Different models:
(1) parabolic
(2) hyperbolic
(3) logarithmic
peak urine flow rate in mL per second by the parabolic model =
= EXP((0.6616 * LN(volume in mL)) - 0.1107)
peak urine flow rate in mL per second by the hyperbolic model =
= 1 / X
X =
= (3.6896 / (urine volume in mL)) + 0.0128
peak urine flow rate in mL per second by the logarithmic model =
= (14.5365 * LN(volume in mL)) - 44.1254
In Figure 3 (page 486) it can be seen that these models match the data up to a volume of around 400 mL. Above this the lines and data diverge. The observed maximum flow rate plateaus at about the flow rate seen at 400 mL per second.
For smaller volumes (< 150 mL) the authors thought that a simple line could be used but never listed the coordinates. If the different models are plotted over volumes < 150 mL and the outputs averaged, one possible line is:
peak urinary flow in mL per second =
= (0.157 * (urine volume in mL)) + 4.4
In addition, the editor (Zinner NR from Los Angeles, page 487) noted the following relationships for urinary flow rates:
peak flow rate in mL per second =
= 1.6 * SQRT(urine volume in mL)
average flow rate =
= 0.7 * SQRT(urine volume in mL)
