Abstract: A urethral valve system includes a fixation balloon that is positioned in and contoured to the geometry of the bladder near the opening to the urethra. The fixation balloon, which is narrower at an end that is closest to the urethra and wider at an opposite end, includes a channel through which urine is directed to flow from the bladder to the urethra. A valve balloon is positioned in the channel and inflates to prevent urine flow through the channel and deflates to allow urine to flow around the balloon and out the end of the channel. The fixation balloon may be attached to a Foley-type catheter, with the catheter providing the channel through the balloon. The fixation balloon then acts as a shock absorber for the system by moving relative to the catheter in response to, for example, a contraction in the bladder. The catheter may contain lumens that provide access to the valve balloon and/or the fixation balloon. The fixation balloon is inserted in a deflated state and inflated to hold the system in place.

Abstract: A system for estimating the volume of fluid in the bladder sequentially scans the bladder with ultrasonic beams that section the bladder into a number of transverse planes. The system determines, from the scan lines associated with a given plane, a plurality of points on each of the front and back walls of the bladder. It then fits a curve to the set of front wall points and another curve to the set of back wall points, to determine an outline of the bladder in the plane. The system next calculates the cross sectional area of the bladder in the plane based on the two curves. After determining the area in each of the planes, the system determines the volume of the bladder by summing weighted version of the planar areas. The system includes a transducer that consists of a plurality of piezo-electric elements held in a relatively thin elastomeric pad and/or substrate that is acoustically impedance matched to skin.