The Wheelchair Guide
Your Wheelchair and Mobility Scooter Resource
Electric Wheelchairs for Seniors
Thursday, May 21st, 2009
Electric wheelchairs, which are often also called power chairs, offer the advantage of a manual wheelchair, in that they are very maneuverable. However, unlike manual wheelchairs, power chairs are powered electronically, so they can typically be operated very easily, requiring very little physical activity of the senior.
A simple joystick control scheme is most popular for controlling electric wheelchairs, which allows the senior to simply push the joystick. The joystick, which is attached to the arm of the power chair, then moves the wheelchair in the direction they wish to travel. Of course, there are a number of alternate wheelchair control systems available as well, including breath controlled systems and remote controlled systems, which are often used by caretakers.
A Brief Background on Electric Wheelchairs
The first electric wheelchairs, which were developed in the early 1950′s, were simply adapted E & J manual wheelchairs.
An electric motor was attached to the manual wheelchair, which was controlled using a simple joystick control scheme, although even during the 1950′s, researchers were already coming up with alternate control schemes. One popular method was to mount something similar to a joystick near the individuals head. They could then use their face to control the electric wheelchair.
The Modern Electric Wheelchair
Today, while some portable electric wheelchairs do use a traditional steel tubed folding wheelchair design, most look much different from a traditional manual wheelchair. Instead, an electric motor and battery is contained in the base of the wheelchair, usually covered by molded plastic.
A captains chair, which, depending on the cost of the power chair, often rivals that of most office chairs, both in comfort and durability, is mounted on the base of the wheelchair. The captains chair often reclines and swivels, to facilitate comfort and make transferring into and out of the wheelchair easier. Some even include an electric lifting system to raise and lower the chair.
While many power chairs share a similar design, one way they are often classified is by their wheels. A mid-wheel power chair features one set of large wheels in the middle of the base and one set of smaller wheels on the front and back of the base. The larger wheels are what does all of the work and are powered by the electric motor. The smaller set of wheels on either side of the drive wheels, provide extra support and stability.
The mid-wheel electric wheelchair offers the advantage of excellent maneuverability. It can turn in much smaller spaces. However, in some cases it might not offer the same stability as a rear-wheel drive wheelchair. This is because the center of balance for a mid-wheel wheelchair is in the middle of the power chairs base.
The other common type of electric power chair is the rear wheel drive wheelchair. These feature a set of rear wheels, which depending on the model might be slightly larger, and a set of front wheels, giving it four wheels in total. The rear wheels, are powered and what actually moves the power chair.
The rear wheel drive wheelchair does not offer the same maneuverability that a mid-wheel power chair does, but does offer increased stability. This is because the weight of the occupant is more evenly distributed across the base, making a wider center of balance.
As is the case with manual wheelchairs, power chairs, both mid-wheel and rear wheel drive models, include anti-tip casters to prevent the wheelchair from tipping over backwards.
Advantages of Electric Wheelchairs
One of the major advantages that an electric wheelchair offers is that it does not require much effort to use. Simply push the joystick and the power chair will move, with many offer very small turning radius and sensitive controls. The speed is often adjustable and some models can reach speeds of over 10 miles per hour.
The range of a power chair varies, but most can travel at least 5 miles without requring a recharge. Some can travel upwards of 20 or 30 miles per charge, but this often is dependent on the terrain and weight of the occupant. For example, if you decided to drive around the hills of San Fransisco, the battery would wear down much quicker than it would when used on flat land.
Along the same lines, if the rider weighed 300 pounds, the battery would wear down quicker than if they weighed 150 pounds. Often, an extra battery pack is purchased for those who use the power chair continuously, as this way when one battery pack wears down, it can be removed and charged, and the fresh battery pack used.
Electric Wheelchairs and Seniors
While the electric power chair can be an excellent device, especially for seniors, it is often cost prohibitive.
Of the three main mobility options, manual wheelchairs, electric wheelchairs, and mobility scooters, electric wheelchairs are by far the most expensive. When compared to mobility scooters, electric wheelchairs often also have a lower range, lower top speed, and are not as well suited to rough terrain. However, for indoor use, they are usually superior to scooters.
Electric Power Wheelchairs: An Introduction
Wednesday, April 29th, 2009
The electric wheelchair is today very popular and has been around since the early 1950′s. Early electric wheelchairs simply used the frame of a manual wheelchair and added an electric motor to it. Unlike manual wheelchairs, which require a great deal of upper body strength to use, electric wheelchairs require virtually no effort on the part of the user. They are also often referred to as power chairs or electric power chairs.
Today, some models are still available that use a traditional manual wheelchair design, but most make use of a molded plastic base, which contains the electric motor. One or more batteries is also contained in the base of the electric wheelchair, which allows it to be used over great distances.
The range and top speed of an electric wheelchair varies by model, but most are able to at least travel 5 miles on a single charge and at speeds of around 4 mph. The weight capacity of electric wheelchairs varies by model, but 250 pounds is almost an industry standard.
