h3>
<p>The implementation of the zero-crossing count in GGIR is an attempt
to imitate the zero-crossed counts previously described by Sadeh, Cole,
Kripke and colleagues in the late 1980s and 1990s. However, it cannot be
guaranteed to be an exact copy of the original approach, which used the
AMA-32 Motionlogger Actigraph by Ambulatory-monitoring Inc. (“AMI”).</p>
<p>No complete publicly accessible description of that approach
exists.</p>
<div class="section level4">
<h4 id="missing-information">Missing 