Francesca Cosmi | Università degli Studi di Trieste (original) (raw)

Papers by Francesca Cosmi

Journal of the Mechanical Behavior of Biomedical Materials, 2009

Skeletal abnormalities reported in humans and laboratory animals after spaceflight, include cance... more Skeletal abnormalities reported in humans and laboratory animals after spaceflight, include cancellous osteopenia, decreased cortical and cancellous bone formation, aberrant matrix ultrastructure, decreased mineralization and reduced bone strength. Although considerable effort has been made up to now to understand the skeletal effects of spaceflight, in order to estimate health risk, our knowledge in this area is still largely incomplete.

Bone tissue is a complex multi-scale material and its morphological and functional characteristic... more Bone tissue is a complex multi-scale material and its morphological and functional characteristics are influenced during one's life by constant changes, physiological and pathological. A recent technique can classify the mechanical response of trabecular bone by simulating the application of loads with a Cell Method model derived from plane radiographic images of the proximal epiphyses in the pa-tient's hand fingers, thus complementing the individual assessment with a low cost exam. The mesoscale pathological modifications (i.e. due to osteoporosis) can be detected and quantified, despite the simplification due to the use of radiograms. In this work, this approach is validated using four idealized structures, modelling different trabecular organizations in the site of interest. Then, the results obtained in six female subjects, age between 35 and 77, are discussed to highlight the potential relevance of this application for the study, in quantitative terms, of the trabecular bone alteration due to age, pathological conditions and lack of exposure to physiological mechanical stimuli (micro-gravity conditions).

Osteoporosis is a very common disease in which the bones become weak and easily break. Besides th... more Osteoporosis is a very common disease in which the bones become weak and easily break. Besides the serious impact on a person's health and quality of life, osteoporosis results in important costs for society. The current diagnosis considers the bone quantity, as evaluated by bone mineral density assessments, and the clinical risk factors, but cannot take into account the bone quality, defined as the structural soundness of the trabecular arrangement. An approach based on the numerical modeling of the behavior of bone architectures, acquired by planar radiograms in the proximal phalanges of the non-dominant hand, has been developed at the University of Trieste. The Bone Structure Index, BSI, summarizes the simulations results for the purpose of bone quality ranking in the clinical evaluation. In this work, we discuss the preliminary design of a portable low dose x-ray scanner intended to be used as a low cost, user-friendly device for imaging the trabecular pattern and for providing a radiogram suitable for BSI evaluation. As an example, two cases in which the chosen device is used to evaluate the BSI are also reported.

Sommario Scopo di questo lavoro è presentare delle applicazioni del Metodo delle Celle nel campo ... more Sommario Scopo di questo lavoro è presentare delle applicazioni del Metodo delle Celle nel campo della meccanica dei solidi. Dopo aver introdotto il CM, viene dapprima presentata un'applicazione del Metodo delle Celle per la modellazione delle caratteristiche meccaniche in campo lineare di materiali porosi, quali i sinterizzati. Successivamente viene adottato il criterio di von Mises e vengono sviluppate le relazioni per la soluzione di problemi elastici non lineari. I risultati ottenuti con il CM vengono confrontati con quelli teorici. Viene discusso l'ordine di convergenza della soluzione in problemi non lineari. Abstract The aim of this paper is to present some applications of the Cell Method in the field of solid mechanics. Following an introduction to CM, a first application to porous – sintered – materials mechanical behavior modelling in the linear field is presented. Successively, von Mises criterion is adopted and non-linear elastic relations are developed. Comparis...

Computer Modeling in Engineering and Sciences

We present a methodology for solving the plane elasticity problem using the cell method. It is sh... more We present a methodology for solving the plane elasticity problem using the cell method. It is shown that, with the use of parabolic interpolation in a vectorial problem, a convergence rate of order 3.5 is obtained. Such a convergence rate compares with, or even is better than, the one obtained with FEM with the same interpolation – depending on the integration technique used by the FEM. The accuracy of the solution is also comparable or better.

An original experimental approach has been proposed, in which micro-tomography and morphological ... more An original experimental approach has been proposed, in which micro-tomography and morphological techniques have been successfully used to investigate the possibility and the significance of a morphology characterization of sclerofoams.

