Is it theoretically possible to build such a device?
Brief History
So how do you think you can make a paralyze walking device?
First of all our walking system is academically approved and internationally patented. After it is published in CORDIS (Community Research & Development Information Service of European Union) database we were invited to Medical Device Conference in Australia. After the theoretical approval of our technology we made the first prototype of our walking system in order to obtain and test the real balance advantage and efficiency of our patented walking system.
We achieved realization processat our research lab at Boğaziçi University by the financial and facility support of “KOSGEB Technological Development Center” which has its own academic committee and application criteria for acceptance. During the prototype building process, we were invited to Innovation Zone of Cebit Euroasia which is especially organized to exhibit extraordinary future products.
The only reason we can claim that is; we have a patented balancing system which makes it possible to build and produce a motorized walker for paralyzed patients.
At the previous section the problems of building such a device is explained in detail. Those were shortly:
This system would not be able to do anything that a robot can’t do
The patient must move his upper body exactly like a robot.
Edema; the side effect of preventing the fall
Production
So to make such a device, (which is the combination of a robot and a suit) a robot with many function is needed.
First of all the robot must be able to do much more actions than today’s robots. As an example its step lengths must be adjustable during the walk. It should climb stairs which are not designed for it. It should change its velocity and direction to move around the objects. In shirt terms every characteristic of its walking must be adjustable during the walk by the using patient.
Second it must be pre-protected from patient’s actions. It must maintain its balance no matter what the patient does and when. Its COM should be so low that even a patient starts to do an action with his upper body or his arm, the projection of COM should stay inside of the carrying foot.
Third it should oscillate the patient as less as possible. Even though it needs a COM much less than one meter, it should carry the patient without any oscillation for prevent edema. It should change the projection of COM with as less oscillation as possible for that. Even when it started to fall it should maintain its balance with minimum actions.
 |
Our System |
 |
And finally all of its components; from size of its motors to its walking diagram and its total height must be adjustable for each patient. It must also be easily adjustable to sell in large numbers.
Today we are very proud of being completed a two legged walking system, which has every characteristic that stated above. To be more precise we can change our two legged walking robots step length, its velocity and its direction in walking any given time. It has a COM at 15 cm high. It walks without any oscillation and provide its balance even we push it to a side while one of its legs is up with no or minimum action. Finally we can adjust every component of our robot (or we can teach someone to do how) for any request.
|
Picture |
 |
The System
The name of our balance system is “Counter Mass Principle”. Briefly for providing the balance the system needs a heavy object, the counter mass, at the carrying food.
The COM is laterally right in the middle in known systems. Because of that if the robot lift one of its feet, as an example right one, it fell down and after it start to lift its foot nothing that the carrying foot does stops this fall.
|
Without Counter Weight |
|
To understand our system you can imagine that there is a heavy rock (off course this rock is a metaphor) standing on the left foot of our robot. Because of this heavy rock, the projection of the COM is inside of the left foot. Since the projection of COM is inside of the left foot nothing that the robot does with is right foot will make it fall, it can easily lift it from anywhere and place it to anywhere you order without the danger of falling. Then you must transfer the rock to the other foot for the next safe step.
|
With Counter Weight |
|
To make it clearer I must explain that our counter object is a high dense (heavy) fluid, which we pump it from one foot to the other with motorized pumps. Both feet in our system are a tank and we place the heavy fluid inside of those tanks when they are on the ground.
The key point in here is placing the tanks lower, inside of the each foot. It is different to place them inside of the upper body because of seven reasons
This way the Com is placed much lower and that makes the robot much more stable.
This way the legs should not carry the weight of the counter mass along with the upper body of the robot.
Even the robot bend its upper body the place of the tanks is standing still in the right place
While transferring the fluid the momentum of the running fluid does not affect ( or has a much lower affect on )the ZMP
This way if the robot looses its balance and starts to fall there are many easy things to prevent it
This way the robot can move its body to anywhere it puts its foot on
This way the robot can move its upper body after it raises its one leg.
With all those advantages lets explain how the walking will be like
The balance analyses of walking for two steps.
|
Animation While Walking and Climbing |
|
|
Video While Walking |
|
In the beginning the heavy fluid is placed in each tank inside of each foot equally.
The pumps transfer the fluid to the left foot so the projection of COM is the left foot.
The robot lifts its right foot and because the COM is inside of the left foot it maintain its balance. The ZMP is also inside of the left foot because the system does not move its upper body; it only moves the empty right leg. So it does not oscillate the patient.
It placed the right leg to the ordered point. The pumps transfer the fluid to the right tank. The COM is inside of the right foot
The robot lift its left foot and place it to the next ordered point.
I must say as long as you place right amount of counter mass on the carrying foot, the robot can never fall. If it falls, it means the amount of the counter mass is insufficient.
The video of our prototype, maintaining its balance despite unexpected outside forces.
|
Balance |
|
Conclusion
After explaining our system and its advantages, probably there are no doubts of that it is possible to produce a walker for paralyzed patients theoretically, because our system has every properties that is needed. In practical you may think that they might be some problems. Those potential problems can be summarized under two questions.
Is it technologically possible to build such a device? (Calculations)
Is it medically possible to build such a device?
Our answer to those three questions is yes. And we will hopefully convince you in the next chapters of this presentation.