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

The value of Augmented Reality in surgery - A usability study on laparoscopic liver surgery

Augmented Reality (AR) is considered to be a promising technology for the guidance of laparoscopic liver surgery. By overlaying pre-operative 3D information of the liver and internal blood vessels on the laparoscopic view, surgeons can better understand the location of critical structures. In an effort to enable AR, several authors have focused on the development of methods to obtain an accurate alignment between the laparoscopic video image and the pre-operative 3D data of the liver, without assessing the benefit that the resulting overlay can provide during surgery. In this paper, we present a study that aims to assess quantitatively and qualitatively the value of an AR overlay in laparoscopic surgery during a simulated surgical task on a phantom setup. We design a study where participants are asked to physically localise pre-operative tumours in a liver phantom using three image guidance conditions - a baseline condition without any image guidance, a condition where the 3D surfaces of the liver are aligned to the video and displayed on a black background, and a condition where video see-through AR is displayed on the laparoscopic video. Using data collected from a cohort of 24 participants which include 12 surgeons, we observe that compared to the baseline, AR decreases the median localisation error of surgeons on non-peripheral targets from 25.8 mm to 9.2 mm. Using subjective feedback, we also identify that AR introduces usability improvements in the surgical task and increases the perceived confidence of the users. Between the two tested displays, the majority of participants preferred to use the AR overlay instead of navigated view of the 3D surfaces on a separate screen. We conclude that AR has the potential to improve performance and decision making in laparoscopic surgery, and that improvements in overlay alignment accuracy and depth perception should be pursued in the future.

Comparison of cervical neck strain in common otolaryngology surgeries

BACKGROUND

Cervical neck strain and surgical ergonomics is an increasingly important topic being addressed in this time and age. With new technologies, visualizations, and approaches to surgeries, there are now different strains and duration of strains to the cervical neck. Recently the effect of chronic cell phone use has been described as "text neck." In a similar fashion we understand that certain otolaryngology surgeries can also impart chronic strain to the cervical neck. We aim to quantitatively describe strain for different types of surgeries by looking at posture, duration of surgery, and anatomic ergonomics of specific surgeries.

METHODS

Lateral photo documentation of posture during 6 common otolaryngology procedures, used to estimate cervical neck angle and calculate force and impulse to cervical neck.

RESULTS

Six common otolaryngology procedures show various cervical neck angles ranging from around 0° to 60° of neck flexion, with subsequent forces ranging from 16 lb to 60 lb of force. When accounting for surgical time, bigger differences arose with impulses ranging from 270,000 N∗s to 3,300,000 N∗s. Noticeably, thyroidectomy and cleft palate showed much higher impulses than the other four types of surgeries.

CONCLUSION

Both cervical neck flexion and duration of surgery play important roles in total neck theoretical strain. Variance exists between neck strains of common otolaryngology surgeries. There is a necessity for continued study and improvement in surgical ergonomics.

Surgeon Positioning During Awake Laryngeal Surgery: An Ergonomic Analysis

OBJECTIVES

While it is acknowledged that otolaryngologists performing microlaryngeal surgery can develop musculoskeletal symptoms due to suboptimal body positioning relative to the patient, flexible laryngoscopy and awake laryngeal surgeries (ALSs) can also pose ergonomic risk. This prospective study measured the effects of posture during ergonomically good and bad positions during laryngoscopy using ergonomic analysis, skin-surface electromyography (EMG), and self-reported pain ratings.

STUDY DESIGN

Prospective cohort study.

METHODS

Eight participants trained in laryngoscopy assumed four ergonomically distinct standing positions (side/near, side/far, front/near, front/far) at three different heights (neutral-top of patient's head in line with examiner's shoulder, high-6 inches above neutral, and low-6 inches below neutral) in relation to a simulated patient. Participants' postures were analyzed using the validated Rapid Upper Limb Assessment (RULA, 1 [best] to 7 [worst]) tool for the 12 positions. Participants then simulated ALS for 10 minutes in a bad position (low-side-far) and a good position (neutral-front-near) with 12 EMG sensors positioned on the limbs and torso.

