Saadé, Raafat George, Tsoukas, Alexander, and Tsoukas, George
Expert Systems with Applications. Oct2004, Vol. 27 Issue 3, p427-438. 12p.
ARTIFICIAL intelligence, OSTEOPOROSIS, NEURAL computers, and SELF-organizing systems
This paper describes a prototype of a decision support system developed to assess patients with osteoporosis. The system was embedded into the clinical workflow environment. This system is being used in two clinics and one hospital center in Canada. Osteoporosis is a disorder with major physical and economical implications. Assessing and properly managing patients with osteoporosis is complex and requires high level of expertise. Expertise alone does not totally address the problem as it involves the attitudes and behavioral states of the general practitioner, the patient and the specialist. The system''s architecture, subcomponents and integrated workflow are described. The system was developed based on the experiences of a specialist with 50 patients. As of the end of 2003, the system was used for 45 patients. The reports generated were shown to general practitioners who were not able to distinguish them from an actual specialist report. In this paper we present one case and demonstrate the main differences between the report generated by the system and a report produced by the specialist. Experiences in using the system as it is integrated into the clinical workflow are discussed. Valuable insights into the integration and use of web-based decision support systems are highlighted. [Copyright &y& Elsevier]
Current Applied Physics. May2010, Vol. 10 Issue 3, p729-733. 5p.
SIMULATION methods & models, MATERIAL plasticity, OSTEOPOROSIS, BONE mechanics, BONE fractures, MEDICAL care, TRAUMATOLOGY, STRAINS & stresses (Mechanics), FINITE element method, and RAPID prototyping
Abstract: Osteoporotic vertebral fractures present a major health care burden worldwide, thereby prompting vigorous investigation of the mechanical properties of vertebral bone. Because most vertebral fractures occur gradually and asymptomatically, they are thought to result from loading in daily activities rather than traumatic events. Hence, with respect to stress resistance, the elastic properties of osteoporotic vertebral trabecular bone have generated many studies. A large part of this data describes the linear elastic properties of the bone, with relatively less focus on the plastic mechanical characteristics which may be closely associated with load-induced fracture. We performed experimental and simulated studies of the plastic mechanical characteristics of osteoporotic trabecular bone using non-destructive technologies, rapid-prototyping (RP), and finite element (FE) analysis to build models based on high-resolution micro-computed tomography (micro-CT) data. Two-dimensional geometries for RP and FE models were derived from micro-CT scans of specimens from the central part of the lumbar vertebrae of aged female donors. A cubic specimen (6.5mm) and a cylindrical specimen (7mm in diameter and 5mm long) were generated for the RP and FE models and analysed in place of real bone specimens. We performed simulated compression tests with the FE models to indirectly validate results of the experimental compression tests. To a remarkable degree, results obtained from experimental and simulated compression tests with the RP and FE models concurred. The results of this study support the use of RP technology and FE analysis in the non-destructive evaluation of the plastic mechanical characteristics of osteoporotic bone. [Copyright &y& Elsevier]
OSTEOPOROSIS, AXIAL loads, THORACIC vertebrae, TOMOGRAPHY, FRACTURE mechanics, BUCKLING (Mechanics), STRENGTH of materials, FLEXURE, and RAPID prototyping
Abstract: Vertebral wedge fractures are associated with combined compression and flexure loading and are the most common fracture type for human vertebrae. In this study, rapid prototype (RP) biomodels of human vertebral trabecular bone were mechanically tested under uni-axial compression loading and also under wedge action loading (combination of compression and flexure loading) to investigate the mode of failure and the ultimate loads that could be sustained under these different loading conditions. Two types of trabecular bone models were manufactured and tested: baseline models which were directly derived from μCT scans of human thoracic vertebrae, and osteoporotic models which were generated from the baseline models using a custom-developed bone loss algorithm. The ultimate load for each model under compression and wedge action loading was determined and a video was recorded of each test so that failure mechanisms could be evaluated. The results of the RP model mechanical tests showed that the ultimate loads that could be supported by vertebral trabecular architectures under wedge action loading were less than those that could be supported under uni-axial compression loading by up to 26%. Also, the percentage reduction in strength from the baseline value due to osteoporotic bone loss was slightly less for the wedge action loading compared to uni-axial compression loading. Analysis of the videos for each test revealed that failure occurred in localised regions of the trabecular structure due to bending and buckling of thin vertical struts. These results suggest that vertebral trabecular bone is more susceptible to failure from wedge action loading compared to uni-axial compression loading, although this effect is not exacerbated by osteoporotic bone loss. [Copyright &y& Elsevier]