Surgical device design: do instruments fit today's surgeons?

Abstract

© Author(s) (or their employer(s)) 2023. Reuse permitted under CC BYNC. No commercial reuse. See rights and permissions. Published by BMJ. Since introduction of laparoscopy in the 1980s, the field of surgery has rapidly transitioned toward minimal access techniques and procedures. Along with this shift, many new surgical devices and instruments have been developed. The design and implementation of these devices is complex and expensive, yet vital to advancing surgery. Medical device companies frequently employ human factors engineers and key opinion leaders to help guide the design of these devices and to understand how to make them useful for physicians. Unfortunately, because surgery has traditionally been a male dominated field, most instruments have been built and designed with the male user in mind. Biomechanics and anthropometry are integral, related components of device development. Biomechanics refers to the structure and function of mechanical aspects of individuals, such as joint function, while anthropometry refers to measurements of the human body. The design of these devices involves incorporating these inherently intertwined dimensions to make them effective for users. These measurements are highly variable among the differing demographics of surgeons. For example, females have less grip strength, grip span and different hand anthropometry compared with male counterparts and a recent commentary by Hallbeck and Lal underscores the fact these measures vary by ethnicity as well. A 2001 medical device ergonomics paper defined the goal of designing laparoscopic instruments: to design a handle that accommodates 95% of the defined user population. This begs the question, who comprises the aforementioned ‘user population’? The field surgery is continuing to diversify and recruit women. This has been a welcome change. But, as the change in the population of surgeons occurs, design of laparoscopic devices has not seen parallel change. An ergonomics paper by van Veelen et al defined the population of laparoscopic surgeons as 90% male and 10% female. While this may have been previously true, this is no longer the case and will continue to change and evolve. Data from the AAMC reports that 44.8% of current general surgery residents are female as of 2021. Further, an overwhelming 85.2% of obstetrics and gynecology residents, a subspecialty which frequently uses laparoscopy, are women. Since it is obvious that the population of people using laparoscopic instruments has changed and will continue to change, the design of these instruments must also start to adapt. These key points are summarized in box 1. While most women and smallhanded surgeons can probably agree that palming bowel graspers and Marylands during laparoscopic cases is feasible, where the ergonomic difference is particularly pronounced is with disposable laparoscopic instruments. These devices are made mostly of plastic and then disposed of as medical waste at the end of cases. In the current world of injection moulds and threedimensional (3D) printers, it seems easy enough to allow for these to be designed in multiple sizes. In fact, a 2020 ergonomics study 3D printed ergonomic handles in multiple sizes and found that surgeons had decreased execution time when using the correct sized handle. Why does all of this matter? Many will argue that women surgeons have been able to effectively and proficiently use laparoscopic instruments and operate at a level comparable to male counterparts.