Recently, traditional impression has been rapidly replaced by digital impression using intraoral scanning. There are more than 7 types of intraoral scanners available in the dental market. It is difficult to make effective strategic choices due to a lack of standards and guidelines for optimal intraoral scanning devices. So far, little has been reported about evaluating the ergonomic aspect of these scanners. This literature review compares current intraoral scanning systems based on different types of handles and suggests the most comfortable, user-friendly intraoral scanners from an ergonomic standpoint.
Human Engineering

Studying some clinical feature of 85 patients with erythematosus systemic lupus showed that the early and frequent symptoms were essential persistent fever (95.29%), tired and weight loss (91.76%), alopecia (84.7%), menstruation disorder (52.56%). The symptoms were evaluated according to the diagnostic standards of arthropathy association of America including underformity arthritis (92.84%), facial rash (82.35%), renal lesion (71.75%), and discoid rash in the body (38.82%), oral mucosal ulceration (22.35%), multimembraine inflammatory (21.17%) and psychotic disorder (7.05%).
Human Engineering ; Workplace

BACKGROUND: Prolonged standing has been hypothesized as a vital contributor to discomfort and muscle fatigue in the workplace. The objective of this study was to develop a decision support system that could provide systematic analysis and solutions to minimize the discomfort and muscle fatigue associated with prolonged standing. METHODS: The integration of object-oriented programming and a Model Oriented Simultaneous Engineering System were used to design the architecture of the decision support system. RESULTS: Validation of the decision support system was carried out in two manufacturing companies. The validation process showed that the decision support system produced reliable results. CONCLUSION: The decision support system is a reliable advisory tool for providing analysis and solutions to problems related to the discomfort and muscle fatigue associated with prolonged standing. Further testing of the decision support system is suggested before it is used commercially.
Fatigue ; Human Engineering ; Muscle Fatigue

BACKGROUND: In 2004, Sharon Keene introduced a video microscope to the hair transplant field and discussed about the benefits such as ergonomics, quality assurance, and easy teaching. In 2009, our clinic set up digital video microscope systems. CCD-chip-loaded hand-held digital video microscope was connected to a 19-inch high definition (HD) LCD monitor. We compared the transection rates and graft-cutting time of two graft-dissecting methods to decide which one is more efficient. METHODS: Two technicians performed follicular unit graft dissection via two different methods of video microscopic and a combination of video microscope for slivering and loupe magnification for graft-cutting. All the procedures were recorded on high-definition digital video camera and cross-checked on the video clips. RESULTS: The transection rate of digital video microscope use was 2.2% while the combination method with 1.6%. For comparison of graft-producing time, the combination method could produce about equal amount of grafts in 186% faster the time. CONCLUSIONS: The work efficiency was greater with the combination method. The total graft productivity was nearly 2 times larger while the transection rates of two methods showed very close results.
Efficiency ; Hair ; Human Engineering ; Transplants

Effective and sustainable prevention of work-related musculoskeletal disorders (WR-MSDs) remains a challenge for preventers and policy makers. Coordination of stakeholders involved in the prevention of WR-MSDs is a key factor that requires greater reflection on common knowledge and shared representation of workers' activities among stakeholders. Information on workers' strategies and operational leeway should be the core of common representations, because it places workers at the center of the "work situation system" considered by the intervention models. Participatory ergonomics permitting debates among stakeholders about workers' activity and strategies to cope with the work constraints in practice could help them to share representations of the "work situation system" and cooperate. Sharing representation therefore represents a useful tool for prevention, and preventers should provide sufficient space and time for dialogue and discussion of workers' activities among stakeholders during the conception, implementation, and management of integrated prevention programs.
Administrative Personnel ; Fertilization ; Human Engineering ; Humans

Biohybrid artificial organs encompass all devices capable of substituting for an organ or tissue function and are fabricated from both synthetic materials and living cells. The viability of engineered tissue could be related to the viability of implanted cells. The system of viability assay for mammalian cell culture can be applied to the determination of cell viability for engineered tissue. This review explores various methods of cell viability assay which can be applied to the viability evaluation of engineered tissue. The major criteria employed in viability assays include survival and growth in tissue culture, functional assay, metabolite incorporation, structural altercation, and membrane integrity. Each viability assay method is based on different definitions of cell viability, and has inherent advantages and disadvantages. In order to be able to assess the viability of cells with one assay method, it is desirable to compare the viability measurements from various assays derived from different criteria.
Animal ; Biomedical Engineering*/methods ; Cell Division ; Cell Survival ; Human

