It is pretty unusual to be reading Bloomberg Businessweek and see an article with the main picture featuring a purple PCB (the picture above, in fact). But that’s just what we saw this morning. The story is about an open source modification to an insulin pump known as the RileyLink. This takes advantage of older Medtronic brand insulin pumps and allows you to control the BLE device from a smartphone remotely and use more sophisticated software to control blood sugar levels.
Of course, the FDA isn’t involved. If they were, the electronics would cost $7,000 instead of $250 — although, in fairness, that $250 doesn’t cover the cost of the used pump. Why it has to be a used pump is a rather interesting story. The only reason the RileyLink is possible is due to a security flaw and an active hacker community.
For the most part, when we break out the soldering iron to make a project for ourselves – we do so for fun. Sometimes we do so for necessity. Rarely do we, however, do so to save our own lives. [Dana Lewis] is one of the 30 million people in the US who suffer from diabetes. It’s a condition where the pancreas fails to make insulin, resulting in a buildup of sugar in the bloodstream. Managing the levels of insulin and sugar in their bodies is a day-to-day struggle for the millions of diabetics in the world. It’s a great deal more for [Dana], however. She sleeps with machines that monitor the glucose levels in her blood, but lives with constant worry.
“I was afraid at night because I am a super-deep, champion sleeper,” Lewis said, “I sleep through the alarms on the device that are supposed to wake me up and save my life…”
What she needed was the glucose data from the device and use it to trigger a louder alarm. It wasn’t long until she found someone who had done just this. Using a Raspberry Pi, she was able to capture the data and then alarm her via her phone. She then setup a web interface so others could see her data and call her if she didn’t wake.
The next step is obvious. Why not make the state of the insulin pump a function of the data? And thus, a sort of artificial pancreas.
The project is open source for anyone to use and improve upon. She was placed on a list for the 100 most creative people in the US for 2017. We’re not strangers to the idea of an artificial pancreas, but it’s always great to see people using things we make video game consoles out of to save lives.
Life as a parent is never easy, but when you’ve got a kid with Type 1 diabetes it’s a little harder. Sometimes it feels like a full-time job in itself; there’s never a break. With carb counts and insulin ratios that change throughout the day, every meal is a medical procedure. A romp in the snow or a long bike ride can send her blood glucose plummeting. The overnights are the worst, though, because you never know if you overestimated the number of carbs at dinner and gave her too much insulin. Low blood glucose is easily treated with a few sips of juice, but if it goes unnoticed in the middle of the night, it could be fatal. That’s why parents of diabetics are always a little glassy eyed — we rarely sleep.
Why is all this necessary? It’s because Type 1 diabetes (T1D) is an autoimmune disease that attacks the insulin-producing beta cells in the pancreas. Once those cells are dead, insulin is no longer produced, and without insulin the rest of the cells in the body can’t take in the glucose that they need to live. Diabetics have to inject just the right amount of insulin at just the right time to coincide with the blood glucose spike that occurs after meals. Knowing how much to give and when is why we say we have to “learn to think like a pancreas.”
Animas Ping insulin pump, partial teardown. The cylinder on the bottom is the battery, the motor and syringe compartment are on top. Source: Animas
Things are better than they used to be, for sure. Insulin pumps have been a game changer for T1Ds. An insulin pump is just a tiny syringe pump. A small motor moves the plunger on a disposable syringe filled with a few days worth of insulin. The hormone is delivered through a small catheter placed under the skin every few days — painful, but better than a needle stick with every meal and snack. A computer keeps track of everything and provides safety against overdosing on insulin, so it’s terribly convenient, but we still need to “think like a pancreas” and calculate the amount to deliver.
Even with its shortcomings, my daughter’s pump has been a blessing, and I’ll do whatever it takes to keep her in the latest gear. Pumps generally cost about $5000 or so, and need to be replaced every three years. While I’m not looking forward to paying the bill when her current pump gives up the ghost, I am certainly keen to do a teardown on the old one. I suspect it’s dead simple in there — a tiny gear motor, some kind of limit switches, and a main board. It’ll be painful to see how little my money buys, but it’ll be cool to play around with it.
