Actually, zooming in the middle button says "STANUFLO." Top and bottom buttons look like some kind of chemical formulae (something to do with blood filtering?). A real doctor could probably make sense of it.
Actually, it's my understanding that it was common practice during the production of TOS to label things with random numbers and letters, sometimes with subscript. Examples include wall plant ons found in engineering, corridors, and elsewhere, the sickbay exam room panel seen in one of my screenshots above, and bridge display graphics. (As a matter of fact, and feek61 can back me up on this, one of the seldom seen bridge display graphics was comprised of nothing but groups of these random letters and numbers.)
Therefore, I doubt any doctor would be able to make sense of it.
If I'm correct, isn't this where the GNDN acronym came from?