1,713 research outputs found
Monitoring the degradation of bone elastic properties induced by microgravity: a proposal.
No full textBackground
Important alterations occurring in living organisms during space flight concern the trabecular compartment of load-bearing bones, and result in significant bone mineral loss and decay of mechanical properties [1, 2].
Composition, mineral content, and the complex micro-scale trabecular microarchitecture contribute together to the macro-scale functional strength of bone as a whole [3]. Bone alterations, including those due to reduced gravitational load conditions, are mainly assessed by measuring bone density, even though, alone, it cannot comprehensively assess skeletal integrity [4]. Micro-tomographic techniques [5], not suitable for monitoring, allow for a pre- and post-mission examination of the trabecular bone component, which undergoes the fastest and most important alterations, placing astronauts at serious risk of fracture upon re-entry [5]. Mesoscale studies in modeled microgravity conditions combined with numerical simulations, show that degradation of apparent mechanical properties must be considered to achieve an accurate description of bone performance [6, 7].
To quantify the pathological alterations in the bone micro-architecture in a clinical setting, a patented, CE marked, software medical device, the Bone Elastic Structure Test, BES TEST, has been developed. Results are uncorrelated to BMD and independent of load [8, 9]. BES TEST has a diagnostic accuracy of 78% as a 3-year fracture risk estimator [10] and can be used to complete the densitometry picture and as monitoring tool for bone follow-up in in rheumatology [9], oncology [11], nephrology [12] and rare bone diseases [13].
Its prospective application for bone alteration monitoring during spaceflights is discussed.
Method
BES TEST simulates the application of forces on an X-ray functional biopsy of the patient’s hand [14-19]. Results are combined in an index, BSI, and its T-score and Z-score (Fig.1). Characteristics: X-ray dose < 0.0005 μSV; CV intra-operator=0.06; 95%CI±8 BSI; CV inter-operator =0.11; 95% CI=±10.8 BSI [20, 21], in line with the diagnostic gold standard.
Requirements for investigation of BES TEST space application:
- Acquisition: x-ray scanner, small detector. Several possible arrangements are possible, tests in simulated space flight will clarify the best configuration.
- Calibration: the acquisition set-up will likely differ from the clinical one.
- Analysis: radiograms upload to automatic service.
Results
BES TEST monitors trabecular bone, which changes more rapidly than cortical bone and BMD in response to physio-pathological alterations, like those occurring during spaceflight.
Conclusion
BESTEST is fast, easy to perform, cost-effective and can be significantly repeated within just weeks, showing potential for monitoring the changes in bone functionality during long-duration space missions.
Acknowledgements
Area Science Park financially supported the development of this work at various stages.
