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

BACKGROUND: To assess the knowledge, attitude, and practice of ergonomics among dental professionals of Hubli-Dharwad twin cities, India. METHODS: Investigator-developed, self-administered, closed-ended questionnaire assessing knowledge, attitude, and practices regarding ergonomics during dental practice was filled in by undergraduates, house surgeons, postgraduates, and faculty members of dental institutions and private practitioners from Hubli-Dharwad twin cities. RESULTS: Data were collected from a total of 250 participants, 50 belonging to each academic group. Overall mean knowledge, attitude, and practice scores were 52%, 75%, and 55%, respectively. Significant correlation was found for age with attitude (chi2 = 10.734, p = 0.030) and behavior (chi2 = 12.984, p = 0.011). Marital status was significantly associated with all the three domains; knowledge (chi2 = 29.369, p = 0.000), attitude (chi2 = 29.023, p = 0.000), and practices (chi2 = 13.648, p = 0.009). CONCLUSION: Participants had considerable awareness and behavior toward ergonomics in dental practice. The high attitude score indicates stronger acceptance of ergonomics principles and guidelines during routine dental procedures. The current study highlights the situation of ergonomics in dental practice in the form of knowledge, attitude, and practices.
Human Engineering* ; Humans ; India* ; Marital Status ; Surveys and Questionnaires

BACKGROUND: This study aimed to investigate the relation between key strike forces and musculoskeletal symptoms (MSS). Moreover, this study presents a key strike force measurement method to be used in a workplace setting. The correlation between key strike force characteristics and MSS was previously studied, but the measurement methods used either a single-key switch or force platforms applied under the keyboard. Most of the studies were conducted in a laboratory setting. The uniqueness of measurement methods in the current study is their ability to measure forces applied to a specific key in a workplace setting and to provide more information about specific key strike forces during typing. METHODS: Twenty-four healthy computer workers were recruited for the study. The demographic questionnaire, and self-reported questionnaires for psychosocial status (General Nordic Questionnaire for Psychological and Social Factors at Work) and for detecting MSS were filled up, which later helped in dividing the participants into two groups (12 participants with pain and 12 without pain). Participants typed a predetermined text that utilized the instrumented keys multiple times. The dynamic forces applied to the keys were recorded and collected, using four thin and flexible force sensors attached to the preselected keys according to their location. RESULTS: The results demonstrated that participants with high levels of MSS, specifically in the back and neck, in the last year exerted significantly higher key strike forces than those with lower levels of symptoms (p < 0.005). CONCLUSION: The key strike force exerted while typing on a keyboard may be a risk factor for MSS, and should therefore be considered in ergonomic evaluations and interventional programs.
Human Engineering ; Methods ; Neck ; Risk Factors ; Strikes, Employee*

The skin acts as a barrier to exogenous substances, pathogens, and trauma. Skin defects caused by burns, venous ulcer, diabetic ulcer, or acute injury occasionally induce life-threatening situations. Tissue engineering provides an alternative for autologous or allogeneic tissue transplantation, which is required because of donor site limitations and the risks of transmitting infection. Currently, skin substitutes are made of only extracellular matrix, mainly cells, or combination of cells and matrices. New biotechnological approaches have led to the development of the skin equivalent, the closest match yet to native human skin in terms of histological and functional properties. This review article focuses upon the development of the in vitro and in vivo epidermis and dermis and their clinical applications.
Biocompatible Materials ; Biomedical Engineering* ; Collagen ; Human ; Keratinocytes/transplantation ; Skin, Artificial*

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*