science

Motorized wheelchair

Motorized wheelchair is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Motorized wheelchair rather than just read about it. In short: A motorized wheelchair, also known as a powerchair, electric wheelchair, electronic wheelchair, electric-powered wheelchair, and electronic-powered wheelchair, is a wheelchair that is propelled by means of an electric motor (usually using differential steering) rather than manual power. Motorized wheelchairs are useful for those unable to propel a manual wheelchair or who need to use a wheelchair over long distances…

Key takeaways

Motorized wheelchair belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Motorized wheelchair to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Motorized wheelchair from memory before moving on to harder problems.

Reference excerpt

A motorized wheelchair, also known as a powerchair, electric wheelchair, electronic wheelchair, electric-powered wheelchair, and electronic-powered wheelchair, is a wheelchair that is propelled by means of an electric motor (usually using differential steering) rather than manual power. Motorized wheelchairs are useful for those unable to propel a manual wheelchair or who need to use a wheelchair over long distances or on terrain that would otherwise be fatiguing in a manual wheelchair. They may also be used not just by people with 'traditional' mobility impairments, but also by people with cardiovascular and fatigue-based conditions.

History

An early motorized wheelchair was invented by Levitt Luzern Custer in 1919 at Dayton Soldiers' Home in Dayton, Ohio to help wounded World War 1 veterans. An electrically propelled tricycle was developed by the R.A. Harding company in England in the 1920s. The first electric-powered wheelchair to be put into production was invented by George Klein, who worked for the National Research Council of Canada, to assist injured veterans after World War II.

Design Powerchair design may be categorized by drive system/chassis, battery, controller, seat, and use. Because of their use as the primary method of locomotion, they must be of the utmost reliability both electrically and structurally, and are classified as Durable medical equipment by Medicare in the United States.

Drive System/Chassis Powerchairs are generally four-wheeled or six-wheeled and non-folding, however some folding designs exist and other designs may have some ability to partially dismantle for transit. Four general powerchair drive systems exist: front-wheel drive, centre-wheel drive, rear-wheel drive, and all-wheel drive. Powered wheels are typically somewhat larger than the trailing/castoring wheels, while castoring wheels are typically larger than the castors on a manual chair. Centre wheel drive powerchairs have castors at both front and rear for a six-wheel layout.

Powerchair chassis may also mount a kerb-climber, a powered device to lift the front wheels over a kerb of 10 cm or less. Some manual wheelchairs may also be fitted with an auxiliary electric power system. This can take one of three forms: integrated with the hub of hand-propelled wheels, so that any force on the pushrims is magnified by the drive system, or mounted under the wheelchair and controlled as for a powerchair, but with the motive force either transmitted to the main wheels via a friction drive system, or delivered directly through an auxiliary drive wheel. Some experimental all-terrain powerchair designs have been produced with tracks rather than wheels, but these are not in common use. Other experimental designs have incorporated stair-climbing capabilities; Dean Kamen's iBOT design, introduced in 1999 and discontinued in 2009, featured both this capability and the ability to 'stand' on its upended chassis using advanced gyroscopic sensors. Some modern power wheelchairs incorporate omnidirectional front wheels, each consisting of multiple small rubber tires that can rotate independently. One example is the WHILL, which uses two such front wheels combined with a four-wheel-drive system and motor controller. This design allows movement in any direction with a tight turning radius suitable for both indoor and outdoor use.

Battery The electric motors of powerchairs are usually powered by 2 batteries that are connected to the 2 motors, the smaller batteries are used in pairs to give the chair enough power to last at least one day between charges. These are available in wet or dry options. As wet-cell batteries may not legally be carried on an aircraft without removing them from the wheelchair and securing them in a shipping container, dry-cell batteries are preferred for powerchair use. Many powerchairs carry an on-board charger which can be plugged into a standard wall outlet; older or more portable models may have a separate charger unit.

Controller

Controllers are most commonly an arm-rest mounted joystick which may have additional controls to allow the user to tailor sensitivity or access multiple control modes. The controller may be swung-away to aid in side-transfers. For users who are unable to use a hand controller various alternatives are available such as sip-and-puff controllers, operated by blowing into a sensor. In some cases the controller may be mounted for use by an aide walking behind the chair rather than by the user. Capabilities include turning one drive wheel forward while the other goes backward, thus turning the wheelchair within its own length (differential steering). Mind-controlled wheelchairs, actually working by the detection of brainwaves or nerve signals via sensors on the scalp or elsewhere, have been demonstrated in the laboratory environments.

Seat The seating on a powerchair can vary in design. Seating ranges from a basic sling seat and backrest made of vinyl or nylon, some chairs have an optional padding, some have more comfortable cushion and backrest options which may include a head rest. There are companies that can fit their own backrests and seat cushions for people with increased need for stability in the trunk, or at increased risk of pressure sores from sitting out. Finally, specialist seating solutions are available for users who need individually tailored support. Leg rests may be integrated into the seating design and may have powered adjustment for those users who need to vary their leg position. Powerchairs may also have a tilt-in-space, or reclining facility for users who are unable to maintain an upright seating position indefinitely. This function can also help with comfort by shifting pressure to different areas for a while, or with positioning in a wheelchair when a user needs to be hoisted in. Certain high-end powerchairs feature a 'standing' capability in which either the entire seat elevates to bring the user to standing height or the seat-base, seat-back and leg rests move in conjunction to bring the user into an upright position. The powerchair may or may not be able to move while in the elevated position.

Environment

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Motorized wheelchair

Start with the simplest possible case. Write down what Motorized wheelchair claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Motorized wheelchair before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Motorized wheelchair ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Motorized wheelchair

In research: Motorized wheelchair appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Motorized wheelchair in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Motorized wheelchair is common in secondary-school and first-year university syllabi. It links to neighbouring topics Canadian inventions, Electric vehicles, Vehicles introduced in 1952, so understanding it makes those chapters shorter.
In everyday life: Look for Motorized wheelchair outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Motorized wheelchair in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Motorized wheelchair means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Motorized wheelchair out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Motorized wheelchair in simple terms?

Why does Motorized wheelchair matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Motorized wheelchair?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Motorized wheelchair.