Recently, I took a power wheelchair for a test drive through downtown Toronto, Ontario. Within a two hour period, I had hit at least 2 doorways, and narrowly missed the ankles of more than one person with my footrests (thankfully being Canadian they jumped out of the way of my rampaging chair with a cheerful “sorry”), avoiding any wheelchair collisions while power wheelchair driving.
This experience made it very clear the challenges associated with driving a power wheelchair-especially in a tight space. The following blog series will focus on the danger associated with operating power mobility devices, and how we can reduce that danger and improve access to power wheelchairs.
It is important to understand the risks associated with power wheelchair use in order to find ways to minimize risks while maximizing the independence of users. It is, however, difficult to measure the prevalence of collisions incurred by power wheelchair users. Statistics are difficult to obtain, as there is no central reporting centre for power wheelchair accidents. There are some research studies that have been done to evaluate the incidence of collisions for power wheelchair users.
Statistics of Wheelchair Collisions for Power Mobility Devices
Many of these studies are focused on the use of power mobility devices in an institutional setting. Here is a brief summary of the results of some of these studies:
- Frank et al. (2000) found that within 4 months of receiving a power mobility device, 13% (15 out of 113) of people surveyed reported at least one accident, including tipping from chairs and falls during transfers.
- Mortenson et al. (2005) report that The Vancouver Coastal Health (VCH) residential facility which has 82 residents using power wheelchairs, reported 16 incidents of property damage in one year from power wheelchair use. This is a conservative estimate, as the author notes that only serious accidents were reported. There were likely far more minor incidents that were not reported.
- Reed, Yochum and Schloss (1993) reported that 30% of long-term care residents surveyed felt that other drivers within the facility drove unsafely.
Challenges with Power Wheelchair Driving and Drivers
Clearly, within an institutional setting, many power wheelchair users have difficulty safely navigating their environment. In such institutions, there is a very high density of power wheelchair users, along with narrow corridors and many obstructions in hallways which present challenges to drivers. One major factor identified as contributing to decreased safety in high density areas is a lack of conformity between drivers.
Mortenson et al. (2005) write that a lack of driving rules for wheelchair drivers in an institution can result in animosity between and towards power wheelchair drivers. For example, not designating a regulated side of the hallway to drive on increases the likelihood of collision and creates an atmosphere of blame and animosity towards power wheelchair drivers (Mortenson et al., 2005).
Challenges Of Wheelchair Navigation for Power Wheelchairs
Measuring statistics only in institutions provides an incomplete view of the magnitude of the prevalence of collisions among power mobility device users. Many wheelchair users that live in the community also suffer accidents, and when navigating through traffic the consequences can be catastrophic. Mortenson et al. (2005) found that six out of ten interviewed power wheelchair drivers report that driving in the community is more difficult than diving in an institution.
Survey of Power Wheelchair Useability
A survey of wheelchair users by Arthanat et al. (2009) found that the usability of power wheelchairs in the community is low. About 40-50% of those surveyed reporting that usability was moderate to very low in the community. The difficulty in navigating in the community with a power wheelchair has been observed by multiple surveys.
- Navigating a wheelchair in traffic is a large hazard of navigating within the community. LaBan & Nabity (2010) found that sixty fatal accidents occurred between a motorized vehicle and a wheelchair in one year. Of these accidents, 94% involved a power wheelchair.
- Chen et al. (2011) surveyed 95 active community wheelchair users about the number of collisions experienced. 52 (54.7%) of wheelchair users reported experiencing at least one collision, and 16 (16.8%) reported experiencing 2 or more collisions within a three year period.
- A report from Edwards and McClusky (2010) of Australian power mobility device users found that one-fifth of respondents (21%) reported having an accident in the previous year when using their device. The most commonly reported accidents were caused by running into doors and walls, the device tipping over, being hit by a car or knocking into/over objects such as shop displays.
- Arthanat et al. (2009) found that 52.8% of wheelchair users surveyed had experienced at least one accident (collision or fall) that resulted in injury.
Clearly, the issue of accidents in power wheelchair driving is prevalent. It is important to start a conversation regarding the risks and rewards of power wheelchair use! If you have experienced a collision in your power wheelchair, or know someone who has, leave a comment!
Want to learn more about what Smart Wheelchairs can do to prevent wheelchair collisions? Download our FREE E-Book on Smart Wheelchair Technology!
References
- Arthanat, S., Nochajski, S. M., Lenker, J. A., Bauer, S. M., & Wu, Y. W. B. (2009). Measuring usability of assistive technology from a multicontextual perspective: the case of power wheelchairs. The American Journal of Occupational Therapy, 63(6), 751.
- Chen, W. Y., Jang, Y., Wang, J. D., Huang, W. N., Chang, C. C., Mao, H. F., & Wang, Y. H. (2011). Wheelchair-related accidents: relationship with wheelchair-using behavior in active community wheelchair users. Archives of physical medicine and rehabilitation, 92(6), 892-898.
