How to make a replacement power supply for the Oridion Microcap and Nellcor N-85 portable capnometers.

The oridion and nellcor portable capnometers are valuable tools offered by Medtronic for continuous etCO2 monitoring outside the OR. I frequently bring the handheld device with me to floor intubations and codes allowing for rapid troubleshooting of ETT placement and monitoring of effective chest compressions.

At the time of this writing there appears to be an abundance of AS-IS devices available on eBay for minimal cost; the majority of the devices do not come with the power cable. I was betting that these items were sold AS-IS because the device uses an unusual RJ-45 (Ethernet) based charging cable and the sellers did not want to invest $200+ on a new cable from Medtronic to test the devices.

I purchased a lot of 3 Oridion Microcaps sold “AS-IS for parts only” from eBay for $75.00.

Since we have a couple of the Nellcor devices at our institution I was able to use the OEM power brick as a reference. The brick has all the necessary info to produce a similar device:


I purchased the following power supply from amazon and wired up a rough adapter following the wiring diagram on the OEM power supply:


The result? All three Microcaps are fully functional. The last component was to produce a more finished product:


Items used for this project:
– Universal DC adapter.
– Female 2.1mm x 5.5mm connector Amazon item listed as an example, however, I purchased mine off eBay for $1 (if you don’t mind waiting 1-2 months).
– Ethernet Cable You likely have one of these sitting around, unused.
– Electrical Tape or wire heat shrink for a nicer appearing repair.
– Wire stripper.