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Laser scanning vs casting: Yes or No!

Discussion in 'Biomechanics, Sports and Foot orthoses' started by nicpod1, Apr 21, 2010.

  1. nicpod1

    nicpod1 Active Member


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    OK, need to keep this simple, as I know the answers will not be, so best not to drag it out!

    Laser foot scanning for orthoses manufacture vs casting:

    Which is best and why?!

    My view, basically, depends on the scanner, depends on the lab it's attached to or is capable of making orthoses from laser images, but not sure whether scanning is better than casting from a precision point of view?

    Opinions would be gratefully received!
     
  2. Griff

    Griff Moderator

    Nic,

    Loads of threads on here about this already and well worth reading through them. The general consensus is that laser scanning is more repeatable, but as we don't know what the 'ideal' position is that could mean it gets it wrong consistently (or right consistently of course).

    Ian
     
  3. Nic also to throw a 3rd into the discussion. There is cast scanning. ie taking the cast in what ever position you want then scan to manufactor the device. Might be the best of both worlds. I was hoping to discuss this with couple of people in England today but some Volcano in Iceland got in the way.
     
  4. Admin2

    Admin2 Administrator Staff Member

  5. Griff

    Griff Moderator

  6. nicpod1

    nicpod1 Active Member

    Ahhhhh!

    I did a search on here for laser scanning, but nothing came up that related to it, so, I apologise - we'll start to look through the posts suggested!

    However, I am already using a lab that scans the casts we send to them and we're really happy with our orthoses, but, locally, there are clinics starting to use scanners (although they are through TOG apparently, so we're not too worried about that), and sometimes you just start to wonder whether you are falling behind technologically?

    I'll look at the posts anyway!

    Thanks!
     
  7. Griff

    Griff Moderator

    Nic,

    As I'm sure you know TOG is a bit different (2D information - not 3D scanning like the Sharpe Shape scanner for example). In my experience people using the TOG system are usually less knowledgeable/confident in what they are doing. Certainly no threat to you in theory - but those pesky patients do love pretty pictures unfortunately!
     
  8. nicpod1

    nicpod1 Active Member

    Hi Ian,

    Yes, that's what I thought, but when you look at the guys website, he says he has a 3D as well as a 2D scanner, so can TOG do orthoses from both types of scan?

    Which leads to the more important question of scanning really, which labs support scanned information being sent to them instead of casts and are there any limitations to the orthoses they produce from the scanned images? If not, then why isn't everyone doing it, because the whole issue with capturing the right position of the foot is the same for scanning as it is for casting, surely?

    For instance, Ian, do you use a scanner? If not, why not and what about the technology would have to change to convince you to use it?

    Nic
     
  9. Griff

    Griff Moderator

    Nic,

    As far as I am aware TOG do not do a 3D scanner. A more likely scenario is that the person's website is misleading (and not necessarily intentionally on his part).

    You may want to read the threads on here on negative model production because that is what we are really talking about here. Some methods are quicker - some are cheaper - some have more of a wow factor but they all essentially do the same thing and we do not necessarily know which is 'superior' with respect to negative model capture or orthoses produced.

    I do not use a scanner no. I did use a 3D one for a time, and found it to be a lot quicker (is this always a good thing if you charge for your time?) and certainly noticed the patients seemed more impressed by it. It was also lovely to be able to just email the data to the lab immediately and not have to faff with posting off POP casts etc. What I didn't like was that it tied me to one lab (I use 3 different ones now) and that if they 'give' you the scanner for free there are usually targets which need to be met and that is not how I roll. I also didnt feel I could manipulate the foot position as easy as I can with POP (e.g plantarflex the 1st Ray etc)

    Just my thoughts you understand - I'm sure someone else may think differently. Rob Issacs did a decent comparison of the negative capture methods in a recent Pod Now (assuming you are in the UK?)

    IG
     
  10. nicpod1

    nicpod1 Active Member

    Excellent Ian, thanks for that!

    I somehow seem to have missed the article in Pod Now, but will back track and have a look at it!
     
  11. Ah, I think that that is a FUTURE Pod Now. Remember you get the pre release version because you are special ;).

    If memory serves it will be the NEXT issue with the casting techniques (May, should be out in the next week or so I think.) June is a commentry on Barefoot running written mostly by our own Ian Griffiths (no photos, he's sold the rights to OK magazine) and july will be on the arguments for and against taking measurements as part of biomechanical assessments.

    The article is a bit longer than my usual, but can be summarised as followed.

    "Whatever works"

    Seriously, so far as being left behind in concerned, don't be. A machine which goes ping may be impressive to the GU but all it can do is capture a shape. If you can capture the same shape in plaster, foam, wet sand, hot wax, Amfit, by direct moulding or however then it won't make a better orthotic.

