. 2019 Aug 16;3(3):e14438. doi: 10.2196/14438
©André Henriksen, Sameline Grimsgaard, Alexander Horsch, Gunnar Hartvigsen, Laila Hopstock. Originally published in JMIR Formative Research (http://formative.jmir.org), 16.08.2019.
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Figure 1.
Instrument placement and Polar M430 illustrations.