unit is configured to extract, by using a plurality of window functions, signal components corresponding to heart sound vibration associated with the heartbeat of the target from the converted signal. The signal processing unit is configured to perform frequency analysis on an envelope signal obtained by performing envelope processing on the signal components corresponding to the heart sound vibration. The signal processing unit is configured to perform processing to calculate a statistical result on the result of the frequency analysis. The signal processing unit is configured to output time-series data on the frequency of the heartbeat of the target on the basis of the calculated result.