Balance Assessment Using a Smartwatch Inertial Measurement Unit with Principal Component Analysis for Anatomical...

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Wearable Sensors

Background:

• Posturography is crucial for assessing balance impairments in populations like the elderly and TBI patients.
• Current inertial measurement unit (IMU)-based posturography relies on precise sensor placement, often limiting usability.
• Anatomical calibration methods are underutilized in IMU-based posturography.

Purpose of the Study:

• To evaluate the efficacy of functional calibration for smartwatch-based IMU posturography.
• To compare balance metrics from a smartwatch IMU against a strictly placed IMU.
• To determine the feasibility of wearable technology for at-home balance assessment.

Main Methods:

• Functional calibration was applied to align smartwatch IMU sensors with body segments.
• Balance-related metrics were collected using both a calibrated smartwatch IMU and a strictly placed IMU.
• Pearson correlation coefficients and statistical significance were used to compare the data.

Main Results:

• Strong correlations (r = 0.861-0.970, p < 0.001) were found between smartwatch and strictly placed IMU posturography scores.
• The smartwatch IMU detected significant variance (p < 0.001) in mediolateral acceleration and anterior-posterior rotation data.
• Functional calibration proved effective in mitigating issues related to precise IMU placement.

Conclusions:

• Functional calibration enables accurate and reliable balance assessment using smartwatch IMUs.
• This approach overcomes key limitations of current inertial-based posturography.
• Wearable, at-home balance assessment technology is now a realistic possibility.