IntroductionThis paper presents a camera sheath that can be assembled to various minimally invasive surgical instruments and provide the localized view of the instrument tip.Material and methodsThe advanced transformable head structure (ATHS) that overcomes the trade-off between the camera resolution and the instrument size is designed for the sheath. Design solutions to maintain the alignment between the camera's line of sight and the instrument tip direction during the transformation of the ATHS are derived and applied to the prototype of the sheath.ResultsThe design solution ensured proper alignment between the line of sight and the tip direction. The prototype was used with the curved micro-debrider blades in simulated functional endoscopic sinus surgery (FESS). Deep regions of the sinus that were not observable with the conventional endoscopes was accessed and observed using the prototype.ConclusionsThe presented camera sheath allows the delivery of the instrument and camera to the surgical site with minimal increase in port size. It may be applied to various surgeries to reduce invasiveness and provide additional visual information to the surgeons.