Friday, October 12, 2007

Your power chair - mobility aid or obstruction?

In response to my recent article in the Spinal Injuries Association magazine concerning changes to EU legislation on wheelchair accessible vehicles (WAVs), Chris Povey has contributed the following article, which sets out one man's so far unsuccessful quest for a suitable powerchair to use as a "drive from" as well as for normal daily activities:-

Chris Povey writes:

"The part of the article where you suggest that wheelchair manufacturers might put disclaimer clauses on their products, rather than going to the expense of modifying them for use in a vehicle is, I feel, the real issue - namely the design of wheelchairs, be they powered or pushers, is wholly unsuitable for users' needs.

I drive a Braun converted Voyager from a powered wheelchair. I have noted/complained about/searched for a solution to the trend for chairs to increase in size and weight since the mid 90s. My last adequate one was the first mark Cheetah: since then seat heights have risen so I could not get knees under hand controls; frame widths compromise side entry (let alone using toilets); total weight makes overcoming steps by man-handling a health & safety issue.

I currently use an obsolete Invacare Twister, modified by a local bike co-op and an auto engineer to address the problems I found with the original design.

For my last vehicle I decided I wanted, after thirty odd years of absence, a head restraint. This could not be fitted to the vehicle, so I pushed for one attached to the wheelchair - if it could be moved out of the way for normal living. Nothing exists in the market so the vehicle converter made one out of a spare ramp actuator. This has worked perfectly for two years.

I then decided to design my own wheelchair seat with the minimum features needed to live all waking hours in the same seat. It would need to pass vehicle crash testing, and more importantly, survive day to day living and be easily repaired. I based my design on high grade, light, strong marine and climbing components, mostly aluminium and titanium. The maximum width is 57 cms (actually it can be less - probably 55 cms - I want to increase comfort by having a wider than normal cushion).

The rising headrest has been incorporated with smaller, lighter actuators and designed so that it rises in an arc to position itself better. The armrests have been the hardest parts to design, probably because I have set myself very difficult requirements.

They must be operable in the dark, one handed with spinal injury C5/6 dexterity. They must work from a single pillar set well back so that the vehicle seat belt works optimally for crash testing.

Another major design problem has been to remove welds, as these break down on armrests.

The original intention was to make a couple of these seats, then transfer them to power bases for the rest of my life. The original fabrication costs (£4000 - £5000) would be absorbed over that period by cheaper bases, which from past experience last about three years.

In Autumn of 2005 I met the CEO of Dundee-based manufacturers, Lomax Mobility at a function, and was very surprised to see that the base of their Powermax wheelchair would nearly fit my requirements.

I negotiated with their engineers that I would get the seat fabricated if they would modify the Powermax frame so it would offer a lower seat option. Their technology is old but reliable; I was willing to sacrifice range for reliability and a very small footprint of chair.

Lomax were then taken over by Sunrise Medical, who shelved the project. Had it continued as I wanted, there would now be a working, marketable, small footprint powerchair admirably suited to the 'drive from wheelchair' option. It would have an integral, retractable headrest; repositioning of seat tilt and back incline - all features vital for a reasonable cost "travel in vehicle" wheelchair. Equally, it would fit easily into a metro-type taxi, would be light enough to avoid breaking its ramp, and would be manoeuvrable into the rearward-facing position required by taxi insurance. The headrest in up position would prevent what I am assured by a vehicle crash testing expert is the inevitable decapitation of a wheelchair user in a forward shunt accident in a taxi.

My design for the ultimate seat on a Lomax base was only the first step. I want a long-range variant. I will probably have to design a base as well, using lithium batteries in a container which can hold two chargers, to run in parallel for fastest charging; transfer board; tools; and spares. The footprint will be as small as possible, for train/bus/taxi travel. The total target weight including batteries is less than 70 kg.

