A probe for measurements of related values of cross-sectional area and pressure in the resting female urethra

A probe for measurement of related values of cross sectional area (c.a.) and pressure in the resting female urethra has been developed. C.a. can be measured in the range 0.07 to 0.79 cm2 by means of the field gradient principle. Pressure is measured in the range 0 to 150 cm H2O. Pressure needed for inflation and deflation of the balloon ranges from +4 to -5 cm H2O with a hysteresis of 3 to 4 cm H2O. The probe is able to follow changes of the c.a. up to 0.7 cm2/sec. The method makes possible estimation of urethral stiffness/rigidity during distension of the balloon, estimation of the capability of contraction of the closure apparatus in terms of isometric and isotonic contraction, muscular work and power. Furthermore, hysteresis during inflation and deflation of the balloon can be described.