Timestamps on electric and ablation structures

1

Hi,

First, I would like to thank for creating such an amazing and usful platform!

I’m working with OpenEP for spatiotemporal analysis of EAM data and I’m trying to clarify how time is represented across the different data structures.

From the Case API, I see that:

  • Electrical data (case.electric.*) contains EGMs and annotations, but I don’t see an explicit timestamp per mapping point.

  • Impedance data exposes a times array.

  • Ablation data also exposes a times array.

I’d like to clarify three points:

1. Electrical data timestamps
Does OpenEP expose any timestamp corresponding to when each electrical mapping point (EGM) was acquired or accepted by the system?
If not, is the ordering of points in case.electric guaranteed to reflect chronological acquisition order?

2. Impedance times
What does Impedance.times represent in practice?
Are these times aligned with electrical point acquisition (i.e. can an impedance time be associated with a specific EGM point), or are they continuous system-level measurements on an independent timeline?

3. Ablation times vs impedance times
Are Ablation.times and Impedance.times recorded on the same time reference, or should they be treated as separate clocks?

Thanks in advance

2

Hi Jocforero, thank for your kind message and interest in OpenEP. We are delighted of course that it is useful!

These are interesting questions and in honesty not something we considered before. We are likely working on a new data format next year and will keep the chronology in order.

In the meantime, the following comes to mind:

1 - No, at the moment OpenEP does not expose the timestamps corresponding to the acquisition time. The ordering matches the system ordering. So, although we cannot guarantee they are chronological, we haven’t yet come across scenarios where they are not (if that makes sense).

2 & 3 - these arrays were designed for point level data plotting, so for example, an impedance drop associated with ablation. I don’t think we can guarantee that they would reflect the chronology of the points acquired.

What system are you working with? I checked some of our EnSiteX and Carto datasets just now; and I think it would be fairly straightforwards to show the acquisition times as recorded. We could add this as a signalProperties array linked to each mapping point which would probably give you what you need.