From Bench to Bedside: Evaluating a Low-Cost Tongue Pressure Device Prototype for Clinical and Community Use

This study evaluated the test-retest reliability, concurrent validity, and usability of the Chulalongkorn University Prototype Tongue Pressure Instrument (CUPTI), a novel low-cost manometer for maximum tongue strength (MTS) measurement, in comparison to the standard Iowa Oral Performance Instrument (IOPI).

Sixty healthy adults (20-80 years) were randomized into two groups in a cross-over design. Participants underwent MTS assessment using both devices. Reliability was assessed through intraclass correlation coefficients, while concurrent validity was evaluated through Pearson correlation and Bland-Altman analysis. Effect size (Cohen's d) was used to assess discriminative ability. Measurement time was compared using a paired t test, and multivariable regression was conducted to assess demographic associations.

Both CUPTI and IOPI demonstrated excellent test-retest reliability (ICC > 0.95). CUPTI consistently recorded lower MTS values, with a mean bias of -8.12 kPa (limit of agreement: -2.52 to 18.76 kPa). A strong correlation (r = 0.93, P < 0.001) was observed between devices. The effect size of 0.61 indicated a moderate, clinically meaningful difference. CUPTI required slightly more time than IOPI for MTS assessment (P = 0.005). Age was the only significant predictor of MTS (P = 0.034).

CUPTI is a valid and reliable alternative to IOPI, offering affordability and accessibility for clinical and community dysphagia screening. Its performance supports implementation in resource-constrained settings and home-based rehabilitation.