Ergonomic evaluation and performance of a new handle for laparoscopic tools in surgery.

This paper presents a new handle for instruments used in laparoscopic surgery. This new handle has been designed to provide the best ergonomic and usability features required in this kind of surgical interventions. The main novelty of this handle is that the opening and closing motion of the end-effector is operated with the thumb using a lever located on the top of the handle. This enables the surgeon to reach the patient's organs without adopting extremely awkward postures. In order to demonstrate its advantages, the handle has been tested and compared with another commercial handle in terms of efficiency, effectiveness, and satisfaction. To this end, volunteers have been selected for participation in the experimental evaluation, which comprised two types of surveys: objective and subjective. Electromyography and goniometric studies provide objective parameters for evaluation. Questionnaires are used for the subjective assessment. Outstanding results include the lower level of pain reported by the individuals working with the new handle, as well as the reduction in the hyperflexion of the wrist. Compared with the conventional handle, electromyography reveals that no muscle load is increased when working with the new handle. The results of the subjective survey show that volunteers expressed a significant preference for the new handle, demonstrating an improvement in the ergonomic characteristics.

Using infrared imaging for assessment of muscular activity in the forearm of surgeons in the performance of laparoscopic tasks.

Surgeons working in laparoscopic surgery are subjected to hard working conditions because of the poor ergonomic characteristics of the workplace. The improvement in the working conditions requires the use of reliable techniques for the assessment of muscular activity. In this article infrared imaging is used and compared with electromyography for the evaluation of muscle activity in the performance of laparoscopic surgical tasks. Electromyography has been widely used for the evaluation of the electrical activity produced by the muscles in the performance of surgery. On the contrary, infrared imaging is an innovative technique that has not been sufficiently explored. An experimental evaluation was carried out using a thermography camera and recording the infrared images from volunteers in different tests. Pearson's correlation was obtained between the electromyography and thermographic measurements in two stages: Endurance Stage (best value: ρ = 0.8401 with p < 0.01) and Surgical Task (best value: ρ = 0.8309 with p < 0.01). The article demonstrates that infrared imaging is a valuable technique for the evaluation of muscle activity in laparoscopic surgery, and it can be compared with electromyography. The main advantages of infrared imaging are that it allows remote measurement and provides activity information in the whole area of interest. However, drawbacks such as delayed response of the infrared imaging due to thermal conductivity of the skin should be considered. Electromyography only provides information in the location of the electrodes, but it is a real-time response. For these reasons, the techniques complement each other.

A study of the prevalence of musculoskeletal disorders in surgeons performing minimally invasive surgery.

INTRODUCTION: Minimally invasive surgery (MIS) has shown significant benefits for patients and healthcare systems. However, due to the poor ergonomic adaptation of operating rooms and surgical instruments, most surgeons suffer from pain caused by musculoskeletal disorders (MSDs). METHODS: A descriptive survey on MIS surgeons working in different surgical specialties has been carried out in Hospital Valdecilla (Spain). The aim is to determine the prevalence of MSDs using a personal interview and the standardized Nordic questionnaire. The study determines the prevalence of MSDs in different parts of the body and their relationship with epidemiological and labor variables. A questionnaire was filled out by 129 surgeons. RESULTS: 90% of surgeons reported MSDs. The higher prevalence appears in the most experienced surgeons. The most affected zones are the lower back (54%), neck (51%), upper back (44%), lower extremities (42%), right shoulder (29%) and right hand (28%). CONCLUSIONS: The prevalence of MSDs is higher in MIS surgeons than in any other occupational group. The most vulnerable group is experienced surgeons and there is a potential risk that symptoms will be increased in the future. Muscle strength is revealed as a protective factor against MSDs.

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. MATERIALS AND 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.