Before I start on this quick post please remember that I am in no way an expert on phreaking, to be perfectly honest I don't really know that much about it at all. With this said I still believe that I am right about this and how it works, if someone feels that I am incorrect please correct me.

I recently have had a few heart problems, nothing too serious just palpitations, anyways I was given a heart monitor for the week to wear to try and record these incidents. The heart monitor was called a 'King of Hearts' monitor and is quite simple in it's design, there is a jack going from the top much like an airplane headphone jack that leads to the pads that attach to the chest, the system also has an LED display for various information. To record an incident all that needed to be done was to push the very large button on the middle of the device, because of its size it was pretty easy to accidently hit the button, the hospital said they would clear any incorrect readings. So that's the basics of the monitor itself and how it worked, now comes the more interesting functionality that instantly sparked the phreak in me.

The recordings were sent over the phone to the hospital and any incorrect readings were also cleared via the phone. I would ring the hospital and push the big button twice, this would then send a certain frequency to start the system on the other end, then the recording would be sent again in intermittent frequencies much like a cardiac monitor (beep...beep...beep). The computer system on the other end of the phone would then take this reading and create a graph. I recorded one accidental incident and rang the hospital to get it removed, the method was very similar this time they asked me to put the microphone (on the button) to the ear piece of the phone and a frequency was sent to clear the monitor.

Of course I had to test this out myself, so I rang the hospital claiming to have accidentally recorded an incident, this time however I put my dictaphone to the receiver and recorded the frequency sent. I am no frequency or phone system expert so I presumed that the recording would differ when play back from the dictaphone however to my surprise when the recorded frequency was played to the monitor it was cleared.

So although this is not a tutorial or really even anything informative, it is a good example of 'modern day phreaking' since actual phone phreaking is highly illegal. I hope you enjoyed the read, and of course if you have any comments on this or ideas of what else could have been achieved please feel free to comment.