Help with the OpenFES Project

[bradzz]

wrong link, sorry:

http://www.verticalchallenge.org/blog/zephyropen/

[mattblan]

Thank you for your interest, Brad. You have a very impressive website. We are always looking for talented, motivated engineers to join us. I sent you an email.

[Lisa Coyle]

Matt, we are looking to make a very crude tandem bike without the electrical stimulation at this point for my C6 friend who has very bad spasticity. This is not even close to a FES bike, but we are just trying to replicate the movement for her right now. I would like to read your research and learn how you made out.
Can you share your research yet?

thanks, Lisa

[mattblan]

Hi,

It has been about two months since my last post. We are currently working on documentation, system integration, and fabrication. The GoogleCode site has been updated with many wiki pages, including concept diagrams, theory of operation, and project cost analysis. You can see the work breakdown for a list of the last few tasks before we can call the prototype "functionally complete". It looks like the FES bike will be cost $2,000 in parts. See the specification wiki for a breakdown of what's included.

Cheers,

Matt

[mattblan]

Current Level of System Integration

Hi Everyone,

Our FES prototype is nearing completion. Here is a look:


I am finishing up the project cost analysis. If I could get a few RTI, Stimmaster, and Ergys owners to post the purchase price of their bikes it would be a big help.

Best,

Matt

[mattblan]

Updates:

We are getting ready for a public demonstration on Thursday. This weekend, we worked on getting a 6-channel TENS board ready for fabrication. Here is a picture of what the board looks like with 1 giant CPLD. We decided to use smaller CPLD's for each of the 6 channels in an attempt to make the design more modular, so the picture is a bit out of date. The big blue widgets are the LM current sense parts. Those we had to get shipped from Germany at $40 a pop.



Cheers,

Matt

[mattblan]

Here is the final board, fully populated. There's a link to the 3D fly-thru video below.


Video Link

[Curt Leatherbee]

Looks good Matt. I'd say the average paid for Stimmasters, TAI and RTI bikes was around 13 to 15 K.

[mattblan]

Final Cost Analysis

Looks good Matt. I'd say the average paid for Stimmasters, TAI and RTI bikes was around 13 to 15 K.

Thanks Curt, that's about what I thought. Here is the price comparison I came up with. The Stimmaster price is what I estimated for a used bike in good operating condition.



Link to the full cost analysis report

[bikeracer]

Awsome!

Matt,

The board looks a real tidy design, have you actually put one together yet that we can see a real photo of?

You mentioned a demo on Thursday this week, did that go ahead and was that an actual demo or a logical demo of the component parts?

Congrats on your progress, if this can be put together for the $2k'ish price then you will have done a great service to the community and hopefully get an excellent grade on your course!

BR

[mattblan]

Hi Bikeracer,

My apologies for the response delay. In regard to your question about the TENS unit design, the modular version that uses the LEM current sense widget (the big blue things) is ready to be fabricated. Now that we have all graduated, we starting playing with the idea of selling these as kit, so we are going to try and reduce the size of the board and the number of parts to make it less expensive before we actually send it out to fab. Instead of one CPLD and LEM per channel, we will probably just use a single large FPGA to control about 12 channels and we will design our own circuit for current sensing. Those LEM parts were about $40 per, and they had to be imported from Germany, so we should save quite a bit of money there. Adding a large enough FPGA also allows us to do real-time adjustment of the stimulation waveform, which some of the FES researchers were asking for.

I expect these two modifications will be made by the end of the year. Once we get the parts put on the final board, I can send you one if you are available to test.

Happy holidays,

Matt

[bikeracer]

Hi Matt,

I would really appreciate the chance to test one of your units once they are ready.

Thanks

BR

[Curt Leatherbee]

No doubt Matt you are going to have a big market for these if you can keep the price below 5 grand. Keep on plugging to make it happen, sounds like you are on the right track with making the bike cost effective, this shoulda been done years ago rather than the regular like clockwork 15 grand for a FES bike.

[mattblan]

Wow, do any of your cripples not code?!?

[mgwmgw]

in Massachusetts

My partner is a T5 para whose insurance is about to stop covering his FES bike therapy. He used to be an electronics technician. I am an unemployed Java programmer. He would be interested in alpha or beta testing OpenFES. He would also be interested in building his own copy if you wanted to share enough of the design.

If you are thinking of selling this as a product, are you looking to open an East Coast sales office? We live outside of Boston.

Mary-Anne