Computer Modeling in Engineering and Sciences

In industrial applications, microstructure inhomogeneities can derive from the manufacturing proc... more In industrial applications, microstructure inhomogeneities can derive from the manufacturing process and the final mechanical properties of the mate-rial depend on the resulting, complex, structural pattern of the constituents. In this paper, Cell Method plane models in the elastic and plastic fields are presented and applied to predict the behaviour of four sintered alloys, where the spatial arrange-ment of voids within the base material contributes to determine the mechanical behaviour. Unlike the Finite Elements and other methods, the Cell Method is a numerical method based on a direct discrete formulation of equilibrium equations, so that no differential formulation is needed in order to write the balance equations. One of the consequences of the Cell Method direct discrete approach is that no re-striction is imposed by differentiability conditions so that the characteristic length of the elementary cell in the discretization can be of the same order of magnitude of the heteroge...

Journal of the Mechanical Behavior of Biomedical Materials, 2015

a b s t r a c t One of the most important alterations that occur in man and experimental animals ... more a b s t r a c t One of the most important alterations that occur in man and experimental animals during spaceflight concerns the skeletal system, and entails important bone loss and degradation of mechanical properties. In the present work we investigate ex vivo the long-term effects of weightlessness (simulated microgravity) on bone tissue, by comparing the mesoscale structural properties of weight-bearing rat tibial epiphyseal cancellous structures of healthy animals (ground controls) with those of identical bone explants maintained ex vivo in the Rotary Cell Culture System (RCCS) bioreactor, used to model, on ground, microgravity conditions. Bone structures were reconstructed by synchrotron radiation micro-CT, morphometric analyses were performed, and the apparent elastic properties were computed by means of a numerical model based on the Cell Method. Two novel results were achieved in this study. First of all, the skeletal modifications found in bone explants after 3-4 weeks of culture in the RCCS bioreactor are in perfect agreement with those observed in vivo after a long-term spaceflight (Mice Drawer System mission, 2009), thus

Computers in Industry, 1993

ABSTRACT This paper describes the significance in human, scientific, and technical terms of the f... more ABSTRACT This paper describes the significance in human, scientific, and technical terms of the first experiment of robotic telesurgery effected between the Telerobotics Laboratory of the Politecnico di Milano and the Jet Propulsion Laboratory, NASA, in Pasadena California, on 7 July 1993. An Italian surgeon controlled from the U.S. A. an Italian robot in the Telerobotics Laboratory in such a way that the robot performed a biopsy, on a model containing the organs of a pig, carrying out an aspiration of organic material and two incisions for the commencement of the surgical operation of laparoscopy. Transmission was effected by means of a double satellite link with three stations -- one in Italy, one in New York and one in Pasadena -- and two geostationary satellites, the first over the Atlantic and the second over the United States.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

CMES: Computer Modeling in Engineering & Sciences, 2011

Abstract: In industrial applications, microstructure inhomogeneities can derive from the manufact... more Abstract: In industrial applications, microstructure inhomogeneities can derive from the manufacturing process and the final mechanical properties of the mate-rial depend on the resulting, complex, structural pattern of the constituents. In this paper, Cell Method plane models in ...

gruppofrattura.it

A new numerical model estimating the effect of randomly located micro-cracks on the structural re... more A new numerical model estimating the effect of randomly located micro-cracks on the structural response of a material is presented. Both heterogeneities of the structure and stress concentrations are taken into account by the model, that makes use of an homogeneous matrix in which ...

Frattura ed Integrità …, 2010

RIASSUNTO. Un'accurata osservazione della geometria tridimensionale di cricche e difetti è n... more RIASSUNTO. Un'accurata osservazione della geometria tridimensionale di cricche e difetti è necessaria per lo studio dei meccanismi alla base del processo di danneggiamento. I metodi convenzionali utilizzati a questo scopo sono distruttivi o non possiedono una sufficiente ...

EuroPACS-MIR 2004 Conference, Trieste, Italy, 2004

This paper introduces a new system that aims at giving an indication on bone structure load beari... more This paper introduces a new system that aims at giving an indication on bone structure load bearing capability and its pathological modifications, and may be re-garded as a complement to the diagnosis methodologies that are now in use. Starting from digital radiographic images, a ...

fstroj.uniza.sk

Resume In future years, fuel cells are expected to represent a promising technology as a source o... more Resume In future years, fuel cells are expected to represent a promising technology as a source of heat and electricity in buildings and of electrical power for vehicles, since fossil fuels are exhausting and significantly degrade air quality. It is well known that, when exposed to a hydrogen ...

