Comanipulation Série Dextre pour la chirurgie Mini Invasive

A minimally invasive surgery, which typically involves endoscopic camera and laparoscopic instruments, may seem to be the ideal surgical procedure for its apparent benefits. However, in comparison to open surgeries, the spatial and mechanical tool limitations posed on surgeons are so high that often MIS is foregone for complex cases and even when it is possible, the procedure requires a high dexterity, caliber and experience from the surgeon. This research was motivated by the need for dexterous surgical instruments that offer an intuitive control and an ergonomic interface, with the final objective of developing a suitable robotic hand-held surgical device for laparoscopic interventions. The research was based on comparative evaluation of different interfaces, control modes and kinematics, using a virtual reality simulator, developed specially for this purpose. The results show that: 1. The optimal interface has a WYSIWYD (what you see is what you do) control mode and is finger-operated. 2. The optimal distal motorized mobilities of the end-effector produce two independent DOF for exion and rotation of the end-effector which are sufficient for complex MIS gestures. 3. Adding a free articulation to the instrument's handle allows the surgeon to have an ergonomic posture. 4. An active trocar makes the rotation of the shaft with a free joint possible. This research also resulted in the development of a proof-of-concept prototype. The prototype was tested successfully, in vitro and in vivo on a porcine model.Une chirurgie minimalement invasive (CMI), qui implique généralement une caméra endoscopique et des instruments de laparoscopie, peut sembler être la procédure chirurgicale idéale pour ses avantages apparents. Toutefois, en comparaison à la chirurgie ouverte, les limites spatiales et outils mécaniques posés sur les chirurgiens sont si élevés que, souvent, la CMI est abandonné pour des cas complexes et même quand elle est possible, la procédure nécessite une grande dextérité, calibre et expérience du chirurgien. Cette recherche a été motivée par la nécessité d'habiles instruments chirurgicaux qui offrent un contrôle intuitif et une interface ergonomique, avec l'objectif final de développer un instrument robotisé adapté aux interventions par laparoscopie. La recherche a été basée sur l'évaluation comparative des différentes interfaces, modes de contrôle et cinématiques, en utilisant un simulateur de réalité virtuelle, développée spécialement à cet effet. Les résultats montrent que: 1. l'interface optimale a un mode de contrôle WYSIWYD (ce que vous voyez est ce que vous faites) et est exploité par les doigt. 2. les mobilités distales motorisées de l'effecteur doivent produire deux degrés de liberté (DDL) indépendants pour la flexion et la rotation de l'effecteur. Ce qui est suffisant pour des gestes SIG complexes. 3. ajouter une libre articulation à la poignée de l'instrument permet au chirurgien d'avoir une posture ergonomique. 4. un trocart actif permettrait la rotation de l'arbre de l'instrument avec un joint libre. Cette recherche a également permis le développement d'un prototype de validation de concept. Le prototype a été testé avec succès, in vitro et in vivo sur un modèle porcin

Anergy and the human skin immune system

An initial study comparing cytokine gene expression in the skin of control vs. anergic patients lacking delayed type hypersensitivity reactivity revealed no difference; but disclosed an apparent absence of detectable CD3+ T cells in the skin of anergic individuals. To assess its significance for anergy, an investigation of the role of skin T cells in DTH-reactive healthy individuals was undertaken. To do so, the phenotypic and functional characteristics of T cells isolated from skin and blood were compared. Analysis by flow cytometry has shown that 74% of skin T cells expressed cell surface HLADR, 66% were positive for the IL-2 receptor CD25, and less than 43% have displayed the VLA integrin $alpha$4 chain as compared to 28%, 7%, 79% for peripheral blood mononuclear cells respectively. The expression of a cutaneous lymphocyte antigen (CLA) was 61% in the former and 14% in the latter. Functionally, skin T cells failed to proliferate in response to all ligands including IL-2, anti-CD3, lectins and phorbol esters with ionomycin, as well as showed a reduced Ca++ flux to phytohemagglutinin. Skin tissue co-cultured with autochtonous PBL could inhibit its proliferative reaction. Despite their ability to proliferate, lymphocytes from skin were shown to be able to produce IFN$gamma$ in response to PHA+IL-12 as well as anti-CD3+IL-2. Inhibition by anti-cytokine mAbs revealed that in both instances IL-12 was obligatory for this production. In an additional study it was established that a hitherto uncharacterized subset of T cells in blood which could secrete IFN$gamma$ consisted of CLA+ cells. This observation established a functional link between these CLA+ skin-seeking T cells and the CLA+ T cells in skin.A major difference between IFN$gamma$-producing cells from blood and skin was found to be the tempo of synthesis: whereas, PBMC was first detected to contain IFN$gamma$ 42 hours following activation, lasting for days, skin cells were positive after 2.5 hrs of activation, (or 16x faster) for a duration of only 90 minutes. These kinetics were confirmed using intact skin in culture. Experiments designed to reveal the mechanism of this fast action have shown that mRNA for IFN$gamma$ is present in unstimulated isolated skin T cells as well as in intact skin, but not in PBMC, and its presence may be attributed to ongoing constitutive transcription. Activation of skin T cells, which has been shown to elicit prompt translation in IFN$gamma$ synthesis has also been shown, at the same time, to terminate IFN$gamma$ gene transcription in an apparently selective manner. Accordingly, it can be seen that the amount of IFN$gamma$ synthesized in skin and the duration of its synthesis is preprogrammed. This mode of regulation may be unique to the skin, and unique for IFN$gamma.$The results presented are interpreted to indicate that r cells present in human skin may play an essential role in the DTH response, and provide evidence for "peripheral sensitization", or lymphocyte activation outside organized lymphoid tissue. Because of its speed, it may represent the antigen-specific component of a first line cutaneous host defence system. The absence of such T cells in the skin of anergic patients may indeed be responsible for a lack of DTH reactivity, and its clinical consequences

