Journal of Biomechanical Engineering-Transactions of the Asme最新文献

The superficial medial collateral ligament (sMCL) of the human knee joint has functionally separate anterior and posterior fiber bundles. The two bundles are alternatively loaded as the knee flexion angle changes during walking. To date, the two bundles are usually not distinguished in knee ligament simulations because there has been little information about their material properties. In this study, we conducted quasi-static tensile tests on the sMCL of matured porcine stifle joints and obtained the material properties of the anterior bundle (AB), posterior bundle (PB), and whole ligament (WL). AB and PB have similar failure stress but different threshold strain, modulus, and failure strain. As a result, we recommend assigning different material properties (i.e., modulus and failure strain) to the two fiber bundles to realize biofidelic ligament responses in human body models. However, it is often inconvenient to perform tensile tests on AB and PB. Hence, we proposed a microstructural model-based approach to predict the material properties of AB and PB from the test results of WL. Such obtained modulus values of AB and PB had an error of 2% and 0.3%, respectively, compared with those measured from the tests. This approach can reduce the experimental cost for acquiring the needed mechanical property data for simulations.

Computational human body models (HBMs) provide the ability to explore numerous candidate injury metrics ranging from local strain based criteria to global combined criteria such as the Tibia Index. Despite these efforts, there have been relatively few studies that focus on determining predicted injury risk from HBMs based on observed postmortem human subjects (PMHS) injury data. Additionally, HBMs provide an opportunity to construct risk curves using measures that are difficult or impossible to obtain experimentally. The Global Human Body Models Consortium (GHBMC) M50-O v 6.0 lower extremity was simulated in 181 different loading conditions based on previous PMHS tests in the underbody blast (UBB) environment and 43 different biomechanical metrics were output. The Brier Metric Score were used to determine the most appropriate metric for injury risk curve development. Using survival analysis, three different injury risk curves (IRC) were developed: "any injury," "calcaneus injury," and "tibia injury." For each injury risk curve, the top three metrics selected using the Brier Metric Score were tested for significant covariates including boot use and posture. The best performing metric for the "any injury," "calcaneus injury" and "tibia injury" cases were calcaneus strain, calcaneus force, and lower tibia force, respectively. For the six different injury risk curves where covariates were considered, the presence of the boot was found to be a significant covariate reducing injury risk in five out of six cases. Posture was significant for only one curve. The injury risk curves developed from this study can serve as a baseline for model injury prediction, personal protective equipment (PPE) evaluation, and can aid in larger scale testing and experimental protocols.

Developing entrepreneurial mindset (EM) can help students understand the bigger picture, recognize opportunities, and learn from mistakes to create value. The purpose of this work was to promote EM development in a required junior-level mechanical engineering course. A pre-existing assistive device project was adapted to incorporate entrepreneurial-minded learning activities requiring students to demonstrate curiosity, make connections, and create value. The project was completed across the entire semester. Students created photojournals and participated in activities to build empathy for project clients. Value propositions were developed and presented before the course content was applied to design and evaluate assistive devices. At the conclusion of the project, the students reported high self-efficacy with the EM-related project objectives.

Belt-positioning booster (BPB) seats may prevent submarining in reclined child occupants in frontal impacts. BPB-seated child volunteers showed reduced lateral displacement in reclined seating in low-acceleration lateral-oblique impacts. As submarining was particularly evident in reclined small adult female occupants, we examined if a booster seat could provide similar effects on the kinematics of the small female occupant to the ones found on the reclined child volunteers in low-acceleration far-side lateral oblique impacts. The THOR-AV-5F was seated on a vehicle seat on a sled simulating a far-side lateral-oblique impact (80 deg from frontal, maximum acceleration ∼2 g, duration ∼170 ms). Lateral and forward head and trunk displacements, trunk rotation, knee-head distance, seatbelt loads, and head acceleration were recorded. Three seatback angles (25 deg, 45 deg, 60 deg) and two booster conditions were examined. Lateral peak head and trunk displacements decreased in more severe reclined seatback angles (25-36 mm decrease compared to nominal). Forward peak head, trunk displacements, and knee-head distance were greater with the seatback reclined and no BPB. Knee-head distance increased in the severe reclined angle also with the booster seat (>40 mm compared to nominal). Seat belt peak loads increased with increased recline angle with the booster, but not without the booster seat. Booster-like solutions may be beneficial for reclined small female adult occupants to reduce head and trunk displacements in far-side lateral-oblique impacts, and knee-head distance and motion variability in severe reclined seatback angles.

