Development Of A Rehabilitation Mobility Assistive Device

The aim of the overall research presented here was to investigate the motion of a wheeled mobile robot in an indoor (structured) setting while following a pre-set trajectory. An example of an application for this research would be automated maneuvering of a smart power wheelchair in a health care setting, such as a hospital, which would benefit the aging Canadian population. For the specific research reported here, the aim was to investigate the mobility of an assistive device for Sit-to-Stand (STS) operation and walking. A rehab robot was developed and was attached to a wheeled mobile robot to accomplish STS operation and to help walk a patient for rehabilitation. Four major phases of this research are: (i) design of the rehab robot, (ii) development of the control algorithm, (iii) experimentation, and (iv) navigation of the mobile robot and the rehab walker (robot). This research project can be extended to lower limb rehabilitation and design of a smart walker. It intensively studied current research and projects, designed a rehab robot and four control algorithms to help people in both STS and walking processes. Experiments were implemented, and the results indicated the effectiveness of the control algorithms and the prescribed navigation algorithm. According to the results, this project achieved the original goals to assist people in standing up and walking, and to navigate to a pre-set location

Development of a Mobility Assistive Device for Sit-to-Stand

The aim of the overall research is to investigate the motion of a wheeled mobile robot in an indoor (structured) setting while following a given trajectory. An example of application for this research project would be automated maneuver of a smart power wheelchair in a medical health care setting, such as a hospital, which will benefit Canada. For this specific research project the aim was to investigate mobility of an assistive device for Sit-to-Stand (STS) operation and walking. A rehab robot was developed and was attached to a wheeled mobile robot to accomplish STS operation and to walk a patient for rehabilitation. Four major phases of this project are: (i) design of the rehab robot, (ii) development of control algorithm, (iii) experimentation, and (iv) navigation of the mobile robot and the rehab walker (robot). In order to design the rehab walker/robot, an intensive literature review was accomplished on reported research work for Sit-to-Stand (STS) and smart walker design for lower limb rehabilitation. Later, conceptual designs were suggested for selection process. One of them was selected to be the mechanical final design, and was designed in detail. Finite element analysis (FEA) was performed, before a prototype was fabricated. Due to different lift methods for STS operation, four different algorithms were developed which can be put into three classes: arm-pad support lift algorithm, handlebar support lift algorithm, and belt support lift algorithm. A friendly interface that governs the communication between users and the device has also been developed. Several participants tested the algorithms and answered a questionnaire. The results were collected and analyzed qualitatively and quantitatively. It showed that designed algorithms helped in STS process, and was able to find the comfortable position for each user within a reasonable time. User experiences were reported to be generally good, and the rehab robot reacted “smartly” depending to detected user intentions. Hence, it can be concluded that major design goals for the rehab robot had been achieved. After the rehab robot had been fully developed, it was attached to a wheeled mobile robot and went through a set of tests to determine whether a previously developed FLB (Fuzzy Logic Based) algorithm was appropriate for this project. The results showed that the FLB algorithm successfully reached its pre-set goals and avoided obstacles on its way. In summary, this project contributed in lower limb rehabilitation and design of a smart walker. It intensively studied current research and projects, designed a rehab robot and four control algorithms to help people in both STS and walking process. Experiments had also been implemented, and results indicate the effectiveness of control algorithms and the predesigned FLB navigation algorithm. According to the results, this project achieved original goals to assist people in rising up and walking, and it also navigated to pre-set goals successfully. However, more research is still needed for marketization purpose, such as collect, more test data to optimize threshold settings of control algorithms, and develop a better navigation algorithm that has a higher degree of comfort

Study on the MOF Frame Pt-TiO₂ Hybrid Photocatalyst and Its Photocatalytic Performance

As the efficient catalysts are synthesized by a simple strategy, photocatalysis offers a sustainable route to solve the problem of environmentally sound treatment of industrial dye wastewater. Herein, Pt-doped TiO2 with MIL-125 as the backbone has been fabricated using thermal synthesis. The photocatalytic efficiency of the synthesized catalyst samples was tested using Rhodamine B (RhB) as the contaminant model. The physicochemical properties of the solid specimens were characterized using XRD, SEM, TEM, BET and EDX techniques. The photocatalytic degradation experiments showed that the photocatalytic degradation of RhB by M-Pt-TiO2 was 98.97% after 30 min of degradation. The radical capture experiments showed that superoxide radicals and conduction band electrons as reactive oxygen species played a major role in the degradation process. After four cycles, the photocatalytic activity of M-Pt-TiO2 decreased from 98.4% to 94.9%, indicating that the photocatalyst sample had good photocatalytic stability

Evaluation of the value of preoperative CYFRA21-1 in the diagnosis and prognosis of epithelial ovarian cancer in conjunction with CA125

Abstract Growing evidence indicates that the tumor biomarker cytokeratin 19 fragment (CYFRA21-1) is significant for a variety of cancers. However, its role in epithelial ovarian cancer (EOC) has rarely been reported. In this study, a receiver operating characteristic (ROC) curve was utilized to estimate the diagnostic efficiency of CYFRA21-1. The correlation between the CYFRA21-1 level and prognosis was analyzed by Kaplan-Meier survival analysis and univariable and multivariable analyses. The relationship between serum CYFRA21-1 levels and different clinicopathological variables was also analyzed. At the same time, the standard serum marker cancer antigen 125 (CA125) was measured. The results demonstrated that CYFRA21-1 expression was significantly increased in EOC compared with expression in benign ovarian diseases and healthy controls, which was similar to CA125 (P < 0.001). CYFRA21-1 expression was positively correlated with CA125 (r = 0.201; P = 0.0032). CYFRA21-1 expression was significantly correlated with lymph node metastasis and ascites (P < 0.001). Furthermore, the median survival time of EOC patients with high CYFRA21-1 expression was 42 months, compared with 54 months in the low CYFRA21-1 expression patients by Kaplan-Meier analysis (P < 0.05), while the high and low CA125 expression groups had no difference in median survival time. Univariate and multivariate analyses indicated that CYFRA21-1 was a poor prognostic factor associated with overall survival (OS), while CA125 was not. Our study indicates that CYFRA21-1 acts as a good complementary diagnostic biomarker and may be superior to CA125 as a prognostic indicator in EOC

Nanoscale ductile fracture and associated atomistic mechanisms in a body-centered cubic refractory metal

Abstract Understanding the competing modes of brittle versus ductile fracture is critical for preventing the failure of body-centered cubic (BCC) refractory metals. Despite decades of intensive investigations, the nanoscale fracture processes and associated atomistic mechanisms in BCC metals remain elusive due to insufficient atomic-scale experimental evidence. Here, we perform in situ atomic-resolution observations of nanoscale fracture in single crystals of BCC Mo. The crack growth process involves the nucleation, motion, and interaction of dislocations on multiple 1/2  {110} slip systems at the crack tip. These dislocation activities give rise to an alternating sequence of crack-tip plastic shearing, resulting in crack blunting, and local separation normal to the crack plane, leading to crack extension and sharpening. Atomistic simulations reveal the effects of temperature and strain rate on these alternating processes of crack growth, providing insights into the dislocation-mediated mechanisms of the ductile to brittle transition in BCC refractory metals