belt-mounted Wii remotes

If it turns out that the overhead string of lights works well for tracking cane arc, I would also like to try a belt mounted unit to watch for veering. It may be that we don't need a camera at the end of the course if we could see at least two lights straight up.  Here are some things to consider:

1. if the wii device is mounted on the person's body instead of on the cane, we should be able to determine placement on the course (y-axis), veering (up to the point that lights are no longer visible), rotation in the x-y plane, cane centeredness (by comparing values from both cane and body-mounted sensors.

2. We have to figure out where on the subject's body to attach the wii device. I am thinking that putting it in a belt holster on the midline-rear of the subject's body, because that seems to me to be less likely to be blocked by swinging arms or upper body. But certainly, we will have to test that and it might be necessary to make a special belt that can hold the device at a precise angle.

sl

Overhead course pole design

Here's an sketch for an idea for making a wiiCane course with an overhead string of LED lights that will allow us to track position along a course and also to observe cane arc and veering. The best part about this is that it is mostly parts from IKEO, so it will be very inexpensive to set up a course. The picture shows a pole with a video screen and a plywood box mounted to it. At a point 8' above the floor, there's a fitting on the pole that is used to hold each of the three cables in tension. A cable comes out of the middle of the pole to supply electric and control to the lights.

new concept: putting the IR lights on a cable overhead

After thinking through the problems associated with constructing a floor mat system for tracking position of a student during cane travel training with a wii remote, I want to consider a new idea that may resolve many  problems.  This approach calls for creating an overhead string of LED lights on a three or four wire cable stretched tightly between two poles.  The poles would be floor-to-ceiling aluminum rods of the type I have here in the office to hold up the desks. These are telescoping poles from IKEA that extend up to 12'. I believe this could be easily installed in a wide variety of places. Even if they didn't have a full 30', they could use set up and use a shorter course.

Here are the pluses and minuses of the proposed system:

1. We can control the distance between the camera and the lights this way. In the floor mat arrangement,  the shortest cane held the Wii device only about 18" or so above the floor, so the portion of the floor that the camera could see at once was very small. If we point the wii device straight up instead of straight down, and if we string the lights on a single cable directly above the course, I believe that we should be able to be far enough from the lights that we would mostly always able to see one light, and usually more than that.  In the floor scenario, we were talking about making multiple rows of lights so that the cane would be seen even when the subject was not standing in the middle of the course. If we are far enough from the lights, we may only need one row. This has to be demonstrated experimentally.

2. The poles will be rigidly held in place, so, as long as they are padded, it won't pose too much of a hazard in the case of inevitable collisions. Because the poles are rigidly supported, we can draw the cables very tight, reducing the amount of sag. We will probably need some kind of mechanical tensioner in the cable for setting up the apparatus. While a little sag might not matter, a large amount of sagging could lead to measurement inaccuracies.  I think this set up is a fairly low hazard level.

3. This apparatus will be much easier to package and ship, much, much cheaper to produce and less prone to damage and wear, because no one will be walking on it.

4. The system will be very scalable. It will be relatively easy to extend or reduce the length of a course. It would also be possible to include additional legs, as long as the subject is prepared to negotiate a free-standing pole along the route.

5. There may be other applications for the set up that I am envisioning, such as Wii Fencing. I just googled it, and it does not appear that wiiFencing has been done. Here's a link to a thread on that subject. A cheap set up for tracking linear motion along a virtual course may have a range of uses in both therapeutic and gaming domains.

So...I am going to go shopping tomorrow and buy stuff to set this up. I will be ready to start testing next week, and if it looks promising, the next thing we have to do is to go to all of the sites and make sure that they have a location where the poles could be set up.

sl

proposed design for wiiCane modular walking surface

After this weekend's meetings, in which I met with Zach Eveland, Annette Gourgey, Raphael Baptista and Gene Bourquin to make plans leading up to our test version of the WiiCane apparatus to take place at four sites in November. We made significant progress in several directions, and I am hoping that Gene, Zach, Rafael, and Annette will also produce posts on this blog capturing their view of the work as it is right now.

I am going to discuss the design for a modular walking surface for the WiiCane system. We decided to go this way after considerable back and forth discussion. We decided in the end that the floor mounted lights will be easier to track along the entire distance of the walking course (compared to lights mounted 30' away at the goal end of the course. Also this approach gives us the ability to make any length track, and even to make courses with turns, etc. (although I can't think of a reason to have that yet). This approach will be more expensive, and much more difficult to transport and set up. But, there are also distinct advantages, and it will be much simpler to achieve reliable position awareness doing it this way. And there are additional complexities, for example because the IR LED's have some thickness and they are crushable, we have to cover them with a surface that will protect them and the associated wiring harness. We also have to camoflage them tactilely, so that cane will not discover them, thereby giving away the straight line travel path, which is what we are training our users to do.

I am proposing a series of folding lightweight panels. 5 of these would lie end-to-end, creating a surface that is 8' wide by 30' long. The panels will be extremely light, and when all folded up, they would fit in a box that is 6' by 4' x 6", which is very manageable. It would fit easily in a station wagon. I am thinking that the panels would be shipped in a wooden box that would then become a head unit at the goal end of the course. This would house a camera, flat panel display, speakers, computer and any other devices. Each of the five panels will consist of a 4' x 6' fixed section and two hinged side pieces that are 2' x 6'. The panels will be 3/8" thick masonite board. When the hinged panels are folded in (covering the treading surface), the whole thing is 3/4" thick. The treading surface will be a long permanent self-adhesive floor banner from the printer we use to make tactiles. that printer produces 30" wide prints of any length, so we will burnish the prints to the masonite and trim off the excess. I want to try to use the prints themselves as a continuous hinge for folding up the panels for shipping, but that will take some experimentation.

The printing on the treading surface can include a long ruler in metric and english units, a big wiiCane logo, and different color lines to indicate set ups for various courses (green course, red course, blue course, etc). I just remembered that I once designed a book cover with Elga Joffee that we nicknamed the Corridor of Pain. It was a rendering of a theoretical hallway with one of each of the hazards disallowed in the ADA regulations, things that you can smack your head on, etc. I was thinking that we could base the placement of obstacles in one of the training course on some of those things, as a way of preparing for those kinds of conditions. The obstacles that we actually use would be inflatable or Nerf material. I like the idea for a future line of nerf obstacles! In any case, we have to start thinking about the pedagogical objectives and capabilities of this way of training people. We should end up the project with a producct manual that explains our reasoning and sources. We should also all be starting to think about publishing this work soon, assuming that we get some good outcomes.

The lights will be in three strips that will run the entire length of the course, one right down the middle and one in either of the two wings. These will be marked on the printed floor surface, so we can just use that as a template when drilling holes. We would pop the little LED through a hole so that they are slightly recessed from the surface of the treading surface, then fill the holes with clear epoxy. This will level the surface and protect the LEDs while allowing IR light to pass through. A cable will connect the lights to a control device in the head unit/storage crate. I don't yet know how to join the units to one another mechanically or electrically yet, so any ideas about that would be appreciated. A big neoprene rubber starting block would be at the opposite end of the course. This would have little semicircular cutouts for their heels while squaring off.

So, please give me feedback. I am going to start building a sample on Wedenday, with the hope of bringing it up with me to Boston during the week of September 28.

sl