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Additive manufacturing played a keyrole in investigating the precision of a recently-developed device that measures the elastic characteristics of the trabecular bone by simulating the application of loads on a virtual biopsy obtained from radiographic images of the proximal epiphyses in the patient’s hand fingers. The simulation results are combined in a Bone Structure Index (BSI), which has shown to be able to detect trabecular bone alterations due to osteoporosis or other pathological situations. In order to obtain a large number of measurements without having voluntary patients undergo unnecessary radiations, the precision assessment tests were carried out on a 3D-printed phantom hand, in which different mimicked trabecular structures (chips) were inserted. Each mimicked bone had a unique internal structure and density and was 3D-printed using radiopaque composite materials. Fifteen different chips were additively manufactured; 20 measurements were performed on each chip. BSI and BSI_T-score precision values were computed according to ISO 5725 and ISCD standards. For all the chips, no relationship was found between the mean [Formula: see text] and standard deviation [Formula: see text] of the measurements in each chip. The range of the 95% confidence interval ([Formula: see text]) was computed assuming the repeatability standard deviation [Formula: see text] as the known standard deviation of the measurement method (average of [Formula: see text] values): [Formula: see text], corresponding to [Formula: see text]. Least Significant Change was evaluated as well: [Formula: see text], corresponding to [Formula: see text]. The 95% confidence intervals are small when compared to the commonly-accepted diagnostic values, where a patient is classified as osteoporotic if T-score -1 and osteopoenic if -2.5

Background and Aims Chronic kidney disease is a frequent condition, characterized, especially in its more advanced stages, by an array of derangements in bone structure and density, resulting in a higher rate of bone fractures. Current strategies to monitor the bone status and assess the risk of bone fractures in CKD patients are limited. The Bone Elastic Structure (BES) test is a recently-developed non-invasive tool that measures the elastic characteristics of the trabecular bone by simulating the application of loads on a virtual biopsy obtained from radiographic images of the proximal epiphyses in the patient’s hand fingers. The simulation results are combined to obtain a parameter defined Bone Structure Index (BSI). The aim of our study is to explore whether the BES test could be a useful monitoring tool of bone status in patients with CKD on dialysis by exploring whether such patients have different BSI values compared with persons without CKD. Method The BES test was performed on a sample of 41 patients undergoing chronic hemodialysis (HD) and the BSI compared with a group of 374 persons with normal renal function who had undergone the BES test in previous studies. Differences in BSI and 95% confidence intervals (CIs) between the two groups were obtained and tested for statistical significance with a linear regression model including BSI as the dependent variable and kidney status (HD vs no HD) as the independent variable, adjusted for age and sex. Subgroup effects were explored by including interaction terms (age x kidney status, age x sex, kidney status x sex) in the model. Finally, to further remove the potential confounding by age and sex, each HD patient was individually matched with up to 4 non-HD participants based on sex and age (with a 5-year caliper) and a matched analysis was conducted on BSI values. Results Average (SD) age was 64 (17) years in the HD group and 60 (12) years in the non-HD group, with a prevalence of males of 49% and 16%, respectively. The individual values of BSI divided by kidney status and sex in Figure. The multivariate linear regression model showed that, after adjustment for age and sex, the BSI in the HD group was significantly lower compared with the non-HD group (HD 145, 95% CI 140, 154; non-HD 179, 95% CI 177, 181; absolute difference −32, 95% CI −40, −25; p-value < 0.001). There was no significant interaction between age, sex and kidney status on BSI values (all p-values > 0.05). Individual matching was successful for 36 out of 41 HD patients, who were matched to 127 non-HD participants; matched analysis confirmed the results (absolute difference −31, 95% CI −40, −23; p-value < 0.001). Conclusion The output of a non-invasive tool to determine the bone elastic structure appeared to be strongly associated with kidney function after control for differences in age and sex. Further studies are needed to determine the potential application of the BES test in patients with CKD.

