Highly Accurate, Patient-Specific, 3-Dimensional Mixed-Reality Model Creation for Surgical Training and Decision-making

JAMA Surgery ◽  
2019 ◽  
Vol 154 (10) ◽  
pp. 968 ◽  
Author(s):  
Laurence Devoto ◽  
Sam Muscroft ◽  
Manish Chand
Author(s):  
Pratima Saravanan ◽  
Jessica Menold

With the rapid increase in the global amputee population, there is a clear need to assist amputee care providers with their decision-making during the prosthetic prescription process. To achieve this, an evidence-based decision support system that encompasses existing literature, current decision-making strategies employed by amputee care providers and patient-specific factors is proposed. Based on an extensive literature review combined with natural language processing and expert survey, the factors influencing the current decision-making of amputee care providers in prosthetic prescription were identified. Following that, the decision-making strategies employed by expert and novice prosthetists were captured and analyzed. Finally, a fundamental understanding of the effect gait analysis has on the decision-making strategies of prosthetists was studied. Findings from this work lay the foundation for developing a real-time decision support system integrated with a portable gait analysis tool to enhance prescription processes. This is critical in the low-income countries where there is a scarcity of amputee care providers and resources for an appropriate prescription.


Author(s):  
S. Minami ◽  
T. Ishida ◽  
S. Yamamoto ◽  
K. Tomita ◽  
M. Odamura

Abstract A concept for the initial stage of the mechanical design and its implementation in the computer-aided design (CAD) are presented. The process of decision making in design is: (1) determining an outline of the whole assembly using a 2-dimensional model that is easy to operate; (2) checking the outline using a 3-dimensional model in which it is easy to identify the spatial relationships; (3) determining details of its sub-assemblies or their components using the 2-dimensional model; and (4) checking the details using the 3-dimensional model. The CAD system must provide consistent relationships through all the steps. For that, following functions are implemented in our prototype system: (1) a 2D and 3D integrated model for consistency between 2- and 3-dimensional shapes, (2) a hierarchical assembly model with dimensional constraints for consistency within an assembly and their components, and (3) a check on constraints for consistency between shapes and designers’ intentions. As a result, the system can provide an environment well fitted to the designers’ decision making process.


2019 ◽  
Vol 30 (3) ◽  
pp. 281-287
Author(s):  
Jim W Pierrepont ◽  
Ed Marel ◽  
Jonathan V Baré ◽  
Leonard R Walter ◽  
Catherine Z Stambouzou ◽  
...  

Background: Optimal implant alignment is important for total hip replacement (THR) longevity. Femoral stem anteversion is influenced by the native femoral anteversion. Knowing a patient’s femoral morphology is therefore important when planning optimal THR alignment. We investigated variation in femoral anteversion across a patient population requiring THR. Methods: Preoperatively, native femoral neck anteversion was measured from 3-dimensional CT reconstructions in 1215 patients. Results: The median femoral anteversion was 14.4° (−27.1–54.5°, IQR 7.4–20.9°). There were significant gender differences (males 12.7°, females 16.0°; p < 0.0001). Femoral anteversion in males decreased significantly with increasing age. 14% of patients had extreme anteversion (<0° or >30°). Conclusions: This is the largest series investigating native femoral anteversion in a THR population. Patient variation was large and was similar to published findings of a non-THR population. Gender and age-related differences were observed. Native femoral anteversion is patient-specific and should be considered when planning THR.


