Beerenobstanbau - Entwicklung wirtschaftlicher Anbauverfahren von Beerenobst mit Überdachung

Hauptkultur im sächsischen Erwerbsobstbau ist der Apfel. Die Weltapfelproduktion wird weiter zunehmen. Im Gegensatz dazu bleibt der Apfelkonsum eher stabil. Dies führt in der Zukunft zu noch größerem Konkurrenzkampf auf den Absatzmärkten. Aus diesem Grund wurde im Rahmen des Projektes „Entwicklung wirtschaftlicher Anbauverfahren von Beerenobst mit Überdachung“ nach wirtschaftlichen Anbauverfahren mit anderen Obstarten zur Ergänzung der Apfelproduktion gesucht. Zu diesem Zweck erfolgte im Obstgut Jentzsch in Bosewitz die Pflanzung einer 1 ha gro-ßen Beerenobstanlage. Ziel war die Produktion von Beerenobst für die Frischmarktbelieferung mit optimaler Fruchtqualität, die Erprobung neuer Sorten, die Optimierung von Erziehung und Schnitt sowie die Prüfung der Wirtschaftlichkeit einer Überdachung unter den Anbaubedingungen in Sach-sen

A System-on-Chip solution for a low power active capsule endoscope with therapeutic capabilities for clip application in the gastrointestinal tract

This paper addresses the circuit implementation challenges resulting from the integration of a therapeutic clip in a magnetically maneuverable wireless capsule intended for colonoscopy. To deal with the size constraints typical of a capsule endoscope, an Application Specific Integrated Circuit (ASIC) has been designed specifically to habilitate the release of the therapeutic clip. The ASIC is a complete System on Chip (SoC) that incorporates a circuit for the low power release of the clip, thus overcoming the limitations of the power supply system. With a size of 14mm2, the ASIC can be incorporated in practically any capsule endoscope, consuming only an idle-state power of 1.5mW

Optical communications through tissue

In capsule endoscopy, the wireless data transmission technologies currently employed suffer from high path loss, heavily impacting on the capsule power budget. Optical data transmission shows, in principle, scope to overcome this limitation, at least in selected tissues. Bench testing technologies, and Monte Carlo simulations on the impact of light scattering on carrier frequency, will be presented and discussed

Frontiers of robotic endoscopic capsules: a review

Digestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd., is an example of disruptive technology and represents an attractive alternative to traditional diagnostic techniques. WCE overcomes conventional endoscopy enabling inspection of the digestive system without discomfort or the need for sedation. Thus, it has the advantage of encouraging patients to undergo gastrointestinal (GI) tract examinations and of facilitating mass screening programmes. With the integration of further capabilities based on microrobotics, e.g. active locomotion and embedded therapeutic modules, WCE could become the key-technology for GI diagnosis and treatment. This review presents a research update on WCE and describes the state-of-the-art of current endoscopic devices with a focus on research-oriented robotic capsule endoscopes enabled by microsystem technologies. The article also presents a visionary perspective on WCE potential for screening, diagnostic and therapeutic endoscopic procedures

Wireless tissue palpation: Head characterization to improve tumor detection in soft tissue

For surgeons performing open procedures, the sense of touch is a valuable tool to directly access buried structures and organs, to identify their margins, detect tumors, and prevent undesired cuts. Minimally invasive surgical procedures provide great benefits for patients; however, they hinder the surgeon's ability to directly manipulate the tissue. In our previous work, we developed a Wireless Palpation Probe (WPP) to restore tissue palpation in Minimally Invasive Surgery (MIS) by creating a real-time stiffness distribution map of the target tissue. The WPP takes advantage of a field-based magnetic localization algorithm to measure its position, orientation, and tissue indentation depth, in addition to a barometric sensor measuring indentation tissue pressure. However, deformations of both the tissue and the silicone material used to cover the pressure sensors introduce detrimental nonlinearities in sensor measurements. In this work, we calibrated and characterized different diameter WPP heads with a new design allowing exchangeability and disposability of the probe head. Benchtop trials showed that this method can effectively reduce error in sensor pressure measurements up to 5% with respect to the reference sensor. Furthermore, we studied the effect of the head diameter on the device's spatial resolution in detecting tumor simulators embedded into silicone phantoms. Overall, the results showed a tumor detection rate over 90%, independent of the head diameter, when an indentation depth of 5 mm is applied on the tissue simulator

FPGA-based High-Performance Collision Detection: An Enabling Technique for Image-Guided Robotic Surgery