The chair of the electric wheelchair in some regards resembles an office chair, with a high back and armrests on either side. It includes a good deal of padding and can be reclined. It also usually swivels to the left or right, allowing for the power chair to be exited in a safe manner. The chair, which is often called the Captain’s Chair, usually has foldable armrests to further facilitate smooth transfers into and out of the chair. Some even have an electrical lifting system, which raises and lowers the chair. This can be important if, for example, using a table that is higher than normal.
Electric Wheelchair Control Systems
Most power chairs use a joystick control that is mounted to the armrest of the chair. This design is the same used on the first electric wheelchairs and can be configured for use on the left or right side of the power chair. There are also a number of alternate controls available for those who are not able to operate the joystick.
Perhaps the most common alternate wheelchair control allows the wheelchair to be controlled by the users breath. Blowing into the wheelchair moves it forward and breathing in moves it backwards. The direction of the wheelchair can also be controlled. There are a number of other alternate controls, including a remote control that can be operated by a caretaker.
Portable Power Chairs
If you want to transport a traditional power chair, it is usually necessary to use a wheelchair lift. However, portable power chairs are available, which are lightweight and can be folded to take up less space. These models closely resemble a manual wheelchair, with a steel or aluminum frame and cloth seat. However, they still weigh a great deal more than a manual wheelchair would.
The motor and battery is installed under the seat and while these units often do not have as far of a range as other power chairs, they are easier to transport.
New ISO Standard for Electric Wheelchairs
Monday, November 10th, 2008
Wheelchairs today offer increased mobility to people all over the world. Even in only the last ten years, there have been many improvements to the design and reliability of the electric wheelchair, but there are still many areas, both around the home and away, that can present an obstacle to a person using a wheelchair. In an effort to help make choosing a wheelchair based on its abilities to navigate these types of obstacles easier, a new ISO standard was recently released.
This ISO standard, ISO 7176-10:2008, is the tenth part of a of an ISO that deals with wheelchairs. Specifically, this new standard is aimed at determining the ability of an electric wheelchair, or power chair, to climb or descend obstacles. This includes curbs, doorways, uneven pavement, and other obstacles that an individual might encounter. It presents a set of test procedures to use, describes the type of equipment required to preform tests, and how to evaluate the findings.
It is hoped that with the adoption of this standard, the consumer will be able to better rate different wheelchairs and find one that specifically meets their needs. This rating will better reflect not only the overall ability of the wheelchair, but also how adept it is at driving over obstacles.
The International Organization of Standardization, or ISO, is an organization that is represented by individuals from across the world. They meet to create international standards and specifications for many types of products, including health and disability related products. Even though the organization is itself not directly tied to the government, many of their standards end up being turned into law.
The ISO 7176 is a series on wheelchairs prepared by a group of professionals and researchers of Assistive products and how these devices can be used by people in wheelchairs. It help provides a method of classifying wheelchairs based on factors like their size, weight, maneuverability, energy usage, ease of control, acceleration, overall strength, crash resistance, quality of brakes, and speed.
Collision Detection on a Wheelchair
Monday, November 10th, 2008
Pooja Viswanathan is a Computer Science student at the University of British Colombia. She has developed a system that can be integrated into most electric wheelchairs to provide collision detection and also learn an area.
Viswanathan observed that often those that have cognitive or physical difficulties have difficulties using an electrical wheelchair. In many cases, it is actually dangerous for them to do so. Commonly these individuals will be given manual wheelchair, but frequently they are unable to move them. She set out to help individuals in these situations and others who use electric wheelchairs.
Her device consists of two cameras that interface to a laptop located under the wheelchairs seat. The cameras work to map the environment where the chair is used. The cameras can calculate distances between objects and detect an imminent collision. If a collision is detected, the wheelchair will take over, but otherwise the wheelchair owner is left to control the chair.
The laptop, tracks where a user goes and begins to learn their behaviors. Eventually it can evaluate the users ability and adapt to provide more or less assistance. The interaction between the person and the laptop is done through audio commands issued from the laptop.
One of the advantages of this type of system is that the wheelchair user is largely free to drive the chair wherever they want. With the collision detection in place, dangerous objects are avoided, so not only are they free to move virtually wherever they please, they are also free from danger.
Wheelchair Controls and BCI
Monday, November 10th, 2008
The first electric wheelchair was invented in the fifties. This chair made use of a simple control stick that could be mounted to either side of the chair. This allowed the chairs occupant to control the movement of the wheelchair using little more than a finger. This control setup is still very common, but, as the inventors in the fifties quickly realized, many people cannot use the joystick system.
Alternative control methods were developed almost as soon as the electric wheelchair was created. Several different control schemes were created, but the most common utilized head movement to control the wheelchairs.
There are many different control setups that are used today, including several that utilize head movements. One of the most common types of alternate wheelchair control uses the breath of the user to control the chair. The occupant will blow or suck through a small straw, which controls the wheelchair.
Several different wheelchair control systems are currently in the development stage, which use computers to control the chair. One uses voice recognition software to control the chair, while another uses a small magnet that is stuck to the riders tongue. A special headset picks up the movements of the magnet and sends them to a computer.
Recently, thought controlled computers have begun to be experimented with. This is commonly referred to as a brain-computer interface (BCI.) The development of a BCI actually began in the seventies, but it wasn’t until the middle of the nineties that an actual working prototype was built.