Osteoporosis is a systemic skeletal disease where an increase in bone fragility is due to low bone mass and micro-architectural deterioration of bone tissue, which occur over a long period of time without clinical significance. Currently, Double Energy X-ray Absorption (DEXA) is the gold standard for bone mineral density assessment and the diagnosis of osteoporosis, but the majority of fractures occur in patients who would not be considered at fracture risk based on their Bone Mineral Density (BMD) values. It has long been known that fracture risk depends not only on mass loss, but also on bone architecture, whose alterations are an independent factor of increased fragility. The Bone Elastic Structure Test, BES TEST®, is a recently introduced analysis that assesses bone quality as expressed by the elastic properties of the trabecular micro-architecture from a virtual biopsy of the patient and could be a helpful add-on to densitometry for predicting fragility fractures and patient monitoring. The aim of this study is the comparison of DEXA and BES TEST® ability as 3-year risk estimators in a clinical application. In the CONTROL group, the BSI T-score is significantly different from the femoral DEXA T-score (p = 0.0005). In the FRACTURED group, the BSI T-score is significantly different from both the femoral DEXA T-score (p = 0.0266) and the lumbar DEXA T-score (p = 0.0051). Inter-group t-test statistical analysis (95% significance) shows that the femoral DEXA T-score (neck) of the CONTROL and the FRACTURED groups are not significantly different (p = 0.1478), while the BSI T-score of the CONTROL and the FRACTURED groups highlights a significant difference (p = 0.0001). Despite the small number of subjects, our data seem to confirm that the BSI could be a helpful add-on to densitometry for predicting fragility fractures and patient monitoring.

The 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.

Background Pituitary down regulators, aromatase inhibitors tamoxifen and chemotherapeutic drugs, all have a negative impact on bone health in breast cancer patients. Although trabecular bone accounts for only 20% of skeleton mass, bone resistance depends also on the its micro-architecture, or quality, of, in addition to bone density. The BESTEST® is an innovative and inexpensive diagnostic method that gives an indication of the quality of the bone structure: it measures the weight-bearing capacity of the bone structure, evaluated from simulated application of loads on bone structure images acquired by radiograms in the proximal epiphysis of the hand. Results are expressed as BSI_T-score and BSI_Z-score (which refers the results to the average value for the same age) and provide precious add-on information to densitometry. We discuss the preliminary results obtained in female patients undergoing breast cancer treatment. Material and methods 100 Caucasian women, took BESTEST® as follow-up while undergoing oncological treatment. Femoral neck DXA T-score available in a subgroup of 60. 10 patients self-reported an osteoporotic fracture, DXA T-score available for 8. Control population: 200 women, accessing BESTEST® and DXA for screening purposes, 30 self-reporting an osteoporotic fracture. Results Statistics: mean (min, max). NAgeBSI_T-scoreBSI_Z-scoreDXA_T-scorePopulation10061 (33, 88)-1.7 (-3.4, -0.0)-1.3 (-2.6, 0.6)NADXA subgroup (of oncological population)6062 (35, 88)-1.8 (-3.4, -0.1)-1.3 (-2.6, 0.6)-1.6 (-3.2, 0.5)Fractured subgroup1067 (56, 82)-2.4 (-2.9, -1.3)-1.8 (-2.6 -0.1)NAFractured subgroup with DXA868 (60, 82)-2.4 (-2.9, -1.3)-1.8 (-2.6 -0.1)-1.5 (-2.9, 0.1)Control20063 (32, 89)-1.1 (-3.6, 2.9)-0.6 (-3.0, 2.9)-1.9 (-3.7, 1.0) The fractured subgroup exhibits significantly lower BSI T-score than the population (T-test p< 0.0100) and results are similar after BSI Z-score correction for age (T-test p = 0.0300). The BSI T-score of the DXA subgroup is representative of the oncological population undergoing treatment (T-test p=0.8668). As expected, BSI T-score and DXA T-score are not correlated: R2 = 0.0917 in the control and R2 = 0.0294 in the population. The DXA subgroup exhibit significantly lower BSI T-score than the control (T-test p = 0.0002) and similar results are obtained after BSI Z-score correction for age. A lower significance (T-test p = 0.0281) is found for DXA T-score. The 8 fractured oncological patients exhibit significantly lower values of BSI T-score that the oncological population (T-test p = 0.038) and all patients have a BSI T-score indicative of a compromised trabecular structure. DXA T-score values cannot be considered statistically different (T-test p = 0.6744) and results span all possible diagnostic results from high risk to normal. Conclusions Statistical analyses show that bone micro-architecture is indeed affected by oncological treatment and that bone alterations due to oncological treatment are easily detected with BESTEST, especially when associated with fractures. This preliminary study clearly provides a rational background for further, deeper investigations into the use of a new, rapid and safe technique for monitoring the effect of breast and prostate cancers therapies on bone micro-architecture modifications. Citation Format: Cosmi F, Del Conte A, Foltran L, Nicolosi A, Saracchini S. New diagnostic tools for bone health assessment: Perspectives in medical oncology [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-03-08.

