video showing 9 section (54 feet long) light track at New York Institute for Special Education

New Lightstrip video

In the short video below I demonstrate the newly-redesigned WiiCane lightstrip and working "find-the-user" routines.

New design for the overhead light track

Here's the latest design.  This one uses anodized aluminum channels with the open side facing down.

Discussions with Dr. Rosen

I have spent the past few weeks in discussions with Dr. Rosen regarding the WiiCane, and being educated in the biomechanical and sensory aspects of veering. I will summarize some of our discussions and end with some implications for product design and teaching approaches with the device.

Sandy has reviewed a few hours of video and I have sent her the recordings of two more students. I should note that the data are not ideal for analysis so Sandy’s comments were based on what was possible to glean from the images.

It is highly improbable that training with the WiiCane is influencing students’ gait. Sandy said, “Gait patterns stabilize around age 6-7 according to all medical research.. . . gait is a very hard one to change long term.” As for posture (particularly pelvis-trunk alignment), which is more “fluid,” we probably are not effectively influencing this either, but we could.

So why is it that we see improvement in some students using the device? First, I’ve come to believe that early and dramatic improvement in straight-line travel is probably just becoming adjusted to using the feedback system. But the long-term changes in walking a straight-line is most likely from the training’s (exercise) impact on proprioceptive awareness. The proprioceptive system is a balance system The one that is not vestibular) — that makes normal, slight adjustments to balance. It is (as Gene understands it) neurologically related to muscle systems and tone. Individuals can be trained throughout life (not like gait patterns) to fine tune this system; effective training is active exercise. What might be happening with the Wii is that the repeated feedback influences this system’s patterns.

So, what are the product and training implications? I will simply bullet some of the more salient points that Sandy makes:

- We must eliminate any incorrect feedback that the system issues now – there is plenty of it evident. We need to use the body orientation data and create a better feedback logic. We should not be giving feedback that causes ping-pong patterns of walking.

- We should be including instructions for the teachers and users to make adjustment to the line of travel by using trunk movement, not feet movement. We need to look at the words/text we use for the feedback and the advice in the user guide.

- We should begin at each end of the course with the student aligned from the floor to the pelvis, then ask the student to align their trunk forward. This need serious consideration, and an effective and easy squaring-off platform that reaches from the floor to around the pelvis.

If all this works perfectly there is one part of the assessment of the device that we have not yet looked at. Sandy and I will talk about how I will do this when I return to the Bronx for final testing in June. THE BIG QUESTION: how much will the proprioceptive changes generalize, and will they be effective in the real world when the student does not travel on an ideal surface. Changes in the travel surfaces are inevitable. These will interpret the new patterns achieved with training, and student will revert to their old patterns. How much training and the degree of benefit in the real world need to be looked at. On this topic I have my single experience (n=1) with a student I trained with the equivalent of over 100 trails on a WiiCane at HKNC. He learned to walk in a straight line indoors, and has demonstrated this in the real world consistently since training. We are looking to see if this will be typical.

WiiCane April 2010 with built in ferrules

This is the final version of the WiiCane that we will go into production with.  This is the child size version, which adjusts from 32" to 42".  There's an adult version which adjusts to the maximum length of standard canes.

This version is a big improvement over the last one. Here, we have worked with the cane manufacturer, Ambutech, to develop a better way for inserting the aluminum fixture that holds the wii remote device and allows it to pivot.  In the earlier version aluminum collars were welded onto the ends of the fixture; set screws were used to hold the ends of the graphite shafts in the collars. Now, we have an internal threaded sleeve that is pressure fit into the cut ends of the shaft, and two big machine screws hold it all together. Not having the collars makes it look sleeker, and it weighs less.  But the big benefit is that the cane feels a lot more rigid and stable, and should not get loose after repeated banging.

New design for the overhead light track

Zach and I made progress in our meeting today on the design of the light strip. We figured out how to connect the strips in such a way that makes it easy for one person to hang it up and connect each 6 foot long strip end-to-end.  This is a three part system: the first part is a plastic clip that gets screwed to the ceiling. The first track section slides around this clip, then the next one is added.  As each track section goes up, the installer places a connector that hides the joint, and makes the 8-wire electrical connection. Here's a detail drawing that illustrates the system's components.

post from Dr. Annette Gourgey

Updated Evaluation Plan

Gene and I met this morning to draw up a revised plan for the WiiCane data analysis. We see this taking form in several ways.

First, Gene has identified some case studies from our first exploratory trials with the WiiCane that suggest ways that the device is beneficial for student learning. He has posted some of these findings on this blog. One set of graphs plots the number of corrective feedbacks given over successive trials, showing that the frequency of these feedbacks may decrease with practice. This suggests that students are learning something from repeated use of the device that carries over into later trials.

A second set of graphs Gene has created shows an effect on veering. When the number of nonveering messages (indicating correct positioning) exceeds the number of corrective messages (indicating veering error), improvement has occurred. A plot of the arithmetic difference (nonveering minus veering messages) shows that this balance may improve with practice. Again, this demonstrates the potential for learning with practice using the device.

The cases analyzed so far took place during the exploratory phase of our trials, when we were experimenting with the optimal number of trials and adjustment of parameters such as the tolerance threshold for veering (which varied from 12 to 18 inches). Our next step would be to set up more consistent trials with several participants, in which the number of trials and the veering tolerance are held constant. Thus, we plan to select three representative students from NYISE and to test them under these conditions: three 30-trial sessions over a period of three days, for a total of 90 trials; and a veering tolerance level of 12”. These conditions are consistent with those identified by Guth in his previous research, which demonstrated that improvement in veering could be observed after several successive days of sessions consisting of 30 trials each.

This experiment would provide a more systematic evaluation of the potential of the WiiCane device to reduce the incidence of veering. With more reliable data from such an experiment, we will be better positioned to design future research with larger samples and to advocate for the benefits of using an automated tool to improve mobility training. This knowledge will be beneficial both for instructors who wish to evaluate how the device will help their students and for our ability to market the device.