Blind transmembrane puncture access : design and development of a novel laparoscopic trocar and blade retraction mechanism

Abstract

Blind puncture access procedures are frequent in medicine but can lead to complications due to over-puncture. When tissue membranes yield under applied stress, the device suddenly accelerates forward into the patient. Clinical background for puncture access procedures and specifically trocar insertion during laparoscopic surgery is presented. A design method is outlined and applied, with functional requirements defined and strategies and concepts detailed. The chosen mechanism concept is developed through geometric analysis. A cost-effective flexure-based mechanism is proposed as an improvement, and flexure mechanics analysis is performed. Flexure samples were manufactured and tested to validate theoretical work and fabrication technique. Prototypes were constructed, revealing the need for further design for assembly and flexure design considerations. Potential solutions are proposed and future steps outlined. The proposed device has the potential to improve safety during blind puncture access procedures by actively opposing forward acceleration of the device upon break-through thus reducing over-puncture incidents.