    There is no magic to this. The object of all casting methods is to capture the shape we want. The method which does this consistently and conveniently for you is the best method... for you.

    To use an analogy, I drive a family saloon car. My friend drives a 2 seater sports car. Both get us from A to B in a similar amount of time. He can't get 2 kiddie seats, 2 kiddies, 1 buggy, 1 changing bag, 234 soft toys, 1 dom case, 10 casting boxes, 1 Lock box, and a box of wheat crunchies in his, I can't get away from the lights as fast in mine. Which is better? It depends HOW you wish to get from A to B.

    Regards
    Robert
     
  12. In My Option the machine that goes ping and when the systems are there to capture a 3D foot shape at a price that people can afford will be the norm.

    Although the 1st step maybe to capture the foot shape. The use of computer added and CAD systems will make for a faster turn around, more specific device and give greater control to the Person who prescribes the device ( the next question is if this is a good thing or not for another thread perhaps).

    With this systems there will be less waste, faster turn around, less middle-person handelling. The problem is that it requires more from the prescriber which maybe an issue maybe not.

    I´m still looking but the technology is at what I can work not quite there and the cost is quite high. I´m hoping time will increase one and decrease the other.

    I sound like a broken record but Bloody Volcano.
     
  13. Griff

    Griff Moderator

    Whoops! Sorry Rob - read it a while back and forgot where I read it. My bad - hope I haven't spoilt the surprise for anyone...

    That'll be why you missed it Nic!
     
  14. Don't be so sure. There is an awful lot of waste when an orthosis is milled from a block of material.
     
  15. Oooooooo. Is greater clinician control a good thing? Now THERE is a question with far reaching consequences!! Are outcomes improved or damaged by the "homogenising" which goes on at the lab?

    BIG thread.
     
  16. Too right. Firstly, can anyone point to a study of clinical outcomes in which custom devices performed better in reducing pathological symptoms than prefabricated devices... Josh Burns?
     
  17. New thread for the question "is greater clianican control in orthotic manufactor a good thing ? over Here
     
  18. pws

    pws Welcome New Poster

  19. Rosso

    Rosso Member

    Firstly I am aligned with a lab that does Scanning
    In the end like casting it depends on the quality of the cast and the scan.
    If the scanner is an bed scanner the podiatrist need to ensure the heel is not touching the glass as the heel on the finished job will tend to flat and this will translate to a flat heel on the orthosis,
    My experience is the non weight bearing scanners give the best scans.
    There is a criteria to do this and only Experienced sellers of the product will be able to put the Podiatrist on the right track.
    We scan casts however we grind and the cast to give a result and a good heel scan. Most Scanner are with accurate to .625mm.
    Some of the cad cam software to design the Orthosis is based on 2D scanners and the results are of poor quality. If you are thinking of using scanning technology thoroughly investigate the results you hope to achieve.
    Hope that was not too long.Rosso:deadhorse:

     
  20. joejared

    joejared Active Member

    Let's break this into specific segments, specifically, data acquisition, design, and manufacture.

    Capturing a data from plaster is more repeatable, only because it captures a moment of time from the foot. It doesn't make it right, but it is an object that can provide repeatable results. Capturing data from the foot directly, sounds nice, but it also depends on the characteristics of the casting method. Perhaps the most subjective portion of the scan is the forefoot, except in pathologically rigid cases. A non-weight bearing scan is probably as close as one can get to replacing plaster, but slightly less repeatable than plaster. Applying any amount of force particularly to the forefoot generally leaves it to the orthotic designer to interpret forefoot expansion as comparable between plaster (non-weight bearing) and biofoam casting (semi-weight bearing), whereas the rearfoot is typically less of an issue.

    The laboratories that read scans in my network learn to interpret the level of expansion based on the red areas of the scan, which imply contact with the window, and react accordingly. Whatever method of casting the practitioner uses, consistency is helpful.


    As for design and manufacturing capabilities, at least one competitor started without any form of data acquisition and laboratories sold devices from that system as a prescription device. Another competitor obviously used the data in a limited fashion, as evidenced by a consistent longitudinal arch peak position. Any cadcam system for orthotic manufacturing should have a flexibility to support any level of fill, or no fill what-so-ever, and should be able to mimic or closely approximate the original surface.
     
  21. Shane Toohey

    Shane Toohey Active Member

    Hi all,

    You'll have to pardon my ignorance about scanning - whatever type
    - and jumping in now.
    I've had a look every so often and have not been able to work out how you can read a reference - for example a rearfooit reference into a scan.
    I have seen feet that have large rigid forefoot eversion alignment balanced from a scan as if the problem was the opposite and had a large rearfoot inversion correction built in. It looks as though the balance on the scan was read off the distorted heel fat pad. I also see this done with casted devices so that is a prescriber error. Nevertheless, the shape floating in space doesn't have the references I want.

