Email Chain about the Lamp Poles

As long as the aluminum isn't too much cheaper than steel, that sounds good.  For the base we currently have some square steel tubing that should work nicely.  We currently have casters that we can put on the base, but they don't have locks, so they might not be worth while (plus on Thursday I was looking at them and the ball bearings are exposed so I'm worried that alot of dirt/dust/grime will get in there and gunk it up).  Currently as a battery we're just going to use AAA's from the flashlights.  They should easily last through the testing phase and are easy to deal with electrically.  Since they're pretty light they'll probably be in the counter-weight.  Since you and Chris are working on the lowest piece it would make sense for you to work on the base, if another group finishes their part first they might work on it (although it's obviously pretty tied in with your joint since you interface with the vertical pole).

Let me know if you have any more questions.

-Steve

Michael H wrote:

Aluminum's a little bit more expensive than steel I think but it should be sturdy enough and it's a lot lighter.  It also doesn't rust as easily.  So I think aluminum is our best bet now?  That's good, I'll start looking for some cheep alum.

Also, what are we doing for the base?  Is the first prototype going to have wheels?  Is the battery going down there?  In some of the drawings I saw the battery as the counter weight but that might be a bit too heavy.  I don't know, I guess we need to know the weight of the head before we can do any torque calculations, but a bowl plus a couple led's aren't going to weigh too much.  I was just wondering because the subteams need to work together at the points of connection.  If no one is working on the base I suppose me and Chris could.

Anyways, just throwing things out there.  Trying to get the whole picture of this lamp.



Quoting Stephen DeWitt :

I don't think it necessarily needs to be made of stainless steel.  Won't a good coat of paint be enough to prevent rust and whatnot?  As for what to use for it, I don't think we had a specific plan, just something lightweight, sturdy, cheap, and non-porous.  We have some steel piping in the project room (I think you've seen it, but I'm not sure), but its pretty heavy.  Do you have any ideas?

Michael H wrote:

Do the tubes for the lamp frame have to be made out of stainless steel to be used in an operating room?  If not, what material were we thinking of using?

Thanks,
Mike

This past week has been really productive, so here's a recap.  Send out an email if there's anything I miss.

1. The design at present
2. Next week
3. Field testing in Uganda

1. The Design as of Now:  These parts might be hard to visualize, so I included a rough paint file to show them.

Horizontal to Vertical Joint - This joint has two degrees of freedom, one that rotates the horizontal beam up and down and one that rotates around.  A bicycle hand brake mounted on the lamp head locks and unlocks the vertical joint.  The vertical beam is capped with a U-shaped piece spanned by an axle that goes through the middle of the horizontal beam.  Connected to the axle is a dumbell spring-loaded clamp.  One end of this clamp is welded to the inside of the vertical beam, the other is connected to the bike brake wire.  When the bike break lever is pulled it squeezes the two clamp pieces together, which releases the clamp from the axle.  For the joint that swivels the horizontal beam around we're planning to make a joint by taking two tubes, one slightly bigger than the other, inserting them partway into each other, cutting slots in the larger one and putting tabs in the smaller one.  This allows the smaller and larger tubes to rotate relative to each other with the tabs keeping them together.  I'm slightly worried this will have too much friction, but I could just be paranoid.

Electrical - Since we're on a tight schedule and are a bit light on electrical expertise, I think we're best off if we just wire the LED heads together in parallel and hook them up to a battery pack made from the AAAs that came with the lamp.  We can wire them to a rocker switch on the lamp head so we can turn all of them on and off at once.  We can toss the batteries in the counterweight on the horizontal beam.

Lamp Head - We still don't have a final solution for this yet.  I suggested using a shallow tupperware bowl and cutting holes in it for the LEDs.  Mike suggested using a hubcap, which we can take a look at when we go to a junkyard to look at parts.

Head Joint - We're planning to use a car's rear view mirror joint.  After playing with the one in Elliot's car, it seemed stiff enough.  As a backup we could use a simple friction tightened hinge or a friction tightened ball and bracket (see the soldering stand in the project room for that joint).

Base - Just 4 legs on casters.  We talked about having the rotation joint here instead of at the horizontal to vertical joint, and we still may.

2. Next Week

We need to finalize our structure and then get a part list and dimensions.  Who is available on Monday to do a final design review?  After that we can break off into teams and start getting parts.  A group of us should head to a junk yard to check about getting parts there.  Did anyone go on the junk yard trips earlier in the year?

We need to get the rest of the LEDs from Home Depot.  Someone with a car will need to pick those up (I don't have a car).  They'll cost ~$200 and you will be reimbursed in about a week.  If someone is willing to drive but can't shell out money for them, let me know and I can go with you to front the bill.
We're pretty close to the point where we can start slapping things together, lets try to start building before the end of the week.

3. Field Testing in Uganda:

The plan is to get our lamp built and tested before April 7th, when we'll send our lamp with Abigail (the applied physics grad student most of you have met).  She'll be in Fort Portal, Uganda for a couple weeks and will take our lamp to some clinics and show it to people working at a local technical school.  This is a great chance for us to get feedback on our design so we can work on making the next iteration much better.

Steve

LED Hack for Surgical Lamps

http://www.instructables.com/id/Replacement-for-surgical-lamp-bulbs-using-LED-circ/

Some Duke BME students made a circuit for using LED's with a surgical lamp.
Might help us spark some ideas for our own circuit.

SF VC Trip

Last week Pratik and I went on the San Fransisco venture capital trip through the Center for Entrepeneurship.  Our goal was to improve the visibility of M-HEAL and to get feedback on our business plan for the lamp.

We talked to a person on the board of the B-School's social venture fund and someone from the social venture club.  It sounds like MBA students are looking for social venture plans to use for a business plan class (I think it's somewhat similar to our senior design) and it looked like there was some interest in using the lamp or some other M-HEAL project for that.

