Mobile laminar air flow screen for additional operating room ventilation: reduction of intraoperative bacterial contamination during total knee arthroplasty

Background Surgical site infections are important complications in orthopedic surgery. A mobile laminar air flow (LAF) screen could represent a useful addition to an operating room (OR) with conventional turbulent air ventilation (12.5 air changes/h), as it could decrease the bacterial count near the operating field. The purpose of this study was to evaluate LAF efficacy at reducing bacterial contamination in the surgical area during 34 total knee arthroplasties (TKAs). Materials and methods The additional unit was used in 17 operations; the LAF was positioned beside the operating table between two of the surgeons, with the air flow directed towards the surgical area (wound). The whole team wore conventional OR clothing and the correct hygiene procedures and rituals were used. Bacterial air contamination (CFU/m3) was evaluated in the wound area in 17 operations with the LAF unit and 17 without the LAF unit. Results The LAF unit reduced the mean bacterial count in the wound area from 23.5 CFU/m3 without the LAF to 3.5 CFU/m3 with the LAF (P<0.0001), which is below the suggested limit for anORwith ultraclean laminar ventilation. There were no significant differences in the mean bacterial count in the instrument table area: 28.6 CFU/m3 were recorded with the LAF (N = 6) unit and 30.8 CFU/m3 (N = 6) without the LAF unit (P = 0.631). During six operations with LAF and six without LAF, particle counts were performed and the number of 0.5 lm particles was analyzed. The particle counts decreased significantly when the LAF unit was used (P = 0.003). Conclusion When a mobile LAF unit was added to the standard OR ventilation, bacterial contamination of the wound area significantly decreased to below the accepted level for an ultraclean OR, preventing SSI infections

Structuring, Aggregating, and Evaluating Crowdsourced Design Critique

Feedback is an important component of the design process, but gaining access to high-quality critique outside a class-room or firm is challenging. We present CrowdCrit, a web-based system that allows designers to receive design critiques from non-expert crowd workers. We evaluated CrowdCrit in three studies focusing on the designer’s experience and bene-fits of the critiques. In the first study, we compared crowd and expert critiques and found evidence that aggregated crowd critique approaches expert critique. In a second study, we found that designers who got crowd feedback perceived that it improved their design process. The third study showed that designers were enthusiastic about crowd critiques and used them to change their designs. We conclude with implications for the design of crowd feedback services. Author Keywords Design; critique; feedback; social computing; crowdsourcin

Microbial biofilm growth vs. tissue integration: "the race for the surface" experimentally studied

Biomaterial-associated infections constitute a major clinical problem. Unfortunately, microorganisms are frequently introduced onto an implant surface during surgery and start the race for the surface before tissue integration can occur. So far, no method has been forwarded to study biofilm formation and tissue integration simultaneously. The aim of this study is to describe an in vitro method to investigate this “race for the surface”. First, a suitable growth medium was prepared that allowed both bacterial and tissue growth in a parallel plate flow chamber. Staphylococci were deposited on the glass bottom plate of the flow chamber in different surface densities, after which U2OS osteosarcoma cells were seeded. U2OS cells did not grow in the absence of flow, possibly due to poisoning by bacterial endotoxins, but under flow both staphylococci and U2OS cells grew. The number of adhering cells and area per spread cell were determined after 48 h in relation to the initial number of bacteria present. Both the number and spread area per cell decreased with increasing density of adhering staphylococci. This demonstrates that the outcome of the race for the surface between bacteria and tissue cells is dependent on the number of bacteria present prior to cell seeding.\u

The Shaping of Form: Exploring Designers’ Use of Aesthetic Knowledge

Research on design and designers has emphasized the tacit nature of the aesthetic knowledge that these professionals draw upon to make decisions about formal properties of objects and spaces, but is less clear about how design teams address the difficulties associated with expressing and sharing this type of knowledge. A ten-month ethnography in a design consultancy revealed a range of multimodal and cross-modal ways in which members of a design team compensate their imperfect capacity of articulating verbally their aesthetic knowledge in order to gradually construct a common knowledge base enabling creative collaboration. In so doing, our study offers two main contributions. It illuminates the interplay between designers’ aesthetic experiences, visceral responses, and intuitive cognitive processes that enable designers to draw upon their aesthetic knowledge to support the collective accomplishment of their task, and provides an interpretation of the design process as a form of ‘creative’ intuition driven by emotional reactions to environmental stimuli and emerging formal solutions

Equal opportunities: Do shareable interfaces promote more group participation than single users displays?

Computers designed for single use are often appropriated suboptimally when used by small colocated groups working together. Our research investigates whether shareable interfaces–that are designed for more than one user to inter-act with–can facilitate more equitable participation in colocated group settings compared with single user displays. We present a conceptual framework that characterizes Shared Information Spaces (SISs) in terms of how they constrain and invite participation using different entry points. An experiment was conducted that compared three different SISs: a physical-digital set-up (least constrained), a multitouch tabletop (medium), and a laptop display (most constrained). Statistical analyses showed there to be little difference in participation levels between the three conditions other than a predictable lack of equity of control over the interface in the laptop condition. However, detailed qualitative analyses revealed more equitable participation took place in the physical-digital condition in terms of verbal utterances over time. Those who spoke the least contributed most to the physical design task. The findings are discussed in relation to the conceptual framework and, more generally, in terms of how to select, design, and combine different display technologies to support collaborative activities

Dutch guideline on total hip prosthesis

Contains fulltext : 97840.pdf (publisher's version ) (Open Access

Human factors and ergonomics design principles and guidelines : helping designers to be more creative

This is a pre-copyedited version of a contribution published in: Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018). IEA 2018. Advances in Intelligent Systems and Computing, vol 824, edited by Bagnara S., Tartaglia R., Albolino S., Alexander T., Fujita Y., published by Springer, Cham. The definitive authenticated version is available online via https://doi.org/10.1007/978-3-319-96071-5_17.The knowledge and application of Human Factors/Ergonomics (HFE) principles and guidelines can help designers to develop better products and services. However, they may also include design constraints that may affect designers’ creativity. Although both HFE principles and guidelines and creativity are considered essential in the design of products and services, the link between them is little researched. In this article a discussion is presented on the influence that HFE principles and guidelines can exert on the creativity of designers. It also presents case studies of HFE principles and guidelines and discusses how they can influence designers’ creativity. In addition, a set of recommendations is suggested to help designers apply ergonomic design principles and guidelines to stimulate creativity. It is concluded that HFE principles and guidelines can assist designers in creating safer and more efficient products and services and can also broaden their creative process and therefore the originality and appropriateness of products and services