Bulletin of Applied Mechanics, 2009

Back pain is reported as one of the main causes of absence from office work. Office furnishing, i... more Back pain is reported as one of the main causes of absence from office work. Office furnishing, in particular office chairs, can help overcoming this problem, improving health and comfort for workers with a correct ergonomic approach. An experimental study was conducted on six different office chairs that were examined and then tested by twelve adult subjects. The effect of chair ergonomics on the perceived level of comfort was investigated by means of objective data obtained by a BPMS (Body Pressure Measurement System) and subjective evaluations were drawn from a questionnaire. Particular attention was paid to the calibration and equilibration of the measurement system. The results point out interesting and unexpected correlations between subjective and objective evaluations of the chairs.

Space …, 1995

The initial phase of the telerobot project FRIEND (Flying Robot with Intelligently Ended Nursing ... more The initial phase of the telerobot project FRIEND (Flying Robot with Intelligently Ended Nursing Dexterity) being developed at Politecnico di Milano, Dipartimento di Meccanica, is described. It has been designed for space activities, such as rescue and recovery of ...

Journal of the Mechanical Behavior of Biomedical Materials, 2014

Densitometry is considered to be the gold standard in bone quality assessment. However, since its... more Densitometry is considered to be the gold standard in bone quality assessment. However, since its introduction, the medical community has been aware that mineral density is only one of the factors that influence the bone risk of fracture, which also depends on the bone's trabecular arrangement and, in particular, on the trabecular architecture's load bearing capabilities. At the University of Trieste, in recent years, a test has been developed that simulates the application of compressive loads on trabecular architecture's reconstructions extracted from digital radiographs. In this work, the test is described, and the results obtained by applying the appraisal in a particular case of severe osteoporosis of the hand, complicating a Complex Regional Pain Syndrome (CRPS) type II, are presented. The test was able to quantify the pathological alterations of bone micro-architecture by means of a Structural Index (SI), which was absolutely significant and relevant to the clinical situation. Important research and clinical opportunities of application of the test include accurate evaluation of osteoporotic bone diseases, careful clinical follow-up and monitoring of responses to therapeutic approaches, and, prospectively, reliable quantification of biological damage (forensic field). (G. Mazzoleni).

Journal of the Mechanical Behavior of Biomedical Materials, 2009

Skeletal abnormalities reported in humans and laboratory animals after spaceflight, include cance... more Skeletal abnormalities reported in humans and laboratory animals after spaceflight, include cancellous osteopenia, decreased cortical and cancellous bone formation, aberrant matrix ultrastructure, decreased mineralization and reduced bone strength. Although considerable effort has been made up to now to understand the skeletal effects of spaceflight, in order to estimate health risk, our knowledge in this area is still largely incomplete.

Bone tissue is a complex multi-scale material and its morphological and functional characteristic... more Bone tissue is a complex multi-scale material and its morphological and functional characteristics are influenced during one's life by constant changes, physiological and pathological. A recent technique can classify the mechanical response of trabecular bone by simulating the application of loads with a Cell Method model derived from plane radiographic images of the proximal epiphyses in the pa-tient's hand fingers, thus complementing the individual assessment with a low cost exam. The mesoscale pathological modifications (i.e. due to osteoporosis) can be detected and quantified, despite the simplification due to the use of radiograms. In this work, this approach is validated using four idealized structures, modelling different trabecular organizations in the site of interest. Then, the results obtained in six female subjects, age between 35 and 77, are discussed to highlight the potential relevance of this application for the study, in quantitative terms, of the trabecular bone alteration due to age, pathological conditions and lack of exposure to physiological mechanical stimuli (micro-gravity conditions).

Osteoporosis is a very common disease in which the bones become weak and easily break. Besides th... more Osteoporosis is a very common disease in which the bones become weak and easily break. Besides the serious impact on a person's health and quality of life, osteoporosis results in important costs for society. The current diagnosis considers the bone quantity, as evaluated by bone mineral density assessments, and the clinical risk factors, but cannot take into account the bone quality, defined as the structural soundness of the trabecular arrangement. An approach based on the numerical modeling of the behavior of bone architectures, acquired by planar radiograms in the proximal phalanges of the non-dominant hand, has been developed at the University of Trieste. The Bone Structure Index, BSI, summarizes the simulations results for the purpose of bone quality ranking in the clinical evaluation. In this work, we discuss the preliminary design of a portable low dose x-ray scanner intended to be used as a low cost, user-friendly device for imaging the trabecular pattern and for providing a radiogram suitable for BSI evaluation. As an example, two cases in which the chosen device is used to evaluate the BSI are also reported.

