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DynaPulse 200M A Shock to the System? A computer-based product recently submitted for review was responsible for a hastily arranged visit to the doctor. Product Review by ROSS TESTER The product in question was a blood pressure monitoring and tracking system, using a computer for both measurement/analysis and record storage. And the reason for the reality shock was a much-higher-than-expected series of readings. What happened was that once installed we dutifully measured all Silicon Chip staff and I was at least a little perturbed to find that my own blood pressure was significantly higher than everyone else's. Further reading con- vinced me to do something about it! Of course, most people would be familiar with the blood pressure meter used by doctors and nurses. Moe correctly known as a sphygmomanometer, it involves an inflatable armband "cuff" which is pressurised to restrict the flow of blood through the arm. Blood flowing through an artery makes characteristic sounds (known as Korotkoff sounds) and the physician listens for these with a stethoscope as the pressure is released. Left: the package includes the unit itself, arm cuff, inflator bulb, serial cable, software on floppy and user manual. 8  Silicon Chip This technique for measuring blood pressure is known as the ausculatory method. With each contraction or pump of the heart, blood pressure rises and falls. The highest blood pressure, as the heart contracts, is called the systolic pressure, while the lowest blood pressure is known as the diastolic pressure. When you hear a blood pressure referred to as "120 over 80", the first figure is the systolic and the second the diastolic. Below: the only control on the unit is the air release index dial. The DynaPulse 200M also measures pressure using a pressurised cuff and arterial pulsation but uses a slightly different method called Pulse Dynamics. This is claimed to be more accurate, agreeing extremely well with pressure-sensing catheter measurements which use a catheter actually inserted into the artery itself. Setting up The hardware consists of the pressure cuff, an inflating bulb with air release screw, connecting tubing and the DynaPulse 200M unit itself. Included is a 64-page instruction manual and software. Of course, you'll need a PC with Windows 95 and a free COM port. Hands up if you've ever read an instruction book all the way through before using anything? No, we didn't think so. We skimmed over the first couple of pages and thought "enough" – and then proceeded to install the software on a computer (from a single floppy disk) and the hardware, which plugs into a vacant COM port. Apart from the fact that we had to go out and buy four AAA batteries before it worked, everything installed and loaded perfectly. (There's a first time for everything...). Taking a reading This part is even easier! Instructions are basically menu driven, as shown in our screen shots. As many "patient" names are entered as required and then the appropriate person is selected from the list. The deflated cuff is slid up the arm to just above the elbow, tightened and held in place via Velcro fasteners, as shown on screen. The "air release index" is a dial on the DynaPulse unit Finally, you are presented with the results. Those shown are at the high end for a normal, healthy person. Anything higher is an indication of hypertension. I wasn't happy when my own readings were quite a bit higher . . . itself and 4 seems about right for most people. If it's not, it will tell you! Next screen tells you to close off the air release while you pump the bulb. When the cuff has enough pressure it will tell you to stop pumping and then you wait for between 15 and 45 seconds while the unit does its measurements. During this time the pressure on the scale drops with little "blips" in time with your heartbeat. Finally, the results screen appears showing systolic, diastolic and mean blood pressures, the heart rate and two histograms – one of the heartbeat cycle and the other showing the heartbeat cycles over the full measurement period. All this information can be saved in the person's file and printed out if required. If used over a period of weeks, months or years a "trend" graph can also be produced – very handy if your physician has you on medication to lower blood pressure. The software can plot a blood pressure and heart rate trend graph. Red trace is systolic, blue is diastolic and yellow is average blood pressure. You can see at a glance if it is working! Conclusion With heart disease the biggest killer in the western world (and Australia is right up there with the worst of them), having accurate, reliable blood pressure data could be the difference between a life and death situation. It's certainly jolted me into action. I know I'm overweight – 20kg, less would be lovely! But I've basically been healthy and don't smoke and drink very little. So high blood pressure has never been top-of-mind for me. Now it is! High blood pressure, or hypertension, is believed to be a major factor in strokes, heart attacks and heart disease. It also means your heart has to work that much harder to circulate the blood around your body. There is no doubt the DynaPulse 200M does its job very well. It's easy to set up, easy to use and having the computer records available for your doctor could be very beneficial. At an RRP of $369 (pre-GST), some might think it expensive. But how SC much is your life worth? Where do you get it? The DynaPulse 200M is available from Microgram Computers, Unit 1, 14 Bon Mace Close, Berkeley Vale NSW 2261. Phone (02) 4389 8444; Fax (02) 4389 8388; website www.mgram.com.au JUNE 2000  9