A micro-scale, high-force, large displacement and low-voltage piezoelectric actuator has been developed using a compact strain amplifying flextensional mechanism. The device is fabricated using an SU-8 beam structure as an external amplifying mechanism for a thin-film PZT strip (area 11.4 × 10−4 cm2, thickness 0.4 µm) sandwiched between Pt top and bottom electrodes. Each actuator ‘cell’ can be arrayed in series and/or in parallel to accommodate different force/displacement requirements. Testing of the initial prototype design showed a maximum blocking force of 55 µN and a peak displacement of 1.18 µm at 10 V. Fabricated devices consisting of three actuator cells in series were tested, demonstrating a strain amplification ratio in excess of 10:1 per cell.

Objective Intracardiac beating-heart procedures require the introduction and exchange of complex instruments and devices. In order to prevent potential complications such as air embolism and bleeding, a universal cardioport was designed and tested. Methods The design consists of port body and a series of interchangeable sleeves. The port uses a fluid purging system to remove air from the instrument prior to insertion into the heart, and a valve system minimizes blood loss during instrument changes. Results The cardioport was tested ex vivo and in vivo in pigs (n=5). Beating-heart procedures such as septal defect closure and mitral valve repair were modeled. Ex vivo trials (n=150) were performed, and no air emboli were introduced using the port. In comparison, air emboli were detected in 40–85% of the cases without use of the port based purging system. Port operation revealed excellent ergonomics, and minimal blood loss. Conclusions A novel cardioport system designed to prevent air entry and blood loss from transcardiac instrument introduction was shown to be an enabling platform for intracardiac beating-heart surgery. The port system improves safety and facilitates further development of complex instruments and devices for transcardiac beating-heart surgery.

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