Noninvasive evaluation of Bjork-Shiley convexo-concave prosthetic heart valves

Prosthetic heart valves of the Bjork-Shiley convexo-concave (BSCC) type have been used extensively in implants; however, there have been reports of cases where one component of the valves failed, leading to the demise of the patient. This paper presents a new method for noninvasive electromagnetic evaluation for this type of valve, using an eddy current transducer with orthogonal coils. In vitro experiments on BSCC prosthetic heart valve replicas have shown that discontinuities of outlet strut with depths equal or larger than 0.4 mm can be detected with a probability of detection (POD) of 86.4%, and in the case of discontinuities with depth equal or larger than 0.6 mm with POD of 97%. Blind tests effectuated on 32 BSCC prosthetic heart valves have shown that, using the proposed method, the tested valves have been correctly classified.