2019 ◽  
Vol 2 (1) ◽  
pp. 24 ◽  
Author(s):  
Jin Hong

Even experienced mountain climbers underestimate key dangers and make poor decisions in stressful, high-risk situations when climbing, leading to injury and death. My own experience indicates that effective education can play a key role in managing these risks and improving experienced climber’s decision making. Current educational approaches for climbers, however, are generally limited to textbooks and ‘on the mountain’ learning. It is vital, therefore, that new approaches and methods are developed to improve learning.    My own experience and emergent case studies indicate that AR (Augmented), VR (Virtual Reality) and MR (Mixed Reality), have affordances (possibilities offered by the technology) to underpin new forms of learning and therefore have the potential to enhance education for high-risk environments. Emergent use of MR immersive technologies includes classroom learning, firefighting and military training. An initial review of literature has indicated though that there are very limited examples of rigorous research on the design and application of MR technologies in authentic education, especially for extreme situations such as mountaineering i.e., no one has rigorously designed for these technologies for learning in extreme environments, evaluated learning outcomes and theorised about how learning can be enhanced.    In response to this gap/opportunity, this research explores the potential of MR technologies to effectively enhance learning for authentic, high-risk situations. The research will use a Design-based research methodology (DBR) to develop design principles informed by key learning theories as they offer recognised and critical approaches for a new way of learning in an extreme environment.  Underpinned by a Constructivist paradigm, initial theoretical frameworks identified include Authentic Learning and Heutagogy (student-determined learning).Herrington and co-authors (2009) recommended 11 design principles for the incorporation of mobile learning into a higher education learning environment, and Blaschke and Hase (2015)’s 10 principles of designing learning for heutagogy. Other theories and frameworks include Constructivist Learning and the ZPD (the Zone of Proximal Development), design for mobile MR learning and user-centred design. Activity Theory will also be utilised in the data analysis.   Initial design principles will be developed by the DBR methodology. These design principles will be tested through the implementation and evaluation of an MR ‘prototype’ app design solution.’ The prototype solution will be iteratively redesigned using further evaluation and feedback from sample cohorts of end-users. Data will be collected from key participant interviews, researcher observation/reflections and biometric feedback. Methodological triangulation (multimodal data approach) will be used to evaluate learning outcomes. The iterative development will lead to transferable design principles and further theorising that can be transferred to other learning situations involving preparation and decision-making as well as knowledge in high-risk contexts.    Reference   Amiel, T., & Reeves, T. (2008). Design-Based Research and Educational Technology:   Rethinking Technology and the Research Agenda. Educational Technology                & Society, 11(4), 29-40.    Blaschke, L., & Hase, S. (2015). Heutagogy, Technology, and Lifelong Learning for Professional   and Part-Time Learners. In A. Dailey-Hebert & K. S. Dennis (Eds.), Transformative Perspectives   and Processes in Higher Education (Vol. 6, pp. 75-94). Switzerland: Springer                   International Publishing.   Cochrane, T., et al., (2017) ‘A DBR framework for designing mobile virtual reality learning  environments’, Australasian Journal of Educational Technology, vol. 33,  6, pp. 27–40. doi: 10.14742/ajet.3613    Engeström, Y. (2015). Learning by expanding: An activity-theoretical approach      to developmental research (2nd ed.). Cambridge, UK: Cambridge University Press.   Hase, S & Kenyon, C. (2001). Moving from andragogy to heutagogy: implications for VET',  Proceedings of Research to Reality: Putting VET Research to Work: Australian  Vocational Education and Training Research Association (AVETRA), Adelaide,  SA, 28-30 March, AVETRA, Crows Nest, NSW.   Kesim, M & Ozarslan (2012), Y. Augmented Reality in Education: Current                 Technologies and the Potential for Education, Procedia - Social and            Vygotsky, L. S. (1978). Mind in society: The development of higher psychological  processes. Cambridge, MA: Harvard University Press.     Behavioral Sciences volume 47, 2012, 297-302.  


2018 ◽  
Vol 15 (3) ◽  
pp. 341-349 ◽  
Author(s):  
Alexander I Evins ◽  
John Dutton ◽  
Sayem S Imam ◽  
Amal O Dadi ◽  
Tao Xu ◽  
...  

Abstract BACKGROUND Currently, implantation of patient-specific cranial prostheses requires reoperation after a period for design and formulation by a third-party manufacturer. Recently, 3-dimensional (3D) printing via fused deposition modeling has demonstrated increased ease of use, rapid production time, and significantly reduced costs, enabling expanded potential for surgical application. Three-dimensional printing may allow neurosurgeons to remove bone, perform a rapid intraoperative scan of the opening, and 3D print custom cranioplastic prostheses during the remainder of the procedure. OBJECTIVE To evaluate the feasibility of using a commercially available 3D printer to develop and produce on-demand intraoperative patient-specific cranioplastic prostheses in real time and assess the associated costs, fabrication time, and technical difficulty. METHODS Five different craniectomies were each fashioned on 3 cadaveric specimens (6 sides) to sample regions with varying topography, size, thickness, curvature, and complexity. Computed tomography-based cranioplastic implants were designed, formulated, and implanted. Accuracy of development and fabrication, as well as implantation ability and fit, integration with exiting fixation devices, and incorporation of integrated seamless fixation plates were qualitatively evaluated. RESULTS All cranioprostheses were successfully designed and printed. Average time for design, from importation of scan data to initiation of printing, was 14.6 min and average print time for all cranioprostheses was 108.6 min. CONCLUSION On-demand 3D printing of cranial prostheses is a simple, feasible, inexpensive, and rapid solution that may help improve cosmetic outcomes; significantly reduce production time and cost—expanding availability; eliminate the need for reoperation in select cases, reducing morbidity; and has the potential to decrease perioperative complications including infection and resorption.


2020 ◽  
Vol 13 (Suppl_1) ◽  
Author(s):  
Andrea R Mitchell ◽  
Grace Venechuk ◽  
Larry A Allen ◽  
Dan D Matlock ◽  
Miranda Moore ◽  
...  