After that I would want to increase the maximum speed so that the powerchair can use cycle paths. The objective being that an urban user should not need private transport - looking towards the day when buses are required to become DDA compliant. From talking to people who are working on projects to motorise such modes of transport as bicycles and rickshaws, it appears that it is cheaper and lighter to buy volts rather than amps; so the motors on powered wheelchairs need to run at much higher voltages.

I want to simplify chair controls. I only need two settings: one to carry drinks and the other to avoid able bodied people who step in my way without looking. The first requires very low acceleration settings, the second requires extremely high settings. A possible third for higher speed on cycle ways will suffice.

I don't need lights, indicators, horns, or seat positioning on the main controller; if you want them, then have them as separate remote/radio controlled units.

What we need is simple, reliable, easy-to-use controllers that won't go 'rogue' as can happen with some more complex units. I don't want seat risers, pneumatic tyres, automatic brakes, suspension, kerb
climbers etc.

I want to use pub toilets, even with a guard on the door - not their car parks. I want to get my knees under restaurant tables. I want to get into those pubs and restaurants in my powerchair - even if they have steps.

The problem is that Sunrise, Invacare, Pride, Balder, Permobil etc do not seem interested in designing to do these things. In my experience, it's not the engineers in these companies that are the problem. They have generally given me pretty good service when necessary.

It appears to be the more peripheral departments, like marketing and legal, who want ever heavier, more stable machines with extravagant options such as suspension, seat risers and standing facilities.

Maybe we the users and our professional advisers are the culprits: we have forgotten that wheelchairs are primarily mobility aids for going to places - and increasing the weight and size cuts down the number of places we can get to."

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3 Comments:

At October 29, 2007 3:50 PM , David Knights - KC Mobility said...

It is a very interesting article and, as always, highly thought provoking as it is based on need rather than a design engineering team’s perceptions.

The whole area of carrying wheelchairs in vehicles is very vague. In 2005 I attended a seminar in London hosted by Anne Frye, the whole discussion revolved around the testing of wheelchairs and their suitability for every day living. Society now accepts that transport for wheelchair users should cover the whole gamut. The problem arises with who takes responsibility for the strength of the wheelchair and its suitability for use with wheelchair tie down systems. It was clearly shown at the seminar that even the most basic manual wheelchair had sufficient strength to withstand a 30MPH/20G load. The problem occurred with the re-coil, in almost all cases, the back of the wheelchair failed and the occupant would suffer possible neck and back injuries. When travelling in a taxi this could be overcome by the wheelchair user being faced to the rear and therefore the back of the wheelchair would no longer be subject to any damaging forces. It is deemed that in a train or bus, due to their physical size, any sudden braking or impact would not impart loads that could possibly expose weaknesses in the wheelchair. In the vast majority of cases wheelchairs are not secured in either trains or buses.

There doesn’t appear to be any legislation in the pipeline to limit the use of wheelchairs in vehicles, especially public service vehicles. When dealing with the private market it is very much in the interest of the wheelchair accessible vehicle manufacturer to ensure that the purchaser of the vehicle has a wheelchair that can be secured and that the occupant will be safe. Should the supplier of the vehicle have concerns regarding the wheelchair he should express them to the purchaser and either ask them to sign a disclaimer or refuse to supply the vehicle. It does, however, take a brave salesman to possibly jeopardise his sale due to concerns relating to the wheelchair. Injuries to wheelchair occupants in vehicles comes under the jurisdiction of the Medical Devices Agency: to my knowledge most of their concerns relate more to the loading of the wheelchair on ramps that are far too steep. The agency has certainly had many communications with Motability and the wheelchair accessible vehicle industry relating to ramp angles and the stability of wheelchairs.

I believe the Medical Devices Agency have been involved with the DIPTAC Standards and have made representation to the European Union on standardisation of wheelchair specifications. There is, of course, a very fine line between individual choice and the dictatorial approach from legislators as to what is right and wrong. At the end of the day it is the individual’s responsibility relating to their own safety and if they choose to use a wheelchair that is untested, then the responsibility lies with them. What needs to be made clear is what is a tested wheelchair and how was it tested? If you have uniformity of testing throughout all wheelchair manufacturers and importers and the product is clearly labelled it then remains the individual’s choice as to whether to buy or not.