    Cheers
    Shane
     
  22. DTT

    DTT Well-Known Member

    Nicpod

    Which web site would that be then ???:rolleyes:

    Ian

    Shame on you :boxing:

    If it is my web site that is being referred to here it most definatly is NOT misleading in any way, as I do have and use BOTH types of scanner the Sharpe Shape is linked to the lab I get the majority of my orthoses from and the Pressure mat is now used mainly to assist me in gait analysis and yes to give the patient the pretty pictures it produces and to educate and help the patient understand what the problems are.

    Why ? Just add's more strings to my bow and choice in application.

    TOG will scan casts if you send the cast in to them I believe.

    Whether that makes you lacking in technology Nicpod I don't know but it's never a good idea to generalise on systems: or practitioners :cool::D

    Cheers both
    Derek;)
     
  23. Griff

    Griff Moderator

    Hi Del,

    I was not aware of who nicpod was talking about nor had I seen the website she was referring to - was just going on what information she gave. She referred to a 3D tog system which is what I based my answer on (I even referred to the sharpe shape being 3D in one of my posts).

    I get the feeling I may have stumbled into a more 'personal' debate by accident - I was trying to be objective about the differences between methods. No offense meant to anyone - but no apologies either as I stand by the comments I made based on the info I had at the time ;)
     
  24. Mutter mutter sulk sulk, you with all your scanners and toys and machines-which-go-ping, mutter mutter.;)

    And you MAY have a better microscope for dermatology than me but I had one FIRST. So ner. And I have a notched stick! Where's your notched stick eh Harland?

    Bloody old experienced Pods with their fancy city ways.

    Robert
    With scanner envy.
     
  25. DTT

    DTT Well-Known Member

    Hi Ian

    Not to my knowledge BUT ...............:D

    You said


    After being informed

    I was simply making the point it is not necessarily "misleading"or "unlikely" :cool:

    AND

    Whats more you have just earned a 2 shot cut on your stated handicap !!!:drinks

    Cheers Fella
    D;)
     
  26. DTT

    DTT Well-Known Member

    Get back to your broken chalk and coloured NHS pencils Isaacs and leave us tekkys be ;)

    Cheers mate
    D;)
     
  27. Griff

    Griff Moderator

    Fair point - perhaps I dived in a bit quick there. But let's be clear - defaming someone elses website is not how I roll. I'll be more careful next time.

    I was recently informed that the highest handicap available is 28 (is that right?). If so feel free to penalise me 2 shots. I'm playing off 27 ;)

    Ian
     
  28. DTT

    DTT Well-Known Member

    Lighten up fella it may not have been my website anyway no worries, I think we are all aware of your intentions and roll ;)

    Ahh yes that was before winter rules were lifted, maximum in the summer is 14 which makes you off 10 SO you give me 4 shots :eek: :D:D

    Cheers
    D;)
     
  29. Griff

    Griff Moderator

    Ouch. That'll learn me. Until then boss.

    IG
     
  30. DTT

    DTT Well-Known Member

    You puppies, Just like Isaacs, bloody reckless and impulsive :rolleyes:

    You'll learn :D

    Cheers
    D;)
     
  31. What to be all cautious and tactful like you :pigs:;)

    I'll have you know my colouring pencils are sharp and everything. Need a new red though. :eek: So long as I can keep sending em to you for a ping o gram.

    I call Pax.
     
  32. DTT

    DTT Well-Known Member

    :D:D If you have the talk use it !!!! but you have to have the "age" to carry it off with the patients ;)

    You know your welcome whenever and with whatever :D

    The scan force (ping o gram)will sort it for you :D
    Cheers my friend
    D;)
     
  33. robby

    robby Active Member

    sorry to drag this back to early posts in this thread-

    it depends which TOG you are talking about.

    The Orthotic Group in Canada, which bought out Langer US orthotic manufacturing have a 3D lasar scanner based on the Veriscan system. this has been in the market place for several years through TOG before they bought out Langer US.

    Obviously we all know Langer US as a major high quality orthotic manufacturing force and TOG now have all of that including the knowledge behind it within their realm!

    TOG are also now entering the UK market in force, with the scanner, on the back of Langer US. they will be a threat!

    do not underestimate them.


    and yes I do have a vested interest. I work for The Langer Group (IE Langer UK).

    robby
     
  34. BEN-HUR

    BEN-HUR Well-Known Member

    Nice bit of PR work there Robby. However...

    Yep, I think this would be the TOG I've had issue with in the past i.e...