Dexterous Serial Comanipulation for Minimally Invasive Surgery

Une chirurgie minimalement invasive (CMI), qui implique généralement une caméra endoscopique et des instruments de laparoscopie, peut sembler être la procédure chirurgicale idéale pour ses avantages apparents. Toutefois, en comparaison à la chirurgie ouverte, les limites spatiales et outils mécaniques posés sur les chirurgiens sont si élevés que, souvent, la CMI est abandonné pour des cas complexes et même quand elle est possible, la procédure nécessite une grande dextérité, calibre et expérience du chirurgien. Cette recherche a été motivée par la nécessité d'habiles instruments chirurgicaux qui offrent un contrôle intuitif et une interface ergonomique, avec l'objectif final de développer un instrument robotisé adapté aux interventions par laparoscopie. La recherche a été basée sur l'évaluation comparative des différentes interfaces, modes de contrôle et cinématiques, en utilisant un simulateur de réalité virtuelle, développée spécialement à cet effet. Les résultats montrent que: 1. l'interface optimale a un mode de contrôle WYSIWYD (ce que vous voyez est ce que vous faites) et est exploité par les doigt. 2. les mobilités distales motorisées de l'effecteur doivent produire deux degrés de liberté (DDL) indépendants pour la flexion et la rotation de l'effecteur. Ce qui est suffisant pour des gestes SIG complexes. 3. ajouter une libre articulation à la poignée de l instrument permet au chirurgien d'avoir une posture ergonomique. 4. un trocart actif permettrait la rotation de l'arbre de l instrument avec un joint libre. Cette recherche a également permis le développement d'un prototype de validation de concept. Le prototype a été testé avec succès, in vitro et in vivo sur un modèle porcin.A minimally invasive surgery, which typically involves endoscopic camera and laparoscopic instruments, may seem to be the ideal surgical procedure for its apparent benefits. However, in comparison to open surgeries, the spatial and mechanical tool limitations posed on surgeons are so high that often MIS is foregone for complex cases and even when it is possible, the procedure requires a high dexterity, caliber and experience from the surgeon. This research was motivated by the need for dexterous surgical instruments that offer an intuitive control and an ergonomic interface, with the final objective of developing a suitable robotic hand-held surgical device for laparoscopic interventions. The research was based on comparative evaluation of different interfaces, control modes and kinematics, using a virtual reality simulator, developed specially for this purpose. The results show that: 1. The optimal interface has a WYSIWYD (what you see is what you do) control mode and is finger-operated. 2. The optimal distal motorized mobilities of the end-effector produce two independent DOF for exion and rotation of the end-effector which are sufficient for complex MIS gestures. 3. Adding a free articulation to the instrument's handle allows the surgeon to have an ergonomic posture. 4. An active trocar makes the rotation of the shaft with a free joint possible. This research also resulted in the development of a proof-of-concept prototype. The prototype was tested successfully, in vitro and in vivo on a porcine model.PARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

‍‍‍Correlation of Pinch and Grip Strength with median nerve conduction velocity (NCV) in Women Referred to Electrodiagnostic Center

