Ryota Nakajima1, Hiroshi Kawahira2, Shimomura Yoshihiro3, Wataru Nishimoto1, Takeshi Saito4, Hisashi Gunji5, Chisato Mori6, Hisahiro Matsubara5. 1Graduate School of Medical and Pharmaceutical Science, Chiba University, 2Center for Frontier Medical Engineering, Chiba University, 3Division of Design Science, Graduate School of Engineering, Chiba University, 4Department of Pediatric Surgery, Graduate School of Medicine, Chiba University, 5Department of Frontier Surgery, Graduate School of Medicine, Chiba University, 6Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University
Introduction: The physical burden on upper limbs of laparoscopic surgeons has been noticed coming from the limit of the forceps operation by the abdominal trocars and longer surgery time than open laparotomy. Particularly, the assistant conducts intermittent maintenance of the upper limbs abduction to keep the surgical field. We hypothesized that those movement was one factor of the burden and evaluated the fatigue of the deltoid muscles by the electromyograph and posture sensor measurement using technique of the biomedical measurement objectively.
Methods and Procedures: We measured the surface electromyograph (EMG) on both sides of deltoid muscles and the abduction angle of upper limbs during the simulation of laparoscpic distal gastrectomy on animal: male swines, 30 kg. Procedure of the simulation accomplished by one experienced surgeon (HK). EMG and the posture sensor measurement used BIOPAC MP150 Data Acquisition Hardware, and the data analysis used AcqKnowledge4.1 & Analysis Software (Zero C Seven, Inc, Tokyo, Japan). The arm abduction angle can be measured by two posture sensors located on both of outside upper limbs.
Results: From the results of EMG, the deltoid muscle activity was constant. The situation that maintained an isometric contraction more than 10%MVC was found, and physical burden by the laparoscopic surgery was confirmed to both operators and assistants. From the results of the abduction angle, the assistant’s upper limbs showed more frequent abduction and higher load than the operator’s.
Conclusion: We confirmed continuous fatigue of the upper limb during laparoscopic distal gastrectomy and suggested that physical burden level of assistant surgeons were highly loaded.