Papers by Thomas Hagedorn
Journal of Biomedical Informatics, 2015
Medical device design Engineering design Function based design Ontology Semantic knowledge manage... more Medical device design Engineering design Function based design Ontology Semantic knowledge management a b s t r a c t Medical device design is a challenging process, often requiring collaboration between medical and engineering domain experts. This collaboration can be best institutionalized through systematic knowledge transfer between the two domains coupled with effective knowledge management throughout the design innovation process. Toward this goal, we present the development of a semantic framework for medical device design that unifies a large medical ontology with detailed engineering functional models along with the repository of design innovation information contained in the US Patent Database. As part of our development, existing medical, engineering, and patent document ontologies were modified and interlinked to create a comprehensive medical device innovation and design tool with appropriate properties and semantic relations to facilitate knowledge capture, enrich existing knowledge, and enable effective knowledge reuse for different scenarios. The result is a Concept Ideation Framework for Medical Device Design (CIFMeDD). Key features of the resulting framework include function-based searching and automated inter-domain reasoning to uniquely enable identification of functionally similar procedures, tools, and inventions from multiple domains based on simple semantic searches. The significance and usefulness of the resulting framework for aiding in conceptual design and innovation in the medical realm are explored via two case studies examining medical device design problems.
The journals of gerontology. Series A, Biological sciences and medical sciences, Jan 20, 2015
Specific regions of the foot are responsible for the gait tasks of weight acceptance, single-limb... more Specific regions of the foot are responsible for the gait tasks of weight acceptance, single-limb support, and forward propulsion. With region foot pain, gait abnormalities may arise and affect the plantar pressure and force pattern utilized. Therefore, this study's purpose was to evaluate plantar pressure and force pattern differences between adults with and without region-specific foot pain. Plantar pressure and force data were collected on Framingham Foot Study members while walking barefoot at a self-selected pace. Foot pain was evaluated by self-report and grouped by foot region (toe, forefoot, midfoot, or rearfoot) or regions (two or three or more regions) of pain. Unadjusted and adjusted linear regression with generalized estimating equations was used to determine associations between feet with and without foot pain. Individuals with distal foot (forefoot or toes) pain had similar maximum vertical forces under the pain region, while those with proximal foot (rearfoot or m...
Journal of Foot and Ankle Research, 2014
Background: Foot disorders are common in older adults and associated with impaired lower extremit... more Background: Foot disorders are common in older adults and associated with impaired lower extremity function. Reduced muscle mass may play a role in the etiology of foot disorders and consequent poor function. Methods: We examined the association of leg lean mass with foot pain, posture and function among 1,795 individuals (mean age 67 years) from the population-based Framingham Foot Study (2002)(2003)(2004)(2005)(2006)(2007)(2008). Pain was assessed via questionnaire, and a pressure mat classified foot posture (arch: high, low, referent) during standing and function (pronation, supination, referent) during gait. Leg lean mass was measured by whole body dual energy x-ray absorptiometry.
PLoS ONE, 2013
Introduction: Foot disorders are common among older adults and may lead to outcomes such as falls... more Introduction: Foot disorders are common among older adults and may lead to outcomes such as falls and functional limitation. However, the associations of foot posture and foot function to specific foot disorders at the population level remain poorly understood. The purpose of this study was to assess the relation between specific foot disorders, foot posture, and foot function.
Osteoarthritis and Cartilage, 2013
Osteoarthritis and Cartilage, 2013
Journal of Biomechanics, 2012
While many studies use gait symmetry as a marker of healthy gait, the evidence that gait symmetry... more While many studies use gait symmetry as a marker of healthy gait, the evidence that gait symmetry exists is limited. Because gait symmetry is thought to arise through laterality (i.e., limb preference) and affects gait retraining efforts, it is important to understand if symmetry exists during gait in older adults. Therefore, the purpose of this study was to evaluate foot and gait symmetry in the population-based Framingham Foot Study as well as to determine the effects of vertical force symmetry on physical performance measures. Members of the Framingham Foot Study were included in this analysis (N=1333). Foot function and force data were collected using the Tekscan Matscan during self-selected gait, with symmetry evaluated using the symmetry index. The short physical performance battery (SPPB) measures of balance, chair stands and gait speed assessed lower extremity physical function. Participants were evaluated using quartiles of gait speed and foot symmetry to determine the effects of symmetry on lower extremity physical function. Individuals with faster gait speed displayed greater foot function asymmetry; individuals with -3.0% to -9.5% asymmetry in foot function performed better on the short physical performance battery (SPPB). Further, with aging, the degree of asymmetry was reduced. While this research suggests that a moderate degree of foot asymmetry is associated with better lower extremity function, the causes of vertical force asymmetry are unknown. Future studies should evaluate the causes of foot asymmetry and should track the changes in symmetry that occur with aging.
Arthritis Care & Research, 2011
Volume 1B: 34th Computers and Information in Engineering Conference, 2014
Within the medical field there has been significant progress in the creation of ontologies to rep... more Within the medical field there has been significant progress in the creation of ontologies to represent and utilize knowledge more effectively. These have culminated in the creation of large, curated medical ontologies for use in a wide array of applications, as well as higher level frameworks to organize and mitigate conflicts between disparate ontologies. While the engineering field has not been as enthusiastic in developing and adopting curated ontologies, there has been extensive research into how to effectively use semantic frameworks in engineering knowledge management and design in general, and specifically for the effective creation and documentation of functional basis models. Functional models are a useful tool in the early phases of product design, as they can help more effectively define goals and represent how a product must behave to accomplish these goals. In the specific realm of medical device design however, this process is complicated by a number of factors, including the complexity of the healthcare system and clinical knowledge as well as a lack of domain specific expertise in the engineering field. Because of these challenges, effective transfer of information from medical domain experts to an engineering context and subsequent utilization of this information is essential to the success of a medical device innovation and design project. Despite the magnitude and importance of this challenge few tools exist to help designers record, contextualize, and utilize medical knowledge for the specific purpose of engineering design. In this paper, we present a framework for directly integrating clinical knowledge relating to medical science and practice into the early phases of the engineering process to assist in medical device innovation and design. To accomplish this, existing medical and engineering ontologies were researched, obtained, and interlinked so as to explicitly tie functional models of medical device designs to the underlying medical clinical knowledge and procedures that define a product's operational environment. The result is a framework that unifies the knowledge embodied in large medical ontologies with the functional basis ontology. This integration facilitates the effective preservation and use of medical knowledge in functional model creation and in the invention and design processes in general. To demonstrate the potential usefulness of this framework, we present a simple example demonstrating how our framework can be used to associate a functional model with a deconstructed medical procedure. As a consequence we are able to integrate a medical perspective directly into an engineering model.
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Papers by Thomas Hagedorn