Pros And Cons For Wheelchair

Around the world, there are a lot of people with ambulatory disabilities. For examples, over $20$ million people have ambulatory disabilities in the United State \cite{US}, and a report on disability and rehabilitation by World Health Organization indicates that about $65$ million people worldwide need wheelchairs in $2008$ \cite{WHO}. Wheelchair is one of the most commonly used supporting devices for people with ambulatory disabilities to improve their personal mobility, which can enhance their health and quality of life \cite{ManualW}. However, users are often constrained to the sitting posture, which can cause severe damage such as pressure sore.

Standing is important to avoid such damage, and it also stretches out the muscles around the

Toileting cannot be done easily for wheelchair users since transferring between the wheelchair seat and the toilet seat requires sufficient upper body capabilities or at least one helper. Toileting is one of the fundamental life functions of human that should be done by him/herself, which is closely connected to their quality of life and self-reliant social life.

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\includegraphics[width=1.0\linewidth]{./Figures/1_Proposed.eps}

\caption{Outline drawing of the proposed passive exoskeleton for assisting voluntary posture transition of the children with impairment on lower limbs. }

%\newline The exoskeleton allows users to realize natural-like posture transition. The design can also allow users to do toilet with the exoskeleton. In addition, the exoskeleton design can can be integrated with a regular wheelchair to have locomotion capability.

\label{figure:Proposed}

\end{center}

Superior (Superior Sweden AB) is a powered wheelchair that can allow a user to have both sitting and standing posture \cite{Sweden}. Laddroller is a powered wheelchair with an exoskeleton that offers simultaneous maneuverability from standing position and posture adjustment without additional complex mechanisms \cite{Laddroller}.

%These mobilities are equipped with a powered mechanism for posture transition.

In our laboratory, Eguchi et al. have also developed a standing mobility vehicle with passive exoskeleton assisting voluntary posture control \cite{Eguchi}. The standing mobility vehicle is capable of assisting voluntary sitting-standing posture transition in addition to high mobility with upright posture.

%The passive exoskeleton using gas springs makes use of a user's center of gravity transition while user's natural sitting and standing posture transition. The sit-to-stand and stand-to-sit transition is an asymmetric motion, which the load moment by the user's weight around the ankle and knee joints are also asymmetric. The exoskeleton uses the human asymmetric properties, and realizes passive posture transition assisting