Evaluating the Performance of a Novel Laparoscopic Tool Handle Design and Upper Extremity Biomechanics

Rami M Shorti, MS, Kryztopher D Tung, MS, Earl C Downey, MD, Donald S Bloswick, PhD, Andrew S Merryweather, PhD

University of Utah

Introdction and Objective:

Laparoscopic surgeons experience physical discomfort and musculoskeletal pain during or after a procedure. Several factors that likely contribute to this include awkward posture, high hand forces, duration of use, and fatigue. These risk factors are commonly reported to contribute to the development of musculoskeletal disorders. The goal of this study is to understand the influence of laparoscopic surgical hand tool design on surgeon performance, resulting biomechanical stresses, and self-reported musculoskeletal pain. We hypothesized that there will be a measurable difference between the performance of the novel versus current laparoscopic tool designs in three categories: upper extremity biomechanical stresses, technical skill, and subjective user ratings.

Tool and Methods Description:

The novel tool handle design incorporates an ergonomic pistol-grip that reduces contact stress points on the hand and fingers, promotes a more neutral posture and influences the magnitude of hand tremor and fatigue.

Twenty participants (10 M, 10 F) with no prior experience with Laparoscopic Surgery and no existing upper extremity musculoskeletal disorders were exposed to a training session with both surgical tool handles. Preliminary training and test trials were performed using a SAGES FLS trainer. Twenty-four hours following training, participants performed three evaluation tasks using both surgical tool handle designs. Participants stood on force plates and were fitted with reflective markers on key anatomical landmarks to quantify upper and lower body posture during 3D motion capture. Additional markers were placed on tool handles in order to quantify hand positioning, economy of movement, and tremor. Surface electromyography electrodes were placed on left and right flexor and extensor digitorum, left and right biceps brachii, and left and right trapezius. The tasks consisted of a peg transfer task, a cutting task, and a suturing task.

Preliminary Results:

Feedback from test participants suggests that the novel tool design influences contact stress in the hands and was preferred by the majority of participants. Preliminary findings from the subjective survey show that, on average and regardless of the task performed, the novel tool received higher ratings than the traditional tool in every scoring category; namely ease of use, level of comfort, and level of exertion. Interestingly, participants also self-rated their performance higher with the novel tool handle design than with the traditional tool. Analyses to determine differences between economy of movement, posture, accuracy, and muscle fatigue are currently in progress.

Conclusions and Future Direction:

The designs of most laparoscopic surgical tool handles neglect ergonomic design considerations. Future designs should consider both surgeon and patient safety and comfort. This novel hand tool design prototype will be iterated and improved based on results from this study. Further testing will be conducted with professionally trained laparoscopic surgeons in a more realistic test environment to evaluate performance metrics including contact stress, posture, muscle fatigue, and economy of movement.

Session: Poster Presentation

Program Number: ETP079

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