Additive manufacturing is gaining greater and greater popularity in recent years: thanks to a dramatic reduction of costs and increasing print quality, more and more people are attracted to 3D printing, even for the production of end-use load-bearing parts. Today, there are no universally accepted norms that guide the engineer through the uncertain task of predicting the mechanical behavior of 3D-printed parts. Even though there are numerous reports and articles in literature regarding this topic, the designer will have to rely mostly on his own mechanical tests. This paper describes the design of an in-house-built machine for 3D-printed material tensile testing. The accuracy of this test-rig has been verified through comparison of results on different 3D-printed specimens: these were realized through fused deposition modelling (FDM) and were divided into four distinct sets, based on the material and their orientation on the buildplate. Some samples were printed in PLA, others in XTCF-20™: a composite material made of a matrix of Amphora™ polymer reinforced with 20% in weight carbon short fibers. PLA samples were printed flat on the buildplate, on one side and standing: this affects directly the orientation of the plastic fibers. Tensile tests were performed both on ours and on a high-end commercial testing machine, following the ISO 527 norm. Maximum stress, strain at maximum stress and Young’s modulus were calculated for each tested specimen: these measures allowed to compare the results of the two testers. Results proved coherent, thus validating the in-house machine, which was realized for a fraction of the cost of an equivalent commercial model.

Additive manufacturing offers several advantages when compared to conventional manufacturing technologies, especially where large scale customization is requested. In this article, a procedure for the design of a fully-customized 3D-printed ankle-foot orthosis (AFO) is described, with reference to a case study regarding a 21-year-old woman with an injured ankle. The first step is the acquisition of the geometrical data from the patient’s foot: this is done using photogrammetry. The second step is the data conversion and import in a CAD modeler; SolidWorks™ is chosen for this purpose. The AFO is modelled parametrically around the foot mesh and optimized in order to resist the predicted mechanical stresses. Finally, the device is 3D-printed on an FDM printer and tested on the patient. An excellent geometrical correspondence between the AFO and the patient’s foot is highlighted: this leads to great comfort and enhances medical functionality. The described procedure can be easily automated, further reducing the lead time and costs of the whole process

Early phase endocrine-expansive breast and prostate cancers are treated with post-operative adjuvant hormonal therapies and chemotherapeutic drugs that have a negative impact on bone heath, blocking estrogen or androgen activity and increasing bone turnover leading to a progressively higher risk of fractures. At present, DXA monitoring of bone loss is widely recommended in prostate and breast cancer patients, but most fractures occur in patients whose DXA result falls outside the osteoporosis ranges, indicating that DXA might not be the elective exam for evaluating the degree of fracture risk in terms of microarchitecture alterations. The recently introduced Bone Structure Index (BSI) gives an indication of the quality of the bone structure. In this work, we discuss the preliminary results obtained in the evaluation of the BSI in female patients undergoing breast cancer treatment

