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Has anyone ever tried High Speed Video for gait analysis?
I have seen this used for horse gait analysis in England and America using special cameras that take footage at 250, 500 or 1000 frames per second compared to the standard digicam speed of 30 frames per second.
Sounds like it would give a lot more detail.
Anyone seen this used clincally?

Hi,

My business partners in Germany built this lab in Munich:

http://www.contemplas.com/motion-ana...highspeed.aspx

They utilised 2 Hi-Speed cameras and 2 DV to film 4 perspectives.


FYI
Most DV cameras (Pal) take 50 frames per second 25 odd and 25 even, these are interlaced to produce 25 fps.

Using a 250 plus camera would create a number of issue as follows

1) Software that supports Hi-Speed, Only Templo (up to 4) and Quintic do - not sure about Silicon Coach - cannot see it on their website. Dartfish doesn't support HSC

2) Light - the faster the shutter speed the more light is required.

3) This is compounded when the aperture is reduced and the shutter speed increased.

4) The resolution is important; most cameras above 100fps provide pretty poor images especially if the resolution drops below 656x490.

5) High speed cameras are, on the whole, built for industrial use – assembly line work.

6) For gait analysis: 100fps, shutter speed of 1/500 sec is adequate and affordable (Therefore you will see 4 times the amount of frames compared to a standard DV camera).


Jonathan

www.mar-systems.co.uk

Thanks Jonathan,
Setting aside the technical difficulties associated with the high speed camera vs other camearas and assuming that the resolution, clarity, etc were the same - would the higher frame rate assist in the diagnosis of gait abnormalities? As you say, 100 fps give you 4 times the information so wouldn't 12 times the info be even better (300fps)?

Hi Highseed,

I wish this were true, but you cannot get a camera (beneath £20,000 plus) to provide 300 fps and that sort of resolution. :(

Cameras like Basler A602CF offer a max resolution of 656x490 pixels at a frequency of 100 frames per second (100Hz).

Higher frame rates of up to 300 fps can be reached by reducing the area of interest (ROI, part of the image).

So at 200 fps you have a resolution of approx. 500x325 pixels (or 435x325 at an aspect ratio of 4:3),

at 300fps a resolution of approx. 480x215 pixels (or 285x215 pixels at an aspect ratio of 4:3).

For comparison: normal (Pal Europe) DV-cameras provide 720x288 pixels at 50 fps.

Therefore you see 12 times as much however with a huge drop in quality.

But good news is coming - 250 fps Ethernet cameras with a resolution of 656x490 +/- pixels at around the same price as a 100fps camera. :)

Working to implement this new solution into our software -

Jonathan

www.mar-systems.co.uk

Thanks Jonathan,
So reading between the lines there is a benefit to using high speed (250fps+) cameras for gait analysis but the cost vs benefit equation doesn't work out due to the high camera cost. Does that about sum it up?

Yep!, until the Ethernet are intergated - I'll send you an personal message when the Ethernet cameras are available.

Jonathan

A company called Innovision Systems in Michigan has high speed cameras and gait software that can be used with any sampling rate/camera.

They have all kinds of cameras, but I like this one that is 250Hz with 640x480 resolution for US$5,000. The great thing about this camera is it has on board memory so you dont have the problems of data streaming. I use my laptop with 4 cameras and plan on adding 2 more very soon.

Gyps

I'm considering bying a highspeedcamera and the analysis software from Contemplas. Searching this forum I only foundthis topic, but it dates from a few years ago.

Is there anyone here already using this system and can tell me something more about it. Is it usefull in the private practice? Does it work as fast a they say it does? And does it also work in a walkway or better using it together with a treadmill?

I'm already using the RSscan-pressure-system and I want to use it together with the Contemplas software. Hope to hear from someone.

Kind regards,
Saskia

Hi Saskia

The Contemplas system is certainly easy to use and I believe a welcome addition to a private practice.You can use it both as a walkway or have the pressure plate inserted into the treadmill.Contemplas usully recoomends the Zebris pressure plate-it has absorptive capacitors in the pressure plate which are more durable.

Contemplas is compatible with RS Scan-make sure that you have a later version ;however the reps should be able to tell you if your particular RS Scan model is compatible with Contemplas.My understanding is that you need to be able to plug the cable directly into the RS Scan portal so that the Contemplas software can interpret and convert the data.I believe that Contemplas also provides better reports.

Having explored a few Motion analysis packages I would ceratinly consider Contemplas.If I had more money I may even consider having the Novel Pedar System or F Scan

Hope that helps.

Good luck

Faye

Hi Faye,
Thanks for your reply! Do you yourself work with Contemplas? And do you also use the highspeedcamera? Only at the frontal plane or also from sagital?
I also would like to have an insole pressure system but for now my RSscan is ok.
Saskia

Hi Saskia

I dont have the Contemplas yet;we will be investing in the future.I have done a considerable amount of research into the system and others hence the choice.I have seen the system at work.Yes you can use high speed cameras and it is my understanding that you can have both sagittal and frontal plane views-however Im certain that you would need more than one camera set up.
The RS Scan is good-just find out if the model is compatible or if you need a special cable etc.

Good luck

Faye