Camera sheath with transformable head for minimally invasive surgical instruments.

INTRODUCTION: This 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 METHODS: The 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. RESULTS: The 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. CONCLUSIONS: The 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.

A Steerable Endoscope for Transnasal Skull Base Surgery.

In this paper, we described the development of an endoscopic system with the application of minimally invasive observation for a pituitary tumor or a craniopharyngioma. The end-effector was manufactured by attaching an image sensor to the end of a manipulator with a diameter of 3 mm (smaller than a commercial endoscope) by making slits on a biocompatible PAI (Polyamide-imide) tube. The end-effector having 2 degrees of freedom for bending is designed not only to cover most of the FOVs (92.8% of the goal) with commercially available fixed-angle endoscopes at 0, 30, and 70 degrees, but also to be able to maneuver the endoscope intuitively. The system consists of a controller, a foot switch, and the end-effector. Through qualitative experiments, basic verification of the proposed system was tested and the potential of this study was recognized through user evaluations from 3 specialists, which generated positive feedback upon the operational procedures.

Development and preclinical trials of a wire-driven end effector device for frozen shoulder treatment.

Several different flexible end effectors have been developed to solve the problem of approaching the lesion in a minimally invasive surgery. In this paper, we developed a wire-driven end effector device to treat frozen shoulder. Since the device is for capsular release surgery, it has a suitable bend radius for the surgery. It is a cylindrical cannula that can fit various surgical tools and can be sterilized after use. The end effector is made of an elastic material called PAI (polyamide-imide) with its outer diameter and total length being 4 and 19 mm. It is controlled by wires that are connected to a motor. Through quantitative evaluation, we confirmed that the end effector can bend up to 90° in an upward or downward direction. Through qualitative evaluation, we confirmed that the device can easier access all regions of the glenoid in a shoulder model than conventional electrocautery. An experiment on a cadaver followed, which allowed us to discuss the real life performance, operation, and areas of improvement of the device with surgeons. From the experiments, we confirmed that our target region, the IGHL (inferior glenohumeral ligament), is within the reach of our device. The surgeon also evaluated that the control of the device caused no inconvenience.