A flexible electronic controller for a manipulator-type robot

Manipulator arm construction has changed little over the decades and is unlikely to change radically in the near future. The mechanical design necessary to achieve dexterity results in a system with complex dynamic properties. However, many manipulator manufacturers choose to ignore this complexity, concentrating on the mechanical design aspects rather than the design of the dynamic controller. In most cases, simple fixed-parameter single-loop PID compensators are utilised. In spite of the fact that the compensators are implemented on programmable devices, there is simply not enough processing power available to implement an improved dynamic control strategy. A multiprocessor controller has been developed which allows all the hierarchical levels of a manipulator controller to be implemented. The major advantage of the new controller is its ability to handle complex and time consuming dynamic algorithms for positioning of the robot end effector. This has been accomplished by adopting a master/slave multiprocessor configuration comprising a 20 MHz IBM PC/AT (80386) with a number of DSP cards based around the NEC 77230 floating-point DSP chip. Analog and digital input/output interfaces are provided for reading position signals and providing command signals. Tile motivation for the provision of such a controller was the desire to implement linear and nonlinear self-tuning control strategies. Both centralised (multivariable) and decentralized (single-loop) control strategies are considered and the new controller caters for both schemes by virtue of (a) the master/slave configuration with individual DSP boards for each joint, and (b) inter-board communications, allowing joint interactions to be catered for. In the paper, some of the identification algorithms required to support the nonlinear self-tuning strategies are described and real-time results presented. These results demonstrate the operation of the new controller and indicate some of its capabilities

Comparing Energy Expenditure During Land and Shallow Water Walking in Overweight and Obese Females

Introduction: The prevalence of overweight and obesity in the United States has reached epidemic levels. Reduction in body weight is of great importance for overweight and obese individuals through the increase in physical activity. One particular mode of physical activity that is currently growing in popularity is shallow water walking, although little research has been done examining the energy cost of this activity in an overweight and obese population. Purpose: To compare the energy expenditure (kcal/min) and rating of perceived exertion (RPE) of a bout shallow water walking at a self-selected pace to a bout of land walking at a matched heart rate response and to a bout of land walking at a self-selected pace in overweight and obese women. Methods: Nineteen participants completed three 10-minute experimental trials including a self-selected pace shallow water walking trial, a matched heart rate response land walking trial, and a self-selected pace land walking trial. Results: Significantly lower energy expenditure (p= 0.046) was observed for shallow water walking (6.46 ± 1.38 kcal/min) compared to the matched heart rate response land walking bout (7.26 ± 1.29 kcal/min), although no significant differences were detected for energy expenditure for shallow water walking and self-selected pace land walking (6.92 ± 1.61 kcal/min). No significant differences were detected for RPE across conditions (p=0.439). Exploratory analyses revealed correlations between measures of body composition (BMI and percent body fat) and the difference in energy expenditure between shallow water walking and matched heart rate response land walking. Conclusions: Findings from the current study suggest that although producing energy expenditure compared to heart rate matched land walking, shallow water walking is a viable alternative that can elicit and increase in energy expenditure performed at a moderate intensity, meeting ACSM criteria. Results of the exploratory analyses revealed an association between measures of body composition and differences in energy expenditure. Although only a limited number of participants of the present study had BMI’s above 35.0 kg/m2 (n=2), findings suggest that water exercise may be an alternative form of exercise and produce higher caloric expenditure at higher ranges of BMI and percent body fat

The Treatment and Outcome of Patients With Soft Tissue Sarcomas and Synchronous Metastases

Introduction: There is a strong association between poor overall survival and a short disease-free interval for patients with soft tissue sarcomas (STS) and metastatic disease. Patients with STS and synchronous metastases should have a very dismal prognosis.The role of surgery in this subgroup of patients with STS has not been defined

Energy Cost of Land and Shallow Water Walking in Females who are Overweight and Obese

Nineteen overweight or obese females completed three 10-minute experimental trials including a self-selected pace shallow water walking trial, a matched heart rate response land walking trial, and a self-selected pace land walking trial. Energy expenditure (kcal·min-1) was computed from expired gases assessed via indirect calorimetry. Results showed energy expenditure was lower (p= 0.046) during shallow water walking (6.46 ± 1.38 kcal·min-1) compared to matched heart rate response land walking trial (7.26 ± 1.29 kcal·min-1), with no significant difference in between shallow water and self-selected pace land walking (6.92 ± 1.61 kcal·min-1 ). The present study did not demonstrate superior energy cost of shallow water walking. However, results demonstrate that shallow water walking elicits an increase in energy expenditure, which may indicate that this form of activity is a reasonable alternative to land-based walking. Moreover, this form of activity may be particularly effective for individuals with mobility limitations during land-based exercise

Energy Cost of Land and Shallow Water Walking in Females who are Overweight and Obese

Nineteen overweight or obese females completed three 10-minute experimental trials including a self-selected pace shallow water walking trial, a matched heart rate response land walking trial, and a self-selected pace land walking trial. Energy expenditure (kcal·min-1)was computed from expired gases assessed via indirect calorimetry. Results showed energy expenditure was lower (p= 0.046) during shallow water walking (6.46 ± 1.38 kcal·min-1) compared to matched heart rate response land walking trial (7.26 ± 1.29 kcal·min-1), with no significant difference in between shallow water and self-selected pace land walking (6.92 ± 1.61 kcal·min-1). The present study did not demonstrate superior energy cost of shallow water walking. However, results demonstrate that shallow water walking elicits an increase in energy expenditure, which may indicate that this form of activity is a reasonable alternative to land-based walking. Moreover, this form of activity may be particularly effective for individuals with mobility limitations during land-based exercise

Alveolar Soft Part Sarcoma Metastatic to Small Bowel Mucosa Causing Polyposis and Intussuseption

A report of alveolar soft part sarcoma metastatic to the small bowel is presented. Hematogenous metastases to the small bowel from primary tumors outside the abdominal cavity are uncommon, and most remain asymptomatic and are not discovered until autopsy. However, small bowel metastases can lead to intestinal obstruction, intussuseption or even perforation. While metastases to the small bowel have been described for other tumor types, including melanoma and lung cancer, this is extremely uncommon for sarcoma, especially alveolar soft part sarcoma. We describe a 42-year-old male with a long history of alveolar soft part sarcoma, metastatic to the lung and brain, who developed an intussuseption from metastases to the small bowel