Fall Detection Device Using Accelerometer and Pressure Sensor
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Solution Overview
Problem
Existing fall detection devices face challenges with high false detection rates due to natural pressure variations and high electrical consumption, particularly with barometric measurements, and limitations in accelerometer-based methods.
Innovation Solution
A method utilizing a three-axis accelerometer to analyze acceleration data, incorporating calculations for free fall, motion analysis, and shock detection, with filtering and threshold comparisons to accurately identify falls, and a device with radio components for alarm transmission, including a pressure sensor and vibrator for validation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If barometric measurement is used for fall detection, then fall detection capability is provided, but false detections increase due to natural pressure variations and electrical consumption increases
Solution Approach 1:
The patent extracts and removes the barometric pressure sensor from the fall detection system, relying solely on accelerometer-based detection. This eliminates the high electrical consumption associated with permanent barometric devices while maintaining fall detection capability through optimized accelerometer algorithms that analyze acceleration patterns, gravity component extraction, and shock detection.
Solution Approach 2:
The patent employs low-cost accelerometers instead of expensive and energy-intensive barometric sensors. The accelerometer is a simpler, more energy-efficient component that can be used continuously without the high power consumption of barometric measurement systems, achieving the same fall detection function at lower energy cost.
2Reliability
If barometric measurement is used for fall detection, then fall detection capability is provided, but false detections increase due to natural pressure variations
Solution Approach 1:
The patent removes the barometric pressure sensor from the system entirely, eliminating the source of false detections caused by natural pressure variations, door openings, air currents, and temperature changes. Fall detection is achieved exclusively through accelerometer-based analysis of motion patterns, gravity component extraction, and shock detection algorithms.
Solution Approach 2:
The patent replaces the unreliable barometric measurement system with a more robust accelerometer-based system that is insensitive to environmental pressure variations. The accelerometer directly measures mechanical acceleration and shock patterns associated with falls, providing more reliable detection without the false positives inherent in barometric methods.
3Use of energy by moving object
If accelerometer-based methods are used for fall detection, then electrical consumption is reduced, but false detections remain a problem
Solution Approach 1:
The patent segments the fall detection process into multiple independent analysis stages: initial shock detection through acceleration threshold comparison, gravity component extraction and analysis, free fall search calculation, and validation through pressure sensor confirmation. Each stage filters out different types of false detections, and the cumulative effect of these segmented analysis steps significantly reduces false positives while maintaining low energy consumption.
Solution Approach 2:
The patent implements feedback mechanisms where detection results from one analysis stage inform subsequent stages. The accelerometer data is continuously analyzed with feedback loops that adjust detection thresholds and trigger validation steps only when initial detection criteria are met. The pressure sensor provides feedback confirmation to validate or reject fall detections, creating a multi-layered feedback system that reduces false detections while maintaining energy efficiency.
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
Significantly reduces false fall detections and minimizes electrical consumption by using a three-axis accelerometer for precise fall detection and alarm validation, ensuring accurate alerts and energy efficiency.
Implementation Method 1
analyzing measurements acquired by a three-axis accelerometer which transmits a measurement combining an acceleration due to gravity and an acceleration due to the movements of said person
Implementation Method 2
The validation or non-validation step can comprise a series of pressure measurements and a pressure variation calculation suitable for detecting lifting of the wearer
Data Source
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AI summary
The invention relates to a method and device for monitoring a person's condition and detecting falls. Fall detection is achieved by analyzing measurements acquired by a three-axis accelerometer, which transmits a combined measurement of acceleration due to gravity and acceleration due to the person's movements. The method combines free-fall detection, movement analysis, and impact detection. The device includes an accelerometer for detecting falls and a pressure sensor to cancel alarms if the person gets up after a fall.