Occupational fall injuries presenting to the emergency department.

OBJECTIVES: This study was performed to evaluate occupational and fall injuries presenting to the ED, the risk factors associated with falls among all occupational injuries, and factors affecting prognosis. METHODS: Data from ED-based Occupational Injury Surveillance System were analysed to investigate the occupational injuries. The 2147 occupational injury subjects were divided into two groups: fall (n = 213, 9.9%) and non-fall (n = 1934, 90.1%). Data including baseline and clinical characteristics were compared between the groups. RESULTS: The mean age was older in the fall group (46 vs 42 years old). The rate of construction site-related injury was 32% in the fall group and only 8% in the non-fall group. Injury occurrence during regular working hours (09.00 hours to 18.00 hours) was 70% in the fall group and 57% in the non-fall group. Injury severity using the Excess Mortality Ratio-adjusted Injury Severity Score (EMR-ISS) was more severe in the fall group than in the non-fall group, and days away from work were longer in the fall group than the non-fall group. Older age, compared with an age <29 years old and presence in a construction area during regular working hours were factors associated with fall injuries. Factors affecting prolonged absence for work were older age, higher EMR-ISS, fall injury and poor workplace environmental conditions. CONCLUSION: Risk factors associated with fall-related occupational injuries include older age and being at a construction area during regular working hours. Falls among occupational injuries are more severe than other injuries and result in longer work loss.

Comprehensive evaluation of layer separation tendency of novel three-layered tablets with geometric and mechanical properties.

The layer separation tendency of a novel three-layered matrix tablet was investigated according to various physical properties and novel experiments. Even though layer separation did not occur during manufacturing process and storage, it was observed during a dissolution test depending on the mid-layer formulation. According to the powder properties of the mid-layer substances, Form A, which had higher porosity and lower density than Form B, displayed a tendency of layer separation. These properties correlated with the degree of absorption of the aqueous medium into the mid-layer, which was evaluated by water uptake and mass loss tests. Water uptake and mass loss profiles of the formulations were similar, but the mass loss property of Form A was about 5% higher at the time points, due to the faster dissolution rate of the mid-layer in the first 0.5h. Using a texture analyzer, the layer separation force of the system and adhesion force between the barrier layers were evaluated to understand the correlation between the geometric property and layer separation tendency. During the first 0.5h, the wrapping property of the swollen barrier layers significantly affected the layer separation tendency. The drug release profiles of two formulations could be divided into three stages on the basis of their geometric property as it showed a sigmoid-type. However, for the first stage (about initial 1h in duration), the drug release of Form A was more than Form B due to the mid-layer's powder properties. The results provided valuable information for detailed understanding of issues in the development of a multi-layered system and indicated the importance of a well-designed tablet formulation and manufacturing process.

Tunable-focus liquid lens system controlled by antagonistic winding-type SMA actuator.

A new tunable-focus liquid lens system is proposed that consists of a liquid-filled PDMS (polydimethylsiloxane) membrane, special liquid injection mechanism based on a cam structure, antagonistic winding-type SMA(shape memory alloys) actuator for changing the surface curvature of the membrane, and liquid injection control system, including a digital signal processing board and actuator driver board. The focal length of the liquid lens is adjusted by changing the radius of the curvature of the liquid lens through redistributing the liquid using an injection mechanism. In the case of liquid lens systems using conventional injection mechanisms, the nonlinear relationship between the focal length change and the actuator displacement makes it difficult to control the focal length of the lens system, as there is only a narrow control range for adjusting the focal length over a wide range. In addition, miniaturization of the lens system is difficult due to the requirement of bulky and heavy actuators, such as an electrical motor and pump[7]. Thus, a relatively light and small SMA actuator is proposed for a compact lens system. This paper then provides a detailed description of the proposed tunable-focus liquid lens system, and an experimental system is also implemented. Finally, the focusing performance of the proposed liquid lens system is analyzed, and its usefulness and effectiveness verified through a series of experiments.

Biomimetic variable-focus lens system controlled by winding-type SMA actuator.

Inspired by the biomechanics of the human eye, which includes a crystalline lens, ciliary muscles, and zonular fibers, the proposed variablefocus lens system consists of a PDMS lens, winding-type SMA actuator, and load arms. The PDMS lens is encircled and stretched by the load arms joined to an outer ring that is rotated by the winding-type SMA actuator, thereby changing the focal length of the lens. In contrast to other single tunable-focus lenses, the proposed system uses a gel-type PDMS lens, which is insensitive to gravity and external vibration, and can be made into a biconvex or aspheric shape. The design of the proposed system is described in detail, and experimental results demonstrate the validity of the proposed system.