A Wearable Insole System to Measure Plantar Pressure and Shear for People with Diabetes

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Podiatry

Background:

• Diabetic foot ulcers are a significant complication, often caused by external factors like pressure and shear stress.
• Existing wearable systems struggle to measure multi-directional stresses accurately for out-of-lab analysis.
• A lack of in-shoe sensing for plantar pressure and shear hinders effective ulcer prevention strategies.

Purpose of the Study:

• To develop and evaluate a novel sensorised insole system for measuring in-shoe multi-directional stresses.
• To assess the system's accuracy, linearity, and safety for use in daily living environments.
• To determine the system's potential for diabetic foot ulcer prevention and footwear assessment.

Main Methods:

• Development of a sensorised insole system capable of measuring plantar pressure and shear forces.
• Laboratory evaluations to determine linearity and accuracy errors.
• In-situ testing on healthy and diabetic participants, including assessments with different footwear.

Main Results:

• Laboratory tests showed linearity and accuracy errors of up to 3% and 5%, respectively.
• Significant changes in pressure (20%) and shear stresses (75-82%) were observed with different footwear in healthy individuals.
• The insole did not notably alter peak plantar pressure in diabetic participants and demonstrated comparable performance to existing devices.

Conclusions:

• The developed sensorised insole system is a first-of-its-kind wearable technology for measuring in-shoe pressure and shear.
• The system is accurate, sensitive, and safe for use by individuals with diabetes, showing potential for real-world applications.
• This technology can aid in assessing diabetic foot ulceration risk and informing footwear choices in daily living environments.