Some more fun at the hospital

Since time immemorial, mankind has been inventing instruments and machines specifically to make life less pleasant for enemies or just people they don’t like so much.
The medical profession has maintained the tradition, a good example being this interesting unit for evaluating respiratory function which I endured for the third time in 12 months today.
To buy myself some recovery time between tests, I asked the technician if anybody ever collapses with hypoxia during the process. She replied that in the 5 years she’d been there, only about 10. I survived without adding to the tally so my respiratory function must be respectable!