Sommario Scopo di questo lavoro è presentare delle applicazioni del Metodo delle Celle nel campo ... more Sommario Scopo di questo lavoro è presentare delle applicazioni del Metodo delle Celle nel campo della meccanica dei solidi. Dopo aver introdotto il CM, viene dapprima presentata un'applicazione del Metodo delle Celle per la modellazione delle caratteristiche meccaniche in campo lineare di materiali porosi, quali i sinterizzati. Successivamente viene adottato il criterio di von Mises e vengono sviluppate le relazioni per la soluzione di problemi elastici non lineari. I risultati ottenuti con il CM vengono confrontati con quelli teorici. Viene discusso l'ordine di convergenza della soluzione in problemi non lineari. Abstract The aim of this paper is to present some applications of the Cell Method in the field of solid mechanics. Following an introduction to CM, a first application to porous – sintered – materials mechanical behavior modelling in the linear field is presented. Successively, von Mises criterion is adopted and non-linear elastic relations are developed. Comparis...

Computer Modeling in Engineering and Sciences

We present a methodology for solving the plane elasticity problem using the cell method. It is sh... more We present a methodology for solving the plane elasticity problem using the cell method. It is shown that, with the use of parabolic interpolation in a vectorial problem, a convergence rate of order 3.5 is obtained. Such a convergence rate compares with, or even is better than, the one obtained with FEM with the same interpolation – depending on the integration technique used by the FEM. The accuracy of the solution is also comparable or better.

An original experimental approach has been proposed, in which micro-tomography and morphological ... more An original experimental approach has been proposed, in which micro-tomography and morphological techniques have been successfully used to investigate the possibility and the significance of a morphology characterization of sclerofoams.

Computer Modeling in Engineering and Sciences

In industrial applications, microstructure inhomogeneities can derive from the manufacturing proc... more In industrial applications, microstructure inhomogeneities can derive from the manufacturing process and the final mechanical properties of the mate-rial depend on the resulting, complex, structural pattern of the constituents. In this paper, Cell Method plane models in the elastic and plastic fields are presented and applied to predict the behaviour of four sintered alloys, where the spatial arrange-ment of voids within the base material contributes to determine the mechanical behaviour. Unlike the Finite Elements and other methods, the Cell Method is a numerical method based on a direct discrete formulation of equilibrium equations, so that no differential formulation is needed in order to write the balance equations. One of the consequences of the Cell Method direct discrete approach is that no re-striction is imposed by differentiability conditions so that the characteristic length of the elementary cell in the discretization can be of the same order of magnitude of the heteroge...

Journal of the Mechanical Behavior of Biomedical Materials, 2015

a b s t r a c t One of the most important alterations that occur in man and experimental animals ... more a b s t r a c t One of the most important alterations that occur in man and experimental animals during spaceflight concerns the skeletal system, and entails important bone loss and degradation of mechanical properties. In the present work we investigate ex vivo the long-term effects of weightlessness (simulated microgravity) on bone tissue, by comparing the mesoscale structural properties of weight-bearing rat tibial epiphyseal cancellous structures of healthy animals (ground controls) with those of identical bone explants maintained ex vivo in the Rotary Cell Culture System (RCCS) bioreactor, used to model, on ground, microgravity conditions. Bone structures were reconstructed by synchrotron radiation micro-CT, morphometric analyses were performed, and the apparent elastic properties were computed by means of a numerical model based on the Cell Method. Two novel results were achieved in this study. First of all, the skeletal modifications found in bone explants after 3-4 weeks of culture in the RCCS bioreactor are in perfect agreement with those observed in vivo after a long-term spaceflight (Mice Drawer System mission, 2009), thus

Computers in Industry, 1993

ABSTRACT This paper describes the significance in human, scientific, and technical terms of the f... more ABSTRACT This paper describes the significance in human, scientific, and technical terms of the first experiment of robotic telesurgery effected between the Telerobotics Laboratory of the Politecnico di Milano and the Jet Propulsion Laboratory, NASA, in Pasadena California, on 7 July 1993. An Italian surgeon controlled from the U.S. A. an Italian robot in the Telerobotics Laboratory in such a way that the robot performed a biopsy, on a model containing the organs of a pig, carrying out an aspiration of organic material and two incisions for the commencement of the surgical operation of laparoscopy. Transmission was effected by means of a double satellite link with three stations -- one in Italy, one in New York and one in Pasadena -- and two geostationary satellites, the first over the Atlantic and the second over the United States.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

