Design and evaluation of a new ergonomic handle for instruments in minimally invasive surgery.
BACKGROUND
Laparoscopic surgery techniques have been demonstrated to provide massive benefits to patients. However, surgeons are subjected to hardworking conditions because of the poor ergonomic design of the instruments. In this article, a new ergonomic handle design is presented. This handle is designed using ergonomic principles, trying to provide both more intuitive manipulation of the instrument and a shape that reduces the high-pressure zones in the contact with the surgeon's hand.


METHODS
The ergonomic characteristics of the new handle were evaluated using objective and subjective studies. The experimental evaluation was performed using 28 volunteers by means of the comparison of the new handle with the ring-handle (RH) concept in an instrument available on the market. The volunteers' muscle activation and motions of the hand, wrist, and arm were studied while they performed different tasks. The data measured in the experiment include electromyography and goniometry values.


RESULTS
The results obtained from the subjective analysis reveal that most volunteers (64%) preferred the new prototype to the RH, reporting less pain and less difficulty to complete the tasks. The results from the objective study reveal that the hyperflexion of the wrist required for the manipulation of the instrument is strongly reduced.


CONCLUSIONS
The new ergonomic handle not only provides important ergonomic advantages but also improves the efficiency when completing the tasks. Compared with RH instruments, the new prototype reduced the high-pressure areas and the extreme motions of the wrist.
Department of Structural and Mechanical Engineering, University of Cantabria, Cantabria, Spain. Electronic address: sancibrr@unican.es.
Ramon
R
Sancibrian
Department of Surgery of the Valdecilla Virtual Hospital, Cantabria Healthcare System, Cantabria, Spain.
María C
MC
Gutierrez-Diez
Department of Electronics Technology, Systems and Automation Engineering, University of Cantabria, Spain.
Carlos
C
Torre-Ferrero
Department of Nursery, Marques de Valdecilla University Hospital, Cantabria, Spain.
Maria A
MA
Benito-Gonzalez
Department of Medical and Surgical Sciences, University of Cantabria, Cantabria, Spain.
Carlos
C
Redondo-Figuero
General Surgery Service, Colorectal Unit, Marques de Valdecilla University Hospital, Cantabria, Spain.
Jose C
JC
Manuel-Palazuelos
D004867:Equipment Design; D006804:Ergonomics; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation*; D018482:Muscle, Skeletal / Q000502:physiology; D012785:Shoulder Joint / Q000502:physiology; D011795:Surveys and Questionnaires; D014955:Wrist Joint / Q000502:physiology*
Ergonomics; Handle design; Human factors; Laparoscopic; Posture; Surgical instruments; Work-related musculoskeletal disorders