I also heard an interesting suggestion from another MBA student.  He suggested that we liscence our design to microlenders.  This increases the sustainability of M-HEAL since we'd be constantly bringing in revenue (assuming the lamp takes off).  An entrepeneur in a developing countries could go to a microlender looking to start a business.  The microlender could then suggest our surgical lamp, assuming the entrepeneur was in a good market for it.  We create value for the microlender because our proven design decreases the risk in his investment.  The business student also told us that many times selling a product at a minimal cost makes it more widely used because the owners have an active investment in it.

We didn't get as much useful feedback on the lamp design as we had hoped for.  Because the conference was focused around venture capital, our design didn't line up with the stated goals of the pitch competition (since we aren't fundable through VC as a student group).  Pretty much we were told that we had a good project and we should pursue startup funding via grants.  I believe they also said that if we ever wanted to spin off into a for profit company, there are some social VCs in the valley who might fund us.

-Steve

WHO statistics on target countries

Here are statistics from the World Health Organization for our target countries. I have included the US too for comparison.

Phil

2/17 Lamp Update

Hey everyone,
Here's lamp business for the week.  Sorry about the length, but make sure to read the "Tasks to be Done" section, since I included something for everyone to do over the next week and a half.

1. Tuesday's Meeting
2. Tasks to be Done
3. Spring Break
4. Meetings After Spring Break

1) Tuesday's Meeting:
Mike Harrison made his first lamp meeting this week.  After introductions Elliot showed us the joint he had looked at for the lamp head joint.  It was based off of a joint that he saw at work (the transportation research center where they test wheelchairs).  It has the same degrees of freedom as a ball and socket joint but Elliot believes it is easier to build.  I have his sketches, but I haven't had a chance to scan them in yet.  Look for them to be up on the blog sometime tomorrow.  We spent some time discussing the merits of this joint versus a ball and socket joint.  We didn't come to any solid conclusions but decided that a staying-in-place system based on friction would be find for the lamp head joint since failure would not be nearly as catastrophic as if the joint on the horizontal bar failed.

Next we looked at the LED flashlights that Carl bought.  Each one has 5 white LEDs and one red LED with a peak output of 100 lumens.  According to my calculations we need ~850 lumens.  Conveniently, without modifying the flashlights they have a 6" spot at 36" just like we want.  We went in the dark and checked to see how much light is outside of the 6" bright spot and found that alot of it goes out at wider angles.  Mike suggested that we have white cones surrounding each LED array to tighten the light distribution.

Phil brought some data on the Philippines and Uganda that he got from WHO.  It shows that the current situation in the two locations is quite different in terms of doctors per capita and treated water.

2) Tasks to be Done:
We're still planning to get a prototype ready for WMR's trip to Liberia during the third week of March.  This means that after spring break we don't have much time to mess around.  All we need is to get a rough prototype ready so the doctors can see the idea we're shooting for, even if we don't have all the functionality we want.  The main things we need are:
- the lamp head joint: Elliot has already done some good work here but we need to pick a joint and buy/make it.
- the horizontal beam join: I don't believe we have much here yet.  For now we can take emphasis away from the pedal and focus on just getting the structure.  We can add the pedal if we are ahead of schedule.
- the LED holder: we need something to hold the LED heads in the proper orientation
- electrical integration: at the very least all the LEDs need to turn on and off from a single switch.  It would be nice to have all of them hooked up to a single large battery with the option of wall power.

Everyone: Get the basic training at Wilson.  We're going to be starting to build the lamp and you need to be able to go in there.  Also, remember to post your progress up on the blog as you go.  It will help everyone keep up to date between meetings and allow people to give you a fresh perspective on your ideas.

Elliot: You've already been working on the lamp head joint so keep at it.  By the Thursday after spring break I want to have a joint in hand.  Use your best judgment on what type of joint to use and let me know before you spend money on anything (just so we stay on budget).

Mike Harrison:  Work with Elliot on the lamp head joint.

Phil:  On Tuesday you said that you will be looking into the LED holder.  Figure out the best material and structure, but don't buy anything until we have all of our LEDs, so that we can test out how everything is going to be arranged.  Also, put your data on Uganda and the Philippines up on the blog.

Mike Weist:  Work with Phil on the LED holder.

Chris:  Work on the joint that connects the two poles.  It needs up and down movement and the ability to swivel.

Seth:  I can't remember when you said you were getting back next week, but take a look at the two LED flashlights we have and start figuring out how to integrate them in the electrical system.

Carl:  On Tuesday you said you would get in touch with Home Depot to order more LEDs.  Also, check with Seth to see if he needs a hand on the electronics.

Mustafa: Familiarize yourself with the business documents on the Ctools site.  Most of them are under Resources->Social Venture Development.  Most of those documents are still pretty accurate, only we're not using car parts anymore, we're using LED flashlights.  In Resources->Lamp Project->Possible countries there is a good paper about the health system in the Phillipines and some stats on various countries.  Also keep an eye out for the data Phil will post on the blog.

3) Spring Break:
I know alot of us will be gone next week for spring break.  Who will be around?

4) After Spring Break:
After spring break we have two weeks to get our lamp built.  This means we're going to have to meet more than just Tuesdays.  We'll definitely have meetings with all of us on the two Tuesdays after break but people working together on various aspects of the lamp will probably have to meet several other times so we can finish in time.  Thursday is a good candidate for a general build session since I know most people said they were free then at the beginning of the semester.


Best of luck on the various aspects of the lamp you're working on.  Let me know if you have any questions or run into any problems.  Have a great break!

Steve

Pedal sketch

Hey guys,

Here is the sketch I brought to last week's meeting of the pedal mechanism.

Phil