Structural characteristics and contractual terms of specialist palliative homecare in Germany

Background Multi-professional specialist palliative homecare (SPHC) teams care for palliative patients with complex symptoms. In Germany, the SPHC directive regulates care provision, but model contracts for each federal state are heterogeneous regarding staff requirements, cooperation with other healthcare providers, and financial reimbursement. The structural characteristics of SPHC teams also vary. Aim We provide a structured overview of the existing model contracts, as well as a nationwide assessment of SPHC teams and their structural characteristics. Furthermore, we explore whether these characteristics serve to find specifc patterns of SPHC team models, based on empirical data. Methods This study is part of the multi-methods research project “SAVOIR”, funded by the German Innovations Fund. Most model contracts are publicly available. Structural characteristics (e.g. number, professions, and affiliations of team members, and external cooperation) were assessed via an online database (“Wegweiser Hospiz- und Palliativversorgung”) based on voluntary information obtained from SPHC teams. All the data were updated by phone during the assessment process. Data were descriptively analysed regarding staff, cooperation requirements, and reimbursement schemes, while latent class analysis (LCA) was used to identify structural team models. Results Model contracts have heterogeneous contract partners and terms related to staff requirements (number and qualifications) and cooperation with other services. Fourteen reimbursement schemes were available, all combining different payment models. Of the 283 SPHC teams, 196 provided structural characteristics. Teams reported between one and 298 members (mean: 30.3, median: 18), mainly nurses and physicians, while 37.8% had a psychosocial professional as a team member. Most teams were composed of nurses and physicians employed in different settings; for example, staff was employed by the team, in private practices/nursing services, or in hospitals. Latent class analysis identified four structural team models, based on the team size, team members’ affiliation, and care organisation. Conclusion Both the contractual terms and teams’ structural characteristics vary substantially, and this must be considered when analysing patient data from SPHC. The identified patterns of team models can form a starting point from which to analyse different forms of care provision and their impact on care quality

Laser-Materie-Wechselwirkung beim Selektiven Laser Sintern von Keramik

Diese Arbeit beschäftigt sich mit den physikalischen Grundlagen der Laser-Materie-Wechselwirkung keramischer Werkstoffe in der additiven Fertigung. Es wurde gezeigt, wie durch Selektives Volumen Sintern (SVS) in einem kompakten Grünkörper aus keramischem Pulver direkt ein Bauteil generiert werden kann. Im Vergleich zu Polymeren und Metallen besitzen Keramiken eine Bandlücke und bieten dafür ein breites transparentes optisches Fenster, welches typischerweise im Wellenlängenbereich von 0,3 bis 5 μm liegt. Dazu wurden optische Untersuchungen an gepressten Siliciumdioxid-Grünkörpern sowie an dünnen Siliciumdioxid-Schichten durchgeführt. Als Funktion der Schichtdicke und Partikelgröße wurden die Transmissions- und Reflexionsspektren im Wellenlängenbereich zwischen 0,5 und 2,5 μm aufgezeichnet. Durch die Wahl des richtigen Verhältnisses zwischen Partikelgröße und Wellenlänge der einfallenden Laserstrahlung ist es möglich, das Laserlicht in das Volumen eines Grünkörpers eindringen zu lassen. Um die Laserenergie in das Volumen eines Grünkörpers zu übertragen, muss neben der Minimierung der Lichtstreuung des Grünkörpers, ebenso das Absorptions-Verhalten so eingestellt werden, dass die Laserenergie gezielt im Volumen des Grünkörpers in Wärme umgesetzt werden kann. Der Laserenergieeintrag sowie eine lokale Sinterung im Grünkörpervolumen konnte in Experimenten gezeigt werden. Desweiteren wird der Laserenergieeintrag über die Oberfläche eines keramischen Grünkörpers beschrieben. Dies ist typischerweise für keramische Rohstoffgemische der einzige Weg ist, Energie ins Material einzutragen, da diese auf Grund ihrer chemischen Zusammensetzung in keinem Wellenlängenbereich Lichttransmission zulassen. Bei der Untersuchung von Silikatkeramiken wurde gezeigt, wie mittels Selektiven Laser Sintern (SLS) Wärme homogen ins Material eintragen werden kann. Durch die Beschreibung der Laserleistung als eine Funktion der Scanvektorlänge beim Selektiven Laser Sintern wird der Laserenergieeintrag in die aufgetragenen Pulverschichten so angepasst, dass ein homogenes Gefüge über den gesamten additiv gefertigten Körper eingestellt werden kann. Somit wurden Bauteile hergestellt, welche im Nachbrand zu dichten Keramiken gesintert werden konnten.The present work is dealing with the basic physics for a novel way to generate a free-formed ceramic body, not like common layer by layer, but directly by Selective Volume Sintering (SVS) in a compact block of ceramic powder. To penetrate with laser light into the volume of a ceramic powder compact it is necessary to investigate the light scattering properties of ceramic powders. Compared with polymers and metals, ceramic materials are unique as they offer a wide optical window of transparency. The optical window typically ranges from below 0,3 up to 5 μm wave length. In the present study thin layers of quartz glass (SiO2) particles have been prepared. As a function of layer thickness and the particle size, transmission and reflection spectra in a wave length range between 0,5 and 2,5 μm have been recorded. Depending on the respective particle size and by choosing a proper relation between particle size and wave length of the incident laser radiation, it is found that light can penetrate a powder compact up to a depth of a few millimeters. With an adjustment of the light absorption properties of the compact the initiation of sintering in the volume of the compact is possible. In case of ceramic raw material mixtures, the laser energy input by absorption of laser irradiation at the surface of a ceramic green body is typically the only way to introduce energy into the material. Due to their chemical composition no light transmission in any wavelength range is possible. By adjustment of selective laser sintering (SLS) process a homogeneously heat transfer into the material can be shown for silicate ceramics. By describing the laser power as a function of the scanning vector length in the SLS process, the laser energy input is adapted to the deposited powder layers in such a way that a homogeneous structure can be achieved across the entire additive generated body. Thus, components were produced which can post-sintered to form dense ceramic bodies

Powder-Bed Stabilization for Powder-Based Additive Manufacturing

The most successful additive manufacturing (AM) technologies are based on thelayer-by-layer depositionof a flowable powder. Although considered as the third industrial revolution, one factor still limiting these processes to become completely autonomous is the often necessary build-up of support structures. Besides the prevention of lateral shifts of the part during the deposition of layers, the support assures quality and stability to the built process. The loose powder itself surrounding the built object, or so-called powder-bed, does not provide this sustenance in most existent technology available. Here we present a simple but effective and economical method for stabilizing the powder-bed, preventing distortions in the geometry with no need for support structures. This effect, achieved by applying an air flow through the powder-bed, is enabling an entirely autonomous generation of parts and is a major contribution to all powder-based additive manufacturing technologies. Moreover, it makes powder-based AM independent of gravitational forces, which will facilitate crafting items in space from a variety of powdery materials