The original link is broken. I could not find the same article, but here’s another article he wrote on this subject: https://www.researchgate.net/profile/Timothy_Roehrs/publication/7936982_Sleep_and_Pain_Interaction_of_Two_Vital_Functions/links/53ea15a60cf2dc24b3cb07be/Sleep-and-Pain-Interaction-of-...

The wayback machine link also did not work for me, so I did some searching. This may be the new home for the information:
https://www.usa.philips.com/c-dam/b2bhc ... lHints.pdf