We obtained an extended description of the abnormalities present in the bone structure in a rare inherited skeletal disorders. The 3D reconstructions of the trabecular architecture in the femur, obtained by CT scans, were the starting point for the morphological evaluation and the numerical elastic characterization of two subjects: a subject whose osteopetrosis was corrected by hematopoietic stem cell transplantation several years before and a healthy control. The Bone Structure Index, a novel parameter computed from the planar radiograms of the trabecular structure in the proximal epiphysis of the hand, was also evaluated. Important differences, that were not reported in literature before, were detected in homologous portions of the subjects

Osteoporosis is a silent disease, characterized by a decreasing bone strength, which leads to a progressive increase in fracture risk. As mean average human lifespan is growing, a parallel rise in the rate of osteoporosis is observed. Currently, diagnosis is made on the basis of bone mineral density, which seems to be a poor fracture predictor in about 40-50% of cases, and of clinical risk factors, but the trabecular structure arrangement should be evaluated as well. The BSI (Bone Structure Index) is a new index computed from simulated application of loads on a virtual biopsy of the patient. In this work, we aim to identify the distributions of BSI and of fragility fracture risk factors recognized by the scientific community in a population of over 300 female volunteers.

The micro-tomographic technique represents an important tool for the analysis of the internal structure in short-fibre-reinforced polymers samples. For the investigation of damage mechanisms, detection of the micro-voids within the matrix can be facilitated by applying a tensile load in-situ during the scan. The investigations here described started from two micro-CT acquisitions, at different strain levels, of the same PA6.6GF10 sample. An original procedure for micro-voids identification is proposed, based on the statistical elaboration of the matrix grey-tone range. In order to validate the suggested procedure beyond visual inspection, an independent method based on an optimisation approach, which puts to use the two available micro-tomographic sets, was developed and applied. The effect of the tensile load, which can induce a progression of the damage within the specimen, was investigated, and the relations among strain, fibre distribution and micro-voids volumetric fraction were studied. Our findings point out that the mechanisms of damage progression, even under static loading as in this case, appear to be more complex than those related to the fibre-density-induced stress concentrations alone and require further investigation.

Osteoarthritis (OA) is a degenerative joint disease that occurs mostly in the knee and in the hip. It is expected that more than 20% of the population over the age of 60 in Europe and in the United States will show signs and symptoms associated with OA, and that one-third of OA patients will experience disability and immobilization, hence the motivation for this research aimed at achieving new insights into the bone structure alterations induced by this disease. In an original approach, the 3D reconstructions obtained by high-resolution X-ray micro-CT were the starting point for: i) a morphological examination and 2) structural 3D analyses by numerical simulation of the bone architectures behavior, thus providing an extended description of the changes in osteoarthritic bone as disease progress. This paper presents the first results obtained by the combination of morphological and structural 3D analyses from on high-resolution micro-CT reconstructions of trabecular bone in early and late stage hip OA.

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).

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.

This article describes the significance in human, scientific, and technical terms of the first experiment in telerobotic surgery carried out between the NASA Jet Propulsion Laboratory in Pasadena, California, and the Telerobotics Laboratory of the Politecnico di Milano on 7 July 1993. An Italian robot in the Telerobotics Laboratory was remotely controlled by an Italian surgeon in the United States. The robot's task was to perform a surgical operation on a model containing a pig's organs, involving execution of a biopsy, aspi ration of organic material, and two incisions in preparation of laparoscopy. Transmission was effected by means of a double satellite link, with three transceiver stations: one in Italy, one close to New York, and one in Pasadena, and two geostation ary satellites, the first over the Atlantic and the second over the United States. The route length of the signals was 150,000 km in each direction, and the two centers are 10,000 km apart.