RESULTS

The position with the worst RULA score was the side/near/high (7.0), and the best was the front/near/neutral (4.5). EMG measurements revealed significant differences between simulated surgery in the bad and good positions, with bad position eliciting an average of 206% greater EMG root-mean-squared magnitude across all sampled muscles compared to the good posture (paired t-test, df = 7, P < .01), consistent with self-reported fatigue/pain when positioned poorly.

CONCLUSION

Quantitative and qualitative measurements demonstrate the impact of surgeon posture during simulated laryngoscopy and suggest ergonomically beneficial posture that should facilitate ALSs.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Ergonomics in gynecologic surgery

PURPOSE OF REVIEW

Work-related musculoskeletal disorders (WMSDs) are prevalent among surgeons and result in significant disability. We aimed to review the English-language literature regarding ergonomic risk, prevalence of WMSDs, and unique ergonomic considerations of gynecologic surgery.

RECENT FINDINGS

Surgeon WMSDs are prevalent, with rates ranging from 66 to 94% for open surgery, 73-100% for conventional laparoscopy, 54-87% for vaginal surgery, and 23-80% for robotic-assisted surgery. Risk factors for injury in open surgery include use of loupes, headlamps, and microscopes. Unique risks in laparoscopic surgery include table and monitor position, long-shafted instruments, and poor instrument handle design. In vaginal surgery, improper table height and twisted trunk position create injury risk. Although robotic surgery offers some advantages in neck and shoulder strain, it remains associated with trunk, wrist, and finger strain.

SUMMARY

WMSDs are prevalent among surgeons but have received little attention because of under-reporting of injury and logistical constraints of studying surgical ergonomics. Future research must aim to develop objective surgical ergonomics instruments and guidelines and to correlate ergonomics assessments with pain and tissue-level damage in surgeons with WMSDs. Ergonomics training should be developed and implemented in order to protect surgeons from preventable, potentially career-altering injuries.

Ergonomics in Surgery: A Review

OBJECTIVE

Work-related musculoskeletal disorders (WMSDs) are prevalent among surgeons and may result in practice modification. We aimed to perform a comprehensive review of the English-language literature regarding ergonomic risk, prevalence of WMSDs, and unique ergonomic considerations by route of surgery.

METHODS

Multiple searches were performed of PubMed and University library resources to access English-language publications related to surgeon ergonomics. Combinations of keywords were used for each mode of surgery, including the following: "ergonomics," "guidelines," "injury," "operating room," "safety," "surgeon," and "work-related musculoskeletal disorders." Each citation was read in detail, and references were reviewed.

RESULTS

Surgeon WMSDs are prevalent, with rates ranging from 66% to 94% for open surgery, 73% to 100% for conventional laparoscopy, 54% to 87% for vaginal surgery, and 23% to 80% for robotic-assisted surgery. Risk factors for injury in open surgery include use of loupes, headlamps, and microscopes. Unique risks in laparoscopic surgery include table and monitor position, long-shafted instruments, and poor instrument handle design. In vaginal surgery, improper table height and twisted trunk position create injury risk. Although robotic surgery offers some advantages, it remains associated with trunk, wrist, and finger strain. Surgeon WMSDs often result in disability but are under-reported to institutions. Additionally, existing research tools face limitations in the operating room environment.

CONCLUSIONS

Work-related musculoskeletal disorders are prevalent among surgeons but have received little attention owing to under-reporting of injury and logistical constraints of studying surgical ergonomics. Future research must aim to develop objective surgical ergonomics instruments and guidelines and to correlate ergonomics assessments with pain and tissue-level damage in surgeons with WMSDs. Ergonomics training should be developed to protect surgeons from preventable, potentially career-altering injuries.

