Cipher Surgical Ltd required a detailed assessment of "Optimisation of a Disposable Design for Cleaning Laparoscope Lenses" in 2019. The work brought together computational fluid dynamics (CFD) and the project information supplied for this healthcare application. The central objective was to connect local flow, thermal, transport or process behaviour with system-level performance, risk and design decisions that the client could implement.

Laparoscopic surgery requires continuously clear vision throughout a procedure. Cipher Surgical has designed a unique device that will clear a laparoscope lens of all fogging, soiling and fluid without removing the scope from the patient for cleaning. The device is a single use disposable sheath and tube set that attaches to the laparoscope. The Disposable is connected to the OpClear® Control Unit that directs carbon dioxide (CO2) and saline into the sheath and across the tip of the laparoscope. Our team has conducted several computational simulations and have validated their results using different experimental methods with an aim of improving the performance of the disposable and design new types of disposable to fit on a wide range of laparoscopes. The simulations in this project required meticulous assessment of the saline and CO2 with accurate boundary conditions. Different image processing techniques used to provide a validation tool for the computational simulations.

The methodology centred on a transient multiphase CFD model of saline and carbon-dioxide flow through the disposable laparoscope sheath. The representation retained the supply passages, sheath tip, lens surface and outlet paths controlling liquid-film coverage, gas sweeping and removal of fogging or soiling. Boundary and operating conditions covered the operating conditions of the control unit, alternative disposable geometries and the range of laparoscope sizes the product needed to accommodate, with material, fluid and equipment properties assigned from the available design information. Resolution was concentrated in regions where steep velocity, thermal, concentration or phase gradients were expected, while the overall model remained efficient enough to compare several credible configurations. This balance allowed system-level performance to be linked to the local mechanisms responsible for it.

The assessment compared sheath and nozzle variants assessed against experiments and image-processing measurements. Performance was judged using lens coverage and clearing, saline distribution, gas flow, pressure, residence and the repeatability of the cleaning action. Results were reviewed through quantitative summaries and engineering visualisations, such as contours, vectors, streamlines, sections and time histories, selected to suit the physics. Important assumptions and operating uncertainties were considered so that the recommendations relied on repeatable comparative trends rather than a single nominal case.

For Cipher Surgical Ltd, the principal value was improved disposable performance and a broader, evidence-based product range for surgical use. The final evidence linked each recommendation to the relevant model or process output, making it suitable for internal design reviews, supplier or contractor discussions and, where applicable, planning, safety or regulatory dialogue. The work also created a reusable baseline that can be updated as geometry, operating data or test results become available, reducing the cost and risk of later design iterations.