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Fecal incontinence caused by sphincter dysfunction is an unresolved problem which has a serious effect on patients, both physically and psychologically. For patients with severe symptoms, treatment with an artificial anal sphincter could be a potential option to restore continence. Acticon Neosphincter still has safety and efficacy problems, which is the only device certified by the US Food and Drug Administration. The biomechanical compatibility is the key problem of artificial anal sphincter in the clinical application. This paper describes an artificial anal sphincter with superelastic shape memory alloys and its mechanical properties assessment in artificial intestine models. The new design was developed as a low invasive and constant force or pressure prosthesis with a simple structure to solve the problem of severe fecal incontinence in patients. [ABSTRACT FROM AUTHOR]

Clamping devices with constant force or pressure are desired in medical device, such as hemostatic forceps and the artificial sphincter, to prevent soft tissues from injures due to overloading. It is easily obtained by stretching an SMA wire. However, studies with SMA bending round bar have seldom been reported before. This paper studied constant force characteristic of C-shaped round bar with shape memory alloys. Optimization designs of the components were carried out with computational simulation. Numerical results show that the phenomenon of constant force strongly depends on contour curve shape and geometric dimensions of the C-shaped round bar of SMA component. [ABSTRACT FROM AUTHOR]