POIM - Peter Osypka Institute of Medical Engineering
Refine
Year of publication
- 2021 (17) (remove)
Document Type
- Article (reviewed) (12)
- Conference Proceeding (3)
- Letter to Editor (2)
Conference Type
Is part of the Bibliography
- yes (17)
Keywords
- Götz von Berlichingen (3)
- Handprothese (2)
- ancient Capua leg (2)
- cardiac ablation (2)
- heart rhythm model (2)
- 3D CAD (1)
- 3D computer-aided design (1)
- 3D print (1)
- 3D-CAD (1)
- 3D-light scanning (1)
Institute
Open Access
- Open Access (10)
- Closed Access (7)
Patients with focal ventricular tachycardia are at risk of hemodynamic failure and if no treatment is provided the mortality rate can exceed 30%. Therefore, medical professionals must be adequately trained in the management of these conditions. To achieve the best treatment, the origin of the abnormality should be known, as well as the course of the disease. This study provides an opportunity to visualize various focal ventricular tachycardias using the Offenburg heart rhythm model. Modeling and simulation of focal ventricular tachycardias in the Offenburg heart rhythm model was performed using CST (Computer Simulation Technology) software from Dessault Systèms. A bundle of nerve tissue in different regions in the left and right ventricle was defined as the focus in the already existing heart rhythm model. This ultimately served as the origin of the focal excitation sites. For the simulations, the heart rhythm model was divided into a mesh consisting of 5354516 tetrahedra, which is required to calculate the electric field lines. The simulations in the Offenburg heart rhythm model were able to successfully represent the progression of focal ventricular tachycardia in the heart using measured electrical field lines. The simulation results were realized as an animated sequence of images running in real time at a frame rate of 20 frames per second. By changing the frame rate, these simulations can additionally be produced at different speeds. The Offenburg heart rhythm model allows visualization of focal ventricular arrhythmias using computer simulations.
Background: This paper presents a conceptual design for an anthropomorphic replacement hand made of silicone that integrates a sensory feedback system. In combination with a motorized orthosis, it allows performing movements and registering information on the flexion and the pressure of the fingers.
Methods: To create the replacement hand, a three-dimensional (3D) scanner was used to scan the hand of the test person. With computer-aided design (CAD), a mold was created from the hand, then 3D-printed. Bending and force sensors were attached to the mold before silicone casting to implement the sensory feedback system. To achieve a functional and anthropomorphic appearance of the replacement hand, a material analysis was carried out. In two different test series, the properties of the used silicones were analyzed regarding their mechanical properties and the manufacturing process.
Results: Individual fingers and an entire hand with integrated sensors were realized, which demonstrated in several tests that sensory feedback in such an anthropomorphic replacement hand can be realized. Nevertheless, the choice of silicone material remains an open challenge, as there is a trade-off between the hardness of the material and the maximum mechanical force of the orthosis.
Conclusion: Apart from manufacturing-related issues, it is possible to cost-effectively create a personalized, anthropomorphic replacement hand, including sensory feedback, by using 3D scanning and 3D printing techniques.
Die vorliegende Arbeit gibt einen Überblick über das Verhältnis zwischen Nutzen und Einschränkungen eines frühneuzeitlichen Riefelharnisches auf die Biomechanik des Menschen. Zu den zentralen Ergebnissen gehört, dass die Rüstung eine gewisse Einschränkung der Beweglichkeit bringt, jedoch durch verschiedene mechanische Konzepte versucht wurde, diese größtmöglich zu minimieren. Besonders das sogenannte Geschübe stellt hierbei einen Kompromiss zwischen Beweglichkeit und Schutzfunktion dar und findet vor allem im Bereich der Gelenke Anwendung. Steife Strukturen werden an Stellen eingesetzt, die kaum Bewegungsfreiheit fordern. Zu diesen Bereichen gehören beispielsweise der Brustkorb oder obere Teile des Rückens. Der Vorteil der steiferen Teile der Rüstung ist ihre erhöhte Schutzfunktion, die ein geringeres Verletzungsrisiko mit sich bringt.
Disturbances of the cardiac conduction system causing reentry mechanisms above the atrioventricular (AV) node are induced by at least one accessory pathway with different conducting properties and refractory periods. This work aims to further develop the already existing and continuously expanding Offenburg heart rhythm model to visualise the most common supraventricular reentry tachycardias to provide a better understanding of the cause of the respective reentry mechanism.
Patients with focal ventricular tachycardia are at risk of hemodynamic failure and if no treatment is provided the mortality rate can exceed 30%. Therefore, medical professionals must be adequately trained in the management of these conditions. To achieve the best treatment, the origin of the abnormality should be known, as well as the course of the disease. This study provides an opportunity to visualize various focal ventricular tachycardias using the Offenburg cardiac rhythm model.
eLetter: "The ancient Capua leg from 300 BC and the 1941 air raid on the Royal College of Surgeons"
(2021)
eLetter zum Artikel "The College of Surgeons, London", veröffentlicht in Science, Vol. 93, Issue 2425, Seite 587 (DOI: 10.1126/science.93.2425.587).