Millimeter-Wave Heart Sound Extraction for Precise Non-Contact Detection
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Solution Overview
Problem
Existing technologies struggle to accurately detect weak vibrations such as a heartbeat with good precision using radio waves, particularly in various environments and applications.
Innovation Solution
An electronic device employing radio waves, specifically millimeter waves, utilizes semi-supervised non-negative matrix factorization to process transmission and reflected waves, generating heart sound waveforms through frequency basis matrices and activation matrices to enhance heartbeat detection precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If radio waves are used to detect weak vibrations such as heartbeat, then the detection range and non-contact capability are improved, but the measurement precision deteriorates due to difficulty in accurately detecting weak vibrations
Solution Approach 1:
The patent segments the complex task of heartbeat detection into multiple processing stages: (1) dividing the detected signal into multiple frequency bands using bandpass filters, (2) performing wavelet transform on each frequency component, (3) calculating energy values for each wavelet coefficient, and (4) synthesizing the final heartbeat waveform from energy values. This segmentation allows precise extraction of weak heartbeat signals from complex background noise by processing different frequency components separately and combining results.
Solution Approach 2:
The patent introduces several intermediary processing steps between the raw radio wave detection and final heartbeat identification: (1) bandpass filters act as intermediaries to isolate specific frequency ranges containing heartbeat signals, (2) wavelet transform serves as an intermediary to decompose signals into time-frequency components, and (3) energy calculation acts as an intermediary to quantify signal strength at each frequency component. These intermediaries enhance the detectability of weak heartbeat vibrations.
2Measurement precision
If complex signal processing is applied to improve heartbeat detection precision, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-defining specific frequency bands where heartbeat signals are expected to occur before processing the detected signal. Bandpass filters are configured with predetermined frequency ranges that correspond to typical heartbeat frequencies, allowing the system to focus computational resources on relevant frequency components and reduce overall processing complexity while maintaining high precision.
Solution Approach 2:
The patent employs dynamic signal processing by using wavelet transform, which adaptively analyzes signals at multiple resolution levels. The wavelet transform dynamically adjusts the analysis scale and frequency resolution based on the characteristics of the input signal, allowing the system to handle varying heartbeat frequencies and amplitudes efficiently without requiring overly complex fixed-structure processing algorithms.
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 precise detection of heartbeats in diverse settings, including stationary and moving objects, enabling applications in healthcare monitoring and vehicle occupant detection.
Implementation Method 1
a received signal received as a reflected wave resulting from the transmission wave being reflected by the subject of monitoring
Data Source
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AI summary
An electronic device includes a signal processing unit. The signal processing unit is configured to detect a subject of monitoring. The detection is based on a transmission signal transmitted as a transmission wave and a received signal received as a reflected wave resulting from the transmission wave being reflected by the subject of monitoring. The signal processing unit is configured to generate a heart sound waveform of the subject of monitoring by using basis information pertaining to a heart sound waveform obtained in advance to perform non-negative matrix factorization of time-frequency analysis information calculated on the basis of the transmission wave and the reflected wave.