A brain-computer interface offers two different services. It can allow an individual to interact with a computer or it can be used to help trigger nerves and possible facilitate movement. In the terms of wheelchair control, the ability to interact with the computer is of most importance, but being able to have the computer signal back if there is an object in the way, could also be extremely beneficial.
In regards to wheelchairs, this technology offers many exciting applications. Computer controlled wheelchairs are currently available and being developed. These machines can be for the most part completely controlled by a laptop, so using BCI, an individual will eventually be able to control their wheelchair with only a thought.
There are two main types of Brain Controlled Interfaces: Invasive and non-invasive. Invasive BCI, involves physically implanting an electrode into the brain. These offer the clearest signal, but pose a health risk, as sometimes the area will scar or weaken. There are also a less invasive version that implants electrodes into the head, but not into the brain. This improves signal, but reduces the risk of irritating the brain.
Non-invasive BCIs are more common today. A user will wear a piece of headgear that is covered in electrodes. The signal is weaker, but it is currently safer to use in this manner.
Brain Controlled Computers will likely play a big part in rehabilitation treatment in the future. Several studies and commercial ventures are currently taking part in research and development of BCI. There are several systems available that allow a user to control a computer with their mind and thereby allowing them to speak and communicate their thoughts.
Electric Wheelchairs
Monday, November 10th, 2008
The first electric wheelchair was developed in the early 1950′s. These early power chairs took an existing wheelchair, usually the E & J manual wheelchair, and outfitted them with an electric motor. These chairs quickly became popular and today millions of people benefit from electric power wheelchairs.
While today, electric wheelchairs are much more advanced than the first electric power chairs, they do share one similarity. The joystick control system was first developed in the fifties and is still one of the most popular means of controlling an electric wheelchair today. The joystick can be mounted on either side of the chair and usually only requires a little bit of pressure for the occupant.
There are many people, however, who can not use this type of control system, so there are also several types of alternate control methods that can be used with an electric wheelchair that do not require the use of the occupants hands.
An electric wheelchair and a manual wheelchair share many similarities in regards to the services they provide, but they are also very different. Since power chairs are electric powered, it is necessary to charge them after each use. The range that a power chair can travel per charge depends largely on the model, but the places that you choose to use it can also effect the range. For example, driving the power chair up a very steep hill will cause the chair to loose its charge quicker. Most can travel a minimum of ten miles on a single charge.
An electric wheelchair will typically have a minimum of 4 wheels, but some have six. In these cases, the extra wheels are more for support. The way the wheelchair is propelled will help determine how many wheels it has. A traditional electric wheelchair usually only has four wheels and the rear wheels are what actually move the chair. These are called rear wheel drive power chairs.
A, relatively, new type of wheelchair has become very popular over the last ten years. These chairs use a mid-wheel drive system, a set of stability wheels located in front and in the back of the chair. The mid-wheel drive wheelchair is incredibly maneuverable and this makes it great for indoor usage.
Electric wheelchairs are incredibly popular today and many people would not be able to get around with them.
Voice Controlled Wheelchairs
Monday, November 10th, 2008
With the development of the first electric wheelchair in the middle of the twentieth century, many peoples lives were greatly improved. The manual wheelchair had been popular for some time, but a number of people, many disabled veterans, did not have the physical capacity to use a manual wheelchair. This meant that they were highly reliant on nurses, caretakers, and family members for pretty much every aspect of their life, however this all changed with the advent of the electrical wheelchair.
The earliest electric wheelchairs used a joystick control that was attached to the arm of the chair. However, scientists quickly realized that there were still many people who would not be able to use this type of chair, so other methods of control quickly developed. Today, the joystick is still predominantly used, but there are also several other options that allow someone without movement of their hands to use their chair. Two professors at MIT have recently announced the development of another control system, which when fully developed should revolutionize the way electric wheelchairs are controlled.
Computer programmers have been trying to develop adequate working voice recognition software for many years, but it has traditionally been very hard to train and very unreliable. However, within the past few years the technology behind voice recognition has greatly improved and today there are several popular software programs available that allow computers to be controlled by a persons voice.
Two professors from MIT, Seth Teller and Nicholas Roy, have set out to apply voice recognition software to the mobility industry and thus far the results look very promising. The system works by first training the wheelchair, then simply issuing it simple voice commands. For example, the chairs occupant will drive the chair to their bedroom and when they are in the bedroom they will say “This is my Bed Room.†The next time they want to goto the bedroom, they can simply issue the chair a voice command and it will know what to do.
This is not the first time that a system like this has been used, but earlier methods had relied extensively upon detailed blueprints and maps. This system differs, because it uses a series of wireless access points, which are positioned around the building or area where the chair will be used. This makes it much more versatile, because it can be easily used in almost any environment.
The system has been extensively tested on MIT’s campus and recently testing has begun at a local nursing home. More than 100 residents of the nursing home are now helping iron out the bugs of these devices, which will benefit not only those in the wheelchairs, but also their caretakers.
Nokia and Microsoft are both helping to fund the development of this project. For more information, check out MIT’s news release