Ergonomic assessment of neck posture in the minimally invasive surgery suite during laparoscopic cholecystectomy.

BACKGROUND: With the expanding implementation of minimally invasive surgery, the operating team is confronted with challenges in the field of ergonomics. Visual feedback is derived from a monitor placed outside the operating field. This crossover trial was conducted to evaluate and compare neck posture in relation to monitor position in a dedicated minimally invasive surgery (MIS) suite and a conventional operating room. METHODS: Assessment of the neck was conducted for 16 surgeons, assisting surgeons, and scrub nurses performing a laparoscopic cholecystectomy in both types of operating room. Flexion and rotation of the cervical spine were measured intraoperatively using a video analysis system. A two-question visual analog scale (VAS) questionnaire was used to evaluate posture in relation to the monitor position. RESULTS: Neck rotation was significantly reduced in the MIS suite for the surgeon (p = 0.018) and the assisting surgeon (p < 0.001). Neck flexion was significantly improved in the MIS suite for the surgeon (p < 0.001) and the scrub nurse (p = 0.018). On the questionnaire, the operating room team scored their posture significantly higher in the MIS suite and also indicated fewer musculoskeletal complaints. CONCLUSIONS: The ergonomic quality of the neck posture is significantly improved in the MIS suite for the entire operating room team.

A newly designed ergonomic body support for surgeons.

BACKGROUND: One of the main ergonomic problems during surgical procedures is the surgeon's awkward body posture, often accompanied by repetitive movements of the upper extremities, increased muscle activity, and prolonged static head and back postures. In addition, surgeons perform surgery so concentrated that they tend to neglect their posture. These observations suggest the advantage of supporting the surgeon's body during surgical procedures. This study aimed to design a body support and to test its potential. METHODS: The optimum working condition for a surgeon is a compromise between the spine and arm positions and the level of effort and fatigue experienced performing a procedure. The design vision of the Medisign group has led to the development of an ergonomic body support for surgeons that is suitable for use during both open and minimally invasive procedures. The feasibility of the newly designed ergonomic body support was assessed during seven surgical procedures. Electromyography (EMG) was performed for back and leg muscles using the body support in an experimental setting. RESULTS: Six of seven participating surgeons indicated that the body support was comfortable, safe, and simple to use. The EMG results show that supporting the body is effective in reducing muscle activity. The average reduction using chest support was 44% for the erector spinae muscle, 20% for the semitendinosus muscle, and 74% for the gastrocnemius muscle. The average muscle reduction using semistanding support was 5% for the erector spinae, 12% for the semitendinosus muscle, and for 50% for the gastrocnemius muscle. CONCLUSION: The results of this study imply that supporting the body is an effective way to reduce muscle activity, which over the long term may reduce physical problems and discomfort. Additionally, the product supports the surgeon in his natural posture during both open and minimally invasive procedures and can easily be adapted to the current layout of the operating theater.

Application of ergonomic guidelines during minimally invasive surgery: a questionnaire survey of 284 surgeons.

BACKGROUND: This study aimed to obtain an answer for the question: Are ergonomic guidelines applied in the operating room and what are the consequences? METHODS: A total of 1,292 questionnaires were sent by email or handed out to surgeons and residents. The subjects worked mainly in Europe, performing laparoscopic and/or thoracoscopic procedures within the digestive, thoracic, urologic, gynecologic, and pediatric disciplines. RESULTS: In response, 22% of the questionnaires were returned. Overall, the respondents reported discomfort in the neck, shoulders, and back (almost 80%). There was not one specific cause for the physical discomfort. In addition, 89% of the 284 respondents were unaware of ergonomic guidelines, although 100% stated that they find ergonomics important. CONCLUSIONS: The lack of ergonomic guidelines awareness is a major problem that poses a tough position for ergonomics in the operating room.

Improved usability of a new handle design for laparoscopic dissection forceps.

BACKGROUND: Recent studies have shown that the shape of most instrument handles causes user discomfort and that none of the handles currently available on the market satisfies all ergonomic criteria. Therefore, we designed a handle with improved usability; i.e., it is easier to manipulate and its use entails less risk of injury for the operator. The aim of this study was to demonstrate that the intended improvements of the new design were successful. METHODS: Six handles representative of the types that are currently available were compared with the new version. Eight surgeons used the seven handles during a precision task and a rough task in a pelvi-trainer. A questionnaire and video analyses were used to assess the usability of the handles. RESULTS: Based on the responses to the questionnaire, we determined that there were significant differences between the new handle and the Aesculap handle (means of rotation and angle between handle and shaft). No significant differences were found between the new handle and the five other handles. The video analyses (documenting extreme vs neutral wrist excursions) showed significant differences between the new handle and the six other handles. CONCLUSION: Compared to the six existing handles, the new handle has significantly improved usability; in particular, its hinged design obviates the need to make extreme wrist excursions.

Improvement of foot pedals used during surgery based on new ergonomic guidelines.

BACKGROUND: This study aims to create new ergonomic guidelines for the design of foot pedals used during surgery. METHODS: Observations in the operating room, a questionnaire among 45 laparoscopic surgeons/residents, an ergonomic literature study, and clog measurements were used to assess the problems occurring during use and to compile new guidelines for foot pedals. Based on these guidelines a new foot pedal was designed and a prototype was manufactured. RESULTS: During the surgical procedure 91% of the subjects occasionally loses contact with the foot pedal, which 56% experience as very annoying. All subjects think that the current foot pedals obstruct their freedom of movement; 75% occasionally hit the wrong switch and 53% experience physical discomfort in their legs and/or feet. Therefore, 93% of the subjects would like to control the diathermy in a different way. The new prototype of a foot pedal was evaluated in a pilot test and proved to be ergonomically better than the currently used foot pedals. CONCLUSION: The new guidelines for foot pedals result in an ergonomic improvement in their design.

