The use of differential pressure as an inferred measurement of a liquid's rate of flow is well known. Differential pressure flowmeters are, by far, the most common units in use today. Estimates are that over 50 percent of all liquid flow measurement applications use this type of unit.
Between 1% and 15% of people globally are affected by kidney stones at some point in their life. In 2013, 49 million cases of occurred, resulting in about 15,000 deaths. They have become more common in the Western world since the 1970s. Generally, more men are affected than women.
With about 100,000 people starting dialysis each year, that means 80,000 patients aren't receiving the preferred standard of care, putting them at a higher risk of infection, blood clots and even death.