Generally People with disability like SCI use wheelchair for most parts of the day. These people do not have any muscle control below the level of injury which limits them from standing independently. It has been documented that standing provides various health and psychological benefits. In India, many people with disability live in rural areas where the terrain is uneven, affordability, portability and maintenance is also a concern. To maximize the benefits of standing, a manual standing mechanism has been incorporated into the wheelchair which could enable the user to get into standing position easily and independently. A support system is essential at the knee of the user to safely get them into the standing position. Getting into the standing position without the knee support could be potentially harmful. A safety mechanism has been incorporated to ensure that the standing mechanism cannot be activated without the knee support being in place. Another safety lock apart from knee support lock, has been designed to improve the safety of the device. The wheelchair is designed to work well on uneven surfaces. The manual configuration of the wheelchair and the standup mechanism ensures the ease of maintenance and affordability of the solution. The key objective of the design is safe manual standing wheelchair for outdoor use.
Some of the known prior art to the inventions are:
U.S. Ser. No. 09/946,455—Provides a body support system to ensure safety of the user in the standing position. While a harness for the user is also provided in our current design, the current work relates to ensuring extra safety by design by disengaging the standing mechanism itself in the attempt to stand without the knee support.
U.S. Ser. No. 06/612,916—Provides a body support system to ensure safety of the user in the standing position. While a harness is typically used to support the body, the current work relates to ensuring extra safety by disengaging the standing mechanism itself should the user make an attempt to stand without the knee support.
EP19970810375—Provides a mechanism to lower the footrest as the user gets into standing position for increased stability. The current design uses a longer base to provide for stability of the wheelchair in the standing position, as well as for ease of outdoor propulsion.
U.S. Pat. No. 4,569,556—Provides a mechanism to take the user into standing position and lower the footrest for stability.
To perform well in outdoor scenario and for extra stability in the standing position without moving the footrest down, the current design uses a longer 3 wheel configuration. This 3-wheel configuration poses other challenges, which have also been addressed in our design. To avoid obstruction with the front castor wheel and to ensure correct standing posture, the footrest is designed to be angled out sideways. A large handle is necessary to reduce the effort required for users with high levels of spinal injury who have very little strength in their upper limbs. In this design, despite the larger size of the handle, it is designed such that it does not interfere with the angled-out legs of the user. The large handle affects the portability of the device, and is hence designed to be removable.
Indian Patent Application No: 4806/CHE/2012 titled ‘A Multi-position wheelchair’—This provides a mechanism to take the wheelchair into standing as well as reclining position. The current work designs the standing mechanism for the 3 wheel base configuration with an ergonomic large handle which does not hit the legs of the user, and which is also removable for portability. The current work also includes the design of the safety mechanisms for the standing mechanism.
USPTO Backgrounds
USPTO Backgrounds