Simplified Blood Pressure Monitor
Problem |
Background |
Self Blood Pressure Monitors |
Commercial Systems |
Previous Academic Papers |
Relavent Websites
INTRODUCTION
About 50 million Americans have high blood pressure, also known as hypertension. Many people think that high blood pressure is not life-threatening, but when uncontrolled, it can increase you risk of serious health problems. I it is often called a silent killer because 30 percent of those who have it do not know it, and could have it for years without knowing. Most people with high blood pressure do not show any signs or symptoms, but it is thought that dizziness, headaches, or nosebleeds can be warning signs and/or symptoms. However, these signs do not typically occur until hypertension has elevated to a more sever stage that is possibly life-threatening. Even though we do not know the prime cause for high blood pressure, it is easy to monitor blood pressure and is controllable.
Blood pressure is the force exerted by the blood on the walls of the arteries. When measuring blood pressure there are two measurements to look at: systolic and diastolic. Systolic measurement (the top number of a blood pressure reading) is the pressure of blood against artery walls when the heart has just finished pumping. Diastolic measurement (the bottom number in a blood pressure reading) is the pressure of blood against the walls of arteries between heartbeats, when the heart is relaxed and is filling with blood. Blood pressure is constantly changing; some factors that cause blood pressure to change are sleep, exercise, and stress. For an adult, age 18 or older, normal blood pressure consists of a systolic measurement of 119 mm Hg (millimeters of mercury) or lower and a diastolic measurement of 79 mm Hg or lower. Hypertension (high blood pressure) describes a blood pressure where the systolic measurement is 140 mm Hg or higher and a diastolic measurement of 90 mm Hg or higher. Hypertension can be broken down into two subcategories: stage 1 hypertension has systolic measurement from 140 to 159 mm Hg and diastolic measurement from 90 to 99 mm Hg, whereas stage 2 hypertension has systolic of 160 mm Hg or higher and diastolic of 100 mm Hg or higher. There is also another category called pre-hypertension where the systolic measurement is between 120 and 139 mm Hg and the diastolic measurement is between 80 and 89 mm Hg. Therapy for persistent high blood pressure consists of sufficient rest, a diet low in salt and alcohol, reduction in weight where there is obesity, and increased exercise. Drug therapy may include diuretics, beta-blockers, calcium-channel blockers, or ACE inhibitors.
Self blood pressure monitors allow individuals to directly observe the impact of changes in medication and changes in lifestyle on their blood pressure levels from the comfort of their own home. For people who are hypertensive, this has many benefits. Taking and recording regularly scheduled readings, usually once or twice daily, can help people keep track of incremental results over a period of time without costly, time-consuming visits to a doctor’s office. Doctors can look as these results and determine a patient’s progress in stabilizing and/or lowering blood pressure. Sometimes, readings taken from self blood pressure monitors can even be more accurate than those taken at a doctor’s office. This is due to white-coat hypertension, which refers to blood pressure that rises above its usual level when it is measured in a clinical setting due to nerves or anxiety. White-coat hypertension accounts for 20 percent of those who are diagnosed with hypertension.
There is a large market for blood pressure measuring devices not only in clinical medicine but also among the public where the demand for self measurement of blood pressure is growing rapidly. Even though self blood pressure monitors are in high-demand for those with hypertensions, but many of the monitors out on the market are not very useful to patients. There are basically types of commercial home blood pressure monitors: aneroid monitors and electronic, or digital, monitors. Aneroid monitors have a dial gauge and a stethoscope attached to an arm cuff, which is inflated by squeezing a rubber bulb. Aneroid monitors typically range between $15 and $30, whereas digital monitor range between $60 and $100. Even though aneroid monitors are cheaper, they are not a reasonable solution for novice or physically disabled users. They require users to have good hearing, vision, and agility. Digital monitors, on the other hand, just require the user to push buttons and wait for results.
*aneroid monitor
Digital monitors also have many different variations which include devices with automatic inflation cuffs for the arm, wrist, finger, etc. Even though the smaller more portable devices may be more appealing to many users, they are not as accurate as the devices with the arm cuffs. Digital monitors are battery powered and instead of inflating the cuff by squeezing a rubber bulb, the user simply has to push a button on the device and the cuff automatically inflates (although the user has the option to stop the inflation at any time by pushing a stop button). These monitors are able to measure the systolic and diastolic pressures by using a microphone inside the cuff that detects blood pulsating through the arteries. Also, the digital blood pressure monitors available on the market today rely on affordable LCD displays to output the results. These interfaces do not allow users to interact with, or manipulate, their data, requiring the user to rely on online software or take initiative using software such as spreadsheets.
*digital armmonitor *digitalwrist monitor *digital finger monitor
Ambulatory measurement of blood pressure using automated devices has also demonstrated benefit in other indications, such as treatment resistance and borderline hypertension, and is recommended by the Joint National Committee for the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure in a number of clinical scenarios. A new automatic blood-pressure (BP) measuring device TONOPORT V was evaluated according to the International Protocol for Validation of Blood Pressure Measuring Devices in adults by the European Society of Hypertension. The accuracy of the device did not vary according to BP values or other patient characteristics. Increasingly, automated blood pressure devices are replacing mercury sphygmomanometers to monitor blood pressure in primary care settings. The review demonstrates that 'accuracy' of the new devices does not equate to the accustomed accuracy of the mercury sphygmomanometer. An emerging concern of great importance to the Agency is the implementation of good human factors practices in the design of medical devices. If device operation is overly complex or counter-intuitive, safe and efficient use of a medical product can be compromised.
Additional features include emailing your blood pressure report, creating a webpage report of your readings, and calculating averages of your readings. If you can send out your readings to your doctor, he can obtain more context specific information directly, instead of relying on a patient's recollection of past events and symptoms, which tend to be vague, incomplete, and error prone.
Relevant Web Sites:
There are many web sites that provide articles and research about high blood pressure and the different types of monitoring devices. These sites contain information including, but not limited to, background information about blood pressure (normal and high), medication available to treat the condition, lifestyle changes such as diet and exercise, and current research. Below is a list of websites that our team found to be particularly useful:
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