Suddenly it happened. A perfect day!

Yesssssss! For the first time in 720 days living with a sensor, it happened: a perfect day. A Time-In-Range (TIR) of 100%. In our case, 24 hours balanced between 4 – 8 mmol/l! This blog is translated automatically to your language here. View all related articles using this link.

First the disclaimer

I am not a healthcare professional. Always consult your doctor before making changes to your diabetes treatment plan. For this blog series, I do not have – and do not want – any sponsorship deals or whatsoever and pay for all equipment just like anybody else.

Table of contents

Blog-specific parts of “a perfect day”:

And the general parts:

My girlfriend was sleeping already. I was too excited and was watching the day close 🙂

Blog-specific parts


At this point in time, a perfect day is not a goal, but a very nice confirmation of the path taken. You see more details of this day below from our Nightscout environment.

Source: our Nightscout daily stats report.
Source: our Nightscout day to day report.

Data collection

Our source software AndroidAPS and xDrip+ is set to store all data in Nightscout. For example, all blood glucose values, manual actions, and automatic interventions. Hosting Nightscout is free in the Heroku cloud environment. Thanks to Nightscout, extensive data analysis is possible.

Nightscout is an open-source cloud application used by people with diabetes to visualize, store and share the data from their Continuous Glucose Monitoring sensors in real-time. Once setup, Nightscout acts as a central repository of blood glucose and insulin dosing/treatment data for a single person, allowing you to view the CGM graph and treatment data anywhere using just a web browser connected to the internet.

Source: Nightscout website


Our closed-loop system currently works with entering carbohydrates before eating. Except for small snacks, the UnAnnounced Meal (UAM) function takes care of it. On the perfect day, there were:

  • 12 manual actions (eat, shower, tube change);
  • 150 automated decisions.

My girlfriend performed the manual interactions, AndroidAPS performed all automated decisions. To improve even more, we will start experimenting with a Full Automated Insulin Closed Loop soon. See section continual improvement below.

Also only 12 manual interactions are tough and a constant reminder of a life with diabetes. If, like me, you do not have type 1 diabetes and want to experience what it is like for 48 hours, download the app DT1 day2day on Google Play or the App Store. You will feel that living with diabetes is an underestimated mental burden. My expectation of closed-loop systems is they will (partially) relieve patients of it.


Because hypos could be extremely dangerous, I have installed xDrip+ ‘as follower’ on my phone. It means I can see my girlfriend’s blood glucose level all day. A loud alarm will sound when it drops below 2.7 mmol/l.

Because of my xDrip+ app, I noticed a possible perfect day before going to bed. I quickly started my laptop, opened the Nightscout site, and started watching from 23:15h – 0:00h. What a relief to see the blood glucose levels stay in range.

Continual improvement

A perfect day is a true gift but an unrealistic goal to set at this point in time. Currently, our goals are:

  • Short-term
    • Feel better by preventing hypos/hypers by targeting a Time-In-Range (TIR) of 80%, between 4 – 8 mmol/l;
  • Long-term

The following improvements are forthcoming:

  1. Physical testing
    Currently, we are in the process of physical testing basal rate, ISF, and I/C. It is necessary to fine-tune our closed-loop system AndroidAPS. This will reduce fluctuations, which contributes to a reduction in hypos/hypers, which contributes to all our goals above.
  2. A brand-new tool:
    Current medical information is lagging behind the – open-source and commercial – possibilities that are now emerging. A website with information and tools to fine-tune closed-loop settings did not exist.

    I have registered, designed, and build A prototype to provide basal suggestions after physical testing. The site contributes to lowering the mental burden of living with diabetes, especially when using new closed-loop systems.

    The prototype has been tested by 130+ users worldwide, from time zone Sao_Paulo to Amsterdam to Moscow. Convinced of the added value, I took some days off to bring this prototype to version 1 (May 22, 2021 – June 6, 2021). The solution uses blood glucose values stored in Nightscout, which are accessible via an API.

    Please note I do not have – and do not want – any sponsorship deals or whatsoever. I pay the small hosting fee myself. It will always be totally free to use. Glad to contribute to the closed-loop movement. #payitforward #wearenotwaiting
  3. Lyumjev, a new ultrafast-acting insulin
    Since May 1, 2021 Lyumjev is available in the Dutch healthcare system. A great opportunity arose from the availability of this new ultrafast-acting insulin: a life without counting carbohydrates or performing a manual bolus!

    The big difference with our current insulin NovoRapid is a peak time of 45 minutes instead of the current 1h15m (75 minutes); see this link. Our hospital is very careful about the results and not (yet 😉 ) convinced of this significant opportunity.

    The open-source community is already testing a few months to understand this new way of life. See this no-bolus for 4 months article and results from Bionic Wonkee. After delivery of our Lyumjev insulin (probably somewhere in May 2021), we can share our experience whether it works for us as expected. To make a success of it, we will combine:
    1. Fine-tuning basic settings, like basal rate, ISF and I/C;
    2. The use of our closed-loop AndroidAPS;
    3. Ultrafast acting insulin like Lyumjev.

General parts

Purpose of this series

The idea of the diabetic patient as a crisis manager is outdated. Using a ‘Do It Yourself Artificial Pancreas System’ (DIY APS), you have less to worry about and can achieve a higher quality of life for yourself and your caregivers. When appropriately configured, the diabetic person may have a healthy HBA1C value. You can start today!

Our blog series is called ‘our journey: from pen therapy to AndroidAPS, a DIY APS’. This T1D series aims to inform the world on current technical possibilities to bring down the effort on (daily) diabetes management activities and be healthier long term.

Follow this blog series to see how you can make a step-by-step shift from pen therapy to a ‘Do It Yourself Artificial Pancreas System’ (DIY APS). A similar project for Apple smartphones is called Loop project. Welcome to the future.

About the author

I am Peter, a millennial born in 1984, living in The Netherlands, and I hope someone will find a cure for type 1 diabetes (T1D) fast. Both of our lives have rapidly changed since my girlfriend got the T1D-diagnose. I became involved as a volunteer on the AndroidAPS project. I commit my IT Service Delivery Management passion to a more comfortable and healthier diabetes life because of all automation possible since 2013. As a professional, I feel comfortable delivering value, overseeing all components while managing staff and costs.

Need some help?

The diabetes community develops all DIY APS possibilities since 2013. Volunteers make the most effort in the online DIY APS community through a pay-it-forward mechanism. Each participant/volunteer has severe perseverance and the will to contribute to the community in their field of knowledge. Please feel free to contact me on whatever related question you may have and request membership in Facebook groups AndroidAPSUsers / TheLoopedGroup / xDrip. Happy to help!

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