A new modular mechanism that allows full detachability and cleaning of steerable laparoscopic instruments

Abstract

Background Ever since the introduction of laparoscopic surgery, researchers have been trying to add steerability to instruments to allow the surgeon to operate with better reachability and less tissue interaction force. Traditional solutions to introduce this often use a combination of springs, cables, pulleys, and guiding structures, resulting in instruments that cannot be properly cleaned and thus are very costly to manufacture and maintain. The aim of the study is to develop a novel affordable, sustainable, cableless, and fully steerable laparoscopic grasper, and to test its ease of assembly, disassembly, and use. Methods A set of requirements was defined to ensure that the instrument can be handled efficiently at the sterilization unit and in the operating room. Based on these, a multisteerable, cableless 5 mm laparoscopic instrument that operates based on shaft rotations was developed. To test its assembly and disassembly, ten participants were asked to fully dismantle the instrument and reassemble it a total of 60 times. In addition, ten medical students were asked to use the grasper in the ForceSense box-trainer system on a newly developed 3D pick-and-place task, to determine the control effort based on learning curves of steering errors, task time, instrument path length, and maximum tissue interaction force. Results All important design requirements were met. The recorded data indicates that ten engineering students were able to fully dismantle and reassemble the instrument shaft in 12 s (SD7) and 65 s (SD43) seconds at the sixth attempt. The learning-curve data indicates that three attempts were needed before the ten medical students started to use all steering functions. At the sixth attempt, on average only 1.25 (SD0.7) steering errors were made. The steepest slope in the learning curves for steering errors, path length, and task time was experienced during the first three attempts. In respect of the interaction force, no learning effect was observed. Conclusion The multi-DOF (degree of freedom) cableless grasper can be assembled and disassembled for cleaning and sterilization within an acceptable time frame. The handle interface proved to be intuitive enough for novices to conduct a complex 3D pick-and-place task in a training setting. Electronic supplementary material The online version of this article (10.1007/s00464-019-06849-0) contains supplementary material, which is available to authorized users.

Comparison of Laparoscopic Steerable Instruments Performed by Expert Surgeons and Novices

“…From dedicated studies, it is known that robotic surgery requires a distinct learning curve different from laparoscopic and open surgery [26]. As this might be similar for steerable instruments, a comparison between steerable hand-held instruments and robotic instruments should be conducted on validated tasks to identify accurate differences in learning curves [27]. Training was demonstrated to be useful for trained and untrained subjects as only a limited number of tasks were necessary to improve both quality and time [28][29][30].…”

A Life Cycle Assessment of reprocessing face masks during the Covid-19 pandemic

“…Other reprocessing candidates, such as instrument blue wrapping paper, drapes, anaesthetic and oxygen masks and oxygen tubing 28, as well as disposable surgical instruments, could be subject to further study and may have a signi cant impact. 29,30 Translating this towards orthopaedic surgery, for instance, up to 6.2 kg of waste per case (patient) is generated, having an estimated recyclable waste of 1.70 kg per patient. 31 A reduction of 1.70 kg waste translates into a reduction of 0.37 kg CO 2 eq being saved per orthopaedic operating procedure.…”

Evaluation of new motorized articulating laparoscopic instruments by laparoscopic novices using a standardized laparoscopic skills curriculum

“…during bowel surgery or partial nephrectomies. Therefore, it would be interesting to explore whether the functionality of the new motorized ALI could be more accurately assessed by more demanding exercises like a “3D pick-and-place task” or ex vivo animal models in further studies [ 8 , 11 , 17 , 20 ]. We chose laparoscopic beginners for our study cohort to ensure that we would obtain a large and consistent study population.…”

“…To address the discrepancy of technical limitations of CLI and high costs of robotic systems, various articulating laparoscopic instruments (ALI)—mechanical or motorized—have been developed [ 7 , 8 ]. The hope is that they may offer enhanced degrees of freedom while being more cost-effective, thus making them affordable to a larger number of institutions.…”