The overall goal of this procedure is to provide detailed instructions on how to assemble and administer a portable obstacle course to evaluate navigation ability in patients with vision impairment. This is accomplished by first identifying a suitable space to construct the course and obtaining all of the necessary equipment. The second step is to create the course infrastructure.
This includes painting the adjacent walls and laying down the floor tiles, as well as painting the obstacles and setting up lights. Next, the testing area is prepared for use. The lighting should be set to the desired illumination and the styrofoam obstacles placed after the course is run.
The results can be analyzed by examining the outcomes of percent preferred walking speed, the number of collisions and errors, as well as the two visual identification tasks. Ultimately, the portable obstacle course for low vision applications can be used to assess navigation and mobility capabilities in persons with low vision or who are using artificial vision devices. One of the main advantages of our course is that there are so many versions that it's very difficult for subjects to memorize it.
In addition, because it's portable, it's easily reproduced if you have a multicenter study. This method helps us answer questions in low vision and artificial vision device fields, such as can subjects avoid obstacles using the device? Now, this method can provide the information about the improvements of an artificial vision device.
It can also help to evaluate subjects who have suffered macular degeneration or stroke. It can also show practitioners and subjects their limitations and their needs for therapy. To begin construction, first, choose an appropriate hallway for the obstacle course.
The dimensions should be 40 feet long by seven feet wide, consisting of 281 foot square beige portable floor tiles. Install the course floor placing tiles with the black trim around the perimeter of the course. Also, paint the adjacent walls to match the beige floor tiles in order to create a monochromatic testing environment.
If the specific color of the floor is not available, a floor tile can be taken to a local hardware store for color matching. Next, install lighting according to the lighting template as seen here. Connect the lights to a dimmer switch.
Then paint obstacles according to painting instructions included with the manuscript accompanying this video. Now prepare the testing area for the experiment. Adjust the lighting to the desired condition, and also check with the light meter at the beginning, middle, and end of the hallway containing the course.
Make sure that the video camera is set to record and that camera placement is appropriate to capture the subjects as they walk through the course. A ceiling mount is recommended, or alternatively, the camera can be handheld. Once the course is prepared, bring in the subject to record the preferred walking speed or PWS position the subject in the center of the walkway so that their toes are behind the border of the walkway.
Then read the instructions to the subject, instructing them to walk down the hallway at their normal walking speed. Stop when told to at the end of the hall, and then turn around and walk back. Begin recording with a stopwatch.
Once the subject's foot crosses the black border and onto the pathway, stop recording time. Once a foot crosses the black border at the other end of the walkway record this time as preferred walking speed one or PWS one. Then have the subject turn around and repeat the procedure in the opposite direction.
Record this time as well as PWS two. Then average the two recorded times and record this as the subject's final preferred walking speed from the randomization scheme. Set up the first course.
Refer to the provided diagram for correct mapping of the obstacles. The floor tiles should be used as the grid upon which the obstacles are mapped. It is helpful to number the tiles along the vertical and horizontal axis with an indelible marker to permit easy placement of the obstacles.
It is also helpful to label the obstacles according to the provided diagrams in an inconspicuous location. Now guide subject to the start of the 40 foot walkway. The subject should be positioned in the center of the walkway, column D with their toes behind the border.
Read the course instructions to the subject again. Begin recording with a stopwatch. Once the subject's foot crosses the black border and onto the pathway, then stop timing.
Once a foot crosses the black border at the other end of the walkway record. This time as the subject's core speed Cs also record. If obstacles are hit and grade the severity of each hit on a three point scale as per the instructions.
The course run should also be videotaped for later confirmation by an independent observer. Upon completion of the course navigation task, turn the subject around to face the course and then position them at the center of the course. Assure that any obstacles that require repositioning in order to view the correct color from the end of the course are rotated.
Then read the course instructions to subject. At this time, the first object identification task will be administered. Ask the subject to turn around and tell the research assistant the total number of objects they can discern within 30 seconds.
And record this number now. Instruct the subject to walk back through the course and point to each obstacle. They can see.
It does not matter if they collide with the obstacle. If a collision occurs, grade the severity of the impact, but do not redirect the subject. The number of obstacles they can see is recorded.
It is helpful to record which obstacles they're able to detect. This is not timed. Next, set up for the next course version that will be run for the subject obstacle.Course.
Navigation and obstacle identification should be repeated for each course iteration that is run, six cited blindfolded cited, and 36 completely healthy blind adult subjects completed the entire obstacle course at baseline, and then again after a 15 to 20 hour structured training protocol with the Brainport device. The percent preferred walking speed at baseline and post training demonstrates that subjects using the brainport walked more slowly than without it. This figure shows baseline versus brainport condition results for the outcome of percent possible errors using the brainport subjects had a trend towards a reduced number of collisions with obstacles compared to the no brainport condition.
Once you're comfortable with the course, the technique take about 90 minutes. If you do it properly, Each level of the course can be run either in dim or bright illumination. This allows you to determine whether or not ambient illumination has an influence on performance.
But don't forget that when you're working with blind subjects, they're not gonna perceive their environment as well as a cited subject would. So it's always important to have a sighted guide with them falling close behind to make sure that they don't stumble.
