At present, routine urodynamic examination for measuring bladder pressure and related values is an invasive approach, involving personnel, resources, and nosocomial infection prevention, etc., which impede urodynamic examination as a routine way for evaluating lower urinary tract dysfunction. This study introduces a novel approach with the measurement of urinating F value as a non-invasive method to measure the bladder pressure.

(1) Using non-invasive urodynamic equipment to measure the urinating F value during micturition (measurement principle: using a digital camera to dynamically capture the urine line during urination, and compare the urinating line with the reference value of F value to calculate and obtain the urinating F value.), maximum urinary flow rate (Qmax), and urethral outlet pressure Po (measurement principle: during the measurement of urinary flow rate, the energy is obtained by the urine stream falling on the collecting web plate, and the leverage is transmitted to the pressure sensing device at the other end, which is calculating urethral outlet pressure Po value), the above three values were measured at the same time during measurement of urine flow rate. (2) Use the verification formula: R=258L/[], Pdif=, Pves = Pdif+Po and , to calculate the minimum urethral resistance (Rmin), urethral consumption pressure (Pdif), bladder pressure (Pves) and bladder pressure (Nves). The urethral pressure Pdif is the pressure consumed by the bladder pressure Pves to drive urine to flow through the urethra.

Based on the urinating F value, using the above-mentioned formula, data values such as urethral resistance Rmin, bladder pressure Pves, and bladder urination power Nves can be calculated to replace them from the routine urodynamic study. When urine volume is 300ml as a regular setting, the urinating F value is 14.5F, the maximum urinary flow rate Qmax is 20.0ml / s, the urethral outlet pressure Po is 20.0cmH2O, the urethral length L is 18cm, and the bladder pressure Pves is 30cmH2O. The actual urethral consumption pressure Pdif is 10cmH2O, the urethral resistance R is 0.025H, the urinary power Nves of the bladder pressure is 600y, the urethral resistance R calculated by the non-invasive method is 0.025H, the urethral consumption pressure Pdif is 9.861cmH2O, and the bladder pressure Pves is 29.861 cmH2O, urinary power Nves of bladder pressure is 597.212y.

Compared with the actual measured bladder pressure, the analysis from the above results demonstrated the value of bladder pressure via non-invasive urinating F-value measurement, has a smaller error and is within an acceptable range. Hence it is replaceable and feasible as a screening approach.

The introduced urinating F value can be used to calculate bladder pressure, and it is possible to develop a new generation of urodynamic study by the above non-invasive approach and the calculating methods.