Portable Ultrasound-Based Device for Detecting Older Adults' Sit-to-Stand Transitions in Unsupervised 30-Second...

Area of Science:

• Gerontology
• Biomedical Engineering
• Rehabilitation Science

Background:

• Lower-limb strength is a critical indicator of functional decline in older adults.
• The 30-second chair-stand test (CST) is a common measure of lower-limb strength.
• Objective and unsupervised measurement methods are needed to monitor functional decline in elders.

Purpose of the Study:

• To assess the feasibility of a low-cost, ultrasound-based device for unsupervised measurement of sit-to-stand transitions during the CST.
• To evaluate the reliability of the device compared to manual counting by a trained professional.
• To determine if the device's measurements are sufficient for clinical decision-making.

Main Methods:

• A device utilizing an ultrasound sensor, Arduino UNO, and Bluetooth module was developed.
• Sit-to-stand transitions were identified using signal filtering (moving minimum filter) and an adaptive threshold.
• An inter-rater reliability (IRR) study was conducted with elders performing the 30-second CST.

Main Results:

• The device successfully captured sit-to-stand transitions, with a moving minimum filter mitigating motion artifact noise.
• The intra-class correlation coefficient (ICC) between the device and manual counts was good (ICC = 0.86).
• The study achieved good inter-rater reliability, indicating consistent measurements.

Conclusions:

• The developed ultrasound sensor system shows promise for unsupervised assessment of lower-limb strength in elders.
• The device demonstrates good reliability in counting valid sit-to-stand transitions.
• Further research is required to confirm the clinical utility and sufficiency of the device for supporting healthcare decisions.