CMES: Computer Modeling in Engineering & Sciences, 2011

Abstract: In industrial applications, microstructure inhomogeneities can derive from the manufact... more Abstract: In industrial applications, microstructure inhomogeneities can derive from the manufacturing process and the final mechanical properties of the mate-rial depend on the resulting, complex, structural pattern of the constituents. In this paper, Cell Method plane models in ...

gruppofrattura.it

A new numerical model estimating the effect of randomly located micro-cracks on the structural re... more A new numerical model estimating the effect of randomly located micro-cracks on the structural response of a material is presented. Both heterogeneities of the structure and stress concentrations are taken into account by the model, that makes use of an homogeneous matrix in which ...

Frattura ed Integrità …, 2010

RIASSUNTO. Un'accurata osservazione della geometria tridimensionale di cricche e difetti è n... more RIASSUNTO. Un'accurata osservazione della geometria tridimensionale di cricche e difetti è necessaria per lo studio dei meccanismi alla base del processo di danneggiamento. I metodi convenzionali utilizzati a questo scopo sono distruttivi o non possiedono una sufficiente ...

EuroPACS-MIR 2004 Conference, Trieste, Italy, 2004

This paper introduces a new system that aims at giving an indication on bone structure load beari... more This paper introduces a new system that aims at giving an indication on bone structure load bearing capability and its pathological modifications, and may be re-garded as a complement to the diagnosis methodologies that are now in use. Starting from digital radiographic images, a ...

fstroj.uniza.sk

Resume In future years, fuel cells are expected to represent a promising technology as a source o... more Resume In future years, fuel cells are expected to represent a promising technology as a source of heat and electricity in buildings and of electrical power for vehicles, since fossil fuels are exhausting and significantly degrade air quality. It is well known that, when exposed to a hydrogen ...

Bulletin of Applied Mechanics, 2009

Back pain is reported as one of the main causes of absence from office work. Office furnishing, i... more Back pain is reported as one of the main causes of absence from office work. Office furnishing, in particular office chairs, can help overcoming this problem, improving health and comfort for workers with a correct ergonomic approach. An experimental study was conducted on six different office chairs that were examined and then tested by twelve adult subjects. The effect of chair ergonomics on the perceived level of comfort was investigated by means of objective data obtained by a BPMS (Body Pressure Measurement System) and subjective evaluations were drawn from a questionnaire. Particular attention was paid to the calibration and equilibration of the measurement system. The results point out interesting and unexpected correlations between subjective and objective evaluations of the chairs.

Space …, 1995

The initial phase of the telerobot project FRIEND (Flying Robot with Intelligently Ended Nursing ... more The initial phase of the telerobot project FRIEND (Flying Robot with Intelligently Ended Nursing Dexterity) being developed at Politecnico di Milano, Dipartimento di Meccanica, is described. It has been designed for space activities, such as rescue and recovery of ...

Journal of the Mechanical Behavior of Biomedical Materials, 2014

Densitometry is considered to be the gold standard in bone quality assessment. However, since its... more Densitometry is considered to be the gold standard in bone quality assessment. However, since its introduction, the medical community has been aware that mineral density is only one of the factors that influence the bone risk of fracture, which also depends on the bone's trabecular arrangement and, in particular, on the trabecular architecture's load bearing capabilities. At the University of Trieste, in recent years, a test has been developed that simulates the application of compressive loads on trabecular architecture's reconstructions extracted from digital radiographs. In this work, the test is described, and the results obtained by applying the appraisal in a particular case of severe osteoporosis of the hand, complicating a Complex Regional Pain Syndrome (CRPS) type II, are presented. The test was able to quantify the pathological alterations of bone micro-architecture by means of a Structural Index (SI), which was absolutely significant and relevant to the clinical situation. Important research and clinical opportunities of application of the test include accurate evaluation of osteoporotic bone diseases, careful clinical follow-up and monitoring of responses to therapeutic approaches, and, prospectively, reliable quantification of biological damage (forensic field). (G. Mazzoleni).