A Decade of Research

Estimating Sit-to-Stand Power from a Single Smart Seat Recording: Validation Against the Supervised Chair-Stand Test in 122 Adults

Review Pending · Not yet peer reviewed

Mattis N

Lower-limb muscle power predicts mobility loss in older adults better than strength or mass, but it is measured with a supervised, stopwatch-timed chair-stand test, so it mostly goes unmeasured. 896 Smart Seat recordings from 124 adults aged 24 to 89, across two IRB-approved collections, were analyzed against a supervised chair-stand reference standard using only the seat's four corner load cells. Estimated relative power correlated with the chair-test reference at a Spearman rho of 0.54 (95% CI 0.39 to 0.67, n = 122), median absolute error 20.0%, and kept ranking people within a single age decade where age alone did not.

In-Home Cardiovascular Monitoring System for Heart Failure: Comparative Study

Conn NJ, Schwarz KQ, Borkholder DA

A toilet seat–based cardiovascular monitoring system integrating ECG, ballistocardiogram, and photoplethysmogram demonstrated clinical-grade measurements of systolic and diastolic blood pressure, stroke volume, and peripheral blood oxygenation. Diastolic BP accuracy: 1.2 (SD 6.0) mm Hg; systolic BP: –2.7 (SD 6.6) mm Hg; stroke volume: –2.5 (SD 15.5) mL compared to echocardiogram gold standard; SpO₂ RMS error: 2.3%.

Nontraditional Electrocardiogram and Algorithms for Inconspicuous In-Home Monitoring: Comparative Study

Conn NJ, Schwarz KQ, Borkholder DA

Validated a toilet seat-based buttocks ECG against a simultaneous 12-lead clinical ECG in 25 normative and 29 heart failure subjects. Achieved clinical-grade accuracy for heart rate, heart rate variability, QRS duration, and corrected QT interval. A modified Pan–Tompkins algorithm yielded >99.82% sensitivity and positive predictive value across 900,059 beats on standard databases.