Measuring in-home walking speed using wall-mounted RF transceiver arrays

Area of Science:

• Engineering
• Biomedical Engineering
• Signal Processing

Background:

• Accurate gait velocity measurement is crucial for health monitoring and fall prevention.
• Existing methods often require wearable sensors, limiting passive and continuous monitoring.
• Non-intrusive sensing methods are needed for unobtrusive, long-term health assessments.

Purpose of the Study:

• To develop and validate a novel passive sensing system for estimating walking speed.
• To assess the system's accuracy using different transceiver array configurations.
• To demonstrate the feasibility of using received signal strength (RSS) patterns for gait analysis.

Main Methods:

• Utilized a small array of radio transceivers (2- and 4-element configurations) placed in a hallway.
• Measured changes in received signal strength (RSS) as individuals walked past the transceivers.
• Calculated walking speed based on the time difference between RSS peaks and signal shape correlation.
• Validated measurements against a ground truth gait mat.

Main Results:

• Achieved root mean square error (RMSE) performance of less than 15 cm/s with a 2-element array.
• Improved RMSE to less than 8 cm/s with a 4-element array.
• Demonstrated repeatable RSS patterns correlating with walking speed.
• Showcased the ability to estimate speed using a single transceiver pair.

Conclusions:

• The proposed radio transceiver system offers a viable method for passively measuring walking speed.
• The system provides accurate gait velocity estimation without requiring wearable devices.
• This technology has potential applications in remote health monitoring and elder care.