References
1. Vico, L. et al. Bone. 1998.
2. Lang, T. et al. J Bone and Mineral Research. 2004.
3. Kleerekoper, M. et al. Calcif Tissue Int. 1985.
4. J.D. Sibonga et al. Aerosp.Med.Hum. perform. 2015.
5. J.D. Sibonga et al. J. Clin. Densitom. 2020.
6. Cosmi F. et al. J. Mech. Behav. Biomed. Mater. 2009
7. Francesca Cosmi et al. J. Mech. Behav. Biomed. Mater. 2015
8. Cosmi F et al. Mater Today: Proc. 2018.
9. Saviola G. et al. Minerva Medica. 2019.
10. Francesca Cosmi et al. 2023.
11. S. Saracchini et al. 2019.
12. M. Ferraro et al. NDT. 2021.
13. Cosmi F and Maximova N. Mater. Today. 2019
14. Wilczek M. L et al. Eur Radiol. 2013.
15. Albanese CV et al. R. Radiol Med. 2011.
16. Alenfeld FE et al. Osteoporosis Int. 1998.
17. Mele R. Osteoporos Int. 1997.
18. Tonti E. Computer Modeling in Engineering and Science. 2001.
19. Cosmi F. Molecular and Cellular Biology. 2015.
20. Cosmi F. et al. Proc IMechE Part C. 2022.
21. Cosmi F. et al. Proc IMechE Part C. 2023
Come stanno le tue ossa? Nuovi strumenti diagnostici per la salute dell'osso
No full textIntervengono Francesca Cosmi, docente di Progettazione meccanica e Costruzione di macchine dell'Università di Trieste e Alessandra Nicolosi, amministratore delegato M2TES
Implementation of correctness criteria for the bone structure analysis by means of a hand-held x-ray system
No full textDensitometry alone has been shown to be inadequate to predict all osteoporotic fractures, since 40-50% occur in people who do not have a low bone density. The BESTEST®, Bone Elastic Structure Test, virtually simulates compressive loads on the trabecular architecture’s reconstructions obtained from digital radiographs of first proximal epiphyses of the non-dominant hand. The radiograms are acquired by a hand-held portable x-ray system equipped with a digital sensor. While in certain cases these systems present risks that are no greater than with standard systems, issues related to: (i) position of the handheld X-ray device relative to the operator, (ii) risk of misalignment of the X-ray units during exposure, (iii) patient protection and (iv) correct positioning of the sensor must still be addressed. A special stand and a customized sensor holder have been therefore designed, so that safety for patient and operator and repeatability of the exam have been improved
La cultura antiquaria di Andrea Sacchi: Lelio Biscia, Leonardo Agostini e l'entourage del cardinale Francesco Barberini
No full textIl testo approfondisce la cultura antiquaria di Andrea Sacchi, cercando di definirne l'entità e individuando alcune delle personalità più significative con cui l'artista entrò in contatto. Tra queste si distinguono il cardinale Lelio Biscia, il teologo Leone Allacci e l'antiquario e archeologo Leonardo Agostini, tre figure dallo spessore diverso che costituirono gli interlocutori privilegiati di Sacchi
Method, device and machine for calculating an index representative of the properties of a material of the bone type
No full textMethod, device and machine. for calculating an. index representative of properties of a material of the bone type of an individual to be subjected to tests....an aim of the present invention is to provide a method for calculating an index that is usable and easy to be interpreted and that classifies, amplifying them, the differences induced by different internal architectures on the mechanical properties of a material of the bone type..
PROCEDIMENTO PER CALCOLARE UN INDICE RAPPRESENTATIVO DELLE PROPRIETA’ DI UN MATERIALE, E DISPOSITIVO DI RILEVAZIONE CORRELATO
No full textUn procedimento per calcolare un indice rappresentativo delle proprietà meccaniche di un materiale, in particolare un materiale di tipo osseo, comprende una prima fase (10) di acquisizione di almeno un’immagine comprendente una pluralità di unità elementari (31, 32, 33, 34) di un campione del materiale, in cui è prevista una fase di generazione di una griglia di elementi geometrici elementari, o celle, che è associata, in particolare sovrapposta, a detta immagine, una fase di elaborazione (12) dell’immagine, in cui è previsto calcolare almeno il modulo elastico apparente (E*) e un coefficiente di densità (C) del materiale, entrambi in funzione di valori caratteristici di ogni cella, e una fase (14) di calcolo dell’indice rappresentativo delle proprietà di un materiale, in cui l’indice è proporzionale al valore del modulo elastico apparente (E*) al netto del contributo del coefficiente di densità (C).
Fig.
Osteoporosi? Niente panico!
No full text“Come mai un professore di progettazione meccanica si mette a studiare l’osso? perché vuole prevenire le rotture, tutte!”
Credo che far resistere le strutture sia un desiderio innato negli ingegneri ed una costruzione complessa ed organizzata come quella dell’architettura interna dell’osso rende la sfida ancor più affascinante.
In un materiale così articolato, il calo della massa ossea non basta da solo per spiegare tutte le fratture osteoporotiche. Da questa considerazione è nato in me il desiderio di approfondire il problema della valutazione del rischio, studiando come la complessa struttura trabecolare influenzi la distribuzione delle forze all’interno dell’osso per migliorare la conoscenza della situazione specifica del paziente
The Bone Structure Index and the requirements for its evaluation with a hand-held x-ray imaging system
No full textThe social costs of osteoporosis are huge and keep growing because of increased life expectancy. Although a low bone mineral density is considered to be associated with a higher risk of fracture, densitometry alone has been shown to be inadequate to predict a significant number of fractures, hence the need to develop innovative and inexpensive diagnostic methods to be used together with the consolidated systems. The Bone Structure Index is computed using a patented technique that virtually simulates the application of compressive loads on the trabecular structure’s reconstructions obtained from the patient’s digital radiographs. The radiograms are acquired by a hand-held portable x-ray system equipped with a digital sensor. This configuration presents specific advantages but the use of a handheld portable X-ray device requires safety procedures specifically designed to protect the operator and the patient, which are discussed in the present paper
PER CALCOLARE UN INDICE RAPPRESENTATIVO DELLE PROPRIETA’ DI UN MATERIALE, E DISPOSITIVO DI RILEVAZIONE CORRELATO
No full textIl presente trovato si riferisce ad un procedimento per calcolare un indice rappresentativo di una proprietà di un materiale, ad esempio un materiale di tipo osseo, a partire almeno da un’immagine di un campione di tale materiale. Il trovato si riferisce altresì ad un sistema di rilevazione configurato per agevolare l’operazione di rilevazione dell’immagine del suddetto campione
Osteoporosis? No need to panic!
No full text“Why should a professor of mechanical engineering decide to study bone tissue? Well, simply because she is interested in preventing any kind of breakage, and fractures are not an exception!” I think enabling structures to resist the applied loads is an innate desire of all engineers. The complex and highly organized inner architecture of bones makes this challenge even more exciting. In such a complex material, loss of bone mass alone cannot justify all osteoporosis-related fractures. Being aware of this I decided to focus my research on the fracture risk assessment and the impact of the complex trabecular structure of bone on internal force distribution, the ultimate goal being to improve knowledge of each patient’s specific conditions
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