I have been working on a few projects recently. Two of them involve having custom PCBs made. I'm currently waiting for them to arrive. In order to prototype and test the circuits, I had to order a bunch of parts, so I took advantage of the buying spree to get myself some better tools.
My favourite so far is my new Agilent U1251A Multimeter. After seeing the great review of the U1253A (which is just the OLED display version of this one, instead of LCD) on the EEVBlog, I found one for a decent price and decided to get it.
Agilent U1251A
Another purchase was a vaccum base vice that can hold small-ish circuit boards. Since I'm going to be doing some surface mount soldering for my intervalometer project, I wanted to make sure I had something better than my helping hands to hold the boards.
New Vice
I plan on doing full write ups of both of these projects once I finish, but here are a few details.
The first one is an intervalometer for my Canon camera which will use an Attiny13 microcontroller and a small CR2032 battery. It will have a configurable time interval and is only 1x1 inches.
Intervalometer PCB
The second one is a simple breakout board for my MBED microcontroller. I plan on using a few of these to permanently attach sets of sensors and other peripherals, while still being able to swap the main MBED board around. It's not the most exiting PCB, but I'm trying out different services to see which one I like better. I ordered the intervalometer board through BatchPCB and the mbed one from DorkbotPDX. I will also do a write-up about those when I get them.
Mbed Breakout PCB
One of my projects requires multiple temperature sensors. I ordered a bunch and tested one earlier. I cut up some phone wires and connected it there so I could put it out the window without exposing the whole board. It seems to be within 1 degree of the actual temperature, which is more than enough for what I'll need.
A few months ago, I found out that my school offers a diving class. I enrolled and was having fun for a few weeks until I messed up an entry off the 3m board and hurt myself. I didn't notice initially, but the next day my hip was hurting a lot.
I went to the doctor, got some x-rays, and began physical therapy. There was no bone damage, so they figured it would sort itself out with the therapy.
After a few months, some of the pain went away, but some still remains. (The injury happened in January!) The doctor recommended that I get an MRI Arthrogram. It's like any other MRI, except they put a contrast solution so they can see the soft tissue better (or something like that.) The catch is that they have to inject this contrast solution, with a huge needle.
I asked the imaging people (who were all really nice!) if I could have the images, so I'll use them here to explain. Here's a quick video someone else made about the contrast placement.
Now here is how mine went:
As usual the first step deals with your clothes. They only let you keep your socks on, along with those stylish hospital gowns. I then lay on a bed with a cool portable x-ray machine above. The first take an x-ray to make sure everything is aligned.
This is the first X-Ray.
A few minutes after they tied down my foot so the leg position wouldn't change, the doctor arrived. They applied some of that yellow antiseptic stuff and let it dry and proceeded to stick me with a smaller needle to apply the anesthetic. It didn't really hurt much, I was expecting a burning sensation for a minute or so, but it was really quick. Now that my hip was all drugged up, they brought out the big one.
You can see the size of the needle here.
That needle needs to be long enough to reach the hip joint and wide enough to let the fluid through in a timely fashion. This step didn't quite hurt, but it sure felt strange. I could feel that they were pressing down, but couldn't quite pinpoint the source of discomfort. Once they started injecting the solution, I could feel it filling up.
Here's another X-Ray with the colors inverted.
The injecting part was really quick. I think they said it was only about 12cc's of solution. They then removed the needle and cleaned me up. After that was done, I went over to the MRI machine and spent ~45 minutes laying motionless. I kept drifting in and out of sleep, which is quite fun. Waking up inside an MRI machine working is quite something.
One of many slices from the MRI.
After that was done, I got my CD with all the images and headed home. The whole experience was not bad at all. I was slightly worried after reading other peoples reactions, but fortunately they did not apply.
