A novel artificial sphincter prosthesis driven by a four-membrane silicon micropump

In this paper we present the state of the art of our artificial sphincter project. A novel silicon micropump has been designed recently for this system that features a four-membrane actuator set-up. The four-membrane micropump can transport fluid bidirectional with a maximum flow rate of 4.1 ml/min and can build up a back pressure of 60 kPa. The total size of the micropump is 30 mm × 12 mm × 1 mm. The novel pump is modeled by a lumped-parameter approach and compared to our three-membrane design. The main advantage of an additional membrane is a reduction of the driving frequency of the micropump while the flow rate remains the same compared to a three-membrane model. Consequently, the power consumption of the micropump can be reduced. A reliability analysis shows that the four-membrane micropump is more reliable then our previous design. The micropump was integrated into the artificial sphincter prosthesis. The first in vivo experiment is described and the measured data of the prosthesis implanted in a mini pig are given.