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WiFi signals can measure heart rate

(news.ucsc.edu)
463 points bookofjoe | 5 comments | 04 Sep 25 14:53 UTC | HN request time: 0.001s | source
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hollerith ◴[04 Sep 25 17:18 UTC] No.45129694[source]▶
WiFi equipment can see your heart beating, but don't worry, it cannot possibly have any harmful effects on human physiology.
replies(6): >>45129788 #>>45129813 #>>45130057 #>>45131028 #>>45131218 #>>45134004 #
ch4s3 ◴[04 Sep 25 17:47 UTC] No.45130057[source]▶
A sonogram can see your heart beating too, but no one thinks sonograms are dangerous(because they are not).
replies(4): >>45130107 #>>45130152 #>>45130689 #>>45131250 #
transpute ◴[04 Sep 25 17:53 UTC] No.45130107[source]▶
Unsolicited remote sonograms are stopped by walls, floors, ceilings and doors, unlike wireless radio networks.
replies(2): >>45130445 #>>45131867 #
1. ch4s3 ◴[04 Sep 25 20:27 UTC] No.45131867[source]▶
A concrete wall stops wifi pretty well.
replies(1): >>45131917 #
2. transpute ◴[04 Sep 25 20:33 UTC] No.45131917[source]▶
How thick a concrete wall is needed to stop wifi? Or does the concrete wall contain fine wire mesh?
replies(2): >>45134270 #>>45134457 #
3. dilyevsky ◴[05 Sep 25 01:48 UTC] No.45134270[source]▶
If by "fine" you mean minimum ~10mm rebar then yes
4. ch4s3 ◴[05 Sep 25 02:29 UTC] No.45134457[source]▶
Have you never walked into a building an lost cell reception?
replies(1): >>45138060 #
5. transpute ◴[05 Sep 25 13:03 UTC] No.45138060{3}[source]▶
Found a table with attenuation by frequency and building material, e.g. low-emission glass can block more than concrete, https://www.signalbooster.com/blogs/news/how-much-which-buil...

                        800Mhz     1900Mhz
  1/2" Drywall          2.03 dB    2.43 dB
  Venetian Plaster      7.91 dB    16.22 dB
  6" Concrete Wall      10.11 dB   19.41 dB
  Glass Window          4.35 dB    4.38 dB
  Low Emission Glass    33.8 dB    33.8 dB
  Brick                 7.57 dB    14.66 dB
  Solid Wooden Door     6.11 dB    12.33 dB