F
ROM THE BENCH
by Jeff Bachiochi (USA)
Build an MCU-Based Automatic Blood Pressure Cuff Personal health products are becoming more and more commonplace. They reinforce regular visits to personal physicians and can be beneficial when diagnosing health issues. This article shows you how to convert a manual blood pressure cuff into an automatic cuff by adding an air pump, a solenoid release valve, and a pressure sensor to a microcontroller circuit.
M
odern electronics and embedded technologies are constantly changing the healthcare industry for the better. As engineers and electronics innovators, we’re in the position to test new ideas and even bring new healthcare-related products to the market. This month I’ll detail how an experience at a blood donation center led me to build my own microcontroller-based automatic blood pressure cuff (see Photo 1).
June 2012 – Issue 263
BLOOD PRESSURE TESTING
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things were racing through my mind. It was clear I wasn’t going to get any work done for the rest of the day. Instead, I Googled the potential causes of high blood pressure and found: poor eating habits, smoking, physical inactivity, stress, and more. Since I don’t smoke, and I enjoy outdoor activities like running (at least during the nicer weather), it seemed like taking a good look at my diet could in fact address two of the causes with one blow. I have a penchant for fried foods and red meat. And, after a few months of decreased activity, I was tipping the scale at more than 200 lbs. It was time to change my eating habits.
Last year around this time, I went to a local high school during its sponsored blood drive. Interestingly, a “bloodmobile”—which is a mobile blood donation center— was set up to handle four donors at a time. Donating has gotten rather uneventful over the years, but that day changed my outlook forever. Typically, during the pre-donation interview, a registered nurse (RN) tests your pulse, blood pressure, and iron content (with a finger prick that for some reason always hurts more than the donation itself). If all is well, you must answer a battery of questions to ascertain whether your blood might be contaminated in any way. Well, when I visited the bloodmobile, I didn’t have to answer any questions. I was rejected Photo 1—I turned a manual blood pressure cuff into an automatic for having high blood pressure. cuff by adding an air pump, a solenoid release valve, a pressure On my way back home, many sensor, and a microcontroller. CIRCUIT CELLAR®
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