During a minimally invasive procedure, a laparoscope's lens has to be maintained clean as the adequate vision is crucial for a safe surgical procedure. Cipher Surgical developed a novel laparoscope attachment - OpClear® that directs an 'on demand' jet of CO2 across the lens, removing blood, peritoneal fluid, particulate matter and condensation/fogging. This allows the surgeon to maintain a clear view during the whole operation, therefore maximising time, enhancing safety and minimising the frustration of having to stop or working with reduced vision.

Computational Fluid Dynamics (CFD) analysis was used to importantly influence the design of the attachment exit section in order for the CO2 jet to provide adequate coverage of the laparoscope lens and the related cleaning potential. Any flow recirculation areas inside the attachment were minimized to develop a uniformly plane distribution of the exiting flow. The total pressure distribution along the exiting jet was analysed in detail as it is proportional to the force the surrounding tissue is subjected to.

The calculated gas pressure was used as a structural load on the attachment to predict stresses and attachment deformations using Finite Element (FE) analysis. The influence of different material properties on the attachment's structural behaviour was also investigated.

The conducted structural FE analysis revealed stress concentration areas where the material is most prone to cracking. It also showed the contact areas between the laparoscope and the attachment, and how their location changes with the attachment deformation. Locations of submillimeter-size gaps were identified. They may lead to gas leakage, which reduces the strength of the exit gas jet and its cleaning potential.