Interfaces for Modular Surgical Planning and Assistance Systems

Modern surgery of the 21st century relies in many aspects on computers or, in a wider sense, digital data processing. Department administration, OR scheduling, billing, and - with increasing pervasion - patient data management are performed with the aid of so called Surgical Information Systems (SIS) or, more general, Hospital Information Systems (HIS). Computer Assisted Surgery (CAS) summarizes techniques which assist a surgeon in the preparation and conduction of surgical interventions. Today still predominantly based on radiology images, these techniques include the preoperative determination of an optimal surgical strategy and intraoperative systems which aim at increasing the accuracy of surgical manipulations. CAS is a relatively young field of computer science. One of the unsolved "teething troubles" of CAS is the absence of technical standards for the interconnectivity of CAS system. Current CAS systems are usually "islands of information" with no connection to other devices within the operating room or hospital-wide information systems. Several workshop reports and individual publications point out that this situation leads to ergonomic, logistic, and economic limitations in hospital work. Perioperative processes are prolonged by the manual installation and configuration of an increasing amount of technical devices. Intraoperatively, a large amount of the surgeons'' attention is absorbed by the requirement to monitor and operate systems. The need for open infrastructures which enable the integration of CAS devices from different vendors in order to exchange information as well as commands among these devices through a network has been identified by numerous experts with backgrounds in medicine as well as engineering. This thesis contains two approaches to the integration of CAS systems: - For perioperative data exchange, the specification of new data structures as an amendment to the existing DICOM standard for radiology image management is presented. The extension of DICOM towards surgical application allows for the seamless integration of surgical planning and reporting systems into DICOM-based Picture Archiving and Communication Systems (PACS) as they are installed in most hospitals for the exchange and long-term archival of patient images and image-related patient data. - For the integration of intraoperatively used CAS devices, such as, e.g., navigation systems, video image sources, or biosensors, the concept of a surgical middleware is presented. A c++ class library, the TiCoLi, is presented which facilitates the configuration of ad-hoc networks among the modules of a distributed CAS system as well as the exchange of data streams, singular data objects, and commands between these modules. The TiCoLi is the first software library for a surgical field of application to implement all of these services. To demonstrate the suitability of the presented specifications and their implementation, two modular CAS applications are presented which utilize the proposed DICOM extensions for perioperative exchange of surgical planning data as well as the TiCoLi for establishing an intraoperative network of autonomous, yet not independent, CAS modules.Die moderne Hochleistungschirurgie des 21. Jahrhunderts ist auf vielerlei Weise abhängig von Computern oder, im weiteren Sinne, der digitalen Datenverarbeitung. Administrative Abläufe, wie die Erstellung von Nutzungsplänen für die verfügbaren technischen, räumlichen und personellen Ressourcen, die Rechnungsstellung und - in zunehmendem Maße - die Verwaltung und Archivierung von Patientendaten werden mit Hilfe von digitalen Informationssystemen rationell und effizient durchgeführt. Innerhalb der Krankenhausinformationssysteme (KIS, oder englisch HIS) stehen für die speziellen Bedürfnisse der einzelnen Fachabteilungen oft spezifische Informationssysteme zur Verfügung. Chirurgieinformationssysteme (CIS, oder englisch SIS) decken hierbei vor allen Dingen die Bereiche Operationsplanung sowie Materialwirtschaft für spezifisch chirurgische Verbrauchsmaterialien ab. Während die genannten HIS und SIS vornehmlich der Optimierung administrativer Aufgaben dienen, stehen die Systeme der Computerassistierten Chirugie (CAS) wesentlich direkter im Dienste der eigentlichen chirugischen Behandlungsplanung und Therapie. Die