The debate over size of wheelchairs and the excess amounts of features that are available on these chairs is about consumer choice together with marketability. I draw comparison with the mobile phone industry: every phone you buy has hundreds of features that the vast majority of people will never use. Until someone realises that there is a market place for a simple straight forward no-nonsense phone then they will continue to market these gadget laden phones. The same things applies to powered wheelchairs. Gone are the days of simple and lightweight, replaced totally with humungous power chairs capable of carrying the Forth Row Bridge.

The costs of these chairs have also risen beyond belief, with chairs such as the Balder costing more than a BMW 320 car! One has to ask the question “why cannot a manufacturer supply a simple straight forward power chair, taking account of the latest technology and bringing the weight down whilst still offering stability and safety?” I am sure if someone offers the Chinese the opportunity they will seize it and you will see an influx of low cost simple power chairs.

Chris Povey’s individual requirements were really interesting as he seemed to be looking for something simple and yet wanting it to travel quicker and farther. As soon as speed comes into the equation then other users of cycle paths and pavements become the controlling element. I fully understand that a bicycle could travel at a speed in excess of 30MPH the bike does however also have the ability to stop and to swerve very quickly. You certainly would not want a scooter or power chair to be travelling at that speed as neither has the stability to manoeuvre as nimbly as the bike. There may be a market place for this type of wheelchair but of course price will always be the governing factor. The only way to keep the price affordable is to manufacture in great volumes. It could be that we will end up with a marketplace such as the car market where we are seeing customisation taking place on every conceivable level from both making it go quicker to replacing the wheels, fitting Hi-Fi systems, etc, etc.

There have been some interesting changes in the market such as the powered wheel unit to fit manual chairs and revolutionary new power chairs such as the Autoadapt Carony Go. There is certainly a dearth of wheelchairs which have embraced materials such as Titanium, Aluminium, Carbon Fibre and the latest battery technology.

Even wheelchairs such as the Balder are in excess of 25 years old. When you think of the developments made in televisions, DVD’s, mobile phones, etc the wheelchair is sadly being left behind. This is probably due to there being a lack of wheelchair bound people heading major corporations or design teams working for these companies.

The driving adaptations for disabled people have been revolutionised in the last 10 years with the use of micro-electronics, etc. We have seen the introduction of robotic technology for the loading of manual chairs into the rear of vehicles. We now have touch sensitive electronic hand controls fully integrated into the vehicles computer system. We know, for instance, that both Mercedes and SAAB have developed and built joystick controlled cars that will be the car of the future. We will see the removal of clutches and manual cars, the car will become like an aircraft with a drive-by wire system. All this is going on and yet the wheelchair just remains basically the same.

I know that I and many of my colleagues within the adaptation and wheelchair accessible vehicle industry would love to see some integration and co-operation with wheelchair manufacturers. In the case of the Carony Go, Autoadapt decided to design their own powered wheelchair, it may be that we in the adaptation industry need to follow their lead and ignore the wheelchair manufacturers; it is all good food for thought.

I would certainly welcome any suggestions and will happily get involved in any discussions that the Independent Living Journal readers and any disability groups are having with the wheelchair manufacturers. I hope my comments have been of some interest to the debate.

 
At November 2, 2007 3:42 PM , Anonymous said...

well done it seems to be so unfair for us who need a chair i have a old badger chair and it is broke and now i am with out a chair as theyt have not got the part nor a replacement for me so i have to wait till then also trying to find a eletrick chair for the boot for me as i amm 23 stone is ner on possable i think you was great to do what you have and i take that on baord thank you for telling us this
from gary in birmingham

 
At December 7, 2007 12:39 AM , Admiral Marschl said...

