Once the Flume catheter tip is inserted through the urethra to the bladder, the balloon that inflates is designed to envelop the tip, with the drainage ports inset low at the base of the balloon.

 
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Here's how the new Flume design tackles the known problems of the Foley

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Here's a video of the Flume prototype being inflated...

Ignore the red collar, what you can see is the balloon inflating over the top of the tip and the protected route to the drainage ports set low at the base of the balloon.