Differential in vivo urodynamic measurement in a single thin catheter based on two optical fiber pressure sensors

Urodynamic analysis is the predominant method for evaluating dysfunctions in the lower urinary tract. Theexammeasures thepressure duringthefilling andvoidingprocess ofthe bladderandismainlyinterested in the contraction of the bladder muscles. The data arising out of these pressure measurements enables the urologist to arrive at a precise diagnosis and prescribe an adequate treatment. A technique based on two optical fiber pressure and temperature sensors with a resolution of better than 0.1 cmH2O(∼10 Pa), a stability better than 1 cmH2O∕hour, and a diameter of 0.2 mm in a miniature catheter with a diameter of only 5 Fr (1.67 mm), was used. This technique was tested in vivo on four patients with a real-time urodynamic measurement system. The optical system presented showed a very good correlation to two commercially available medical reference sensors.Furthermore,theopticalurodynamicsystemdemonstratedahigherdynamicandbettersensitivitytodetect small obstructions than both pre-existing medical systems currently in use in the urodynamic field.