Sarah Withee
Polyglot software engineer. @geekygirlsarah on all the social things!
I Built an Open Source Artificial Pancreas!
Sarah Withee
@geekygirlsarah
Artificial Pancreas
Thank you!
Artificial Pancreas???
Quick Rundown of How Carbohydrates Work
- You eat carbohydrates
- Your body breaks them into glucose and fructose
- Glucose goes into blood
- Pancreas sees extra glucose, makes hormone insulin
- Insulin triggers cells to start using up glucose
- Your cells use glucose+insulin for energy
Quick Rundown of Diabetes
Diabetes - When that process doesn't work
Type 1 - Auto-immune disease, Insulin-making cells
destroyed
Type 2 - Cells are resistant to use what you do
make
There are other rarer types too
Quick Rundown of Diabetes
In US, measured in mg/dL (milligrams per deciliter)
Normal people: 70-99 mg/dL
Diabetics aim for: 80-150 mg/dL
After eating, the number goes up
Why Diabetes Is Hard
Glucose too high (hyperglycemia)?
Slowly get bad circulation problems,
organs slowly die
Glucose too low (hypoglycemia)?
Shaking, sweating, weakness, could land
in hospital
Why Diabetes Is Hard
1 “unit” of insulin = 1/100 mL
Carb ratio: number of carbs / unit of insulin taken
Can be from 3g-50g per unit (3:1 to 50:1)
Varies by person, time of day, conditions, and over lifespan
Why Diabetes Is Hard
Carbs start absorbing within
10-20 mins
Insulin absorbs slowly
Fastest around 45-60 mins
Absorbs totally over 5 hours
(blue line)
Why Diabetes Is Hard
Stressed?
Sick?
Exercise?
Little bit of alcohol?
Lots of alcohol?
Hormones?
Glucose goes up
Glucose goes up
Glucose goes down
Glucose can go up
Glucose can go down
Glucose can go up/down
Why Diabetes Is Hard
Stressed?
Sick?
Exercise?
Little bit of alcohol?
Lots of alcohol?
Hormones?
Glucose goes up
Glucose goes up
Glucose goes down
Glucose can go up
Glucose can go down
Glucose can go up/down
Continuous
glucose
monitor
Insulin pump
Technology to the Rescue!
So... What's This Artifical Pancreas?
OpenAPS - Open Artificial Pancreas System
- Linux-based IoT Device
- Has 915 MHz transceiver
- All open source-based software
CGM sends values over Bluetooth to xDrip+
Stored in Nightscout
Values load into OpenAPS rig
Rig sends RF to pump to dose differently
Live Demo (sorta)!
URL: clicky
SSHing into "Sar-borg"
"Uh, it's not slimey"
"It can't be real if it's not inside of you, right?"
tl;dr It's not a REAL pancreas, but replicates the functions
"Whoa... is this safe?"
tl;dr yes
"It's online... Can't it be hacked?"
tl;dr anything can be hacked, but it's too obnoxious/slow to do
"Is it annoying to carry all this around?"
tl;dr kinda, but worth it
"What if you lose internet/battery dies?"
tl;dr analytics stop, but pump goes back to default
Before Sar-borg
After Sar-borg
Where's It At?
OpenAPS-based system:
- Instructions: https://openaps.readthedocs.io
- OpenAPS: github.com/openaps/oref0
- Nightscout: github.com/nightscout/cgm-remote-monitor
- xDrip+: github.com/NightscoutFoundation/xDrip
LoopKit-based:
- Instructions: loopkit.github.io/loopdocs/
- LoopKit: github.com/LoopKit/Loop
- RileyLink: github.com/ps2/rileylink
Open Source Software to Change Lives
What if our software could change lives?
- Young type 1 children and their parents
- Older people
- Low income
- Those without health insurance
I Built an Artificial Pancreas
By Sarah Withee
