610 Medizin, Gesundheit
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This review gives a short overview of the physical processes involved in the formation of the polyelectrolyte multilayers (PEMs) and their destruction. These two processes are vital for the formation of PEMs with desired physical and chemical structures, and for loading them with active substances and their spatial controlled release. It includes a survey of the physical and chemical properties that are key points for controlling film nanostructure in relation to biological processes and different possibilities for controlling cell behavior by means of film composition, bioactivity, mechanical properties, and three-dimensional organization.
The number of publications in the field of breath analysis using different types of ion mobility spectrometers (IMS) has increased over the last few years. In this paper, the publications between 2010 and 2013 are reviewed with respect to different types of IMS such as differential mobility spectrometers, high-field asymmetric waveform ion mobility spectrometers and multi-capillary columns coupled to conventional IMS. The analytes detected by IMS and declared with significance to a specific medical question were considered further with respect to medical and analytical questions. In total, 42 different analytes were found to be detected using IMS on a high significance level and were compared to findings using other analytical methods with respect to the individual analyte.
In breath analysis, ambient air contaminations are ubiquitous and difficult to eliminate. This study was designed to investigate the reduction of ambient air background by a lung wash-out with synthetic air. The reduction of the initial ambient air volatile organic compound (VOC) intensity was investigated in the breath of 20 volunteers inhaling synthetic air via a sealed full face mask in comparison to inhaling ambient air. Over a period of 30 minutes, breath analysis was conducted using ion mobility spectrometry coupled to a multi-capillary column. A total of 68 VOCs were identified for inhaling ambient air or inhaling synthetic air. By treatment with synthetic air, 39 VOCs decreased in intensity, whereas 29 increased in comparison to inhaling ambient air. In total, seven VOCs were significantly reduced (P-value < 0.05). A complete wash-out of VOCs in this setting was not observed, whereby a statistically significant reduction up to 65% as for terpinolene was achieved. Our setting successfully demonstrated a reduction of ambient air contaminations from the airways by a lung wash-out with synthetic air.
Rats are commonly used in medical research as they enable a high grade of standardization. The exhalome of ventilated rats has not as yet been investigated using an ion mobility spectrometer coupled with a multi-capillary column (MCC-IMS). As a first step, a rat model has to be established to measure potential biomarkers in the exhale with long-term settings, allowing constant and continuous analysis of exhaled air in time series. Therefore, eight animals were anaesthetized, prepared and ventilated for 1 h. A total of 73 peaks were directly detected with the IMS chromatogram. Thirty five of them were assigned to the ventilator system and 38 to the animals. Peak intensity varied within three measurements. The intensity of analytes of individual rats varied by a factor of up to 18. This new model will also enable continuous measurements of volatile organic compounds (VOCs) from rat's breath in long-term experiments. It is hoped that, in the future, variability and progression of VOCs can be monitored in different models of diseases using this set-up.
Influence of the respirator on volatile organic compounds : an animal study in rats over 24 hours
(2015)
Long-term animal studies are needed to accomplish measurements of volatile organic compounds (VOCs) for medical diagnostics. In order to analyze the time course of VOCs, it is necessary to ventilate these animals. Therefore, a total of 10 male Sprague–Dawley rats were anaesthetized and ventilated with synthetic air via tracheotomy for 24 h. An ion mobility spectrometry coupled to multi-capillary columns (MCC–IMS) was used to analyze the expired air. To identify background contaminations produced by the respirator itself, six comparative measurements were conducted with ventilators only. Overall, a number of 37 peaks could be detected within the positive mode. According to the ratio peak intensity rat/ peak intensity ventilator blank, 22 peaks with a ratio >1.5 were defined as expired VOCs, 12 peaks with a ratio between 0.5 and 1.5 as unaffected VOCs, and three peaks with a ratio <0.5 as resorbed VOCs. The peak intensity of 12 expired VOCs changed significantly during the 24 h measurement. These results represent the basis for future intervention studies. Notably, online VOC analysis with MCC–IMS is possible over 24 h in ventilated rats and allows different experimental approaches.