Sources of pain in laparoendoscopic gynecological surgeons: An analysis of ergonomic factors and proposal of an aid to improve comfort

Minimally invasive surgery (MIS) offers cosmetic benefits to patients; however, surgeons often experience pain during MIS. We administered an ergonomic questionnaire to 176 Korean laparoscopic gynecological surgeons to determine potential sources of pain during surgery. Logistic regression analysis was used to identify factors that had a significant impact on gynecological surgeons’ pain. Operating table height at the beginning of surgery and during the operation were significantly associated with neck and shoulder discomfort (P <0.001). The ability to control the operating table height was the single factor most significantly associated with neck (P <0.001) and shoulder discomfort (P <0.001). Discomfort of the hand/digits was significantly associated with the trocar site (P = 0.035). The type of electrocautery activation switch and foot pedal were significantly related to surgeons’ foot and leg discomfort (P <0.001). In evaluating the co-occurrence of pain in 4 different sites (neck, shoulder, back, hand/digits), the neck and shoulder were determined to have the highest co-occurrence of pain (Spearman’s ρ = 0.64, P <0.001). These results provide guidance for identifying ergonomic solutions to reduce gynecological laparoscopic surgeons’ pain. Based on our results, we propose the use of an ergonomic surgical step stool to reduce physical pain related to performing laparoscopic operations.

Ergonomics in the operating room

Background

Since the introduction of minimally invasive surgery, surgeons appear to be experiencing more occupational musculoskeletal injuries. The aim of this study is to investigate the current frequency and effects of occupational musculoskeletal injuries on work absence.

Methods

An online questionnaire was conducted among all surgeons affiliated to the Dutch Society for Endoscopic Surgery, Gastrointestinal Surgery, and Surgical Oncology. In addition, this survey was conducted among surgeons, gynaecologists, and urologists of one cluster of training hospitals in the Netherlands.

Results

There were 127 respondents. Fifty-six surgeons currently suffer from musculoskeletal complaints, and 30 have previously suffered from musculoskeletal complaints with no current complaints. Frequently reported localizations were the neck (39.5 %), the erector spinae muscle (34.9 %), and the right deltoid muscle (18.6 %). Most of the musculoskeletal complaints were present while operating (41.8 %). Currently, 37.5 % uses medication and/or therapy to reduce complaints. Of surgeons with past complaints, 26.7 % required work leave and 40.0 % made intraoperative adjustments. More surgeons with a medical history of musculoskeletal complaints have current complaints (OR 6.1, 95 % CI 1.9–19.6). There were no significant differences between surgeons of different operating techniques in localizations and frequency of complaints, or work leave.

Conclusions

Despite previous various ergonomic recommendations in the operating room, the current study demonstrated that musculoskeletal complaints and subsequent work absence are still present among surgeons, especially among surgeons with a positive medical history for musculoskeletal complaints. Even sick leave was necessary to fully recover. There were no significant differences in reported complaints between surgeons of different operating techniques. Almost half of the respondents with complaints made intraoperative ergonomic adjustments to prevent future complaints. The latter would be interesting for future research.

Methodological Infrastructure in Surgical Ergonomics: A Review of Tasks, Models, and Measurement Systems

Though in its infancy, the discipline of surgical ergonomics is increasingly valued. Still, little has been written regarding this field's tasks, models, and measurement systems. These 3 critical experimental components are crucial in objectively and accurately assessing joint and postural control as exhibited by expert laparoscopic surgeons. Such assessments will establish characteristic patterns important for surgical training. In addition, risk factors associated with both minimally invasive surgical instruments and the operating room environment can be identified and minimized. Our review focuses on evidence-based experimental ergonomic studies undertaken in the field of laparoscopic surgery. Publications were located through PubMed and other database and library searches. This article describes tasks, models, and measurement systems and considers their specific applications and the types of data obtainable with the use of each. Advantages and limitations, especially those of measurement systems, are compared and discussed. Future trends and directions believed necessary for optimal investigation and results are also addressed.

Minimally invasive surgery training using multiple port sites to improve performance

BACKGROUND

Structural learning theory suggests that experiencing motor task variation enables the central nervous system to extract general rules regarding tasks with a similar structure - rules that can subsequently be applied to novel situations. Complex minimally invasive surgery (MIS) requires different port sites, but switching ports alters the limb movements required to produce the same endpoint control of the surgical instrument. The purpose of the present study was to determine if structural learning theory can be applied to MIS to inform training methods.

