I have terminal curiosity. I am interested in the technology of looping using Dash pumps.
Dash is designed to connect to a PDM. 1st question, how is Dash connected to a smart phone? 2nd - Android or iPhone or only Android? 3rd - does the software in the phone use CGM data to control pump insulin delivery?
I’m not interested in using Dash/loop systems just want a clearer understanding of the mechanics of it. I can’t help it. I always want to know how things work that grab my attention.
All omnipods are basically the same design. Eros uses an old RF protocol. Dash and 5 use bluetooth. Dash is factory paired only to a PDM (reskinned Android phone). 5 is factory paired to either a PDM, Android or Iphone (as of a few days ago). Dash can be repaired to DIY Android and Iphone applications that can also loop.
One of the main reasons I’m on Dash instead of 5 is the availaability of an Iphone app. So maybe I’ll rethink things in the coming months.
@CarlosLuis Presumably you’re referring to the Loop app vice “looping” in general (the terms get mis-used and mis-understood). If you’re looking more for general looping origins, check out: OpenAPS - Wikipedia, Dana Lewis | DIYPS.org, and The diabetes patients who hacked a pancreas - Experience Magazine. If you’re looking specifically for the Loop app itself, a history is available at: The History of Loop and LoopKit. Reflecting on the past in celebration… | by Nate Racklyeft | Medium. In reality, all the various DIY programs owe gratitude to broad community of T1 people and parents of T1 children in the DIY community around the world, but I think you’ll find most stories trace back to John Costick.
Both Android (OpenAPS/ AAPS) and iPhone (Loop, Trio, iAPS) are supported by several different developers (individuals and groups). In most, if not all, of the apps (Loop is one), the phone app “listen’s” for the CGM bluetooth signal communicating the BG level (timing depends on the CGM in use), then uses that and previous levels in an algorithm on the phone (and other settings the person sets in the app), an the app issues instructions via bluetooth to the pump. The Loop app used to use a Riley Link, Orange Link, or similar to send the Omnipod Eros pods instructions on the correct signal frequency, but with the advent of the Dash pods, it uses a bluetooth signal, making the Riley Link un-necessary. All of this is possible because the Omnipod’s codes and security measures were deciphered by the developers several years ago including Pete Schwamb, Sergei Skorobogatov, Joe Moran, interpreted and translated from the CGM to the app and then to the pod. Of course, various manufacturers use different codes and security mechanisms to protect users from un-authorized people being able to control the pump and dose the user. Additionally, current CGM and pump users report some venues (usually large gatherings with heavy bluetooth use) the apps used for both commercial and DIY apps have difficulty receiving BG levels or sending pump instructions.
I find the back story of these DIY systems fascinating. Deciphering the codes/security is very much a puzzle I wish I had more aptitude at working through. It continues as the system’s develop, I’m not sure if it’s a white hat or black hat issue. The FDA got involved by asking both the public and manufacturer’s for input on the security of medical devices two years ago; the results aren’t clear s yet (that I know of), but manufacturers are obviously not keen to share their IP or processes with the DIY community, at least not openly. Hope this answers your question.
@TomH Thanks your words and the links were so interesting. Even though I hate coding I have a lot of respect for those who do. I think the developers of open source loop did their hard work out of the goodness of their hearts.
Paul showing that string of hexadecimal code brought back memories. The telco switches I worked with used digital (0&1) octal (base 8) and hexadecimal (base 16). I can’t do it anymore but I could convert them to each other and to base 10 in my head.