Rolle der intraoperativen Cholangiografie bei der laparoskopischen Cholezystektomie

Nach Einführung der laparoskopischen Cholezystektomie ist die Rolle der früher bei der offenen Cholezystektomie praktisch obligaten intraoperativen Cholangiografie stark relativiert worden. In verschiedenen Untersuchungen und Umfragen wird deutlich, dass die Anwendung der routinemäßigen intraoperativen Cholangiografie heute bei weit unter 10 % der laparoskopischen Cholezystektomien liegt. Im Zeitraum von 1991 - 2000 wurden insgesamt 1.573 Patienten aufgrund einer symptomatischen Cholezystolithiasis laparoskopisch operiert, 1.311 davon mit IOC und 262 ohne IOC (überwiegend unmittelbar nach Einführung der laparoskopischen Operationsmethode.) Die Erhebung der Daten erfolgte retrospektiv. Auf Grund der Auswertung der vorliegenden Daten und der Auswertung der Literatur sollte die IOC nicht nur selektiv, sondern routinemäßig bei jeder laparoskopischen Cholezystektomie durchgeführt werden. Nur in drei Fällen (von 1.573 erfolgten Cholezystektomien) erfolgte eine irrtümliche Durchtrennung des Ductus choledochus. Diese konnte durch die IOC unmittelbar diagnostiziert und entsprechend durch Reanastomosierung behandelt werden. Der oft komplizierte Verlauf nach verschleppter Diagnostik führt häufig zu entzündlichen Komplikationen bis hin zu einzelnen Todesfällen und macht meist die Anlage einer biliodigestiven Anastomose notwendig. Eine erhöhte Operationsmorbidität und eingeschränkt gute Langzeitergebnisse begründen die große Bedeutung der rechtzeitigen Diagnostik und konsequenten Therapie einer Choledochusläsion. Auch bei der akuten Cholezystitis mit oft schwer entzündlich veränderten anatomischen Strukturen, welche die intraoperative Darstellung der Anatomie erheblich erschwert, führt eine routinemäßige IOC ebenfalls zur Reduktion von iatrogenen Verletzungen

Vision Controlled Autonomous Stakebot for Driving Stakes and Its Digital-Twin

In this thesis a novel vision-based AI driven autonomous ‘StakeBot’ is proposed to serve the agricultural 4.0 industries of the future. In recent years supply, demand and production of vegetables that are harvested from plants with weak stems like bell pepper, tomato, eggplant has been significantly up by several fold. With growing demand and new green-house establishments across the country production of vegetables will require a tremendous number of labors which will be hard to supply soon. To overcome the issues in addition to the labor shortages, automation through robotics will be the only viable solution. Plants like bell peppers require support to avoid contamination of the pepper from touching the ground. Thus, a workforce is needed to place these stakes on several acres of land. Alternatively, as adopted in greenhouses across the world, the stakes are placed at a longer distance and rope or wires are tied between them to create continuous support, which makes the plants grow even taller. This is indeed labor-intensive work. To overcome the labor challenges in this thesis, an AI driven robotic solution is proposed that is capable of placing and removing stakes in the ground. With over 210,000 jobs, agribusiness is South Carolina’s No. 1 industry and will be immediately benefited by the proposed solution. The proposed robot is called the StakeBot. The StakeBot is an autonomous self-driving robot which meets the requirements provided by the local farmers from South Carolina. The uniqueness of the StakeBot is its self-driving capabilities which are made possible with a newly developed vision system capable of successfully driving the StakeBot. This vision system utilizes Stereo depth technology paired with the capability of modern Linux based single board computers. This grants the StakeBot the ability to “see” making it capable of avoiding obstacles and making decisions on how to proceed based on the environment. The StakeBot’s vision system is not unique to the StakeBot alone. The developed algorithms can be intergraded for any robotic system that is designed for navigating through its environment. The vision system has shown great success with an average of about 15 FPS, capable of fast response times for vehicles moving at speeds less than 7 MPH

Studies on germ cells. IV. Protoplasmic differentiation in the oocytes of certain Hymenoptera

No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50238/1/1050260304_ftp.pd

Surface structure and frictional properties of the skin of the Amazon tree boa Corallus hortulanus (Squamata, Boidae)

The legless locomotion of snakes requires specific adaptations of their ventral scales to maintain friction force in different directions. The skin microornamentation of the snake Corallus hortulanus was studied by means of scanning electron microscopy and the friction properties of the skin were tested on substrates of different roughness. Skin samples from various parts of the body (dorsal, lateral, ventral) were compared. Dorsal and lateral scales showed similar, net-like microornamentation and similar friction coefficients. Average friction coefficients for dorsal and lateral scales on the epoxy resin surfaces were 0.331 and 0.323, respectively. In contrast, ventral scales possess ridges running parallel to the longitudinal body axis. They demonstrated a significantly lower friction coefficient compared to both dorsal and lateral scales (0.191 on average). In addition, ventral scales showed frictional anisotropy comparing longitudinal and perpendicular direction of the ridges. This study clearly demonstrates that different skin microstructure is responsible for different frictional properties in different body regions