Phase 1 Open-label Preliminary Assessment of a Thin, Flexible Pressure Sensor for Therapeutic Compression Garments Using a Cohort of Healthy Adults

Background: Venous leg ulcers (VLUs) are the most common wounds of the lower extremities (LEs), affecting approximately 600,000 patients at a cost of $2.5-3.5 billion USD annually. Low-cost therapeutic compression garments (TCGs) can deliver complete healing rates of >60% at 12 weeks and >90% at 6 months. However, pressure thresholds (>40 mmHg) must be achieved and patients must consistently wear TCGs for these results. Currently, actual pressure delivered by TCGs and patient adherence are not routinely measured, significantly reducing the real-world efficacy by as much as 2.5x, highlighting a significant unmet clinical need for a device capable of providing accurate interface pressure measurements in vivo for TCGs.

Objective: To assess whether a thin, non-invasive, skin-like pressure sensor is able to accurately measure interface pressure in a cohort of healthy normal adults.

Methods: A healthy adult (18-65 years) convenience sample was recruited. The experimental Flexiforce 401 sensor (Tekscan, South Boston, MA) was placed at two standardized locations on each LE. Using a blood pressure cuff, 0 mmHg-60 mmHg of pressure was delivered in 10 mmHg increments. Interface pressure readings were recorded from the experimental sensor at each increment. 

Results: Preliminary sensor testing indicates good interface pressure agreement at two distinct LE locations (largest circumference of calf, n=8: mean average error 3.7-7.9; apex of gastrocnemius muscle, n=8: mean average error 1.8-8.5.

Conclusions: Preliminary assessment of this flexible pressure sensor demonstrates accurate interface pressure readings. Future clinical studies with larger samples will better inform safety and efficacy based on primary (pressure accuracy) and secondary outcomes (skin irritation measures, survey results) in VLU patients.