“Who’s the coolest guy in the hospital?”/“The ultra-sound guy.”

A hospital riddle is:
 
Q: Who’s the coolest guy in the hospital?
A: The ultra-sound guy.
 
“Q: Who’s the coolest person in a hospital? A: The ultra sound guy” was posted on Twitter by Ian Sealy on May 21, 2008. “Whos the coolest guy in a hospital?The ultrasound guy. Who fills in when hes on holiday? The hip replacement guy” was posted on Twitter by Lee Mifsud on April 28, 2009.
 
         
Wikipedia: Ultrasound
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from “normal” (audible) sound in its physical properties, except in that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
   
Twitter   
Ian Sealy
@iansealy
Replying to @jemimakiss
@jemimakiss Q: Who’s the coolest person in a hospital? A: The ultra sound guy.
6:15 PM - 21 May 2008
   
Twitter
Lexlacey
@Lexlacey
Made me chortle: Who’s the coolest person at a hospital?The ultra sound guy!
5:52 AM - 5 Dec 2008
   
Twitter
Lee Mifsud
@LeeMifsud
Whos the coolest guy in a hospital?The ultrasound guy. Who fills in when hes on holiday? The hip replacement guy :3
4:55 AM - 28 Apr 2009
 
Google Groups: Glow
mailing list
andrew hilton
6/10/10
Who’s the coolest guy in a hospital…..
 
Reddit—Funny
The ultrasound guy
Who’s the coolest guy in the hospital? (self.funny)
submitted July 7, 2011 by frgn8r
The ultra-sound guy.
Who is it when he’s on holiday?
The hip replacement guy.
   
Google Books
The Mammoth Book of One-Liners
Edited by Geoff Tibballs
London, UK: Constable & Robinson Ltd
Pg. ?:
Who is the coolest person in the hospital?
The ultrasound guy.
 
Reddit—3amjokes
Who is the coolest guy in the Hospital? self.3amjokes
Submitted July 1, 2013 by magnetoencefalografy
The ultra sound guy.
COMMENTS
magnetoencefalografy
Who do people like to hang around with when he’s not there?

The hip replacement guy.
   
20 January 2014, Evening News (Edinburgh, Scotland), “You’ve got to laugh” by Jen Lavery, pg. 13:
“Who’s the coolest guy in the hospital? The ultra-sound guy.
 
Reddit—Jokes
Who’s the coolest guy in the hospital?
submitted January 21, 2015 by technomilitia
The ultra-sound guy.
   
Google Books
3000 Jokes, 2997 Laughs
By Mike Haskins
London, UK: Portico
2017
Pg. ?:
Q: Who is the coolest person working in the hospital?
A: The ultrasound guy.
 
Twitter
lorraine Jo King
@LahLahBean
#wednesdaywit
Who’s the coolest person in a hospital? 
The ultra sound guy.
12:00 PM - 12 Sep 2018