For the second assignment, Low Fidelity Prototyping, we are challenged to brainstorm and come up with solutions of swim support for Liam, who suffers from severe ataxia. It is hard for him to adequately control his body (he has fair head control in upright positions with adequate trunk control), and  while in water there is some relief from the struggle due to buoyancy. Our mission is to design a swim support with the following features:

1.Allow the majority of his body to be underwater, including his trunk, legs and possibly arms.

2.Keep his neck and head above water

3.Easy to maneuver by supporting adults (Especially assisting Liam to get in/out the device).

4.Significant trunk support (keep him upright/slightly reclined).

The first thing I tended to pay attention when brainstorming is the safety issue, and it is majorly related with feature 2 and feature 4 from above. Thinking about ways to keep his neck and head above water, I came up with 2 approaches — using buoyancy of water with air bags or low-density materials (foam etc.), and structural support. Then I came up with 5 possible solutions starting from these approaches. (Models will be updated. I forgot to take pics)

 

#1. Supporting Seat attached on Air Bag

          

First to keep Liam’s position stable under water, the buoyancy supporter should be balanced around him, so I first think of the idea of a life ring around his neck. However this approach may be very uncomfortable, as his body weight will be supported by the ring on his neck. Threfore I decided to take away 2 parts from the ring, first making a gap on the ring so it is easier for Liam to put on, and then make a cut 180 degrees away from the gap, so the ring became 2 connected air bags and Liam can put his arms on the bar in the middle (so the ring will be at his shoulder level). And to provide trunk support a seat with holes that allow his legs go through is attached to the ring.

 

3.

     

After coming up with the first model, I asked myself:  Is it possible to design an integrated air-bag system that supplies trunk support while providing buoyancy?  Similarly, starting from a life ring with a gap for the ease of  use. A slightly reclined seat back from hip to head is also part of the air-bag. Also, with a slightly reclined position, if Liam could move his feet under water the same way he did in his walking device, a pair of diving fins would allow him to slowly move backwards on his own!

#3 Tri-Ball

     

This design also utilizes buoyancy. The difference is that instead of using a single ring shaped device, this design takes advantage of the stability of triangles. Three foam balls are placed on the corner of the outer triangle to provide stable buoyancy, then the inner triangle is where Liam going to find himself in. He will be facing the direction of the arrow, and his arms can be locked on the two sides forming the angle he is facing. Also, in order to let him move around the pool, the balls attached to the front side will have motors and the one on the corner behind him will be equipped with a steering paddle.

 

#4.  ‘The Backpack’

        

There are also 3 foam balls that provide buoyancy. Instead of the tri-ball system that Liam has to ‘ride’, this device is smaller in size, easier to carry and use and more comfortable. The way Liam use it is like having a backpack on his back. The strap system serves 3 functions: providing trunk support when tightened, supporting the foam balls, and supporting the motor. The adjustable parts of the strap system are the two shoulder straps and the waist belt — When Liam put the device on, just pull the straps on his shoulder to make them shorter and thus tight on his shoulder like a backpack, and buckle up the waist belt from his back. The driving system is also simplified, with a single motor that is capable of spinning under a range of angles to change direction of movement.

 

5. The Moving Seat

    

This model adopts the second approach of keeping his head above water, structural support. Liam is going to sit on a chair made from nets and has his arms fastened on the armrests for safe. The chair can be locked on a chair support connected to the sides of the pool with 4 extendable bars. The horizontal bars will be movable on the vertical direction, and simultaneously the vertical bars will elongate or shrink like antennas on old radios. Vice Versa. So the position of the chair will be determined by a x and y values. the depth of the chair support will be designed such that water is allowed to cover his shoulder. The problem about this device is the expense.