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In this paper, a concept for an anthropomorphic replacement hand cast with silicone with an integrated sensory feedback system is presented. In order to construct the personalized replacement hand, a 3D scan of a healthy hand was used to create a 3D-printed mold using computer-aided design (CAD). To allow for movement of the index and middle fingers, a motorized orthosis was used. Information about the applied force for grasping and the degree of flexion of the fingers is registered using two pressure sensors and one bending sensor in each movable finger. To integrate the sensors and additional cavities for increased flexibility, the fingers were cast in three parts, separately from the rest of the hand. A silicone adhesive (Silpuran 4200) was examined to combine the individual parts afterwards. For this, tests with different geometries were carried out. Furthermore, different test series for the secure integration of the sensors were performed, including measurements of the registered information of the sensors. Based on these findings, skin-toned individual fingers and a replacement hand with integrated sensors were created. Using Silpuran 4200, it was possible to integrate the needed cavities and to place the sensors securely into the hand while retaining full flexion using a motorized orthosis. The measurements during different loadings and while grasping various objects proved that it is possible to realize such a sensory feedback system in a replacement hand. As a result, it can be stated that the cost-effective realization of a personalized, anthropomorphic replacement hand with an integrated sensory feedback system is possible using 3D scanning and 3D printing. By integrating smaller sensors, the risk of damaging the sensors through movement could be decreased.
Background: This paper presents a novel approach for a hand prosthesis consisting of a flexible, anthropomorphic, 3D-printed replacement hand combined with a commercially available motorized orthosis that allows gripping.
Methods: A 3D light scanner was used to produce a personalized replacement hand. The wrist of the replacement hand was printed of rigid material; the rest of the hand was printed of flexible material. A standard arm liner was used to enable the user’s arm stump to be connected to the replacement hand. With computer-aided design, two different concepts were developed for the scanned hand model: In the first concept, the replacement hand was attached to the arm liner with a screw. The second concept involved attaching with a commercially available fastening system; furthermore, a skeleton was designed that was located within the flexible part of the replacement hand.
Results: 3D-multi-material printing of the two different hands was unproblematic and inexpensive. The printed hands had approximately the weight of the real hand. When testing the replacement hands with the orthosis it was possible to prove a convincing everyday functionality. For example, it was possible to grip and lift a 1-L water bottle. In addition, a pen could be held, making writing possible.
Conclusions: This first proof-of-concept study encourages further testing with users.
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.
Fünf Jahre vor seinem Tod, im Jahr 1932, wurde der berühmte französische Komponist Maurice Ravel (1875–1937), der an einer frontotemporalen Demenz (M. Pick) mit primär progressiver Aphasie litt, bei einem Unfall verletzt, als er in einem Pariser Taxi saß. In diesem Fallbericht wird der Unfallmechanismus unter bestimmten Annahmen dargestellt und diskutiert. Ausgehend von diesen Überlegungen ist ein Unfall bei geringer Kollisionsgeschwindigkeit wahrscheinlich. Trotz eines Unfalls mit nur geringer Geschwindigkeit ist nicht von der Hand zu weisen, dass dieser Unfall zumindest zu einer deutlichen Verschlimmerung der Krankheitssymptome geführt haben könnte, da Ravel seit diesem Taxiunfall bis zu seinem Tod keine weiteren Kompositionen mehr vollendet hat.
In dieser Arbeit wird ein historischer Fallbericht des bis heute weit über seine Landesgrenzen bekannten italienischen Kriminalanthropologen Cesare Lombroso (1835–1909) vorgestellt. In diesem Fallbericht wird der berüchtigte und psychisch auffällige Dieb Pietro Bersone mit Hilfe eines sog. Hydrosphygmographen überführt, einem zur damaligen Zeit neuartigen technischen Gerät, das den Puls nicht-invasiv aufzeichnen konnte. Lombroso ist vermutlich einer der ersten, wenn nicht sogar der erste, der durch den Einsatz eines solchen Geräts die Idee zum „Lügendetektor“ vorweggenommen hat. Die vorgestellte Textstelle aus Lombrosos Buch „Neue Fortschritte in den Verbrecherstudien“ ist daher ein besonderes Fundstück auch für die Geschichte der Polygraphie.
eLetter zum Artikel "The Hannes hand prosthesis replicates the key biological properties of the human hand" von Matteo Laffranchi et al., veröffentlicht in Science Robotics, Vol. 5, Issue 46, eabb0467 (doi.org/10.1126/scirobotics.abb0467)
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).
eLetter zum Artikel "Condiciones neuropsi-quiátricas y probable causa de muerte de Maurice Ravel" von Gómez-Carvajal AM, Botero-Meneses JS, Palacios-Espinosa X und Palacios-Sánchez L., veröffentlicht in Iatreia 35(3), Seite 341-8 (DOI: https://doi.org/10.17533/udea.iatreia.154).
This book, now in its third, completely revised and updated edition, offers a critical approach to the challenging interpretation of the latest research data obtained using functional neuroimaging in whiplash injury. Such a comprehensive guide to recent and current international research in the field is more necessary than ever, given that the confusion regarding the condition and the medicolegal discussions surrounding it have increased further despite the publication of much literature on the subject. In recent decades especially the functional imaging methods – such as single-photon emission tomography, positron emission tomography, functional MRI, and hybrid techniques – have demonstrated a variety of significant brain alterations. Functional Neuroimaging in Whiplash Injury - New Approaches covers all aspects, including the imaging tools themselves and the various methods of image analysis. Details on biomechanics, including the finite element method and facts on historical whiplash experiments and crash tests have now been added to this new edition. The book will continue to help physicians, patients and their relatives and friends, and others to understand this condition as a disease.