Optimization problems are frequently not straightforward. This is due, among other reasons, to the predefined design constraints and simultaneous target goals that have to be satisfied. In addition, uncontrollable variations can influence the robustness and stability of the design. Moreover, engineers often have to optimize mechanical components that are part of complex assemblies, in which it is difficult to extrapolate and define the boundary conditions to be applied for component optimization. The aim of this work is to present a step-procedure for the multi-goal optimization of components that are integrated in multi-part engineering systems. In order to illustrate the method, optimization of a carry-mould, part of a blowing machinery composed by several components, was used as a test case. Minimization of the carry-mould moment of inertia and the global mass were imposed as the target goals of the optimization process, while the maximum allowable displacement was set for a number of control points. The proposed procedure was capable of a time efficient and cost saving extensive investigation of the optimization design space.

A recent numerical method, the cell method, was applied for the dynamic analysis of an L-shaped steel plate subjected to a sinusoidal load. The calculated stress time histories were post-processed in order to assess fatigue life under four different high-cycle fatigue criteria: two formulations of the equivalent Von Mises approach and two critical plane methods. The latter require the definition of amplitude and mean value of the shear stress acting on a material plane: when considering periodic stress histories, this is commonly achieved by the construction of the minimum circumscribed circle (MCC), encompassing the shear stress load path on the assumed fracture plane. In this study, a novel algorithm to determine the MCC has also been proposed and applied. The fatigue life assessment results were discussed and compared to point out the relevant characteristics of each method.

A discrete model for the estimation of the effect of random voids on the structural properties of a two-dimensional solid is presented. Triangular void cells are used to simulate randomly located micro-cracks. The proposed model is solved using Cell Method, a recent numerical method that allows a direct discrete formulation of balance equations. Both heterogeneities of the structure and stress concentrations due to voids distribution are taken into account by the model. Following an introduction, some aspects of Cell Method for plane elasticity that are relevant for this paper will be briefly recalled and results from simulations in the elastic field will be discussed. Next, the proposed model will be extended to plastic field and more simulations will be presented. Results show that this model can be successfully employed to assess the structural response of a 2D solid with randomly distributed voids.

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 USA 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. The route length of the signals was 150,000 km in each direction and the two centres are 14,000 km apart. >

This paper analyses human control performance by means of a telemanipulation system and measurements of muscular activity during teleoperations. The task is performed with the aid of different types of interfaces. The control loop of a telerobotic manipulation system includes the human motion program. The control strategy for human motion is closely dependent on the type of interface available, that is, on the way the performance knowledge is presented to the operator. The analysis here proposed concerns the sensory and logical evaluation of this dependence in a telerobotic application, by means of EMG signal acquisition during teleoperations both in real and virtual environments. The experiments have been performed with a new paradigm for the evaluation of human feedback during the telemanipulation performance of a touch task. The paradigm adopted in this research is the result of the integration of robotics and neurology. >

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.

SummaryThis paper deals with the first transatlantic experiment of robotic telesurgery. A robot in Milan (Italy) performed an operation on a model of a pig, and the surgeon controller was in JPL, Pasadena (USA). By means of two communication satellites and of an optical fibre network, the robot performed a biopsy and a preliminary cut for a laparoscopic mini-invasive surgery operation.

The mechanical characterization of materials is often performed by expensive experimentations: for this reason the research is often developed with the collaboration of several laboratories, finally collating al the results. At this stage problems may arise due to data scattering: previous studies showed that it is often due to lateral or angular misalignments between the fixed and the moving machine crossheads. The object of this work is to design, manufacture and experimentally validate a novel loading-constraining device for misalignment compensation: conceptual design is applied to determine the optimal technical solution. The developed device, which can be mounted on different testing machines, achieves misalignment reduction with the use of a thrust bearing with sphered housing washers. The bearing is mounted beneath one of the specimen heads: the inverted orientation of the upper ring, allowing relative lateral displacement between the two rings, and the spherical shape of the housing compensate for offset and angular misalignments. Experimental results showed that such misalignments are respectively reduced to less than 0.02 mm and 0.05°, while the bending strain is lowered to just 6% of the nominal one, so that the requirements in different standards for mechanical testing can be fulfilled.