Im Fokus der Arbeit steht die Unterstützung der Stentgraftauswahl bei endovaskulärer Versorgung eines infrarenalen Aortenaneurysmas. Im Rahmen der Arbeit wurde eine Methode zur Auswertung von Ergebnissen einer Finite Elemente-Analyse zum Stentgraftverhalten konzipiert, implementiert und im Rahmen einer deutschlandweiten Benutzerstudie mit 16 Chirurgen diskutiert. Die entwickelte Mensch-Maschine-Schnittstelle ermöglicht dem Gefäßmediziner eine interaktive Analyse berechneter Fixierungskräfte und Kontaktzustände mehrerer Stentgrafts im Kontext mit dem zu behandelnden Aortenabschnitt. Die entwickelte Methode ermöglicht eine tiefergehende Auseinandersetzung der Mediziner mit numerischen Simulationen und Stentgraftbewertungsgrößen. Hierdurch konnte im Rahmen der Benutzerstudie das Einsatzpotenzial numerischer Simulationen zur Unterstützung der Stentgraftauswahl ermittelt und eine Anforderungsspezifikation an ein System zur simulationsbasierten Stentgraftplanung definiert werden. Im Ergebnis wurde als wesentliches Einsatzpotenzial die Festlegung eines Mindestmaßes an Überdimensionierung, die Optimierung der Schenkellänge von bifurkativen Stentgrafts sowie der Vergleich unterschiedlicher Stentgraftdesigns ermittelt. Zu den wesentlichen Funktionen eines Systems zur simulationsbasierten Stentgraftauswahl gehören eine Übersichtskarte zu farbkodiertem Migrationsrisiko pro Stentgraft und Landungszone, die Visualisierung des Abdichtungszustandes der Stentkomponenten sowie die Darstellung von Stentgraft- und Gefäßdeformationen im 3D-Modell.
Die Erfindung betrifft einen Rollstuhl mit einem Gestell mit Rädern, einem Sitz sowie zwei gegenüber dem Sitz verlagerbaren Fußplatten und ein Trainingsgerät zur Bewegungstherapie der unteren Extremitäten einer in dem Rollstuhl sitzenden Person. Um das Trainingsgerät vereinfacht auszubilden, enthält das Trainingsgerät unabhängig von einer Fahrbewegung des Rollstuhls betreibbar eine an dem Gestell befestigbare, von einer Steuereinheit gesteuerte Elektromaschine, welche zur wechselweise erzwungenen Verlagerung der beiden Fußplatten mit den Fußplatten mechanisch gekoppelt ist.
Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration.Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N2 to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFAor PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol,with PTFE as an alternative.
Diese Arbeit liefert einen Konzeptentwurf, der die Integration verschiedener Systeme mit prozessrelevanten klinischen Diensten gewährleistet. Chirurgische Abläufe werden in Form von Prozessen modelliert. Die Wahl der Notation und die Art der Modellierung dieser Prozesse spielt in der heutigen Forschung in diesem Gebiet eine zentrale Rolle. Sind diese Prozesse modelliert, besteht die Möglichkeit, diese in einer Workflow-Engine automatisiert auszuführen. Im Rahmen der Entwicklung eines Workflow-Managment-Systems stellt sich die Frage, wie die Anbindung dieser Workflow-Engine mit anderen Systemen erfolgen soll. In der Arbeit werden Schnittstellen abstrakt in der Web Services Description Language (WSDL) definiert. Darum werden automatisiert Artefakte erzeugt. Auf der Grundlage dieser Artefakte erfolgt die Integration der Systeme. Die Workflow-Engine kommunizieren über SOAP-Nachrichten (Simple Object Access Protocol) mit den entsprechenden Systemen. Dieser Ansatz wurde mithilfe eines Prototyps validiert und umgesetzt.
This paper contributes to the automatic detection of perioperative workflow by developing a binary endoscope localization. Automated situation recognition in the context of an intelligent operating room requires the automatic conversion of low level cues into more abstract high level information. Imagery from a laparoscope delivers rich content that is easy to obtain but hard to process. We introduce a system which detects if the endoscope's distal tip is inside or outsiede the patient based on the endoscope video. This information can be used as one parameter in a situation recognition pipeline. Our localization performs in real-time at a video resolution of 1280x720 and 5-fold cross validation yields mean F1-scores of up to 0,94 on videos of 7 laparoscopies.