In the field of providing mobility for the elderly and disabled, the aspect of dealing with stairs continues largely unresolved. This paper focuses on presenting the development of a stair-climbing wheelchair mechanism with high single-step capability. The mechanism is based on front and rear wheel clusters connected to the base (chair) via powered linkages so as to permit both autonomous stair ascent and descent in the forward direction, and high single-step functionality for such as direct entry to and from a van. Primary considerations were inherent stability, provision of a mechanism that is physically no larger than a standard powered wheelchair, aesthetics, and being based on readily available low-cost components.
Lung transplantation is the last option for the treatment of end stage chronic lung disorders. Because the shortage of donor lung organs represents the main hurdle, lung regeneration has been considered to overcome this hurdle. Recellularization of decellularized organ scaffold is a promising option for organ regeneration. Although detergents are ordinarily used for decellularization, other approaches are possible. Here we used high alkaline (pH12) sodium hydroxide (NaOH)-PBS solution without detergents for lung decellularization and compared the efficacy on DNA elimination and ECM preservation with detergent based decellularization solutions CHAPS and SDS. Immunohistochemical image analysis showed that cell components were removed by NaOH solution as well as other detergents. A Collagen and GAG assay showed that the collagen reduction of the NaOH group was comparable to that of the CHAPS and SDS groups. However, DNA reduction was more significant in the NaOH group than in other groups (p < 0.0001). The recellularization of HUVEC revealed cell attachment was not inferior to that of the SDS group. Ex vivo functional analysis showed 100% oxygen ventilation increased oxygen partial pressure as artificial hemoglobin vesicle-PBS solution passed through regenerated lungs in the SDS or NaOH group. It was concluded that the NaOH-PBS based decellularization solution was comparable to ordinal decellularizaton solutions and competitive in cost effectiveness and residues in the decellularized scaffold negligible, thus providing another potential option to detergent for future clinical usage.
Earlier analyses of the laminar radially inward throughflow of Newtonian incompressible fluid between parallel corotating disks have been used to calculate the performance of multiple-disk turbines using such flow passages as the rotor. Such turbines are characterized by certain dimensionless parameters and a large number of computerized calculations has enabled preparation of turbine performance maps for turbines idealized as having no losses external to the rotor (except for assumed zero pressure recovery in the turbine exhaust). These maps show the quantitative dependence of turbine efficiency, total pressure and delivered power on the turbine geometry and speed, the turbine nozzle direction and pressure drop, and on the fluid properties; full admission around the periphery of the rotor is assumed. Conventional loss information for the nozzles, and conventional bearing, seal and “disk friction” loss information, must be applied in the design process to provide prediction of actual turbine performance and comparison with conventional turbines.
The purpose of this paper is to outline a radical approach toward providing wheeled mobility to the elderly or disabled. A robotic-hybrid wheelchair designed for operation in barrier present environments (the real world) is currently under construction at the Nagasaki Institute of Science (Japan). The wheelchair is targeted towards providing increased independence for wheelchair users andl or provide much needed assistance to care workers in the field of facilitating mobility to those who cannot be independently mobile. The wheelchair incorporates a hybrid of 4 robotic legs resembling human legs in operation interfacing wheels. Each leg provides three degrees of fYeedom which are actuated hydraulically, two degrees for lift and one degree for dynamically variable track width. Each foot is further equipped with independently operated steering and drive motors. The resultant wheelchair is estimated to be capable of negotiating stairs and a single step of up to 70 cm to allow for direct boarding to a vehicle. The proposed control is via a radio control for operation by the user or assistant in the case of care worker assisted mobility. Key in the design are aspects of safety, aesthetics and not exceeding the size of a standard powered wheelchair.
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