Wednesday, April 10, 2013

A new CPAP machine

I hinted a few weeks ago that I was commencing the series of events which would lead to me getting a new CPAP machine. For some reason, the health fund insists that one sees a ENT doctor in order to get an appointment with a sleep doctor; this seems to be needless bureaucracy. Once that first and simple hurdle had been cleared, I was pleased to discover that the sleep doctor makes weekly visits to my local town, which means that I didn't have to go to Jerusalem each time. My appointment with the sleep doctor was similarly brief; I told her that I suffer from sleep apnea and was diagnosed five years ago. She signed a paper then sent me to a neighbouring office where a young woman was waiting with several CPAP machines. Her job was to match patients with machines and monitor the results.

So I left the clinic with a new (to me) CPAP machine and more importantly, a new mask. Even though I had told the technician what the settings on my old machine were, she set the machine to determine those settings automatically. The machine starts at a certain pressure: if I told her that 7 cmH2O was the determined setting, then the machine starts at 10 cmH2O, then slowly reduces the pressure until a certain rate of apnea are measured. The machine then raises the pressure and the rate of apnea should be reduced. This game continues until the machine establishes what the most effective pressure is. Not surprisingly, this was 7 cmH2O.

After a week of varying pressure, I returned to the clinic, where the technician reset the machine so that there would be a constant pressure of 7 cmH2O. I used the machine for another week then returned to the clinic in order to analyse the results. It seems that I had on average 15 apnea per hour during that week; considering that previously I had about 10 apnea per hour, it was clear that this machine was not helping me.

The technician didn't have a better machine with her, but after a few days, another technician (in reality, a salesman) paid me a visit at home and set me up with a different machine which has better diagnostics. After a week with the new machine, the salesman extracted the data and we discovered that I had on average 6 central sleep apnea events per hour and 0.5 obstructive sleep apnea events per hour. I am pleased that the number of apnea per hour decreased substantially but am somewhat surprised that I have CSA and not OSA: CPAP can overcome the latter but not the former.

A small misunderstanding left me for two nights with my old machine and old mask; I get the feeling that I didn't sleep too well during those nights. Then the salesman came and set me up with my new machine. There have been advances in diagnostics and connections in the five years since I got my first machine: that one had an old style serial port socket (I think it's RJ-45: similar to a telephone socket) for which the technician had a lashed-up cable with RJ-45 on one end and a nine pin 'new style' serial plug on the other. I think that the first machine which I tried this year gave its diagnostics via coded read-outs which the technician typed into a program in order to decode them. Certainly she didn't connect the machine to her computer.

The new machine has some form of connector (I don't remember which) but more importantly comes built in with an extractable memory card. Every morning when I turn the machine off, I see a little red light come on while the machine writes its data to the card. According to the salesman, data is written in the form of an Excel spreadsheet. I haven't had a chance to verify this yet as I don't have a card reader. I thought that I would be able to put the card in the mp3 player which I bought a few months ago but this card is much larger than the mp3 player's card.

So I went looking for a card reader. At first I tried Israeli sites, but a google query pointed me to an American site. I bought a reader for the princely sum of $2.50 with free postage to Israel! I hope that it works! I can hardly lose at this price.

I hadn't thought about this before, but that phrase data is written in the form of an Excel spreadsheet intrigues me, seeing as I've spent no small amount of time in the past few days doing exactly that. The gory details will come probably in my next blog.

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