Login to Access Video or Poster Abstract: MP90-03
Sources of Funding: None

Introduction

Improved methods of stone prevention are needed to combat rising rates of nephrolithiasis. Achieving adequate fluid intake is an effective strategy; yet, patient compliance with recommendations is generally poor. Mobile health applications and smart technology show promise as tools to improve compliance with medically indicated dietary treatments; however, have yet to be applied specifically towards stone formers with low urinary volume. Recently, a smart water bottle (HidrateSpark^TM, Boulder, CO) was introduced as a noninvasive fluid intake monitoring system. This device could conceivably help patients who form stones from low urine volume achieve sustainable improvements in hydration, but has yet to be validated as a useful instrument. We sought to verify its accuracy prior to considering its potential as a medical aide.

Methods

HidrateSpark (Figure 1) uses capacitive touch sensing via a sensor extending from the lid to base, which calculates volume measurements by detecting changes in water level. Data from the bottle is sent wirelessly to users&[prime] smartphones through an application. A pilot study was conducted to assess accuracy of measured fluid intake over 24 hour periods when used in a real life setting. Subjects were provided smart bottles to sync with their smartphone and given short tutorials on their use. Accuracy was determined by comparing 24 hour measurements recorded through the smart bottle to hand measurements from the corresponding 24 hour period.

Results

Eight subjects performed 62 24-hour measurements (range 4-14). Mean 24 hour hand measurement was 57.2 ozs (21-96). Corresponding mean 24 hour smart bottle measurement underestimated true fluid intake by a mean of 0.5 ozs (95% CI -1.9, 0.9). The percent difference between hand and smart bottle measurements was 0.0% (95% CI -3%, 3%). The intraclass correlation coefficient (ICC) was calculated to assess consistency between hand measures and bottle measures. The ICC (95% CI) was found to be 0.97 (0.95,0.98) indicating and extremely high consistency between measures.

Conclusions

4 hour fluid intake measurements taken through a novel fluid monitoring system (HidrateSpark) are accurate to within 3%. Such technology may be useful as a behavioral aide and/or research tool particularly among recurrent stone formers with low urinary volume.

Funding

None