METHODS

A tablet laptop running bespoke software was placed within a laparoscopic box trainer and connected to a monitor situated at eye level. Participants (right-handed, non-surgeons, mean age = 23.2 years) used a standard laparoscopic grasper to move between locations on the screen. There were two training groups: the M group (n = 10) who trained using multiple port sites, and the S group (n = 10) who trained using a single port site. A novel port site was used as a test of generalization. Performance metrics were a composite of speed and accuracy (SACF) and normalized jerk (NJ; a measure of movement 'smoothness').

RESULTS

The M group showed a statistically significant performance advantage over the S group at test, as indexed by improved SACF (p < 0.05) and NJ (p < 0.05).

CONCLUSIONS

This study has demonstrated the potential benefits of incorporating a structural learning approach within MIS training. This may have practical applications when training junior surgeons and developing surgical simulation devices.

Ergonomic considerations in endoscopic sinus surgery: lessons learned from laparoscopic surgeons

BACKGROUND

Endoscopic sinus procedures are increasingly common, and more technically difficult procedures are being undertaken to provide patients with minimally invasive alternatives to traditional open surgical techniques. However, such endoscopic approaches have increasing physical demands on the surgeon. The aim of this review is to summarize current literature on surgical ergonomic principles as they relate to endoscopic sinus and skull base surgery and focus on future needs for our specialty.

METHODS

Literature review was performed of surgical ergonomics and, particularly, laparoscopic ergonomic principles.

RESULTS

Existing ergonomic principles for laparoscopic surgery can be applied to endoscopic sinus and skull base surgery and can be expected to offer benefits in terms of surgeon fatigue, physical discomfort, and task efficiency.

CONCLUSION

Increasing surgeon awareness will allow for many basic ergonomic principles to be applied to endoscopic sinus and skull base surgery. Although many simple changes can be immediately made, there is a clear need for further study and abundant room for innovation.

Effect of visual displays and locations on laparoscopic surgical training task

The number of minimally invasive surgical (MIS) procedures has substantially increased since its introduction due to health and recovery benefits for patients. However, there are potential performance issues in MIS for surgeons due to perceptual processing demands associated with supporting technologies. Monitor location has been identified as a major factor influencing performance in these types of procedures. This study examined the effect of multiple monitors on performance during a laparoscopic surgical training task (peg transfer among instruments). Twenty-four novice subjects were exposed to different monitor conditions including a default position, a biomechanically compatible position, and a position collocated with the operating surface as well as the combination of the latter two. Subjective rankings and cognitive workload were also assessed. Results revealed a significant effect of monitor position on task time when compared to subjects' baseline training task time using the default monitor setup. Collocating the monitor with the operating surface was shown to be superior in terms of task time. There were no significant differences among monitor positions in terms of perceived workload. The results of this study provide an applicable guide for the design of MIS setups in the operating room to promote surgeon performance.

An ergonomic analysis of the effects of camera rotation on laparoscopic performance

BACKGROUND

Minimal access surgery is associated with increased risk of complications, particularly early in a surgeon's laparoscopic career. This is mostly due to loss of depth cues, degraded tactile feedback from surgical instrument, and the "fulcrum effect". Degraded and restricted image on the monitor makes camera orientation very important. The objective of this study is to investigate the effects of camera rotation on laparoscopic performance.

METHODS

In two separate studies 100 laparoscopic novices and 7 experienced laparoscopic surgeons ([300 laparoscopic procedures) were asked to perform a simple laparoscopic cutting task and tie intracorporeal square-knots (respectively) under 0, 15, 45, 90, and 180 camera rotation.

RESULTS

In study 1 camera rotation significantly degraded performance of laparoscopic novices (p\0.00001) and also increased their error rate (p\0.00001). In study 2 camera rotation significantly increased the length of time it took surgeons to tie an intracorporeal square-knot (p\0.00001) and the number of errors made (p\0.0001).

