Development of a Novel Artificial Urinary Sphincter: A Versatile Automated Device

Management of male severe stress urinary incontinence is currently achieved by the treatment of choice: an artificial urinary sphincter (AUS). This implantable system is designed to exert a constant circumferential force around the urethra. Although continence is totally or partially recovered in most of the patients, this method has some significant drawbacks. Besides the difficulty and discomfort of using the device, the revision rate caused by constant urethral compression, leading to urethral injuries, remains high. We present in this study a new AUS concept, with an ergonomic control, providing a lower exerted pressure on the urethral tissues and improving the continence efficiency. In fact, the implant includes a system which automatically detects circumstances involving high-intravesical pressure and adapts the occlusive pressure accordingly. The device was evaluated using isolated goat urethra, and then, in vivo. Recorded data of 16 human subjects performing different daily exercises were used to assess the detection algorithms. It is shown that occlusive pressure can be controlled by the implant with an accuracy of 1
$\hbox{cm H}_{2}\hbox{O}$
(98 Pa). Acceptable detection performance of seven of the eight targeted activities was observed.