Evaluation of the usability of two types of image display systems, during laparoscopy.

BACKGROUND: This study was performed to assess the optimal display location of a flat-screen monitor for laparoscopy. It was also performed to assess the posture (objective), opinion, and preference (subjective) of subjects using a flat-screen monitor positioned in the optimal display location and a cathode-ray tube monitor on a tower next to the operating table (current situation). METHODS: Twelve surgeons performed cholecystectomies using the two display systems alternately. The postures of the operator and the assistant were assessed by an infrared video analysis system. RESULTS: The posture of the assistant is significantly better when using a flat-screen monitor [more neutral head flexions (p = 0.036) and neutral neck torsions (p = 0.012)]. No significant differences were found for the posture of the operator. The operators and assistants felt more comfortable when using a flat-screen monitor (p = 0.008) and they preferred this display to the use of a monitor on a tower. CONCLUSIONS: The use of flat-screen monitors is better for the physical and psychological comfort of the users, even though the technical performance is inferior in comparison with that of regular monitors.

Improvement of the laparoscopic needle holder based on new ergonomic guidelines.

BACKGROUND: The aim of this study is to create new ergonomic guidelines for the design of laparoscopic needle holders. METHODS: An ergonomic literature study, observations in the operating room, handle-shaft angle measurements, and anthropometric data were used to compile new ergonomic criteria, specified to the function of a laparoscopic needle holder. Based on these guidelines a new needle holder was designed. The prototype and three currently available needle holders were evaluated according to the new guidelines. In addition, a pelvi-trainer test was done to measure the extreme wrist excursions. RESULTS: The ergonomic evaluation of three commonly used handles and the new prototype indicate that the new handle is an ergonomic improvement in the field of laparoscopic needle holders: only the new handle satisfies all criteria. This is validated by the results of the pelvi-trainer test, which showed that the new prototype significantly (p <0.001) reduced the extreme wrist excursions. CONCLUSION: The new design guidelines for a laparoscopic needle holder result in an ergonomic improvement of the instrument.

Ergonomic problems encountered by the medical team related to products used for minimally invasive surgery.

BACKGROUND: The aim of this study is to gain insight into the problems encountered by the medical team related to products used for minimally invasive surgery. METHODS: An inventory was made of the problems encountered during 12 endoscopic operations performed in one city hospital (Eindhoven, the Netherlands). After the observation, a questionnaire was distributed to all medical staff involved. RESULTS: All categories of personnel had physical, perceptional, and cognitive problems, especially surgeons, residents, and the sterile operation nurse. The main causes were the positioning of apparatus and staff, work clothing, and the limited reach of apparatus and/or instruments. Of the questionnaires, 80% were returned: 50% of the medical staff experienced perceptional problems and 63% had physical discomfort during the surgical procedure. CONCLUSION: The diversity of problems observed and/or reported by the staff during minimally invasive surgery decrease the comfort, efficiency, and safety of the operating-room work environment. Therefore, a new design approach is needed for MIS products in order to address the problems that occur with the current equipment.

Ergonomics and design of laparoscopic instruments: results of a survey among laparoscopic surgeons.

This study determined which types of laparoscopic instruments are most often used in Europe, why they are being used, and what problems exist while using the instruments. The handles were also evaluated according to ergonomic design criteria. A questionnaire was send to 62 experienced surgeons in 19 countries. The laparoscopic instruments were divided into four groups: instruments with similar functionality and handgrip model were grouped together. Eight questions were asked for every group about the type of instrument (disposable, reusable, or semireusable), the type of handle, the reason for using a specific instrument, and the experience of discomfort while using the instrument. The handles of the instruments of the group that were associated with the greatest discomfort were ergonomically evaluated on eight aspects (dimensions, angles, and control). Half of the questionnaires were returned. In every group, about 80% of the instruments the surgeons employed were reusable. The chief reason for using a specific type was the good cost-quality of the product and satisfying experiences with other products of the brand. The discomfort was pressure on thumb and fingers (scissors handle) and fixating the tip (ratchet). The handle of the instruments that causes the most discomfort met only three of the eight ergonomic requirements. Most of the laparoscopic instruments employed by surgeons in Europe are reusable. A significant number of the instruments cause discomfort. These instruments do not meet standard ergonomic requirements.

Assessment of the ergonomically optimal operating surface height for laparoscopic surgery.

PURPOSE: The aim of this study was to find the ergonomically optimal operating surface height for laparoscopic surgery in order to reduce discomfort in the upper extremities of the operators and the assistants. The operating surface height was defined as the level of the abdominal wall of a patient with pneumoperitoneum. MATERIALS AND METHODS: Two pelvi-trainer tests were performed. One test was performed on six different operating surface heights. The (extreme) joint excursions of the shoulder, elbow, and wrist were measured by a video analysis method. Another test was performed by holding a laparoscope for 15 minutes while an electromyelograph of the biceps brachii was made. The results of both tests were evaluated subjectively by a questionnaire. RESULTS: The ergonomically optimal operating surface height lies between a factor 0.7 and 0.8 of the elbow height of the operator/assistant. At this height, the joint excursions stay in the neutral zone for more than 90% of the total manipulation time, and the activity of the biceps brachii when holding the laparoscope stays within 15% of the maximum muscle activity. CONCLUSIONS: The operating surface height influences the (extreme) upper joint excursions of the surgeon. The ergonomically optimal operating surface height reduces the discomfort in the shoulders, back, and wrists of the surgeon during laparoscopic surgery. This optimal table height range for laparoscopic surgery is lower than those currently available.