[Avodah] Fitbit on Shabbos

[Micha Berger via Avodah]

: On 2/17/2016 6:15 PM, Jay F. Shachter via Avodah wrote:
: I can't answer all of your questions but I can throw out one
: possibility for one issue, the motion detectors. Rav Rabinovitch has
: ruled that the basic issue with these devices are "ovdah d'chol". ...
: Therefore, RR concludes that any device set off when someone passes
: by these devices is not a problem.
: http://ravtzair.blogspot.co.il/2014/07/blog-post_6.html

Related question.... The Fitbit.


Many of the pedometers, sleep trackers, etc... have no display. Of
those that do, they generally display the time and only show exercise
and health info after one presses a button. Typically they sync to a
phone, tablet, or computer via bluetooth and there you can keep track
of progress. (Which is why some devices don't even bother with a display.)

If someone were to wear one on Shabbos, every step is counted (or toss
and turn in bed recorded, or...) but the only effect on Shabbos is in
the voltage levels in microscopic traces within chips.

After Shabbos, however, the effects of what he did on Shabbos are
observable.

I presume this is either gerama or not even gerama.

If gerama, it might be permissible only to someone who is morbidly obese
or has a sleeping disorder or some other medical need. There is a nafqa
mina lemaaseh.

Thoughts?

Tir'u baTov!
-Micha

-- 
Micha Berger             The Maharal of Prague created a golem, and
micha at aishdas.org        this was a great wonder. But it is much more
http://www.aishdas.org   wonderful to transform a corporeal person into a
Fax: (270) 514-1507      "mensch"!     -Rav Yisrael Salanter