# PaedPlot - offline growth charts **Category:** [Growth Charts](https://forum.rcpch.tech/c/rcpch-digital-growth-charts/6) **Created:** 2026-07-17 09:27 UTC **Views:** 15 **Replies:** 1 **URL:** https://forum.rcpch.tech/t/paedplot-offline-growth-charts/742 --- ## Post #1 by @njclarke1 Hi all! Thanks for allowing me to join the incubator, the work you're doing on producing this app looks really exciting and I love what you have already. I am a Paeds SpR working in Bristol, and before I knew this app existed I was trying to do something similar myself. https://njclarke1.github.io/paedplot/src/paedplot.html I needed an app that emulated the paper charts, but operated 100% offline so I could use it in the basement and next to the MRI machines haha! So I was working on a single html file tool with no external dependencies. Please feel free to have a look at it, comment, test or borrow any code you like if it is of any help to you! I went a slightly different tack in that I was attempting to be as faithful to the paper charts as possible to make it familiar. Visually I think it looks pretty faithful so far! I have implemented the following features: 1. Multi date and metric input - add as a table for easy quick entry on the wards 2. Quick switch between the traditional chart ages with 1 single 2y-18y selector (which is pretty unwealdy on mobile devices) 3. A review of specific datapoints and their centiles at the bottom of the graph 4. Attempts at both mobile and desktop functionlity (though this requires lots more testing than I can achieve on my own) 5. Device browser based data storing, with no calls to servers for privacy Features to fix / future prospects: 1. Fix the print function (I had aimed for a selector of which traditional chart you wanted printing then a full render for paper patient notes) 2. Improved zoom scaling on mobile, currently forced to fit to width only. 3. Adding in OFC and specific growth charts for T21 etc. 4. Added BMI calculation (and posible m%BMI for ED patients if needed) Anyway, let me know what you guys think and whether any of this could be integrated into your app. Full disclosure Claude has been used a lot for much of the coding as it's so much faster. The app can run through pages on github with the above link, but you can also just download the html file directly to any device and run locally if you prefer (it's only 320kb). Nick - https://github.com/njclarke1/paedplot PS. there is a small toggle for dev tools where you can quickly plot some sample patients of different ages to see how data randers without putting them in one by one. Becasue I am a lazy tester. --- ## Post #2 by @michael.barton Thanks so much for sharing @njclarke1! It's wonderful and heart warming to see clinicians building the tools they need day to day, that's exactly what my team are here to support. Here are some thoughts below, please don't take any of them as criticism just interested reflections on the needs for growth charting in different settings. Believe it or not you're actually the first person we've had for charts with a hard offline requirement. This is an important discussion point for us as at the moment our calculation engine (the [digital-growth-charts-server](https://github.com/rcpch/digital-growth-charts-server)) is our registered medical device, not the charts which are then embedded into whatever is consuming the API responses, normally an EHR. The underlying calculations come from our open source Python library [rcpchgrowth-python](https://github.com/rcpch/rcpchgrowth-python/) and there is no technical reason that could not run offline. But each consumer of that would need to be it's own registered medical device, including our app moving forward. However we've always advocated for as direct as possible an integration into the EHR. Part of this is to avoid people opening and logging in to yet more specialist apps and web pages but also because we believe organisations owning their own growth data is important for the future. Maybe one day people could even report on it! Because of that we don't have a good story for data input. We're more a set of components you'd integrate into a host system that handles that. But for our own app we'll of course need that and it's great to see what you've done with multiple inputs to save time, I'll definitely be cribbing that! > Device browser based data storing, with no calls to servers for privacy Yeah we've had push back against making an external API call from many clients doing integrations but in the end they always go with our API to get the medical device coverage essentially for free. Our API is totally stateless so we never store the data, it's just a calculator in the cloud. > Fix the print function (I had aimed for a selector of which traditional chart you wanted printing then a full render for paper patient notes) We regularly get requests for PDF charts and generally push back on it because our product is a "digital growth chart" and we want it to be integrated into an EHR directly. But in practice we now have several customers who have built their own print functionality on top of our charts and as you say that's something we should perhaps have stronger guidance on or some extra libraries to help to avoid inaccuracy. What sold printing to me as a key feature was organisations who get in touch because they have no EPR, just a document management system but still need charts. There's not a product I'm aware of that serves that sort of use case well at the moment. > PS. there is a small toggle for dev tools where you can quickly plot some sample patients of different ages to see how data randers without putting them in one by one. Our API (and underlying Python library) have fictional child data generators which might help you generate tests: https://github.com/rcpch/digital-growth-charts-server/blob/f4ede6003100da7137b9545d88dd01796fdba3a3/routers/ukwho.py#L247. On a technical note what's made a big difference for us on the charting visual side has been visual regression testing, so every time we land a change on `live` any visual changes are flagged up to us for review. We use Chromatic and Storybook but it's less the specific tools and more the workflow and principal. I think for clinical charting in particular it's vital because you can't really "unit test" a chart in the same way you can code but it is really important to have some confidence that new changes to the code don't break other things and this gets harder the more references and chart types you add. Hope my thoughts are useful but cool project and let's definitely keep in touch :slight_smile: --- **Canonical:** https://forum.rcpch.tech/t/paedplot-offline-growth-charts/742 **Original content:** https://forum.rcpch.tech/t/paedplot-offline-growth-charts/742