A fully autonomous artificial pancreas system consisting of
a home-grown insulin pump, a Dexcom® continuous glucose monitor, and an Android phone.
The goal of TOP is to eliminate the burdens of living with Type 1 Diabetes.
The Other Pancreas (TOP) is designed to make carb-counting a thing of the past. Humans aren't good at carb-counting. If you guess too high and do too much insulin, your blood sugar goes low. If you guess too low and don't do enough insulin, your blood sugar ends up high.
TOP overcomes this by delivering the necessary boluses every five minutes. TOP's algorithms are designed to handle meals and other glucose changes without any user interaction.
Much like a real top, The Other Pancreas is designed to magically balance all of the forces influencing your diabetes. TOP occasionally requires a little push to keep it spinning. That push is as simple as calibrating your CGM, changing your infusion site, reloading your insulin cartridge and swapping your battery. If TOP gets those few simple pushes then it can keep spinning in what appears to be a magic defiance of gravity. In reality, hundreds of precise calculations and treatments are being executed automatically on your behalf, allowing you to pretend like you no longer have diabetes.
TOP was designed to be a smart, easily-upgradable, easy-to-use platform unhindered by a pump's limited computing and input power. The TOP mobile app uses bluetooth to communicate with the pump and Dexcom®, then uses the phone's incredible computing power to review the past week and quickly make hundreds of decisions to determine what the optimal treatment is.
The actual infusion pump was designed to be "dumb" with all of the brains and controls being inside a smart phone. As such, the 3D printed pump can be built for as little as $100. Even with such inexpensive hardware, the pump still delivers very precise doses, and will continue to deliver basal if the smart phone dies or goes out of range. The pump also injects insulin fast, which allows it to start working faster.
TOP communicates directly with Dexcom®'s industry leading continuous glucose monitoring to track your glucose and respond accordingly. No intermediary devices are required. You don't even need to install any Dexcom® apps. Calibrations and sensor management are all handled with ease in the TOP app.
The following configurable algorithms are optionally employed to prevent you from having to bolus for meals, and to prevent hypoglycemia and hyperglycemia.
Every 5 minutes when TOP gets a glucose reading it determines how much insulin you have on board (IOB). Based on your correction ratios (ISF) it checks to make sure your IOB will get you to your target glucose. If you don't have enough insulin to get you to your target glucose the system will quickly dose your basal and enough insulin to get you to your target. This is basically the same as automatically using an old pump's bolus wizard every 5 minutes.
If your glucose is below target, or your glucose is decreasing and you have more insulin on board (IOB) than you need to get to target, the system will withhold all insulin. In this situation any excess IOB is used in place of basal. Once glucose is above target and it's safe to do so the system will deliver whatever amount of insulin is necessary to get your basal on board back to the expected level.
If your glucose raises far enough above your target the system will deliver a super bolus. This means the system immediately delivers all of the basal you would have received over the next hour. Then as soon as your glucose stops raising the system withholds basal insulin until the amount of basal on board is back to normal.
When your glucose is raising fast enough the system can safely assume you have eaten carbs. When this happens the system reduces your target glucose and doses accordingly. Then over the next hour your target linearly returns to normal. This meal detection can optionally trigger a Super Bolus as well.
Dose forecasting assumes your glucose will continue to change at the same rate for the duration of the forecast. If your glucose is raising 2mg/dL each minute then a 5 minute forecast will dose for your current glucose plus the 10mg/dL it forecasts your glucose will raise.
If you eat meals at approximately the same time each day, liver priming sets your target glucose lower for an hour prior to your meal to prepare your body to better utilize the insulin you will soon receive in response to your meal.
Every time the system calculates a treatment it will review the past 7 days and see if the correction ratio (ISF) set at this time of day is correct. If you ended up low as a result of the correction ratio set then the system knows the ratio is too aggressive. If it took more insulin than expected to get down to target then the system knows the correction ratio was too weak. The system uses all of this data to fine tune your correction ratio every 5 minutes. Autopilot does not dose insulin, it simply tweaks correction ratios.
TOP APIs make it trivial to expand or change functionality without having to worry about the nuts and bolts of an artificial pancreas system. You can add on to all of the algorithms TOP or other 3rd party apps employ, or throw them out and take complete control of each treatment. If you're interested in automating you or your patient's treatments in a novel way we haven't thought of check out the full API on Github.
The following non-clinical stats are compiled live from all active TOP users.
In addition to making all treatment decisions the TOP mobile app also automatically backs up each user's data securely and for free on The Other Pancreas webservers. If the user opts-in then their data is made available to the public or to specific individuals. Where the user does not opt-in their data is still presented in aggregate with all other users as seen above. The data seen above is raw data that cannot be modified by users.
To use TOP you will need to build your own TOP pump.
This quick video shows how easy it is to build.
Detailed build instructions can be found here.
TOP requires a TOP pump, an Android phone, and the following medical supplies:
As TOP is still in its early stages we are controlling who has access in hopes of better managing expectations and quickly ironing things out so each new person to use TOP can have a more excellent experience than the person before them. If you are a driven DIY-er that is willing to put up with unpolished hardware, give lots of feedback, as well as monitor and take responsibility for the automated decisions TOP will make, then click Get Started and let's see if we can work together to make your life better!