Continuous, Accurate, and Robust Flowmeter for Liquid Samples*

Acute Kidney Injury (AKI), a condition that can often begin with no observable clinical symptoms or signs, is a prevalent and costly issue, impacting as many as 20% of all hospital admissions. Its silent onset and lack of immediately effective diagnostic methods distinguish it from other critical conditions like heart attacks or strokes, making it a complex problem to manage. The unfortunate consequences of AKI result in approximately 2 million deaths per year, along with significantly elevated inpatient costs, amounting to roughly $42,000 per hospitalization. The biomarkers currently used to detect AKI include serum creatinine levels and urine excretion rates. Despite the crucial information provided by these markers, real-time measurement of serum creatinine is not yet feasible. However, the real-time monitoring of urine volume, which can offer significant insight into kidney function, is possible. In the current scientific and medical landscape, various state-of-the-art technologies are employed for measuring urine flow. This work delves into these existing methodologies while also introducing our novel device designed explicitly for urine flow measurement. The device we have developed demonstrates a high degree of accuracy. When comparing urine volume measurements obtained from our device with those obtained through gravimetric analysis (a standard method of measuring mass), we found a strong correlation, with a coefficient of 0.98. This suggests that our device provides an accurate and reliable method of measuring urine flow, potentially offering a valuable tool in the diagnosis and management of AKI.