The geometrical representation of muscles in computational models of the musculoskeletal system typically consists of a series of line segments. These muscle anatomies are based on measurements from a limited number of cadaveric studies that recently have been used as atlases for creating subject-specific models from medical images, so potentially restricting the options for personalisation and assessment of muscle geometrical models. To overcome this methodological limitation, we propose a novel, completely automated technique that, from a surface geometry of a skeletal muscle and its attachment areas, can generate an arbitrary number of lines of action (fibres) composed by a user-defined number of straight-line segments. These fibres can be included in standard musculoskeletal models and used in biomechanical simulations. This methodology was applied to the surfaces of four muscles surrounding the hip joint (iliacus, psoas, gluteus maximus and gluteus medius), segmented on magnetic resonance imaging scans from a cadaveric dataset, for which highly discretised muscle representations were created and used to simulate functional tasks. The fibres' moment arms were validated against measurements and models of the same muscles from the literature with promising outcomes. The proposed approach is expected to improve the anatomical representation of skeletal muscles in personalised biomechanical models and finite element applications.
- MeSH
- biologické modely * MeSH
- biomechanika MeSH
- kosterní svaly * diagnostické zobrazování fyziologie MeSH
- kyčelní kloub * diagnostické zobrazování fyziologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mrtvola MeSH
- počítačová rentgenová tomografie MeSH
- počítačové modelování podle konkrétního pacienta * MeSH
- senioři nad 80 let MeSH
- Check Tag
- lidé MeSH
- senioři nad 80 let MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND OBJECTIVE: Physiological cross-sectional area (PCSA) of a muscle plays a significant role in determining the force contribution of muscle fascicles to skeletal movement. This parameter is typically calculated from the lengths of muscle fibres selectively sampled from the superficial layer of the muscle. However, recent studies have found that the length of fibres in the superficial layer often differs significantly (p < 0.5) from the length of fibres in the deep layer. As a result, PCSA estimation is inaccurate. In this paper, we propose a method to automatically reconstruct fibres in the whole volume of a muscle from those selectively sampled on the superficial layer. METHODS: The method performs a centripetal Catmull-Rom interpolation of the input fibres within the volume of a muscle represented by its 3D surface model, automatically distributing the fibres among multiple heads of the muscle and shortening the deep fibres to support large attachment areas with extremely acute angles. RESULTS: Our C++ implementation runs in a couple of seconds on commodity hardware providing realistic results for both artificial and real data sets we tested. CONCLUSIONS: The fibres produced by the method can be used directly to determine the personalised mechanical muscle functioning. Our implementation is publicly available for the researchers at https://mi.kiv.zcu.cz/.
- MeSH
- kosterní svalová vlákna fyziologie MeSH
- kosterní svaly anatomie a histologie MeSH
- lidé MeSH
- pohyb MeSH
- svalová kontrakce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
At least 1% of the general population have an aneurysm (or possibly more) in their cerebral blood vessels. If an aneurysm ruptures, it kills the patient in up to 60% of cases. In order to choose the optimal treatment, clinicians have to monitor the development of the aneurysm in time. Nowadays, aneurysms are typically identified manually, which means that the monitoring is often imprecise since the identification is observer dependent. As a result, the number of misdiagnosed cases may be large. This paper proposes a fast semi-automatic method for the identification of aneurysms which is based on the analysis of the skeleton of blood vessels. Provided that the skeleton is accurate, the results achieved by our method have been deemed acceptable by expert clinicians.
- MeSH
- algoritmy MeSH
- arteriae cerebrales patologie radiografie MeSH
- databáze faktografické MeSH
- intrakraniální aneurysma patologie radiografie MeSH
- lidé MeSH
- mozek krevní zásobení MeSH
- mozková angiografie MeSH
- počítačové zpracování obrazu metody MeSH
- pravděpodobnost MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of this article is 3D analysis of the temporomandibular joint (TMJ) patient, who underwent surgery, during which the right TMJ was resected along with the ramus of mandible and consequently the joint was reconstructed with subtotal replacement. The main goal is to give a suitable formulation of mathematical model, which describes the changes of stresses in TMJ incurred after the surgery. The TMJ is a complex, sensitive and highly mobile joint which works bilaterally so each side influences the contralateral joint and because of this the distribution of the stresses is changed in the healthy joint as well. Detailed knowledge about function these are necessary for clinical application of temporomandibular joint prosthesis and also help us estimate the lifetime of the prosthesis a possibilities of alteration in the contra lateral joint components. The geometry for the 3D models is taken from the CT scan date and its numerical solution is based on the theory of semi-coercive unilateral contact problems in linear elasticity. This article provides medical part with case report, discretion of treatment, than the methods of mathematical modeling and his possibilities are described and finally results are reported.
- MeSH
- analýza metodou konečných prvků MeSH
- biomechanika MeSH
- cysty čelistí patologie radiografie chirurgie MeSH
- lidé MeSH
- mandibula - protézy MeSH
- modely anatomické MeSH
- nemoci temporomandibulárního kloubu patologie radiografie chirurgie MeSH
- počítačová rentgenová tomografie statistika a číselné údaje MeSH
- počítačová simulace MeSH
- senioři MeSH
- temporomandibulární kloub fyziologie patofyziologie chirurgie MeSH
- zobrazování trojrozměrné metody MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
- MeSH
- dějiny 16. století MeSH
- dějiny 17. století MeSH
- dějiny 18. století MeSH
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny lékařství MeSH
- lidé MeSH
- významné osobnosti MeSH
- Check Tag
- dějiny 16. století MeSH
- dějiny 17. století MeSH
- dějiny 18. století MeSH
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- lidé MeSH
- Publikační typ
- biografie MeSH
- MeSH
- literatura MeSH
- vnitřní lékařství MeSH
- vzdělávání odborné MeSH
- Publikační typ
- biografie MeSH
- O autorovi
- Thomayer, Josef, 1853-1927 Autorita
- MeSH
- botanika MeSH
- vnitřní lékařství MeSH
- vzdělávání odborné MeSH
- Publikační typ
- biografie MeSH
- Geografické názvy
- Švédsko MeSH
- O autorovi
- Linné, Carl von, 1707-1778 Autorita
Podáváme zprávu o 4 odlévačích olova, u nichž vyšetření koncentrace olova ve vlasech svědčilo pro zvýšenou expozici olovu, která byla potvrzena stanovením koncentrace olova v moči po mobilizaci. Vyšetření olova ve vlasech se osvědčilo jako užitečná screeningová metoda.
We report on four lead casters in which the examination of lead concentration in hair indicated an increased exposure to lead which was proved by the examination of lead concentration in urine after mobilization. The examination of lead in hair has proved as a useful screening method.
- MeSH
- lidé MeSH
- nemoci z povolání diagnóza MeSH
- olovo moč škodlivé účinky MeSH
- otrava olovem diagnóza MeSH
- pracovní expozice MeSH
- vlasy, chlupy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kazuistiky MeSH