- Edwards, K., & McCluskey, A. (2010). A survey of adult power wheelchair and scooter users. Disability and Rehabilitation: Assistive Technology, 5(6), 411-419.
- Frank AO, Ward J, Orwell NJ, McCullagh C, Belcher M. Introduction of a new NHS electric powered indoor/outdoor chair (EPIOC) service: benefits, risks and implications for prescribers. Clinical Rehabilitation. 2000;14:665–673. [PubMed]
- Mortenson, W. B., Miller, W. C., Boily, J., Steele, B., Odell, L., Crawford, E. M., & Desharnais, G. (2005). Perceptions of power mobility use and safety within residential facilities. Canadian Journal of Occupational Therapy, 72(3), 142-152.
Most people who operate any sort of motorized vehicle have aids to help them see what is going on around them. Mirrors, cameras and sensors are commonly used to help people when driving cars. So, what about people who drive wheelchairs? There are various visual aids for wheelchair users, which provide information about what is going on in blind spots. This blog will discuss the pros and cons of these solutions.
Backup Cameras for Wheelchair Users
Backup cameras are popular visual aids for wheelchair users to get information about what is behind them. Cameras designed for attachment to trailer hitches and license plates can be adapted for wheelchair users and attached to the back of a chair. These devices typically relay video information to the driver on a smartphone or tablet. This requires the wheelchair user to mount their phone/ tablet in an easily visible location.
Pros of Backup Cameras
- Cameras are useful when driving outside or in large spaces, especially when operating a wheelchair safely on roads or in busy traffic areas.
- They are good at allowing the user to track objects such as cars or pedestrians moving through their field of view.
- These systems are fairly low cost, and take advantage of technology the user already owns by using a tablet/smartphone to relay information.
- Many aftermarket backup camera products are magnetic, making installation on a wheelchair easy.
Cons of Backup Cameras
- For drivers with low vision, video is ineffective at relaying information.
- It also may be distracting to monitor a video screen when driving.
- A tablet/smartphone large enough to clearly view will block the driver’s forward facing vision, creating another blindspot for the driver.
- Navigating indoors using a camera may be difficult, due to difficulty differentiating between objects and walls on the screen.
- Adequate lighting is required to make video feedback worthwhile.
- If using a smartphone for video relay, the driver is unable to use their smartphone for other tasks while driving, such as DJing that perfect playlist!
- Mounts for these cameras aren’t designed for wheelchairs, and may be difficult to mount.
Rear-View Mirrors
Rear-view mirrors are low-tech visual aids for wheelchair users that provides the user with instantaneous feedback regarding their environment.
Pros of Rear-View Mirrors
- Mirrors are the lowest cost solution, with wheelchair specific mirrors costing under $100.
- Mirrors don’t require charging.
Cons of Rear-View Mirrors
- In order for the mirror to be effective, it must be positioned in a very specific way, which may be an inconvenient position for the driver.
- Mirrors are also bulky to catch a large enough frame of view, which will create an additional blindspot for drivers.
- Mirrors don’t provide exact location information about objects. “Objects in mirror are closer than they appear” may be okay when on the roads, but inside a house it is important to know exactly how close you are to an object/wall.
- Adequate lighting is required to make feedback useful from a mirror.
- Mirrors have a small range of vision, so drivers will still have blind spots they can’t monitor.
Sensor Systems
Sensor systems are new to the market, and provide wheelchair users with information about objects in their environment. Sensors detect objects and obstacles, and that information is fed back to the user through different modalities. For example, Braze Mobility offers blind spot sensor systems that provide up to 180 degrees of rear-view blind spot coverage, and customizable 45 degrees of coverage. This information can be relayed through vibration, visual or audio feedback.
Pros of Sensor Systems
- Customisable coverage makes it possible to monitor multiple blind spots at once. This means that people with decreased peripheral vision can easily monitor both side and rear view blind spots.
- Coverage area of sensors is much higher than mirrors and video.
- People with vision impairments are able to interpret feedback easily using either vibration or audio feedback.
- The device was designed to not block vision in any way.
- The device was designed for wheelchair use, and can be easily installed on any wheelchair.
- The device is powered via a USB power bank, and therefore can easily be charged. One charge can last all day, due to the very low power requirements of the device.
- Ultrasonic sensors do not rely on proper lighting to provide the user with feedback.
- Feedback from the device splits the rear view vision into three distinct areas. This makes navigating in tight spaces and through doorways easier.
Cons of Sensor Systems
- Feedback does not provide information about what is in your blind spot, but just that there is something there.
- The cost of an ultrasonic sensor system designed for wheelchair use is higher than the cost of a mirror, or rear view camera designed for a car.
