Millimeter Wave Radar Fall Detection Using Elevation and RCS Analysis

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Solution Overview

Problem

Existing technologies face challenges in accurately detecting fall events and distinguishing them from non-fall activities using wireless sensors, particularly in ensuring high reliability and minimizing false alarms.

Innovation Solution

An end-to-end system for wireless ambient sensing using millimeter wave radar, which differentiates fall activity from non-fall activity by analyzing changes in elevation angle, rate of change of elevation angle, and radar cross-section (RCS) associated with the user's body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wireless sensors are used to detect human activity, then ambient intelligence is provided without sensors on the body, but false alarms occur in fall detection

Engineering Contradiction:
Improvefall detection reliabilityVSAvoidactivity differentiation precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system segments the human body into multiple scattering centers (head, torso, limbs) and tracks their individual positions and movements. By analyzing the spatial-temporal patterns of these segmented body parts rather than treating the body as a single object, the system can distinguish between fall patterns and non-fall activities with higher precision, thereby reducing false alarms while maintaining reliable detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from traditional single-dimensional or two-dimensional sensing to three-dimensional millimeter wave radar sensing. By utilizing elevation angle information and creating 3D spatial maps of body part positions, the system gains an additional dimension for analyzing fall patterns. This dimensional enhancement enables more accurate differentiation between falls and non-fall activities, resolving the contradiction between reliability and measurement precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If traditional sensors are used for fall detection, then detection capability is provided, but false alarms increase and reliability decreases

Engineering Contradiction:
Improvefall event detection precisionVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system introduces millimeter wave radar as an intermediary sensing modality between the user and the detection system. This intermediary technology provides intermediate measurements of body part positions, velocities, and spatial relationships that serve as mediators for inferring fall events. These intermediate measurements enable more precise and reliable detection by providing additional evidence beyond what traditional sensors can capture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces traditional mechanical or contact-based sensors with wireless millimeter wave radar sensing. This substitution eliminates the need for physical contact or body-mounted devices while providing more precise measurements of motion patterns. The radar-based mechanical substitution enables accurate fall detection through non-contact measurement of body part trajectories, velocities, and spatial relationships, thereby improving both precision and reliability.

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

3Measurement precision

If multiple body points are monitored using mmWave radar, then fall detection accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvefall detection accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the body into key scattering centers (head, torso, limbs) and applies dedicated tracking algorithms to each segment. By processing each body part's signal independently and then integrating the results, the system achieves high detection accuracy while managing complexity through modular processing. This segmented approach allows parallel processing of multiple body points without exponentially increasing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary identification and tracking of body part scattering centers before conducting fall detection analysis. By pre-establishing the spatial relationships and motion patterns of individual body parts, the system prepares the data structure in advance, reducing the computational complexity required for the actual fall detection decision. This preliminary action organizes the complex multi-point data into a form that is more amenable to efficient processing.

Inventive Principle:
Principle #10Preliminary 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

Improves the detection of fall events by providing accurate differentiation between fall and non-fall activities, reducing false alarms, and ensuring high reliability in human activity detection.

Implementation Method 1

receiving, by a radar sensor, reflections from at least two points on a body of a user

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

receiving reflections from at least two points on a body of a user

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentUS20250118185A1End-to-end system for wireless ambient sensing using millimeter wave radar
Publication Date: 2025.04.10 SAMSUNG ELECTRONICS CO LTD
  • US20250118185A1 patent drawing
  • US20250118185A1 patent drawing
  • US20250118185A1 patent drawing

AI summary

A method comprises receiving, by a radar sensor, reflections from at least two points on a body of a user. The method comprises determining, by a processor operatively coupled to the radar sensor, a change of an elevation angle and a rate of change of the elevation angle of the user with respect to the radar sensor, based on the reflections from the at least two points on the body of the user. The method comprises determining changes of a radar cross-section (RCS) associated with the body of the user along an elevation dimension. The method comprises determining whether a fall event occurred based on at least one of: the rate of change and the change of the elevation angle, or the changes of the RCS.