Science, technology, engineering, and mathematics (STEM) education workshops and programs play a key role in promoting early exposure to scientific applications and questions. Such early engagement leads to growing not only passion and interest in science, but it also leads to skill development through hands-on learning and critical thinking activities. Integrating physiology and engineering together is necessary especially to promote health technology awareness and introduce the young generation to areas where innovation is needed and where there is no separation between health-related matters and engineering methods and applications. To achieve this, we created a workshop aimed at K-12 (grades 9-11) students as part of the Summer Youth Programs at Michigan Technological University. The aim of this workshop was to expose students to how engineering concepts and methods translate into health- and medicine-related applications and cases. The program consisted of a total of 15 h and was divided into three sections over a period of 2 weeks. It involved a combination of theoretical and hands-on guided activities that we developed. At the end of the workshop, the students were provided a lesson or activity-specific assessment sheet and a whole workshop-specific assessment sheet to complete. They rated the programs along a 1-5 Likert scale and provided comments and feedback on what can be improved in the future. Students rated hands-on activities the highest in comparison with case studies and individual independent research. Conclusively, this STEM summer-youth program was a successful experience with many opportunities that will contribute to the continued improvement of the workshop in the future.

Diversity, equity, and inclusion (DEI) are interconnected with bioengineering, yet have historically been absent from accreditation standards and curricula. Toward educating DEI-competent bioengineers and meeting evolving accreditation requirements, we took a program-level approach to incorporate, catalog, and assess DEI content through the bioengineering undergraduate program. To support instructors in adding DEI content and inclusive pedagogy, our team developed a DEI planning worksheet and surveyed instructors pre- and post-course. Over the academic year, 74% of instructors provided a pre-term and/or post-term response. Of responding instructors, 91% described at least one DEI curricular content improvement, and 88% incorporated at least one new inclusive pedagogical approach. Based on the curricular adjustments reported by instructors, we grouped the bioengineering-related DEI content into five DEI competency categories: bioethics, inclusive design, inclusive scholarship, inclusive professionalism, and systemic inequality. To assess the DEI content incorporation, we employed direct assessment via course assignments, end-of-module student surveys, end-of-term course evaluations, and an end-of-year program review. When asked how much their experience in the program helped them develop specific DEI competencies, students reported a relatively high average of 3.79 (scale of 1 = "not at all" to 5 = "very much"). Additionally, based on student performance in course assignments and other student feedback, we found that instructors were able to effectively incorporate DEI content into a wide variety of courses. We offer this framework and lessons learned to be adopted by programs similarly motivated to train DEI-competent engineering professionals and provide an equitable, inclusive engineering education for all students.

Design projects, particularly those related to assistive technology, offer unparalleled educational opportunities for undergraduate students to synthesize engineering knowledge with a clinically driven need to produce a product that can improve quality of life. Such projects are most effective when engineering, clinical, and business perspectives are considered throughout. However, the logistics of successfully implementing such interdisciplinary projects can be challenging. This paper presents an auto-ethnography of 12 undergraduate design team projects in assistive technology performed by 87 students from five majors (including engineering, business, and clinical students) over the course of 5 years. The overarching goal of our work was to establish an undergraduate integrated design experience at a university in the absence of a dedicated biomedical engineering major. The focus of this experience was to foster the creation of student-led prototypes to address real-world problems for people with disabilities while keeping commercialization potential at the forefront throughout. Student participation demonstrated a clear enthusiasm for completing biomedical engineering-themed projects. To encourage the implementation of similar approaches at universities where a biomedical engineering major does not exist, we identify common obstacles that can arise and present strategies for mitigating these challenges, as well as effective approaches for catalyzing cross-disciplinary collaborations. High impact practices include close involvement of end-users in the design process; cross-disciplinary team composition (e.g., engineering, business, and health sciences students); and choosing cross-disciplinary leads for project management. Teams experienced a high degree of success with all 12 teams producing functional prototypes. We conclude that at universities that do not offer a biomedical engineering major, health-focused integrated design experiences offer students important interdisciplinary perspectives, including a holistic approach to project implementation. Furthermore, for many students, these projects ultimately served as a gateway to subsequent careers and graduate study in biomedical engineering.