CONCLUSIONS

Unintentional camera rotation during surgery should be avoided to eliminate one potential source for errors.

Ergonomic problems encountered during video‐assisted thoracic surgery

In laparoscopic surgery, the way of thinking about operating room design is beginning to include ergonomic requirements. No study has yet been published about ergonomic concerns in Video-Assisted Thoracic Surgery (VATS). The aim of this paper is to describe ergonomic issues encountered in VATS and to propose recommendations for operating room design for thoracoscopic surgery. To obtain an inventory of the ergonomic problems fifteen thoracoscopic operations were attended at the Institut Mutualiste Montsouris (Paris, France). Ergonomics can be divided into three divisions: physical, perceptual and cognitive ergonomics. During the observations of thoracoscopic operations the physical problems were registered. The perceptual and cognitive problems were obtained from a literature study. In general two different positions of the surgeon can be distinguished, depending on the placement of the trocars and the endoscope. One position resembles the body position during laparoscopy, involving the same problems such as fatigue of the legs, a static body position, a large working area, extreme movements of the upper limbs and the wrist and stiffness of the neck. The other position is specific for VATS resulting in a rotated upper body while the surgeon has to lean over the patient to be able to handle the instruments. This awkward position causes even more serious problems. The study resulted in a list of ergonomic problems encountered during VATS. Reorganisation of the operating room set-up and monitor position, design of a dedicated operating table and specific instruments might help to overcome the current ergonomic problems.

Improved physical ergonomics of laparoscopic surgery

One of the main and basic ergonomic problems associated with laparoscopy is the surgeon's non-neutral posture during laparoscopic procedures. There are five main issues that influence the posture of the surgeon: the (hand-held) instrument design, the position of the monitor, the use of foot pedals to control diathermy, the poorly adjusted operating table height, and the static body posture. This paper gives an overview of the ergonomic guidelines that have been developed in these five areas and shows product solutions that have been developed according to these guidelines. The guidelines can be used by operating room (OR) staff to evaluate the ergonomics of their OR environment and to improve issues that do not satisfy the ergonomic guidelines. When designers use these guidelines to design new OR equipment, the new designs are an improvement in the field of human factors compared to the currently used laparoscopic products. When all these products are applied in the laparoscopic operating room, a new and ergonomic environment is created for the surgeon as well as for the assistants.

Optimal ergonomics for laparoscopic surgery in minimally invasive surgery suites: a review and guidelines

BACKGROUND

With minimally invasive surgery (MIS), a man-machine environment was brought into the operating room, which created mental and physical challenges for the operating team. The science of ergonomics analyzes these challenges and formulates guidelines for creating a work environment that is safe and comfortable for its operators while effectiveness and efficiency of the process are maintained. This review aimed to formulate the ergonomic challenges related to monitor positioning in MIS. Background and guidelines are formulated for optimal ergonomic monitor positioning within the possibilities of the modern MIS suite, using multiple monitors suspended from the ceiling.

METHODS

All evidence-based experimental ergonomic studies conducted in the fields of laparoscopic surgery and applied ergonomics for other professions working with a display were identified by PubMed searches and selected for quality and applicability. Data from ergonomic studies were evaluated in terms of effectiveness and efficiency as well as comfort and safety aspects. Recommendations for individual monitor positioning are formulated to create a personal balance between these two ergonomic aspects.

RESULTS

Misalignment in the eye-hand-target axis because of limited freedom in monitor positioning is recognized as an important ergonomic drawback during MIS. Realignment of the eye-hand-target axis improves personal values of comfort and safety as well as procedural values of effectiveness and efficiency.

CONCLUSIONS

Monitor position is an important ergonomic factor during MIS. In the horizontal plain, the monitor should be straight in front of each person and aligned with the forearm-instrument motor axis to avoid axial rotation of the spine. In the sagittal plain, the monitor should be positioned lower than eye level to avoid neck extension.

