A MUCH debated question is whether sex differences exist in the functional organization of the brain for language1–4. A long-held hypothesis posits that language functions are more likely to be highly lateralized in males and to be represented in both cerebral hemispheres in females5,6, but attempts to demonstrate this have been inconclusive7–17. Here we use echo-planar functional magnetic resonance imaging18–21 to study 38 right-handed subjects (19 males and 19 females) during orthographic (letter recognition), phonological (rhyme) and semantic (semantic category) tasks. During phonological tasks, brain activation in males is lateralized to the left inferior frontal gyrus regions; in females the pattern of activation is very different, engaging more diffuse neural systems that involve both the left and right inferior frontal gyrus. Our data provide clear evidence for a sex difference in the functional organization of the brain for language and indicate that these variations exist at the level of phonological processing.

Sex differences in the functional organization of the brain for language

Augmented reality applications in design and manufacturing

BACKGROUND: Surgeons are increasingly being scrutinized for their performance and there is growing interest in objective assessment of technical skills. The purpose of this study was to review all evidence for these methods, in order to provide a guideline for use in clinical practice. METHODS: A systematic search was performed using PubMed and Web of Science for studies addressing the validity and reliability of methods for objective skills assessment within surgery and gynaecology only. The studies were assessed according to the Oxford Centre for Evidence-based Medicine levels of evidence. RESULTS: In total 104 studies were included, of which 20 (19.2 per cent) had a level of evidence 1b or 2b. In 28 studies (26.9 per cent), the assessment method was used in the operating room. Virtual reality simulators and Objective Structured Assessment of Technical Skills (OSATS) have been studied most. Although OSATS is seen as the standard for skills assessment, only seven studies, with a low level of evidence, addressed its use in the operating room. CONCLUSION: Based on currently available evidence, most methods of skills assessment are valid for feedback or measuring progress of training, but few can be used for examination or credentialing. The purpose of the assessment determines the choice of method.

Objective assessment of technical surgical skills

Assessment of the cerebral cortex during motor task behaviours in adults: a systematic review of functional near infrared spectroscopy (fNIRS) studies.

Minimally invasive surgery represents one of the main evolutions of surgical techniques aimed at providing a greater benefit to the patient. However, minimally invasive surgery increases the operative difficulty since the depth perception is usually dramatically reduced, the field of view is limited and the sense of touch is transmitted by an instrument. However, these drawbacks can currently be reduced by computer technology guiding the surgical gesture. Indeed, from a patient’s medical image (US, CT or MRI), Augmented Reality (AR) can increase the surgeon’s intra-operative vision by providing a virtual transparency of the patient. AR is based on two main processes: the 3D visualization of the anatomical or pathological structures appearing in the medical image, and the registration of this visualization on the real patient. 3D visualization can be performed directly from the medical image without the need for a pre-processing step thanks to volume rendering. But better results are obtained with surface rendering after organ and pathology delineations and 3D modelling. Registration can be performed interactively or automatically. Several interactive systems have been developed and applied to humans, demonstrating the benefit of AR in surgical oncology. It also shows the current limited interactivity due to soft organ movements and interaction between surgeon instruments and organs. If the current automatic AR systems show the feasibility of such system, it is still relying on specific and expensive equipment which is not available in clinical routine. Moreover, they are not robust enough due to the high complexity of developing a real-time registration taking organ deformation and human movement into account. However, the latest results of automatic AR systems are extremely encouraging and show that it will become a standard requirement for future computer-assisted surgical oncology. In this article, we will explain the concept of AR and its principles. Then, we will review the existing interactive and automatic AR systems in digestive surgical oncology, highlighting their benefits and limitations. Finally, we will discuss the future evolutions and the issues that still have to be tackled so that this technology can be seamlessly integrated in the operating room.

Augmented reality in laparoscopic surgical oncology.

Background
This study was carried out to investigate whether eye-hand coordination skill on a virtual reality laparoscopic surgical simulator (the LAP Mentor) was able to differentiate among subjects with different laparoscopic experience and thus confirm its construct validity.

Construct validity for eye–hand coordination skill on a virtual reality laparoscopic surgical simulator

This paper suggests an ultrasound guided needle insertion instrument which can track target motion in real-time. Under traditional ultrasound guided needle insertion therapies, surgeons have had much burden to find out the precise targeting position, particularly when the organ is moving due to the respiration or heartbeat. We developed a new needle insertion instrument which can track moving target based on visual servo control. In addition, this paper proposed a tumor specific active contour model which can conduct a fast and robust segmentation for tumor, and utilized Hough transform for needle recognition. In the experiment, the proposed system could track a moving phantom successfully at speed of 3 frames/sec processing.