There has to be less standardisation and more choice.
I agree with the comments about having a simpler chair but feel I have to say that the chair described may well be perfect for you but not for me. I use a scandinavian mobility corbie executive. It is now very old, the company went out of business years ago becoming invacare I have been told. I love the chair. I also have an invacare twister with lift and tilt on power and a gas operated reline. It has lots more facilities but I don't like it as much and it is used only as my spare if anything goes wrong with the corbie. With my medical condition I need tilt and recline and a comfortable seat which for me is a recaro. What bothers me is that recently all I see everywhere are lightweight small wheeled chairs, I find the driving properties of the corbie to be ideal for my needs especially its ability to travel over rougher terrain large cobbles etc, I do not like the small wheeled chairs as they are difficult to manouver over rough ground, as i am a large man over 18 stone I am at the chairs weight limit and find smaller chairs to be bad for me, I would probably end up breaking some them just by sitting down, the engines seem to be getting slower, the corbie can reach 6mph which I consider too slow in places such as the aforementioned cycle tracks and public footpaths, yet some of the chairs I see can only reach 2 mph with dealers talking excitedly about 4mph machines, and I just think what are they on about 'Thats slow' I have tried invacares spectra(horrible) Storm (not much better)Powermax(a beast which constantly pulled to the right) modular travelor (not too bad till the wheels started to drop off) The only test drive I had in recent years which I liked (Immensely) was for the Ibot 3000, down Blaydon bank which is / extremely steep. This thing had four wheel drive and gyros. I could drive at speed straight off the kerb
(8 inch) over the grassy island in the middle equally as high and up the kerb on the other side without even slowing and not feel a thing, this was the best powerchair I have ever been in though the price was huge, they have now pulled out of the uk. As far as buses and taxis are concerned I never use them nor want to, the only taxis I use are the one local man who is considerate and lets me use my own ramp which he takes with him and stores in his garage for when he picks me up. I have a large van which accomodates my large powerchairs and we need one that big anyway as we are a family with two powerchair users both over 17 stone. My point is every disabled person has individual needs and these are not being met. I want a latge sturdy 4 wheel drive with power tilt recline and lift and large rear wheels with large tyres capable of driving over those cobbles or sanddunes, climbing hills with shingle paths and heather, independent suspension on all four wheels,
comfortable recaro style seat preferably with further spring suspension, axles which tilt in space such as on the cyclone mobility 4x4, the ability to go anywhere, as for access, the ibot could also climb stairs, since I believe that most of the users of this website will be well dead and buried before any DDA type law makes all places pubs etc accesible, perhaps in a hundred years if we're lucky then I would rather have the chair which could climb stairs now rather than wait for them. I take the users point about lightweight chairs being able to be lifted up kerbs etc but I think this may be the perspective of a paraplegic with good upper body strength and while it is true for many spinal injuries people it is not true for all and is certainly no good for myself or anyone with a condition of muscular weakness or fatigue.
I admire greatly the work of paras in the past who redesigned their chairs away from the horrible heavyweight NHS things of old and welcome the same challenge to design new powerchairs, I completely agree with the comment about metals and alloys such as titanium, we need something ulra strong durable but as lightweight as we can get even for heavier chairs such as mine, the batteries etc would provide enough weight for stability, my own preference is lightweight titanium frame, smaller but more powerful batteries and much larger more powerful motors. If any engineers are reading this and would like to hear more about my heavy duty offroad use of powerchairs and my needs I will be happy to respond, I would welcome taking part in a trial run or design team working on such projects as off road 4 wheel drive powerchairs and also design of track racing powerchairs which could be much wider and lower to the ground with batteries along the sides enough space for 8 or 10 40 amp batteries and much higher speeds. I end by saying that the last thing we need is more eurocratic lawmaking safety nazi types and we need the manufacturers and especially the designers to listen a hell of a lot more to us the users and a whole hell of
lot less to Occupational therapists etc etc

Contact me on
area96@fsmail.net

Mike

 

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