Safety, hazards and ergonomics in the operating room

OBJECTIVE

The objective for this study was to address the lack of information regarding the working conditions in the operating room (OR). Safety issues in the OR need to be discussed not only for the sake of patients, but also for personnel, as hazards may occur for all persons within the OR.

METHODS

To evaluate the workplace conditions in the operating room, a survey was conducted among surgeons working in German hospitals. Sixty questions were asked regarding the personal profile, the architectural situation, the devices and instruments as well as working posture and associated pain.

RESULTS

The survey showed elementary ergonomic deficiencies within all fields. Surgeons stated that these deficiencies lead to potential hazards for patients and personnel, potentially on a frequent basis. 97% of the surveyed surgeons see ergonomic improvement in the operating room as necessary.

CONCLUSION

The survey results display a high potential for improvement within all fields. Therefore, industry, surgeons and their professional organizations are asked to work on the optimization of the workplace conditions in the operating room in terms of improvement of quality and efficiency.

Safety, hazards and ergonomics in the operating room

OBJECTIVE

The objective for this study was to address the lack of information regarding the working conditions in the operating room (OR). Safety issues in the OR need to be discussed not only for the sake of patients, but also for personnel, as hazards may occur for all persons within the OR.

METHODS

To evaluate the workplace conditions in the operating room, a survey was conducted among surgeons working in German hospitals. Sixty questions were asked regarding the personal profile, the architectural situation, the devices and instruments as well as working posture and associated pain.

RESULTS

The survey showed elementary ergonomic deficiencies within all fields. Surgeons stated that these deficiencies lead to potential hazards for patients and personnel, potentially on a frequent basis. 97% of the surveyed surgeons see ergonomic improvement in the operating room as necessary.

CONCLUSION

The survey results display a high potential for improvement within all fields. Therefore, industry, surgeons and their professional organizations are asked to work on the optimization of the workplace conditions in the operating room in terms of improvement of quality and efficiency.

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.

Screen height as an ergonomic factor in laparoscopic surgery

BACKGROUND

The increasing number of routinely performed laparoscopic operations causes the surgeons' "screen work" time to rise constantly. A new ergonomic workload on the surgeons' upper spine and shoulders is created as a result of the standard screen height position on top of the laparoscopy towers.

METHODS

Eight surgeons in the authors' surgical department were evaluated for the inclination/reclination angle of their cervical spine when using the laparoscopy towers in the authors' department and also at their favorable screen height.

RESULTS

The laparoscopy towers used in the authors' department made 3 degrees to 14 degrees reclination of the cervical spine necessary. The interviewed surgeons preferred a position of slight inclination, with a median of 160 cm measured from the central screen height to the floor.

CONCLUSION

Monitors of laparoscopy towers should be adapted to the surgeon's preferred screen height: at eye level frontally with a neutral or slight inclination of the cervical spine. The authors suggest a central screen height of 160 cm, with the monitor positioned in front of the surgeon. Newer equipment from the industry should be provided.

Ergonomic testing of two different types of handles via virtual reality simulation

BACKGROUND

Ergonomics in laparoscopic surgery is an unsolved problem. Deficiencies of the instrument handles are well-known and described in several reports and studies. Today, virtual training modules for laparoscopic surgery are available. The aim of this study was to evaluate the ability of a virtual reality (VR) simulator to determine the ergonomic properties of two different laparoscopic instrument handles.

METHODS

Two different types of handles, a ring and an axial handle from Richard Wolf, were used to perform the short clip and cut task of the Xitact 500 LS simulator. The task was repeated every 2 days for a period of 5 weeks. After every trial the volunteers were asked structured questions about their preferences while using the two handles.

RESULTS

The axial handle was superior or equal to the ring handle in all criteria. Learning curves over the entire time and day by day were similar. No differences were found for travel distances and error rates, but task times were different for both handles. The subjects preferred the axial handle at the end of the study.

CONCLUSION

It is possible to determine differences in ergonomics of handle design with a VR trainer. In this study, the Richard Wolf axial handle was superior to the ring handle.