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A Motion Adaptable Needle Placement Instrument Based on Tumor Specific Ultrasonic Image Segmentation

Laparoscopic suturing skills are important for advanced laparoscopic surgery. However, objective assessment of these skills has not yet been established. The aim of this study was to assess the laparoscopic suturing skills of novice and experienced surgeons using an electromagnetic motion-tracking system. A total of 18 surgeons, who were all right-handed, were divided into the following two groups according to their experience as an operator in laparoscopic surgery: 9 novice surgeons (fewer than 10 laparoscopic procedures) and 9 experienced surgeons (more than 50 laparoscopic procedures). The subjects performed an intracorporeal suturing task in an inanimate box laparoscopic trainer while the movements of their forceps were evaluated using an electromagnetic motion-tracking system. Their laparoscopic skills were assessed on the basis of the time, path length, and average speed of the forceps in each hand. Experienced surgeons completed the suturing task significantly faster than novice surgeons did. The left path length was significantly shorter for experienced surgeons than for novice surgeons, whereas the right path lengths did not differ. The right average speed of knot tying was significantly faster for experienced surgeons than for novice surgeons, whereas the left average speeds did not differ. Evaluation of psychomotor skills in laparoscopic suturing using an electromagnetic motion-tracking system revealed better results for experienced surgeons than for novice surgeons in terms of the time taken, left path length, and right speed of knot-tying. Furthermore, surgical proficiency due to experience can affect surgical dexterity of each hand differently. The present study also demonstrates the efficacy of this system for objective evaluation of laparoscopic suturing skills.

Objective assessment of laparoscopic suturing skills using a motion-tracking system

Objectives In laparoscopic liver surgery, intraoperative navigation is strongly recommended. We developed a navigation system based on intraoperative ultrasound (IOUS). The purpose of this study was to evaluate the usefulness and accuracy of this system using an animate model.

A real-time navigation system for laparoscopic surgery based on three-dimensional ultrasound using magneto-optic hybrid tracking configuration

BACKGROUND/AIMS Laparoscopic splenectomy is now increasingly being performed. However, controversy remains regarding the effectiveness of a laparoscopic splenectomy for patients with portal hypertension. METHODOLOGY Seventy-three patients with portal hypertension who underwent a laparoscopic splenectomy from February 1992 until October 2000 were reviewed and the effectiveness of the procedures for portal hypertension was evaluated. Forty-two patients had esophagogastric varices and twenty had a concomitant hepatocellular carcinoma. The indications for surgery were bleeding tendency due to thrombocytopenia (n = 40), difficulty in receiving treatment for hepatocellular carcinoma due to thrombocytopenia (n = 18), and sclerotherapy-resistant esophagogastric varices (n = 15). RESULTS A laparoscopic splenectomy was successfully performed in all the patients. The rate of conversion to conventional open surgery was 9.6% (7/73). The mean operative time was 210.1 +/- 101.9 minutes, and the estimated blood loss was 374.7 +/- 352.4 mL. There were no cases of mortality, and morbidity was encountered in 11.0% of patients. The increase in the platelet count correlated significantly to the spleen weight (P < 0.001). The platelet count had been maintained at over 10 x 10(4)/mm3 for over three years. Eighteen patients with hepatocellular carcinoma successfully underwent treatment for hepatocellular carcinoma after surgery and no recurrence of esophagogastric varices was encountered. CONCLUSIONS A laparoscopic splenectomy resulted in the successful secondary treatment of hepatocellular carcinoma and esophagogastric varices. Portal hypertension was not a contraindication. A laparoscopic approach is therefore the procedure of choice for a splenectomy in portal hypertension.

Kozo Konishi

Papers

Construct validity for eye–hand coordination skill on a virtual reality laparoscopic surgical simulator

A Motion Adaptable Needle Placement Instrument Based on Tumor Specific Ultrasonic Image Segmentation

Objective assessment of laparoscopic suturing skills using a motion-tracking system

A real-time navigation system for laparoscopic surgery based on three-dimensional ultrasound using magneto-optic hybrid tracking configuration

Laparoscopic splenectomy for portal hypertension.