    [​IMG]

    They may have this 3D Laser scanner... but do they use it when a cast is sent in??? Does the assessment/scan play a role in the final orthotic product??? I had alarming issues with their orthotics i.e. orthotic (i.e. Diabetic Flex Orthotic) far too thick to fit into standard Rockport walking shoes (patient was only able to fit the toes past the top part of tongue of the shoe)... not resembling the patient's foot morphology, wrong gait plate etc...

    - Classic example: 14 year old Down Syndrome foot (wide foot - severe pronation) with exactly the same shape/contour orthotic as a 65 year old normal foot structure with mild degree of correction needed. Exactly the same contour/shape/correction & size orthotic. However both their feet were the same size... here I wonder lays the hint in their orthotic manufacturing practices!! ... sized prefabs!

    "Knowledge"?! They make an orthotic way too thick to fit into a normal shoe (i.e. Diabetic Flex), they can't read prescription notes (i.e. orthotic type & correction needed), they have poor resolvement skills, poor technical support & don't return emails... just to name a few.

    Yep, a threat to your patients & the integrity of your practice!

    Oh please... "do not underestimate" the headache & frustration they will give you & your patients.

    You don't say.

    Yes I do own GaitScan... yes I did use their orthotics... & yes I have obviously given them a fair go to resolve their ways. After all, the system was not cheap!

    ... & yes I do have plenty of photographs & notes to support the above statements.
     
  35. Passionate stuff Matthew!

    Ok, let me stir the pot a little.

    As some may know I am a frustrated Lab technician forced to do clinical work (as opposed to a clinician forced to work in the lab). I've made literally thousands of orthotics, including not a few cast by other podiatrists. Some of these casts are pretty good, some are horrifically bad. Some are SO bad that the amount of "cast correction" required to get to a workable orthotic means it AMOUNTS to a pre fab in any case.

    Almost all labs do this "cast correction". What it amounts to, by and large, is homogenisation. So my question is this.

    How close are "custom casted" orthotics to a homogenised shape by the time the lab has had its way with them?

    Here's a fun study for someone. Take a positive cast. Press it into 4 foam boxes so you have 4 identical negative casts. Send the boxes to 4 different labs with identical prescriptions and instructions. When you get the insoles back scan them with a 3d laser invert them on an amfit machine or even just plain measure them at certain points with a digital caliper.

    If the custom cast is truly a custom cast made to the specifications requested then all 4 orthotics will be of a muchness, showing that the shape of the insole is informed by nothing more than the shape of the cast and the prescriptions. If they are homogenised to a great degree they will vary depending on the variation in the labs' cast correction protocols, or how the plaster technician happened to be feeling that day.

    I'd take a £20 bet that variables like arch height at a set co-ordinate, width of shell at set points and suchlike would vary considerably between labs, say by more than 10% of the measurement. I'd take a further bet that if I threw the measurements of a pre fab of my choice in to make a 5th insole, nobody would be able to identify which data set was from the pre fab. Any takers?

    A simpler still study would be to make changes to the positive before remoulding so you had 4 subtely different negative (say with arch height increased in 3 mm increments) and send them off to the SAME lab to see if the 4 insoles would be correspondingly different, or if the differences would be homogenised out.

    Fancy doing that one with me when your MSc is finished Ian? Neat little study that, though I suspect it would win few friends.
     
  36. I've been meaning to do this type of study for ages. If you want to do it Rob, I'm in and will provide some funding. You can take it a step further and test the claims made by some labs of "calibration"- send identical casts but add different body weights on the prescription. If you want to catch out the guys palming of prefabs as customs send them a really cavus cast and a really planus cast.
     
  37. Just had a deja vu moment.

    This one got me thinking about Morgan's meat pie paradigm. Did a swift search to refresh my memory and we were talking about pretty much this same think in 2006!

    And 2007, 2008, 2009, and now 2010 as well. I hereby request that Morgans Meat Pie Paradigm be given its own tag.
     
  38. Done. Lets do it. I think the stiffness one is a great one too, perhaps a bit much to do in the same study?

    Ian, you want in?
     
  39. Our lab does not use any scanning. We simply complete corrections the old fashioned way. You know what they say " if it is not broken, do not fix it"

    After viewing several different scanners I believe that it will take a few more years before they can come up with the right scanning system.

    Andre Shervanian
    Alliance Orthotics LLC
    www.allianceorthotics.com
    andre@allianceorthotics.com
     
  40. joejared

    joejared Active Member

    That's a valid question, for both cad-cam based systems and the labs that use cad-cam based systems.

    Given the difference in cost of manufacturing, it's beyond stupid to sell prefabs to a practitioner unless they ask for them.

    GaitScan for orthotics? Right at this moment, I wish I could find some cranky old woman to scream, "Where's the arch?"
     
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