Monitor position in laparoscopic surgery

BACKGROUND

One of the key problems in laparoscopy is the ergonomic positioning of the monitor. In this study we tested task performance and muscle strain of subjects in relation to monitor position during laparoscopic surgery.

METHODS

Eighteen subjects simulated laparoscopic suturing by threading tiny pearls with a curved needle. This was repeated in three monitor positions (15 min each): frontal at eye level (A), frontal in height of the operating field (B), and 45 degrees to the right side at eye level (C). Subjects were not allowed to turn their heads during these sessions. After the test they were asked for their preferred monitor position. During all tests the electromyographic (EMG) activity of the main neck muscles was recorded and the number of pearls was counted.

RESULTS

The EMG activity was significantly lower for position A compared to positions C and B (p < 0.05). No significant difference was found between positions B and C. The number of threaded pearls as an indicator for task performance was highest for position B. The difference was statistically significant compared to position C (p = 0.0008) but not between positions A and C (p = 0.0508) or A and B (p = 0.0575). When asked for the preferred monitor position, nine subjects chose two monitors in the frontal positions A and B. No subject preferred the monitor at the side position (C).

CONCLUSION

Regarding EMG data, the monitor positioned frontal at eye level is preferable. Reflecting personal preferences of subjects and task performance, it should be of advantage to place two monitors in front of the surgeon: one in position A for lowest neck strain and the other in position B for difficult tasks with optimal task performance. The monitor position at the side is not advisable.

Evaluation of Face-Mounted Binocular Video Display for Laparoscopy: Outcomes of Psychometric Skills Testing and Surgeon Satisfaction

OBJECTIVES

Improved digital video cameras and high-resolution video displays have greatly enhanced laparoscopic surgery. However, the size and distance of the video display and the location of the monitor continue to be impediments in laparoscopy, providing unsatisfactory operative visualization and causing the development of neck and back strain in surgeons performing long procedures. The purpose of this study was to evaluate the use of a face-mounted binocular high-resolution video display by means of standardized measurements of laparoscopic skill, and to compare procedure speed and surgeon satisfaction with the binocular display, open operative visualization, and standard laparoscopic monitor views.

METHODS

The surgical faculty and resident trainees (n = 22) underwent two standardized laparoscopic psychometric skills tests of fine motor control and bimanual operative facility. Testing was performed first with the use of laparoscopic instruments in direct view of the participants; sufficient repetitions were allowed so that plateau levels were obtained in task speed. Video camera-based imaging displayed on the face-mounted binocular video display and a standard video monitor were then used to repeat identical tests. Test times were compared between the open view, face-mounted display (FMD) view, and standard laparoscopic monitor view groups. A Likert-scale based assessment was conducted to examine operator impressions of neck and back strain, visual acuity, and overall satisfaction.

RESULTS

Performance with the standard laparoscopic monitor was significantly slower than with the direct view on both fine motor (mean, 85.0 +/- 7.1 s vs. 56.4 +/- 5.7 s; P <.0001) and bimanual (mean, 80.8 +/- 7.0 s vs. 40.2 +/- 2.6 s; P =.009) psychometric skills tests. The FMD view performance was significantly faster than the standard laparoscopic monitor performance for both the bimanual (mean, 72.2 +/- 7.6 s vs. 85.0 +/- 7.2 s; P =.001) and fine motor (mean, 59.3 +/- 4.7 s vs. 80.8 +/- 7.0 s; P =.004) tests. The scores on a Likert Scale satisfaction survey of the use of the FMD unit for neck and back strain (mean, 4.27 +/- 0.20), visual acuity (mean, 3.93 +/- 0.10), and overall satisfaction (mean, 4.16 +/- 0.20) were high (scale: 1, worst; 5, ideal).

CONCLUSIONS

A face-mounted high-resolution video display unit reduces neck and back strain and improves both visualization and overall satisfaction in comparison with standard laparoscopic display monitors; surgical performance is better than with standard laparoscopic imaging as assessed by standardized psychometric skills testing.