Self-Driving Wheelchairs
Self driving cars are beginning to drive themselves into the market, and wheelchairs might not be too far behind! Currently, self driving chairs are not available commercially, however they are being used in research studies.
Pros of Self-Driving Wheelchairs
- Self driving chairs will reduce barriers to accessing power mobility devices. People with low vision, decreased cognition or other reason for being denied access to power mobility may be able to operate a self-driving chair.
- Self-driving chairs will likely be safer than regular power mobility devices, due to a lack of blind spots.
Cons of Self-Driving Wheelchairs
- These chairs will likely be extremely expensive.
- Depending on the level of control of the driver versus the chair, self driving wheelchairs may decrease the autonomy of the driver.
Do you have experience with any of these feedback methods? We’d love to hear about your experience and your opinion! Comment below to start the conversation!
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The Smart Wheelchairs in Assessment and Training (SWAT) State of the Field workshop was an initiative to gather various stakeholders in power wheelchair training and assessment and create a comprehensive review of the current state of the discipline. The participants involved a balance of both clinical and technical experts on wheelchair training and assessment and the outcomes of the workshop are published in an AGEWELL report. The 3-part Braze Mobility SWAT Blog Series will discuss some key outcomes of this workshop.
According to the SWAT report, the main challenges faced by practitioners in wheelchair training and assessment and those being assessed and trained for wheelchair use are:
- High cost of equipment and funding constraints
- Lack of available resources to train and supervise users safely
- Limitations in commercially available technology to accommodate client needs
What Solutions Have Been Proposed to Combat These Challenges?
1. Lack of Available Resources to Train and Supervise Users on Safe Use
In order to gain the maximum impact from the limited resources available, therapists can use technologies such as Smart Wheelchairs. Smart Wheelchairs have many different benefits that will help to increase the efficiency of training and assessment sessions.
The first is that these devices can monitor users at all times, not just when in the clinic. This provides therapists with a more holistic view of their clients’ driving habits, and can help them to identify problems that occur in settings outside of the clinic environment or assessment hours.
For example, smart wheelchair technology could be used to detect if clients experience more collisions after a certain time due to fatigue or side effects of medication. This data can also be used to determine skills requiring additional training sessions, and target therapy sessions accurately towards the needs of the user. This could in turn reduces the required one-on-one evaluation time.
Smart wheelchairs can also provide the user with feedback about their driving, and hazards in their environment. This allows for training to occur outside of the clinic, maintaining client safety without requiring one-on-one therapist supervision. These benefits could reduce the time constraints on therapists, as well as increase the amount of training the user is able to obtain from each session.
2. Limitations in Commercially Available Technology to Accommodate Client Needs
Translating research into clinical practice was found by the report to be critical to ensuring progress in adaptive technology. In adapting research into commercially available products, usercentered design must be used to develop the technologies through engaging end users in the design process. The SWAT report identifies that potential technological solutions to accessibility challenges mostly involve solutions that engineers already have the technological know-how to create, and therefore progress is within reach. There is currently a commercially available option to provide a wheelchair user with feedback outside of the clinic.
The Braze Sentina Plus provides users with 180 degrees of blind spot detection, with the possibility of adding up to three Echo heads for 45 degrees of customizable coverage. The Sentina can provide visual, auditory or vibration feedback to the user, alerting them of objects in their environment and helping them to navigate tight spaces independently. This product was developed using the outcomes of the SWAT report along with extensive user feedback, and can be used with almost any wheelchair. To learn more, click here!
3. High Cost of Equipment and Funding Constraints
In order for smart wheelchairs to be economically viable, there must be access to funding for those who would benefit from the device. The SWAT report found that the additional cost in development and production of a smart wheelchair is justified by the benefit provided to the user, as access to powered mobility devices for safe and independent mobility is a human right. Low-cost solutions are another possible solution, such as the Braze Hydra which is available for $770 USD! For more information on funding challenges and solutions, stay tuned to the Braze blog, as our next series will tackle available funding in Canada!
Read More About Smart Wheelchair Technology
- Download our FREE E-Book on Smart Wheelchair Technology!
- Read Part 1: The 5 things you should know about Smart Wheelchair technology!
- Read Part 2: The Current State of Wheelchair Training and Assessment
References
- Viswanathan, P., Wang, R., Sutcliffe, A., Kenyon, L., Foley, G., Miller, W., Bell, J., Kirby, L., Simpson, R., Mihailidis, A., Adams, M., Archambault, P., Black, R., Blain, J., Bresler, M., Cotarla, S., Demiris, Y., Giesbrecht, E., Gardner, P., Gryfe, P., Hall, K., Mandel, C., McGilton, K., Michaud, F., Mitchell, I., Mortenson, B., Nilsson, L., Pineau, J., Smith, E., Zambalde, E., Zondervan, D., Routhier, F. & Carlson, T. (2018). “Smart Wheelchair in Assessment and Training (SWAT): State of the Field” AGEWELL.