39 ms·

Now if only it were accurate...

Bishonen88 8y ago
Am a Garmin user for years. Was in a hospital ~10 months ago and was connected to a heart-rate-monitoring-thingy via a finger-clip. At the same time I had my Garmin Fenix 3 on my other arm. Was looking at the screen and comparing it to what my watch was showing and it was +-2 points at all times. Tried holding my breath to see what happens and both were almost identical.
- com2kid 8y ago
  Optical heart rate when not moving is pretty easy to do. Measurements are much harder when the user is moving around erratically, such as is typical with exercising. Source: I worked on a fitness product using optical HR for 3 years.
  - stephengillie 8y ago
    Even the phone apps work pretty well while stationary: https://play.google.com/store/apps/details?id=com.repsi.heartrate&hl=en_US https://play.google.com/store/apps/details?id=com.repsi.hear... https://play.google.com/store/apps/details?id=com.supersimpleapps.heart_rate_monitor_newui&hl=en_US https://play.google.com/store/apps/details?id=com.supersimpl... https://play.google.com/store/apps/details?id=si.modula.android.instantheartrate&hl=en https://play.google.com/store/apps/details?id=si.modula.andr...
  - lostlogin 8y ago
    My experience of hospital grade equipment for monitoring the heart is that it isn’t great with movement either. This was in an MR scanner (magnetic field and RF) so I ones milage may vary.
    - com2kid 8y ago
      > My experience of hospital grade equipment for monitoring the heart is that it isn’t great with movement either. For anything optical, you need accelerometers and lots of fun algorithms to compensate for motion. Soon as the motion is something the algo wasn't trained on, everything falls apart.
      - lostlogin 8y ago
        Optical, electrical (from chest or skull) and even a BP cuff (pneumatic) were used. It’s a hard problem.
- 013a 8y ago
  I did something similar during a cardiac stress test, with a Fitbit Versa. My best conclusion was that the Fitbit is at least +/-5 BPM off and it lagged behind the hospital equipment by roughly 15 seconds (judging by heart rate peaks).
ack0 8y ago
I think this is the real problem. My wife was worried her heart rate according to fitbit was high. Her doctor measured it at 15-20 bpm lower. After she started doing up the fitbit band one notch tighter the average heart rate it recorded dropped 10 bpm.
- rando444 8y ago
  Is that really a problem with the equipment though? They explain exactly this in the booklet it comes with. If a sphygmomanometer gives an inaccurate reading because the doctor doesn't put the cuff on properly is the machine to blame? I only say this because I've tested both a fitbit, and a garmin on each arm while wearing a chest strap and found both results to be within a satisfactory deviation of the chest strap.
justaguyhere 8y ago
This is just one data point, but still... Yesterday, my fitbit shows me I had walked 800 steps - I wasn't wearing it and it was just lying there on my desk. Bought it last Christmas, so it is not even a year old. I didn't even bother testing the heart rate data
- sulam 8y ago
  That’s really odd. I can’t talk about accuracy, but getting steps while it’s literally sitting on a desk would be novel in my experience. Do you have mobile track enabled (the feature where we can use the phone’s accelerometer to try and record steps)? You should also try reaching out to customer support, we invest very heavily in being able to debug it when things go weird.
  - justaguyhere 8y ago
    I am not sure if mobile track is enabled, but it shouldn't matter because my phone wasn't moving either. Both were on the desk, till evening. After work (I work from home and I only use the watch when I step out), I stepped out and was surprised to see it was showing ~800 steps. It was a bit amusing!

Am a Garmin user for years. Was in a hospital ~10 months ago and was connected to a heart-rate-monitoring-thingy via a finger-clip. At the same time I had my Garmin Fenix 3 on my other arm. Was looking at the screen and comparing it to what my watch was showing and it was +-2 points at all times. Tried holding my breath to see what happens and both were almost identical.

com2kid 8y ago
Optical heart rate when not moving is pretty easy to do. Measurements are much harder when the user is moving around erratically, such as is typical with exercising. Source: I worked on a fitness product using optical HR for 3 years.
- stephengillie 8y ago
  Even the phone apps work pretty well while stationary: https://play.google.com/store/apps/details?id=com.repsi.heartrate&hl=en_US https://play.google.com/store/apps/details?id=com.repsi.hear... https://play.google.com/store/apps/details?id=com.supersimpleapps.heart_rate_monitor_newui&hl=en_US https://play.google.com/store/apps/details?id=com.supersimpl... https://play.google.com/store/apps/details?id=si.modula.android.instantheartrate&hl=en https://play.google.com/store/apps/details?id=si.modula.andr...
- lostlogin 8y ago
  My experience of hospital grade equipment for monitoring the heart is that it isn’t great with movement either. This was in an MR scanner (magnetic field and RF) so I ones milage may vary.
  - com2kid 8y ago
    > My experience of hospital grade equipment for monitoring the heart is that it isn’t great with movement either. For anything optical, you need accelerometers and lots of fun algorithms to compensate for motion. Soon as the motion is something the algo wasn't trained on, everything falls apart.
    - lostlogin 8y ago
      Optical, electrical (from chest or skull) and even a BP cuff (pneumatic) were used. It’s a hard problem.
013a 8y ago
I did something similar during a cardiac stress test, with a Fitbit Versa. My best conclusion was that the Fitbit is at least +/-5 BPM off and it lagged behind the hospital equipment by roughly 15 seconds (judging by heart rate peaks).

ack0 8y ago

I think this is the real problem. My wife was worried her heart rate according to fitbit was high. Her doctor measured it at 15-20 bpm lower. After she started doing up the fitbit band one notch tighter the average heart rate it recorded dropped 10 bpm.

rando444 8y ago
Is that really a problem with the equipment though? They explain exactly this in the booklet it comes with. If a sphygmomanometer gives an inaccurate reading because the doctor doesn't put the cuff on properly is the machine to blame? I only say this because I've tested both a fitbit, and a garmin on each arm while wearing a chest strap and found both results to be within a satisfactory deviation of the chest strap.

justaguyhere 8y ago

This is just one data point, but still... Yesterday, my fitbit shows me I had walked 800 steps - I wasn't wearing it and it was just lying there on my desk. Bought it last Christmas, so it is not even a year old. I didn't even bother testing the heart rate data

sulam 8y ago
That’s really odd. I can’t talk about accuracy, but getting steps while it’s literally sitting on a desk would be novel in my experience. Do you have mobile track enabled (the feature where we can use the phone’s accelerometer to try and record steps)? You should also try reaching out to customer support, we invest very heavily in being able to debug it when things go weird.
- justaguyhere 8y ago
  I am not sure if mobile track is enabled, but it shouldn't matter because my phone wasn't moving either. Both were on the desk, till evening. After work (I work from home and I only use the watch when I step out), I stepped out and was surprised to see it was showing ~800 steps. It was a bit amusing!