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A clear visualization of the operative field is of critical importance in endoscopic surgery. During surgery the endoscope lens can get fouled by body fluids (eg, blood), ground substance, rinsing fluid, bone dust, or smoke plumes, resulting in visual impairment. As a result, surgeons spend part of the procedure on intermittent cleaning of the endoscope lens. Current cleaning methods that rely on manual wiping or a lens irrigation system are still far from ideal, leading to longer procedure times, dirtying of the surgical site, and reduced visual acuity, potentially reducing patient safety. With the goal of finding a solution to these issues, a literature review was conducted to identify and categorize existing techniques capable of achieving optically clean surfaces, and to show which techniques can potentially be implemented in surgical practice. The review found that the most promising method for achieving surface cleanliness consists of a hybrid solution, namely, that of a hydrophilic or hydrophobic coating on the endoscope lens and the use of the existing lens irrigation system.

Endoscopic endonasal surgery is currently regarded as the 'gold standard' for operating on pituitary gland tumors, and is becoming more and more accepted for treatment of other skull base lesions. However, endoscopic surgical treatment of most skull base pathologies, including certain pituitary tumors, is severely impaired by current instruments lack of maneuverability. Especially, gaining access to, and visibility of, difficult-to-reach anatomical corners without interference with surrounding neurovascular structures or other instruments, is a challenge. In this context there is the need for instruments that are able to provide a stable shaft position, while both the orientation and the position of the end-effector can be independently controlled. Current instruments that allow for this level of maneuverability are usually mechanically complex, and hence less suitable for mass production. This study therefore focuses on the development of a new actuation technique that allows for the required maneuverability while reducing the construction complexity. This actuation technique, referred to as multi-actuation, integrates multiple cable routings into a single steerable structure. Multi-actuation has been successfully integrated and tested in a handheld prototype instrument called HelixFlex. HelixFlex contains a 4 degrees of freedom maneuverable 5.8 mm (diameter) tip and shows promising results concerning its maneuverability and potential rigidity.

Recent developments in flexible endoscopy and other fields of medical technology have raised the need for compact slender shafts that can be made rigid and compliant at will. A novel compact mechanism, named FORGUIDE, with this functionality was developed. The FORGUIDE shaft rigidifies due to friction between a ring of cables situated between a spring and an inflated tube. A mathematical model for the FORGUIDE mechanism working principle was made and used to obtain understanding of this mechanism, predict the maximum rigidity of a FORGUIDE shaft design, and tune its design variables. The mathematical model gave suggestions for significant performance improvement by fine-tuning the design. A prototype FORGUIDE shaft was built and put to a series of bench tests. These tests showed that the FORGUIDE mechanism provides a reliable and simple way to control the rigidity of a flexible shaft., (© 2011 IEEE)

Background: Passing an instrument through a small incision alters the kinematics of the instrument, thus hampering hand-eye coordination. Nevertheless, the incision provides a stable, nearly invariant, point of rotation for instrument movements. Therefore, we set out to evaluate the effects of the altered kinematics on hand-eye coordination. In addition, we assessed the hypothesis that the hand-eye coordination of laparoscopic surgeons incorporates the incision as a point of reference., Methods: Eight surgeons with experience in laparoscopy repeatedly performed a positioning task on a two-dimensional endoscopic manipulation simulator. Task time was measured. In the first experiment, normal endoscopic manipulation was compared to a condition in which the kinematic effects of the incision were compensated for. In the second experiment, the instrument shaft on the monitor was not visible during half of the trials, so that all visual information about the location of the incision was obscured., Results: Task performance improved significantly when the kinematic effects of the incision were compensated for (p = 0.001). Task performance improved when the instrument shaft was clearly visible on the monitor (p <0.05)., Conclusions: Compensating for the kinematic effects introduced by the incision improves hand-eye coordination. The results of this study indicate that the incision provides a point of reference for hand-eye coordination during endoscopic manipulation.