Other factors that affect liquid flow rate include the liquid's viscosity and density, and the friction of the liquid in contact with the pipe. Direct measurements of liquid flows can be made with positive-displacement flowmeters. These units divide the liquid into specific increments and move it on.
And while the number of people dying while waiting for an organ transplant has decreased from 614 in 2011 to 469 in 2014, there have still been 195 individualsâ deaths this year after patients failed to find a donation in time.
1 In 2009, the average waiting time for a donor heart for a SynCardia Total Artificial Heart patient in the U.S. was 144 days.  About 3,100 people in the United States are on the waiting list for a heart transplant on any given day. Only 2,200 donor hearts are available each year.