The liberation that wheelchairs provide is obvious to most: The ability to sustain mobility in everyday
environments. However, what's not so obvious is that for those with very involved disabilities, a wheelchair
is only part of the mobility equation, where other medical components must work in conjunction with the
wheelchair in order for one to achieve mobility. This fact is especially evident when it comes to respiratory
ventilators, and one's understanding of exactly how ventilators interface with wheelchairs is an important
move toward optimizing mobility for those with very advanced needs.|
A Brief History of Ventilators
The first "negative pressure ventilator" was used in 1928, and quickly adopted the name, Iron Lung. An
iron lung was a large, cylindrical chamber that encapsulated a person from the neck down, creating artificial
breathing function by decreasing and increasing air pressure within the chamber by moving the lungs of
those who were paralyzed. During the 1940s and 1950s, the iron long was at its height of usage, saving
the lives of countless individuals paralyzed by polio.
Ventilator Ward Circa 1950
However, the iron lung was a disturbingly debilitating device. While an iron lung kept one alive,
it rendered one entirely immobile, typically confined to a hospital ward, unable to move, encapsulated
in a huge machine.|
In 1952, the "positive pressure ventilator" was invented, forever improving
lives. The new ventilator design was a small, portable pump that forced air into one's lungs via a single
breathing tube. Rather than being encapsulated in an iron lung, one could now remain in bed or in one's
According to CNN, in 2007, only 30 iron lungs remain in use in the United
States, with "portable" ventilators now the health care standard. Today, it's common to see ventilators
mounted on wheelchairs, with those of complex disabilities leading strikingly liberated lives, from home
to office and beyond.
Common Types of Portable Ventilators
The Achieva portable ventilator
by Puritan Bennett, has long been the industry standard for ventilator use on wheelchairs. Measuring
10.75"H x 13.30"W x 15.60"D, the Achieva is about the size of a large toaster oven, and weighs 32lbs.
In addition to the Achieva, itself, an external battery is used, ranging from a U1 to a 22NF (though,
the unit does contain an internal back-up battery for emergency use of up to 4 hours).
The leading edge of portable ventilator technology is the Pulmonetics LTV series, dramatically reducing
the size and weight of ventilator technology. The LTV only weighs approximately 13.5lbs, and is just
a scant larger than a notebook computer, measuring 3"H x 10"W x 12"D. What's more, the LTV operates via
internal power or an external lithium-ion battery, both of which further dramatically reduce overall
size and weight.
Mounting Portable Ventilators to Wheelchairs|
When it comes to mounting ventilators on wheelchairs,
manual wheelchairs are the most clear-cut. Used namely on manual wheelchair tilt-in-space models, ventilators
sit on a tray underneath the seat, secured to a "vent tray" that houses both the ventilator and the battery.
This combination creates a stable - albeit, heavier - manual wheelchair/ventilator combination, where
the wheelchair's dimensions do not notably increase.
However, mounting ventilators on power wheelchairs
is a much more subjective, consequential proposition. Because all of the space beneath power wheelchair
seating is consumed by the power base, itself - batteries, motors, and electronics - the only place to
mount a ventilator is on the rear of the power wheelchair. Achieva-type ventilators mount on a rack on
the rear of the power wheelchair via a gimbled vent tray that places the ventilator on top, and its U1
or 22NF battery below it. This configuration not only typically increases the power wheelchair's length
by 15", but also adds a total of approximately 60 pounds to the very rear of the power wheelchair, affecting
overall maneuverability, stability, and performance (and, for these reasons, vent trays are only offered
on certain power wheelchair models and seating).
The compact LTV series of ventilators is unquestionably a far more practical vent to mount, typically
adding very little - if any - length to a power wheelchair. Further, because the LTV is so light at 13.5lbs,
and is commonly used with its lithium-ion battery technology, it places very little weight on the rear
of the power wheelchair, allowing nearly normal handling.
Optimizing Ventilator Use with Power Wheelchairs|
The fact is, when one needs a ventilator, there's
no choice but to use it, including with a power wheelchair when required for mobility. However, ventilators
installed on power wheelchairs can detract from a power wheelchair's performance, so thought should be
given to their installation.
Firstly, the ideal compatibility with a power wheelchair is the
LTV series of ventilators, where they're light and compact. However, due to funding constraints and respiratory
needs, not everyone qualifies for an LTV ventilator. Therefore, optimizing use of the larger, Achieva-style
ventilators is important.
Of major consequence to using an Achieva-style ventilator on a power
wheelchair is that the weight placed on the rear of the wheelchair - consisting of the ventilator and
its battery, around 60lbs. - can cause "fishtailing" at higher speeds, making the power wheelchair more
difficult to steer. Therefore, minimizing a ventilator's weight on the rear of the power wheelchair serves
overall performance. This is accomplished on select power wheelchair models that are designed with a
battery box in the power base that holds two Group-24 batteries as standard, or three 22NF batteries
(two that power the wheelchair, and one that powers the ventilator). As a result, the ventilator's battery,
weighing approximately 30lbs., can be repositioned from the rear of the power wheelchair to underneath
the seat, in the power base, increasing overall performance, including enhancing tracking and stability.
(Moving from two Group-24 batteries to the three 22NF battery configuration will slightly reduce driving
range; however, many users find that being able to place the ventilator battery in the power base, rather
than hanging it on the rear of the power wheelchair, notably enhances overall performance - a meaningful
trade-off for slightly reduced range.)
Getting It Right from the Start
an LTV series ventilator is unquestionably the best technology to combine with a wheelchair - light and
compact. However, if one uses the more-common Achieva-style ventilator, ordering a power wheelchair with
the capacity to hold the ventilator battery within the power base will increase overall wheelchair performance.
When one requires both a wheelchair and a ventilator, considering how to optimally combine the
two will optimize one's overall mobility, where a ventilator will compliment one's mobility, not detract
Published 3/09, Copyright 2009, WheelchairJunkie.com