Collision detection, which refers to the computational problem of finding the relative placement or con-figuration of two or more objects, is an essential component of many applications in computer graphics and robotics. In image-guided robotic surgery, real-time collision detection is critical for preserving healthy anatomical structures during the surgical procedure. However, the computational complexity of the problem usually results in algorithms that operate at low speed. In this paper, we present a fast and accurate algorithm for collision detection between Oriented-Bounding-Boxes (OBBs) that is suitable for real-time implementation. Our proposed Sweep and Prune algorithm can perform a preliminary filtering to reduce the number of objects that need to be tested by the classical Separating Axis Test algorithm, while the OBB pairs of interest are preserved. These OBB pairs are re-checked by the Separating Axis Test algorithm to obtain accurate overlapping status between them. To accelerate the execution, our Sweep and Prune algorithm is tailor-made for the proposed method. Meanwhile, a high performance scalable hardware architecture is proposed by analyzing the intrinsic parallelism of our algorithm, and is implemented on FPGA platform. Results show that our hardware design on the FPGA platform can achieve around 8X higher running speed than the software design on a CPU platform. As a result, the proposed algorithm can achieve a collision frame rate of 1 KHz, and fulfill the requirement for the medical surgery scenario of Robot Assisted Laparoscopy.published_or_final_versio

DATA CENTER CONDENSER OPTIMIZATION: A DISCRETIZED MODELLING APPROACH TO IMPROVE PUMPED TWO-PHASE COOLING CYCLES

Rising interest in high-performance servers in data centers to support the increasing demands for cloud-computing and storage have challenged thermal management systems. To prevent these increased power density servers from overheating due to the high heat fluxes dissipated, new cooling methods have continued to be investigated in recent years. One such solution is pumped two-phase cooling which shows promise over traditional air cooling due to the reduced power consumption it requires to operate, while also being able to dissipate large amounts of heat from the small components in servers.      Although pumped two-phase systems as a cooling strategy have existed for multiple decades, sub-optimal component design have hindered the potential efficiencies achievable. This is especially prevalent in the condenser where, in order to meet required metrics, these heat exchangers are commonly oversized due to maldistribution at low vapor qualities and a lack of understanding about the condensation behavior within certain geometries. Through the work presented in this thesis, the capabilities of an air-cooled microchannel condenser model are explored for future use in optimization studies for data center applications. To perform this research, an investigation into the boundary conditions of these systems and common condenser modeling strategies were carried out. Using this knowledge, a flexible discretized condenser model was developed to capture the behavior of pumped two-phase cooling in data centers under a wide range of operating conditions. In conjunction, an experimental test setup was sized, designed, and constructed to provide validation for the model. Then, using the model, some initial parametric studies were conducted to identify the sensitivity effects of various parameters on overall condenser performance. In this initial study, some favored boundary conditions and geometries were found that both minimize refrigerant pressure drops and maximize heat transfer. For an air-cooled condenser operating with R1234ze(E), these include: refrigerant entering the condenser around 40% quality, operating at moderate refrigerant mass fluxes through the channels (130 - 460 kg/m^2-s), and designing microchannel condenser tubes with many tightly packed square ports. Continued investigation into the contributing parameters of weight in the future using the tools developed in this thesis will lead to further optimized condenser designs and operating conditions.</p

Beerenobstanbau - Entwicklung wirtschaftlicher Anbauverfahren von Beerenobst mit Überdachung

Hauptkultur im sächsischen Erwerbsobstbau ist der Apfel. Die Weltapfelproduktion wird weiter zunehmen. Im Gegensatz dazu bleibt der Apfelkonsum eher stabil. Dies führt in der Zukunft zu noch größerem Konkurrenzkampf auf den Absatzmärkten. Aus diesem Grund wurde im Rahmen des Projektes „Entwicklung wirtschaftlicher Anbauverfahren von Beerenobst mit Überdachung“ nach wirtschaftlichen Anbauverfahren mit anderen Obstarten zur Ergänzung der Apfelproduktion gesucht. Zu diesem Zweck erfolgte im Obstgut Jentzsch in Bosewitz die Pflanzung einer 1 ha gro-ßen Beerenobstanlage. Ziel war die Produktion von Beerenobst für die Frischmarktbelieferung mit optimaler Fruchtqualität, die Erprobung neuer Sorten, die Optimierung von Erziehung und Schnitt sowie die Prüfung der Wirtschaftlichkeit einer Überdachung unter den Anbaubedingungen in Sach-sen