The extensive regenerative capacity of hepatocytes and the key roles of the liver in metabolic processes have generated interest in the liver as an appropriate target for cell and gene therapy. If cells were considered as natural biomaterials, then liver cell transplantation would fall within the general field of bioengineering. While unmodified hepatocytes engraft in the liver and ectopic sites, biological modifications and optimization of bioengineered systems would facilitate engraftment and survival of transplanted cells, especially in ectopic locations. Acute liver failure, chronic liver disease and metabolic deficiency states are among the conditions that can potentially be treated by cell transplantation. In acute liver failure, cell transplantation into the liver, along with the creation of an extrahepatic reservoir of cells might be required because engraftment and proliferation of transplanted cells in the liver needs time. In other situations, gradual liver repopulation alone might well be effective without additional manipulations.
Animal ; Biocompatible Materials* ; Biomedical Engineering* ; Hepatocytes/transplantation* ; Human ; Liver*

Job hazard analyses were conducted to assess exposure to musculoskeletal disorder (MSD) risk factors in seven workers of three dry-cleaning establishments. In accordance with the Washington State Ergonomics Rule, the analyses were performed in two separate steps: (1) observation and checklist approaches were made to identify a “caution zone job” in the seven workers' pressing operations across the three shops; and (2) detailed posture and motion analyses were undertaken to determine a “MSD hazard” in one worker's operation using a video technique. One “caution zone job” was identified and it was the pressing operation job in which five physical risk factors were found in the pressing operations. The detailed analyses confirmed that one “MSD hazard”, i.e., awkward posture in shoulders, was prevalent in the pressing operations of the three dry-cleaning facilities. It would be desirable to reduce MSD risk factors including awkward shoulder posture in the dry-cleaning industry.
Checklist ; Human Engineering ; Posture ; Risk Factors* ; Shoulder ; Washington

BACKGROUND: The present rapid shift of industrialization from developed to developing countries requires developing countries to understand issues related to work organization, management, and working conditions. There are many factors slackening production, of which working conditions is part. A complete inquiry into the workers' working conditions can enable managements to reduce risks in the workplaces and improve productivity. Understanding and awareness of the benefits of workplace research and a probe into the working conditions in the Ugandan apparel assembly plants are urgently required. METHODS: A total of 103 (70 women and 33 men) workers from five different plants were interviewed. Together with the top management of various plants, questionnaires about the workers' opinions of their physical working conditions were prepared. Data was collected using two methods: (1) questionnaire; and (2) observation of the workers during their work. RESULTS: The results indicated that poor plant working conditions were mainly contributed by the workers' social factors and the management policies. CONCLUSION: The government, together with the management, should work to improve the working conditions in the apparel assembly plants, as it greatly affects both.
Developing Countries ; Efficiency ; Female ; Human Engineering ; Humans ; Plants ; Uganda

OBJECTIVES: The introduction of computerized numeric control (CNC) technology in manufacturing industries has revolutionized the production process, but there are some health and safety problems associated with these machines. The present study aimed to investigate the extent of postural discomfort in CNC machine operators, and the relationship of this discomfort to the display and control panel height, with a view to validate the anthropometric recommendation for the location of the display and control panel in CNC machines. METHODS: The postural discomforts associated with CNC machines were studied in 122 male operators using Corlett and Bishop's body part discomfort mapping, subject information, and discomfort level at various time intervals from starting to end of a shift. This information was collected using a questionnaire. Statistical analysis was carried out using ANOVA. RESULTS: Neck discomfort due to the positioning of the machine displays, and shoulder and arm discomfort due to the positioning of controls were identified as common health issues in the operators of these machines. The study revealed that 45.9% of machine operators reported discomfort in the lower back, 41.8% in the neck, 22.1% in the upper-back, 53.3% in the shoulder and arm, and 21.3% of the operators reported discomfort in the leg. CONCLUSION: Discomfort increased with the progress of the day and was highest at the end of a shift; subject age had no effect on patient tendency to experience discomfort levels.
Anthropometry ; Arm ; Human Engineering ; Humans ; Male ; Neck ; Surveys and Questionnaires ; Shoulder