Development Team Member
Registered: 1380484167 Posts: 1,501
Hallo Roger. We discuss a 2 MOXY 5/1/ rowing on the forum and as you can see there was some questions concerning overlap. It turns out that one unit seem to have lost data collection in different areas, but it does no look like a connection or light signal problem as the datas onGC seem t be not missing. .
Ryinc. Yes great thanks as I checked that last night by looking all the raw datas of VL and yes there are a lot of gaps there for example by 18.32.36 than 4 seconds jumps and many more to come. So question to Roger . how can we fix that? is that a one moxy model problem of this person or is that happening for any one ? ?
Development Team Member
Registered: 1482688495 Posts: 44
I have two Moxys and I have been experiencing gaps with both.
Sometimes the gaps are only for a few seconds, sometimes longer. I will look at the Garmin FIT files and send them to Roger. I think that the GoldnCheetah program I used to create plots does some sort of interpolation and gap filling, because I have used CSV files to create them (and not FIT files from the watch).
Registered: 1340810797 Posts: 245
It looks like there are a couple of things going on here.
First is that we're seeing a lot of data gaps and the SmO2 and THb values bounce around a lot when the gaps occur. We should be able to do the entire test without a single missed reading. This problem is most likely due either to ambient light or due to the sensor not staying in contact with the skin. Halogen lights or bright incandescent lights tend to be more of a problem for ambient light than fluorescents. With fluorescents, you typically don't need any light shielding. With incandescents, a pair of shorts over the sensor usually is sufficient. In direct sunlight, you need something like the Moxy light shield. Sometimes the sensor can come off the skin just due to the changing shape of the muscles especially if the sensor is mounted close to a joint like the elbow or knee. Moving closer to the belly of the muscle can fix that. It doesn't need to be pressed in to the skin, just touching it. Sometimes more aggressive taping or strapping that encircles the limb can actually aggravate the issue. The adhesive attachments work well if you have to be near a joint or if the muscle is changing shape a lot. The Cover Roll Stretch tape works well too. The second issue is in how Golden Cheetah is smoothing the data. This appeared to work correctly when I imported the data from the .csv file. The .csv file skips over any missing data. My guess (correct me if I'm wrong) is that this data was imported via the .FIT file instead. The FIT file typically has a row of data every 1 second. When there is a missed reading, it enters a 0 in for THb and SmO2. It looks like it is including the 0's in the smoothing. That's why the THb values on the LV dropped down to about 4. It was mixing a bunch of 0's in with the rolling average of the valid 11's. The Golden Cheetah smoothing algorithm appears to have features to deal with gaps in time properly, but I didn't find an option to exclude 0's For right now, this Golden Cheetah issue can be worked around by fixing the source of the missed readings or by setting the smoothing down to 0. (Hover you mouse pointer near the top of the graph and slide the slider all the way to the left) I will look into a better longer term fix. I can make it write the most recent SmO2 and THb values instead of 0's in the .FIT file when a no-read occurs. I'm not sure if there is an option to leave the reading "empty" in the .FIT file. I will also poke around in Golden Cheetah to see if they have an option to exclude 0's from the smoothing calculation. Please email or post the FIT files so I can look a little closer at how Golden Cheatah is handling them.