Ryan Yannelli

Type 1 diabetes

I was diagnosed in November 2023, in an ICU. My insulin is now dosed by an open-source closed loop that I run and maintain myself.

Diagnosed
2023-11
Age at diagnosis
26
Sample interval
5 min
HbA1c
4.9%

Reported values from my own records, not a live feed. The live glucose trace is on the home page, and the loop that produces it is described below.


Diagnosis

It started as what felt like a cold, then a bad flu. I was admitted to intensive care at 108 pounds and six feet tall, in severe diabetic ketoacidosis, with an HbA1c over 15% and positive GAD65 antibodies. The DKA tore muscle and left a hematoma. I went home on a walker, moved to a cane, and walk normally now.

For two or three years before that there were small symptoms, and they were dismissed. Adult-onset Type 1 gets missed regularly, because the working assumption is that Type 1 is a childhood diagnosis. It is not.

Type 1 is autoimmune. The immune system destroys the insulin-producing cells in the pancreas. Nothing I did caused it, nothing reverses it, and there is no cure yet. Insulin is not optional and it is not a lifestyle intervention. People die when they cannot afford it.

2023-11on admission

Weight
108 lb
Height
6 ft
HbA1c
>15%
GAD65
positive

The loop

loopdocs ↗

Loop is open-source software written by people with diabetes. It reads a continuous glucose monitor, decides how much insulin to deliver, and drives an insulin pump. I run it on a Dexcom G7 and an Omnipod Dash. It is a feedback controller on a five-minute tick.

01 senseA Dexcom G7 reads interstitial glucoseThe sensor sits on my arm and streams to my phone. 288 readings a day, without finger sticks.every 5 min
02 decideLoop projects forward and picks a doseThe algorithm runs on the phone. No server in the path, so it keeps working with no signal.30–60 min horizon
03 deliverAn Omnipod Dash pod delivers itThe pod adjusts basal rate and gives micro-doses of Lyumjev. Nothing to carry, nothing to charge.continuous

That is 288 readings a day and a dosing decision on each one. The loop does the arithmetic; the rest of it is still mine. Sensors fail, pods occlude, and a low at three in the morning still needs carbohydrate and attention. My HbA1c came down from over 15% at diagnosis to 4.9% on the loop.

The DIY community built this before commercial systems got to the same place, and published it as source anyone can read, audit, and run. The tag it organized under is #WeAreNotWaiting.


Where I put time

DIY Loop community

Active in the open-source movement building DIY closed-loop insulin systems.

Breakthrough T1D Walk

Walk the Westchester event every year to raise awareness and money for T1D research.

Insulin access

Pushing for better access to insulin and pump supplies. Nobody with Type 1 gets to skip a month. I run Omnipod Dash with DIY Loop myself.

Breakthrough T1D, formerly JDRF, is the largest funder of Type 1 research. I walk the Westchester event each year with Team Yannelli.


Organizations

Most of these fund or build diabetes technology. NGLCC NY has nothing to do with diabetes and is here because I support it.


If you were recently diagnosed, are running Loop, or are building in this space, get in touch. I answer these.