WiiCane Course Layout-Scheme No. 1

This image shows one way that a course could be constructed for the WiiCane. Here, a 30' path is marked on the floor. A user is shown walking along the path towards the light bar at the goal end. The light bar is an 8' long horizontal beam that is supported on two adjustable stancions. In this rendering, the light bar is about 40" above the floor. A visual spectrum camera is mounted to the mid point of the light bar. This camera faces the user, and is intended to track a color dot that is pinned on the person's torso. The camera will track the person's absolute x-axis position (left or right of the travel path). Then, lights mounted on the face of the light bar provide information on arc width, arc-centeredness, and arc height at mid-swing. In this version, there are no lights on the floor. In this image, the floor has visual markings to help an observer determine the user's position in terms of distance from the starting point and amount of veering. A 24 inch wide starting block allows the user to square off at the beginning of the route.

wiiCane version 1.0

This image shows a photograph of our first wiiCane. This is a standard mobility cane that has been modified as follows:

1. An 8" section (just below the grip) of the cane was chopped out.

2. A plastic part was inserted in place of the removed section of the cane. This part looks like two tuning forks connected end-to-end at their tines.

3. A smaller 3d printed part (painted red here) was mounted with screws to the first part so that it can pivot 360 degrees. This smaller part holds the wii device.

The completed wiiCane is slightly heavier than a standard cane, but not so much so that it becomes difficult or awkward to use. It also appears to be well-balanced, regardless of how the wii is rotated in the fixture. Now that we have this assembly, we can begin to do in-depth testing of a variety of different light configurations, so that we can determine which arrangement offers the most options for motion tracking during cane travel exercises.

Here's a picture of our new 3d printer. It's the UPrint desktop printer from Stratysis. I got it for the purpose of outputting prototype enclosures for the NimblePad that we are working on under contract to Nimble Assessment Systems. But I am hoping to use this for many other things, including making lots of audio-tactile models and other touch-sensitive interactive displays. With the new usb sensor device that Zach is making producing now, and plastic models printed from this machine, we can make detailed very strong exhibits cheaply and rapidly. Right now, I am printing a pivoting fixture for mounting the wii remote to a mobility cane. I am hoping that other interesting new things will emerge from this, and would welcome comments or suggestions.

steve

wiiCane curriculum pedigogical objectives

Now that we are starting to get more detailed in our understanding of what can be accomplished with the envisioned WiiCane system, we need to start thinking also about how it will be most effectively used in actual teaching. While it is too early to make any decisions about specific lessons or activities, we would be smart to begin developing how instruction with the wiiCane used in a rehab or school setting will probably occur. Gene will be the leader for this part of the work, and I am hoping that he will faciliate a discussion about teaching parallel to the one we are having about the technical aspects. We should start brainstorming about how we image using the system in a teaching environment, because that discussion will shape our decisions about what to emphasize in taking measurements.

As a starting point for this discussion, I suggest that we look at SAL, which is Sally Mangold's curriculum for braille literacy. In that, there are a set of short actitivies that are organized in order of ascending difficulty and skill mastery requirements. I am not sure if the aquisition of travel skills is analogous to learning braille, so it may be the wrong model, but this gives people something to respond to. Gene?

Mobility perspectives for post-Kalamazoo

For technical reasons please continue by reading the follow up comments to this post.
Thanks Gene

Technology options

The following is a list of the technology options we are considering for obtaining information about a traveler's movement and their cane handling technique.

• Inertial measurement - uses movement information supplied by the Wii Remote's built-in accelerometers (and possibly the Wii MotionPlus gyrometers). This gives relative movement information from inside the Wii Remote's frame of reference.




• Good for: detecting taps, determining cane orientation, detecting cane movement in the absence of other sensing methods


• OK for: measuring arc width


• Not good for: determining cane position, detecting veering






• Light strip - an array of computer-controlled infrared lights on the floor which are visible to the Wii Remote's IR sensor. Like the light bar method this gives us an idea of the traveler's absolute position.




• Good for: very precise arc width measurement when lights are in view, precisely determining traveler location, detecting veering


• OK for: might be able to measure cane-centeredness and coverage


• Not good for: easy installation (requires careful positioning of light strips or installation of walking surface)






• Light bar - similar to the Wii's Sensor Bar this method uses the same principle as the light strip method - an array of infrared lights which can be seen by the Wii Remote's IR sensor gives us an absolute position reference to work with. In this case, several lights are mounted horizontally at the end of the course and are seen by the Remote's IR sensor.




• Good for: arc width measurement, detecting veering, determining traveler location, simple setup


• OK for: might be able to measure cane-centeredness and coverage


• Not good for: less accurate than light strip






• Rear-facing IR sensor - a second Remote or IR sensor mounted on the cane is positioned to view the traveler. Markers or lights affixed to the traveler's clothing are seen by the Remote or sensor.




• Good for: very precise cane-centeredness and wrist isolation measurement, precise measurement of coverage if arc width is known


• OK for: might be able to measure arc width


• Not good for: detecting veering, determining traveler position






• External camera - a computer-connected video camera at the end of the course records the traveler's progress. Computer vision software analyzes the video to determine information about traveler and cane movement.




• Good for: measuring cane-centeredness and wrist isolation, detecting veering, measuring coverage if arc width is known, easy installation


• Not good for: determining traveler location, precise measurement of arc width or coverage, long courses - even a 30-foot course may be too long

As no single method provides all necessary information, it is very likely that the ultimate embodiment of the WiiCane system will use two or more complementary methods. We will continue to refine the inertial measurement methods and investigate the other options.