CAS verwendet Methoden der Robotik, digitalen Bild- und Signalverarbeitung, künstlichen Intelligenz, numerischen Simulation, um nur einige zu nennen, zur patientenspezifischen Behandlungsplanung und zur intraoperativen Unterstützung des OP-Teams, allen voran des Chirurgen. Vor allen Dingen Fortschritte in der räumlichen Verfolgung von Werkzeugen und Patienten ("Tracking"), die Verfügbarkeit dreidimensionaler radiologischer Aufnahmen (CT, MRT, ...) und der Einsatz verschiedener Robotersysteme haben in den vergangenen Jahrzehnten den Einzug des Computers in den Operationssaal - medienwirksam - ermöglicht. Weniger prominent, jedoch keinesfalls von untergeordnetem praktischen Nutzen, sind Beispiele zur automatisierten Überwachung klinischer Messwerte, wie etwa Blutdruck oder Sauerstoffsättigung. Im Gegensatz zu den meist hochgradig verteilten und gut miteinander verwobenen Informationssystemen für die Krankenhausadministration und Patientendatenverwaltung, sind die Systeme der CAS heutzutage meist wenig oder überhaupt nicht miteinander und mit Hintergrundsdatenspeichern vernetzt. Eine Reihe wissenschaftlicher Publikationen und interdisziplinärer Workshops hat sich in den vergangen ein bis zwei Jahrzehnten mit den Problemen des Alltagseinsatzes von CAS Systemen befasst. Mit steigender Intensität wurde hierbei auf den Mangel an infrastrukturiellen Grundlagen für die Vernetzung intraoperativ eingesetzter CAS Systeme miteinander und mit den perioperativ eingesetzten Planungs-, Dokumentations- und Archivierungssystemen hingewiesen. Die sich daraus ergebenden negativen Einflüsse auf die Effizienz perioperativer Abläufe - jedes Gerät muss manuell in Betrieb genommen und mit den spezifischen Daten des nächsten Patienten gefüttert werden - sowie die zunehmende Aufmerksamkeit, welche der Operateur und sein Team auf die Überwachung und dem Betrieb der einzelnen Geräte verwenden muss, werden als eine der "Kinderkrankheiten" dieser relativ jungen Technologie betrachtet und stehen einer Verbreitung über die Grenzen einer engagierten technophilen Nutzergruppe hinaus im Wege. Die vorliegende Arbeit zeigt zwei parallel von einander (jedoch, im Sinne der Schnittstellenkompatibilität, nicht gänzlich unabhängig voneinander) zu betreibende Ansätze zur Integration von CAS Systemen. - Für den perioperativen Datenaustausch wird die Spezifikation zusätzlicher Datenstrukturen zum Transfer chirurgischer Planungsdaten im Rahmen des in radiologischen Bildverarbeitungssystemen weit verbreiteten DICOM Standards vorgeschlagen und an zwei Beispielen vorgeführt. Die Erweiterung des DICOM Standards für den perioperativen Einsatz ermöglicht hierbei die nahtlose Integration chirurgischer Planungssysteme in existierende "Picture Archiving and Communication Systems" (PACS), welche in den meisten Fällen auf dem DICOM Standard basieren oder zumindest damit kompatibel sind. Dadurch ist einerseits der Tatsache Rechnung getragen, dass die patientenspezifische OP-Planung in hohem Masse auf radiologischen Bildern basiert und andererseits sicher gestellt, dass die Planungsergebnisse entsprechend der geltenden Bestimmungen langfristig archiviert und gegen unbefugten Zugriff geschützt sind - PACS Server liefern hier bereits wohlerprobte Lösungen. - Für die integration intraoperativer CAS Systeme, wie etwa Navigationssysteme, Videobildquellen oder Sensoren zur Überwachung der Vitalparameter, wird das Konzept einer "chirurgischen Middleware" vorgestellt. Unter dem Namen TiCoLi wurde eine c++ Klassenbibliothek entwickelt, auf deren Grundlage die Konfiguration von ad-hoc Netzwerken während der OP-Vorbereitung mittels plug-and-play Mechanismen erleichtert wird. Nach erfolgter Konfiguration ermöglicht die TiCoLi den Austausch kontinuierlicher Datenströme sowie einzelner Datenpakete und Kommandos zwischen den Modulen einer verteilten CAS Anwendung durch ein Ethernet-basiertes Netzwerk. Die TiCoLi ist die erste frei verfügbare Klassenbibliothek welche diese Funktionalitäten dediziert für einen Einsatz im chirurgischen Umfeld vereinigt. Zum Nachweis der Tauglichkeit der gezeigten Spezifikationen und deren Implementierungen, werden zwei modulare CAS Anwendungen präsentiert, welche die vorgeschlagenen DICOM Erweiterungen zum perioperativen Austausch von Planungsergebnissen sowie die TiCoLi zum intraoperativen Datenaustausch von Messdaten unter echzeitnahen Anforderungen verwenden

