Wheeled vehicles are often incapable of transporting heavy materials over rough terrain or up staircases. Lower extremity exoskeletons supplement human intelligence with the strength and endurance of a pair of wearable robotic legs that support a payload. This paper summarizes the design and analysis of the Berkeley Lower Extremity Exoskeleton (BLEEX). The anthropomorphically-based BLEEX has seven degrees of freedom per leg, four of which are powered by linear hydraulic actuators. The selection of the degrees of freedom, critical hardware design aspects, and initial performance measurements of BLEEX are discussed.

(далее…)

Категория: Научные статьи | Нет комментариев »

Being a young discipline, Biomedical Engineering (BME) offers too few good textbooks for undergraduates. Moreover, in some of the available undergraduate BME textbooks, the levels of mathematics and engineering science were compromised in favor of a more qualitative approach. I was therefore happy to discover that in the recent title by Ritter et al., there is not only in-breadth overview on current BME fields, but also, in-depth analysis of specific selected topics that are supported by appropriate mathematical models, equations, quantitative data charts and tables. This indicates, however, that this book is intended for BME undergraduates at the sophomore, junior or senior years (but not for freshmen). Specifically, to work with this textbook, a student should have already learned calcu-lus, differential and integral equations, and basic engineering courses such as statics, dynamics, solid and fluid mechanics and analog electrical circuits. It should be acknowledged that the authors provide overviews on some of these topics where relevant.

(далее…)

Категория: Научные статьи | Нет комментариев »

An apparatus and method for extracting energy from an internal combustion engine includes a chamber having a primary piston and a secondary piston with a combustion portion of the chamber situated adjacently between the primary piston and secondary piston. The secondary piston includes a substantially lesser mass than that of the primary piston. The chamber includes at least one fluid port for supplying fuel to the combustion portion and an out-take port for releasing combustive exhaust. The chamber includes a controller for controlling the combustion therein at selected cycles of the primary piston. The secondary piston is configured to draw a portion of energy from combustion controlled by the controller in the chamber. Such portion of energy is provided with a rapid response to an energy transferring portion interconnected to the secondary piston, which in turn, transfers and/or converts the energy for acting on a load or external application.

(далее…)

Категория: Патенты | Нет комментариев »

In this population-based, observational study, we document the personal burden of fracture and utilization of community and health services for women during the 12-month period following a fracture. Participants were 598 women (aged 35–92 years) with inci-dent fracture in the years 1994–1996 who were enrolled in the Geelong Osteoporosis Study. Almost all hip fracture cases and 27% of nonhip fracture cases were hospitalized. Homes were modified in 14% of cases, and 32% of the women purchased or hired equipment to
assist with activities of daily living. Three-quarters of women with hip, pelvis, or lower limb fractures were confined to the ho-me, had to walk with a walking aid, or could walk only short distances for several weeks. After a year, nearly one-half had not re-gained prefracture mobility. One-seventh of women with upper-limb fractures did not venture outside the home for at least 6 weeks. Nearly half of all fracture cases needed help with personal care and housework during the first 6 weeks. After 6 months, 3.4% of all patients and 19.6% of hip, 12.8% of humeral, and 4.7% of spine fracture patients required assistance with bathing and show-ering. After a year, more than half of the hip fracture cases remained restricted regarding housework, gardening, and transport. These findings have important implications for rehabilitation therapy. A fracture, regardless of site, had a major impact on a woman’s lifestyle and wellbeing. Most women were restricted in their activities of daily living and suffered loss of confidence and independence. Short-term morbidity was common for all fractures, with varying degrees of prolonged morbidity often extending to at least a year postfracture.

(далее…)

Категория: Научные статьи | Нет комментариев »

A sit-to-stand assist device can serve the needs of people suffering from muscle weakness due to age or disabilities that make sit-to-stand a difficult functional task. The objective of this paper is to design a passive gravity-balancing assist device for sit-to-stand motion. In our study, it has been shown that the contribution to the joint torques by the gravitational torque is dominant during sit-to-stand motion. On the basis of this result, a gravity balanced assistive device is proposed. This passive device uses a hybrid method to identify the center-of-mass of the system using auxiliary parallelograms first. Next, appropriate springs are connected to the device to make the total potential energy of the system due to the gravity and the springs constant during standing up. A demonstration prototype with the underlying principles was fabricated to test the feasibility of the proposed design. The prototype showed gravity balancing and was tested by the authors. This prototype will be modified appropriately for clinical testing.

(далее…)

Категория: Научные статьи | Нет комментариев »