It is on the Ubuntu computer upstairs in ~/Desktop/newtrigger . It contains subdirectories for reading and clearing the flash. Refer to the readme in ReadFlash for information on how to read the flash.

The three modified triggers are currently programmed with this program.

-need a better location for bed motes (more accessible)

-need to be attached to surface differently – magnets didn’t work; sticky tape didn’t allow it to be adjusted and was hard to get off after the experiment

-motes need to be attached in box differently – sticky tape wasn’t sticky enough; USB cables could come off easily

-next time, add batteries?

Pyramids

-need longer cables to plug them in

-put a sticker in a more visible location to identify it as part of the experiment

-put a “This Side Down” sticker on the bottom to avoid people flipping them over

-try to cover the switch so nobody can turn it off

Pagers

-check all the USB/charge lights with the cables we use

-figure out the flash problems

-lighter design? towards the end, nurses still complained about the weight

Pucks

-more sturdy – pucks take a lot of beating depending on the day and the person using it, so they need to be able to stand up to that; the screws also started to come loose toward the end of the experiment

-keep the blue light visible

-simpler hardware – taking them apart to replace a battery or adjust the sensitivity took a lot of time

-put out new designs in the hospital earlier to see the problems they face – different people pump differently and it would be really hard to mimic that in the lab

-come up with something for free-standing bottles

-need something that wouldn’t be as complicated to replace and/or to change out bottles

The second idea is to use a magnet to trip a reed sensor located inside the bottle.  This seems like a very convenient technique, but we’re not confident that we can get the right combination of magnet and reed sensor so that we can make a repeatable process that doesn’t require lots of tweaking.  The magnet goes inside the plunger mechanism and the reed goes on the outside of the foaming chamber.  This demo seemed to work pretty reliably, but required a movement of several mm before actuation.  Some minimum distance is required because there appears to be some hysteresis in the mechanism.

Gregg holds the demo he assembled.  The rectangular magnet sits in the gap between the clear plastic and the white top of the lever.  In the working demo tape holds the reed switch connected to the two leads.  When the magnet is close to the reed switch, it closes, which could trigger the mote.

There are also other lithium-ion batteries out there worth looking into. It would be nice if the next version of the door minder had at least as much battery life as the current one.

We could use a chip to handle most of the measurements.  The PCF8883 is a capacitive proximity switch with auto-calibration, large voltage operating range and very low power consumption.  I’m ordering an evaluation board for this so we can check it out.

1.     Design considerations for parts mass-produced on the mill:

a.     Number of operations

                                               i.     Additional operations will increase cycle time by more than 25 seconds (time it takes to place a new part into the mill)

                                              ii.     Additional operations will also increase setup time

1.     Fixture the part appropriately

2.     Program a new CAM sequence

b.     Number of parts

                                               i.     It may save time by making fewer but more complex parts than by making more but simpler parts for a device due to decreased setup and turnover time  

c.      Accuracy/Tolerance

                                               i.     Thinner materials are more likely to deflect

                                              ii.      Softer materials are more likely to deflect

                                             iii.     Stock size will vary

                                             iv.     Accuracy is inversely proportional to cycle time

                                              v.     Smaller end mills will deflect more, especially with deeper cuts (>1”)

d.     Rounded Corners

                                               i.     The inside corners will have a radius that is half the diameter of the end mill

e.     Fixtures needed

                                               i.     Parts that are thin (<0.25”), have non-rectangular geometries, or irregular angles may need a fixture because of the inability to hold the part in the vise  

1.     Increases setup time (Time needed to design and fabricate a fixture that would yield accurate and consistent results)

2.     Manufacturing Considerations

a.     Resource allocation

                                               i.     Parts turnaround time could be reduced with addition of more people

1.     Setup time could be as long as the production time depending on part complexity and number of parts made

                                              ii.     Always purchase more stock than required

1.     It is almost guaranteed that parts will be scrapped during the manufacturing

                                             iii.     Also make more than what is required

1.     Setup of subsequent operations may cause some materials  to become scrap

b.     Programming efficient operations

                                               i.     Bigger end mill = shorter cycle time

                                              ii.     Use a large end mill to rough the part and a small end mill for finishing (if needed)

c.       Provide samples before mass production

                                               i.     An error in the CAD file or wrong tooling may cause parts to not conform to specifications

d.     Do one operation at a time when mass producing

                                               i.     Reduces setup time

exit door: 3′ 10″

Double door: 7′ 7″

“1 and a half” door: 6′ 10″