A critical analysis of the profit based methods for satisfying the comparables test in UK transfer pricing regulations

The arm’s-length principle (ALP), the transactions taken place between unrelated parties acting at an arm’s length in competitive markets, is used by income tax authorities to determine transfer pricing, the pricing of goods, services and intangibles transferred between affiliates of a multinational enterprise (MNE), and is an important international tax issue for a number of reasons. First, globalization creates integrated businesses with enormous cross-border transfers whilst corporate income tax systems remain nationally based. Second, governments insist that globalization provides MNEs with more opportunities to manipulate transfer prices and reduce taxes than in the past, thus the need for tighter regulation. Third, there is an increased desire amongst tax authorities faced with tight fiscal situations, to protect and enhance their revenue base encouraging stricter regulation of MNEs. Profit is seen as only one of the many goals that motivate the behaviour of MNEs and the newly introduced profit based methods of transfer pricing has increased the reliance on comparables significantly. As the number of specified methods was increased and the hierarchy of acceptable methods was replaced by either the best method rule or the method of last resort, taxpayers are expected to document their transfer pricing policies. The documentation has to be contemporaneous and available upon request. The methods newly introduced by the Organization for Economic Cooperation and Development’s (OECD, 1995), Transaction Net Margin Method (TNMM), and US Internal Revenue Service’s (IRS, 1994) Comparable Profit Method (CPM), vary in relation to their application and views in controlling for function and risk when developing comparables. This suggests a degree of discretion may be exercised under different regulations that may be detected through ownership and tax. This study attempts to identify the level of discretion provided under both OECD (TNMM) and US IRS (CPM) methods. It is also tests the scope of ownership effect on the reported profit of Japanese-owned companies and US-owned companies compared to their UK counterparts. Finally this study examines whether the reported tax expense has changed subsequent to tax policy changes, specifically the latest UK transfer pricing regulations introduced in 1998 corporation tax self-assessment. The empirical analysis confirms differences between OECD and US IRS profit ranges and variations between profit level indicators (PLIs). Foreign-owned Japanese and US companies are also found to exhibit low profitability compared to UK companies. This research discovered low performance among a high number of the Japanese-owned companies with operating losses when compared to their UK counterparts and offers evidence of the low tax expenses reported by foreign-owned Japanese companies

A General Performance Model for Design-Build Highway Pavement

New challenges are revealed as more projects are delivered and contracted through innovative methods such as design-build project delivery and performance-based specifications. One challenge from the owner's perspective is lack of control, especially over design decisions and construction procedures. Due to this problem, highway agencies have adopted various additional contractual provisions, of which one is warranty. Warranty is intended to be a method of protecting the owner from possible quality defects and also of improving the initial and long-term performance of the facility.The research question is how warranty characteristics (i.e., warranty period) and other project characteristics impact the performance of highway pavement projects. To answer this question, a decision model was developed to simulate warranty impacts on project performance. Also, simulations were run to estimate the outcomes of projects with varying scope, contracting, and delivery methods in order to examine the impact of project characteristics on warranty decisions and project outcomes.A probabilistic decision-modeling technique, General Performance Model (GPM), is adopted for this warranty decision model. GPM is one method that is being used widely and has been proven to work for both alternative comparison and selection decision. Since GPM has been developed specifically for the purpose of comparing probable performance outcomes for various decision alternatives, it fits the purpose of this research.According to the simulation results, the contract price tends to increase as the warranty period becomes longer and higher-level performance is required. On the other hand, the agency's expected maintenance and repair costs tend to become less with longer and stricter warranty. Where the life-cycle cost (LCC) of a facility is concerned, the simulation shows that warranty is more beneficial for projects with certain characteristics such as sufficient contractor control, innovation opportunity, design-build delivery method, and performance-based specifications. The results of sensitivity analysis show that warranty period and required-performance level influence project outcomes significantly. Among intermediate factors, amount of warranty risk, motivation for quality improvement, and innovation effort were found to be more sensitive than others.A model is constructed to represent some aspects of the dynamic behavior of a real system. Therefore, a properly developed model can serve as a tool for investigating the behavior of the system and predict future outcomes with reasonable enough accuracy. In order to check the validity of the model, the process of requisite-model validation was applied, and a number of checkpoints were examined through expert interviews.Because of the representative nature of the model, a few assumptions had to be made. Also, the model has some limitations due to its method and scope. First, the project outcomes are measured in the form of life-cycle-cost (LCC) only. The performance measures other than LCC are not considered in the model. Also, the timing of warranty decision is limited to after-project development and prior bidding. Warranty decisions at different times, such as warranty option, which is practiced after construction, are not considered in this model. Finally, the model is limited to asphalt highway pavement projects. Although warranties are often used in other types of projects, such as concrete pavement, bridges, and ITS, they were not considered in this research. The model could be expanded to cover a wider range of project types, decision timing and performance measures in future research

Data bases and data base systems related to NASA's aerospace program. A bibliography with indexes

This bibliography lists 1778 reports, articles, and other documents introduced into the NASA scientific and technical information system, 1975 through 1980