Introduction: Human hand is a complex and fine structure whose function and strength can be affected by even a mild injury. Hand dynamometry is one of the most accepted methods for evaluating the integrity of hand function. Nerve conduction velocity (NCV) is a noninvasive procedure to ensure neuromuscular integrity of the hand. Materials and Methods: In a cross-sectional study, 39 women with an age ranging from 30 to 60 years who attended the Vahid Electrodiagnostic Center (Isfahan-Iran) during the fall of 2009 were studied. Informed consent was signed by all subjects. All participants were asked to perform grip and all types of pinch grip with a dynamometer. Nerve conduction velocity was conducted for both hands. All data obtained from the dynamometer and NCV were statistically analyzed via Pearson correlation test using SPSS software version16. Results: There were significant differences between sensory and motor NCV of median nerve for Pinch strength (maximum correlation was noted for Motor NCV with Palmar Pinch1, P < 0.001, r = 0.379) versus Grip strength (maximum correlation was with Motor NCV, P < 0.002, r = 0.342). There were significant differences between Median Severity Scale for different types of Pinch strength (max correlation with Palmar Pinch1, P < 0.001, r = -0.613), different types of Grip strength (P < 0.001, r = -0.563) and NCV (max correlation with Sensory NCV, P < 0.001, r = -0.562) Conclusion: Dynamometer may be a prognostic tool to determine the amount of median nerve involvement since it measures the strength of thenar musculature. Also Median Severity Scale is a good clinical means to prognosticate median sensory and motor NCV. Keywords: Pinch strength, Grip strength, Nerve conduction velocity, Dynamomete

Covariance tracking: architecture optimizations for embedded systems

International audienceCovariance matching techniques have recently grown in interest due to their good performances for object retrieval, detection, and tracking. By mixing color and texture information in a compact representation, it can be applied to various kinds of objects (textured or not, rigid or not). Unfortunately, the original version requires heavy computations and is difficult to execute in real time on embedded systems. This article presents a review on different versions of the algorithm and its various applications; our aim is to describe the most crucial challenges and particularities that appeared when implementing and optimizing the covariance matching algorithm on a variety of desktop processors and on low-power processors suitable for embedded systems. An application of texture classification is used to compare different versions of the region descriptor. Then a comprehensive study is made to reach a higher level of performance on multi-core CPU architectures by comparing different ways to structure the information, using single instruction, multiple data (SIMD) instructions and advanced loop transformations. The execution time is reduced significantly on two dual-core CPU architectures for embedded computing: ARM Cortex-A9 and Cortex-A15 and Intel Penryn-M U9300 and Haswell-M 4650U. According to our experiments on covariance tracking, it is possible to reach a speedup greater than ×2 on both ARM and Intel architectures, when compared to the original algorithm, leading to real-time execution

Analysis of asymmetry of the forces applied on the lower limb in subjects with nonspecific chronic low back pain

Objective. Several studies have investigated asymmetry and loading patterns in different spine pathologies, motor disorders, and other conditions; there is a lack of knowledge on these aspects in chronic low back pain (CLBP). The aim of this study was to analyse asymmetry and loading patterns in patients with nonspecific chronic low back pain (NCLBP) compared to normal individuals, during walking. Method. Forty participants (20 healthy subjects and 20 patients with NCLBP) participated in the study. Asymmetry of the force was measured based on the Asymmetry Index (ASI). The difference in the mean values of all data between the two groups was examined using the independent t-test. Results. The mean value of the first peak of ground reaction force of normal subjects was 1.02 ± 0.0354 N/BW compared to 1.038 ± 0.099 N/BW in NCLBP patients ( = 0.25) and 0.1004 ± 0.036 N/BW mediolateral force applied on the leg in normal subjects compared to 0.089 ± 0.022 N/BW in NCLBP patients ( = 0.214). The Asymmetry Index (ASI) of the first peak of vertical force was 2.59% ± 1.89% and 3.88% ± 2.94% for NCLBP and normal subjects, respectively, P = 0.2. Conclusion. Therefore, it can be concluded that NCLBP subjects follow avoidance-endurance model without any limitation during walking

Toward the Development of a Hand-Held Surgical Robot for Laparoscopy

Minimally invasive surgery (MIS), which typically involves endoscopic camera and laparoscopic instruments may seem to be the ideal surgical procedure for its apparent benefits. However, in comparison to open surgeries, the spatial and mechanical tool limitations posed on surgeons are so high that often MIS is foregone for complex cases and even when it is possible, the procedure requires a high dexterity, caliber, and experience from the surgeon. Particularly, suturing procedure through MIS is known to be extremely challenging. We are working toward the development of a robotic hand-held surgical device for laparoscopic interventions that enhances the surgeons' dexterity. The instrument produces two independent DOFs, which is sufficient for enabling MIS suturing procedure in vivo. The end-effector's orientation is controlled by an intuitive and ergonomic controller and its position is controlled directly by the surgeon. Different control modes, handles, and end-effector kinematics are primarily evaluated using a virtual reality simulator before choosing the best combination. A proof-of-concept prototype of the device has been developed