The last time I was monitored in an ER, I noticed an analog trace for respiration. I asked if this was done by some non-contact [impedance] method. I was told t

The last time I was monitored in an ER, I noticed an analog trace for respiration. I asked if this was done by some non-contact [impedance] method. I was told that some EKG chest electrodes also served to measure bulk resistance.