A Smart Diaper System Using Bluetooth and Smartphones to Automatically Detect Urination and Volume of Voiding: Prospective Observational Pilot Study in an Acute Care Hospital (Preprint)

Abstract

BACKGROUND Caregivers of patients who wear conventional diapers are required to check voiding every hour because prolonged wearing of wet diaper causes health problems including diaper dermatitis and urinary tract infection. However, frequent checking is labor-intensive and disturbs patients’ or caregivers’ sleep. Furthermore, assessing urine output of the patients with diapers in an acute care setting is difficult. Recently, a smart diaper system with wetness-detection technologies has been developed to solve these issues. OBJECTIVE We aimed to evaluate the applicability of the smart diaper system for urinary detection, its accuracy for measuring voiding volume, and incontinence-associated dermatitis (IAD) occurrence in an acute care hospital. METHODS This prospective, observational, single-arm pilot study was conducted at a single tertiary hospital. We recruited 35 participants aged ≥50 years who were wearing diapers due to incontinence between August and November 2020. When the smart diaper was wet, the smart diaper system notified the caregiver to change the diaper and measured voiding volume automatically. Caregivers were instructed to record the weight of wet diapers on the frequency-volume charts (FVCs). We determined the voiding detection rate of the smart diaper system and compared the automatically calculated urine volume by the smart diaper system with the recorded volume on FVCs. Agreement between the two measurements was estimated using the Bland-Altman plot. We also checked the occurrence or aggravation of IAD and bed sores. RESULTS A total of 30 participants completed the protocol. Three hundred and ninety episodes of urination were recorded. There were 108 records (27.7%) on the FVCs and the smart diaper system concurrently, 258 (66.2%) on the FVCs alone, 18 (4.6%) on the smart diaper system alone, and six (1.5%) on the FVCs with sensing device lost. The detection rate of the smart diaper system was 32.8% (126/384). In analysis of records concurrently listed in both the FVCs and the smart diaper system, linear regression showed a strong correlation between the two measurements (R2=0.88, P<.001). The Bland-Altman assessment showed good agreement between the two measurements with a mean difference of –4.2 ml and 95% limits of agreement between –96.7 and 88.3 ml. New occurrence or aggravation of IAD and bed sores was not observed. Bed sore was improved in one participant. CONCLUSIONS The smart diaper system showed acceptable accuracy for measuring urine volume, and it could replace the conventional FVCs in acute setting hospitals. Furthermore, the smart diaper system showed its potential advantage to prevent IAD development and bed sore worsening. However, the detection rate of the smart diaper system was below than the researchers’ expectation. Detection rate polarization among participants was observed, and improvements in user interface and convenience are needed for aged individuals who are unfamiliar to the smart diaper system.