The global learning initiative at Northeastern University is focused on fostering intercultural communication skills. The Dialogue of Civilization (DOC) program serves as a mechanism to achieve such a goal by offering faculty-led international experiences. In this paper, we have presented a detailed account of a DOC program that took place in Norway. The primary objective of the program was to teach mechanical engineering and bio-engineering students computational skills while stimulating critical thinking about the cultural and social aspects of technology and engineering in Norway. The program focused on two courses: a technical course and a special topics course. The technical course introduced students to finite element analysis, with practical applications and site visits in Norway to enhance experiential learning. In the special topics course, the interplay between modern technologies, like green energy, state policies, and the rights and traditions of the indigenous Sámi people was explored. The course highlighted both the progressive social policies in Norway and the historical discrimination against the Sámi. Student feedback was positive and experiential learning components such as guest lectures and site visits were particularly appreciated. Additional surveys showed that students' self-confidence was higher following the DOC program. In addition, female-identifying students had higher confidence in their future success after completion of this program as compared to their male-identifying counterparts. Our paper is expected to serve as a resource for educators seeking to integrate technical education with intercultural experiences and discussions on social and cultural impacts in engineering.

To help foster interest in science, technology, engineering, and math (STEM), it is important to develop opportunities that excite and teach young minds about STEM-related fields. Over the past several years, our university-based research group has sought to help grow excitement around the biomechanics and biomedical engineering fields. The purposes of this technical brief are to (1) discuss the development of a partnership built between a St. Louis area high school and biomechanics research lab and (2) provide practical guidance for other researchers looking to implement a long-term outreach program. The partnership uses three different outreach opportunities. The first opportunity consisted of 12th-grade students visiting university research labs for an up-close perspective of ongoing biomedical research. The second opportunity was a biomedical research showcase where research-active graduate students traveled to the high school to perform demonstrations. The third opportunity consisted of a collaborative capstone project where a high school student was able to carry out research directly in a university lab. To date, we have expanded our reach from 19 students to interacting with over 100 students, which has yielded increased interest in STEM related research. Our postprogram survey showed that outreach programs such as the one described herein can increase interest in STEM within all ages of high school students. Building partnerships between high schools and university researchers increases the interest in STEM amongst high school students, and gives graduate students an outlet to present work to an eager-to-learn audience.

Measurements of brain deformations under injurious loading scenarios are actively sought. In this work, we report experimentally measured head kinematics and corresponding dynamic, two-dimensional brain simulant deformations in head surrogates under a blunt impact, with and without a helmet. Head surrogates used in this work consisted of skin, skull, dura, falx, tentorium, and brain stimulants. The head surrogate geometry was based on the global human body models consortium's head model. A base head surrogate consisting of skin-skull-brain was considered. In addition, the response of two other head surrogates, skin-skull-dura-brain, and skin-skull-dura-brain-falx-tentorium, was investigated. Head surrogate response was studied for sagittal and coronal plane rotations for impactor velocities of 1 and 3 m/s. Response of head surrogates was compared against strain measurements in PMHS. The strain pattern in the brain simulant was heterogenous, and peak strains were established within ∼30 ms. The choice of head surrogate affect the spatiotemporal evolution of strain. For no helmet case, peak MPS of ∼50-60% and peak MSS of ∼35-50% were seen in brain simulant corresponding to peak rotational accelerations of ∼5000-7000 rad/s2. Peak head kinematics and peak MPS have been reduced by up to 75% and 45%, respectively, with the conventional helmet and by up to 90% and 85%, respectively, with the helmet with antirotational pads. Overall, these results provide important, new data on brain simulant strains under a variety of loading scenarios-with and without the helmets.