Watch Heart Rate Monitor Info

Discussion in 'Apple Watch' started by BillyTrimble, Apr 20, 2015.

  1. BillyTrimble macrumors 6502a

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  2. Argentine86 macrumors regular

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    #2
  3. undies1993 macrumors 6502a

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    #3
    Thanks for posting this. Really looking forward to seeing this data.
     
  4. twisted-pixel macrumors 6502a

    twisted-pixel

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    #4
    definitely looking forward to trying this out...and dumping the chest strap
     
  5. urbancity macrumors member

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    #5
    Is Apple's statement Blood is red because it reflects red light and absorbs green light correct?

    I thought blood is red because it absorbs all wavelengths except red; it doesn't absorb just green light..
     
  6. undies1993 macrumors 6502a

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    #6
    It might be more accurate to say green spectrum.
     
  7. Julien macrumors G3

    Julien

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    #7
    Both are correct but Apple had to choose a wavelength color for the LEDs. I believe green is 2ed most efficient LED color to use behind red. Also I believe blue (lower frequency) LEDs use the most power.
     
  8. kdarling macrumors demi-god

    kdarling

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    #8
    I did some research and wrote a short post on this topic back in March:

    http://forums.macrumors.com/showthread.php?p=20893422

    Red LEDs allow looking for oxygen level as well, but get confused by blood changes caused by arm motions instead of heartbeats.

    Green LEDs have recently been adopted for wrist HRMs because they don't read as deeply, and thus are not as easily fooled by motion related blood changes.

    Apparently green is also better for people with darker skin tones.
     
  9. Goalieed macrumors member

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    #9
    I'm surprised it monitors every 10 minutes as a regular thing
     
  10. jafingi macrumors 65816

    jafingi

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    #10
    Hmm, it's not a new article? I remember reading it last week on Apple's website.

    But it definitely seems like they've put a lot more work into the sensor than the competitors.
     
  11. Hicks. macrumors regular

    Hicks.

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  12. kdarling, Apr 20, 2015
    Last edited: Apr 20, 2015

    kdarling macrumors demi-god

    kdarling

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    #12
    From a basic implementation standpoint, they're just using what has been found out by all those who have been making such monitors for years.

    That's where the IR and green LEDs came from. (When IR is overwhelmed by sunlight skin reflection, that is one case where it must switch to green.)

    .
     
  13. Lloydbm41 macrumors 68040

    Lloydbm41

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    #13
    More work? Not sure about that? Apple has had "more time to study the competition and build their heart rate sensor module" might be a better way to put it.
    Seems as though everyone is using the multiple green led lights for heart rate, but maybe apple doubled up on the number of led's is all?
    [​IMG]

    [​IMG]

    and considering the 360 is now nearly a year old:
    [​IMG]
     

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