Background: Decision aids frequently focus on decisions that are preference-sensitive due to an absence of superior medical option or qualitative differences in treatments. Out of pocket cost can also make decisions preference-sensitive. However, cost is infrequently discussed with patients, and cost has not typically been considered in developing approaches to shared decision-making or decision aids. Determining a therapy’s value to a patient requires an individualized assessment of both benefits and cost. A decision aid addressing cost for sacubitril-valsartan in heart failure with reduced ejection fraction (HFrEF) was developed because this medication has clear medical benefits but can entail appreciable out-of-pocket cost. Objective: To explore patients’ perspectives on a decision aid for sacubitril-valsartan in HFrEF. Methods: Twenty adults, ages 32-73, with HFrEF who met general eligibility for sacubitril-valsartan were recruited from outpatient HF clinics and inpatient services at 2 geographically-distinct academic health systems. In-depth interviews were conducted by trained interviewers using a semi-structured guide after patients reviewed the decision aid. Interviews were audio-recorded and transcribed; qualitative descriptive analysis was conducted using a template analytic method. Results: Participants confirmed that cost was relevant to this decision and that cost discussions with clinicians are infrequent but welcomed. Participants cited multiple ways that this decision aid could be helpful beyond informing a choice; these included serving as a conversation starter, helping inform questions, and serving as a reference later. The decision aid seemed balanced; several participants felt that it was promotional, while others wanted a more “positive” presentation. Participants valued the display of benefits of sacubitril-valsartan but had variable views about how to apply data to themselves and heterogenous interpretations of a 3% absolute reduction in mortality over 2 years. None felt this benefit was overwhelming; about half felt it was very small. The decision aid incorporated a novel “gist statement” to contextualize benefits and counter tendencies to dismiss this mortality reduction as trivial. Several participants liked this statement; few had strong impressions. Conclusion: Out of pocket cost should be part of shared decision-making. These data suggest patients are receptive to inclusion of cost in decision aids and that a “middle ground” between being promotional and negative may exist. The data, however, raise concerns regarding potential dismissal of clinically meaningful benefits and illustrate challenges identifying appropriate contextualizing language. The impact of various framings warrants further study, as does integration of decision aids with patient-specific out-of-pocket cost information during clinical encounters.


2020 ◽  
Vol 13 (Suppl_1) ◽  
Author(s):  
Birju Rao ◽  
Neal W Dickert ◽  
Alanna A Morris ◽  
Candace Speight ◽  
Graham Smith ◽  
...  

Background: Patients with heart failure with reduced ejection fraction (HFrEF) take on average 6 medications daily and can face considerable out-of-pocket medication costs. This issue has become particularly salient as newer medications such as sacubitril-valsartan have emerged as beneficial. As clinicians attempt to maximize benefits for this population, discussions of medication costs between patients and clinicians are critical. However, cost discussions are known to be infrequent and often suboptimal. Objective: To explore patients’ perspectives on discussing out-of-pocket medication costs with clinicians. Methods: 49 adults, aged 44-70, with HFrEF meeting general eligibility criteria for sacubitril-valsartan were recruited from outpatient heart failure clinics and inpatient services. Descriptive quantitative analysis of closed-ended and multiple-choice responses was conducted. Qualitative descriptive analysis of open-ended text data was performed. Results: About half (49%) of participants reported any previous discussion with clinicians about out-of-pocket cost related to medication. These participants described their experience with cost discussions at the time of prescription as generally positive. Specific ways these discussions were helpful included clarifying cost-benefit tradeoffs and identifying opportunities for cost reduction. Most participants (96%) were open to cost discussions with their clinician, and many (69%) specifically preferred that clinicians initiate discussions regarding medication cost. There were no differences in cost discussion preferences between participants who employed different decision-making approaches about initiation of sacubitril-valsartan or across levels of financial burden. Conclusion: Out-of-pocket cost is a relevant component of patient-centered medical decisions, particularly for patients with HFrEF. These data suggest patients with HFrEF are receptive to incorporating cost discussions into care and identify some of the ways these discussions may be helpful. Further research is needed to clarify how best to identify patient-specific cost at the time of clinical encounters and how to work with patients to make cost-benefit assessments.


2020 ◽  
Vol 10 (18) ◽  
pp. 6409 ◽  
Author(s):  
L. Esposito ◽  
V. Minutolo ◽  
P. Gargiulo ◽  
H. Jonsson ◽  
M. K. Gislason ◽  
...  

Total Hip Arthroplasty has been one of the most successful surgical procedure in terms of patient outcomes and satisfaction. However, due to increase in life expectancy and the related incidence of age-dependent bone diseases, a growing number of cases of intra-operative fractures lead to revision surgery with high rates of morbidity and mortality. Surgeons choose the type of the implant, either cemented or cementless prosthesis, on the basis of the age, the quality of the bone and the general medical conditions of the patients. Generally, no quantitative measures are available to assess the intra-operative fracture risk. Consequently, the decision-making process is mainly based on surgical operators’ expertise and qualitative information obtained from imaging. Motivated by this scenario, we here propose a mechanical-supported strategy to assist surgeons in their decisions, by giving intelligible maps of the risk fracture which take into account the interplay between the actual mechanical strength distribution inside the bone tissue and its response to the forces exerted by the implant. In the presented study, we produce charts and patient-specific synthetic “traffic-light” indicators of fracture risk, by making use of ad hoc analytical solutions to predict the stress levels in the bone by means of Computed Tomography-based mechanical and geometrical parameters of the patient. We felt that if implemented in a friendly software or proposed as an app, the strategy could constitute a practical tool to help the medical decision-making process, in particular with respect to the choice of adopting cemented or cementless implant.


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