This may not be the right place to ask this question. If this is the case, please suggest an alternative and I will gladly move this question to a suitable forum. I am trying to wirelessly capture an ECG signal using the EPIC sensor from Plessey Semiconductors. As marketed on their website, it seems that their sensors can pick up the signal at a distance.

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I have read all the datasheets on their websites but they are more confusing than helpful. On the website, some the sensors (especially the PS25203) are said to allow capturing an ECG signal at a distance. However, there is no specification of the distance between the sensor and the person. If anyone on this forum has ever used the sensor, would you please elaborate on:

  1. Practical distance between the person and sensor to capture an ECG signal
  2. Analog circuit interface to the sensor
  3. Which EPIC sensor (PS25201, PS25251,PS25203, etc), is appropriate for this? It seems PS25102 used in their EPIC demo kit is expensive ($504.00) and, according to the datasheet, does not differ much with other sensors.

Again, if there is a better forum to post this type of questions to please let me know and I will move the question.

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    \$\begingroup\$ The linked page says "Contact mode : ... EEG". Even the manufacturer doesn't suggest you can pick up the tiny EEG signals in non-contact mode, so if that is your plan I suspect you will be disappointed. \$\endgroup\$ – Brian Drummond Aug 22 '16 at 9:01
  • \$\begingroup\$ @Brian Drummond, I am well aware that some sensors were designed to be used in a contact mode. However, the manufacturer also suggests they can be used in a non-contact mode. Please check out [this link] (powersystemsdesign.com/…) or a more technical paper that describe a demo on how the sensor can be used in a car seat. \$\endgroup\$ – Dillion Ecmark Aug 22 '16 at 9:11
  • \$\begingroup\$ Sensing through contact via clothing (as in a car seat) is already pretty impressive. \$\endgroup\$ – Brian Drummond Aug 22 '16 at 9:16
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    \$\begingroup\$ I think I might actually know the inventor. It's a nice unit that can work, say, in a shirt pocket, if it's what I'm thinking of. \$\endgroup\$ – Scott Seidman Aug 22 '16 at 11:19
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    \$\begingroup\$ plesseysemiconductors.com/… . The FAQ talks about room corners \$\endgroup\$ – Scott Seidman Aug 22 '16 at 11:23

What is the "range" of the EPIC sensor for motion sensing?

This depends on the charge on the target, the rate of motion and the local environmental conditions. It is best to think of the EPIC sensor as being characterized by its input referred noise and its gain rather than trying to describe a range. Adult humans can carry anywhere between zero and several thousand volts, depending on clothing and their surrounding environment. This can mean that a moving human target is detectable from say a metre worst case, up to several metres best case. Recent developments suggest that maybe it is best not to measure perturbations in the quasi DC field but to use already existing AC fields that surround us in our normal day to day life. For example 50/60 Hz signals Using changes in the detectable signal strength amongst an array (or even between a pair) of electrodes it may be possible to locate targets at a greater range and with more reproducibility.

  • \$\begingroup\$ Thanks a lot for the quick answer. Whaoh! So, you are suggesting that you can use the sensor to detect a motion of a person at least 1m away? How about capturing his ECG? Could that still work? Also, don't you think "several thousand volts" is too much? Thanks for the clarifications! \$\endgroup\$ – Dillion Ecmark Aug 22 '16 at 7:38
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    \$\begingroup\$ "Several thousand volts" is very realistic. That's the (sometimes) painful "zap" you can get from wakling across a carpet then touching a grounded object. \$\endgroup\$ – JRE Aug 22 '16 at 8:21

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