Automatic Radar-Based Step Length Measurement in the Home for Older Adults Living with Frailty

Area of Science:

• Gerontology
• Biomedical Engineering
• Sensor Technology

Background:

• Aging population necessitates assistive technologies for aging in place.
• Gait speed monitoring using radar is established for risk prediction.
• Step length is critical for risk prediction but underutilized in radar home monitoring.

Purpose of the Study:

• To develop and validate a radar-based system for measuring step length in older adults' homes.
• To address the gap in radar-based step length measurement for in-home applications.
• To assess the accuracy and reliability of the proposed system in clinical and home settings.

Main Methods:

• A radar system using point cloud detection, tracking, and torso Doppler speed profiling was developed.
• The system was evaluated in a clinical setting with 35 frail older adults.
• The system was further assessed in the homes of 21 frail older adults.

Main Results:

• The radar system achieved a 4.5 cm/8.3% error compared to the Zeno Walkway system in a clinical setting.
• Excellent reliability (ICC=0.91) was observed in uncontrolled home environments.
• Strong consistency (ICC=0.81) was found between home and in-clinic measurements.

Conclusions:

• The proposed radar-based system accurately measures step length in uncontrolled home environments.
• This technology facilitates unobtrusive gait monitoring for aging in place.
• The system shows promise for early fall risk prediction and intervention in older adults.