MEMS-powered Portable Blood Pressure Monitors
As people increasingly realize the importance of managing their own health, OMRON has responded with helpful devices such as home-use digital blood pressure monitors. These devices have made it possible for people in their own homes to easily measure their blood pressure, which is an important indicator for health conditions. Recently, ultracompact and lightweight units such as finger- and wrist-type monitors enjoy a great deal of popularity because of their portability, which allows them to be used even when away from home on business or vacation. Thanks in large part to MEMS technology, blood pressure monitors as small as a business card have become available. Though usually unnoticed by users of the product, these monitors incorporate the world's smallest MEMS pressure sensor for measuring blood pressure. The pressure sensor is a system that can detect and gauge the pressure of gaseous materials and liquids.
OMRON's sensor is very small yet is sensitive enough to measure blood pressure from a person's finger. The secret is in its "donut structure" created through MEMS micromachining technology. Although conventional pressure sensors use a disc configuration, the new donut structure can enlarge the blood pressure sensing area to five times that of conventional sensors, enabling super-high sensitivity in detecting pressure levels. In addition, conventional measurement methods were based on the detection of pressure changes, so the readings were affected by ambient temperatures. To alleviate this drawback, OMRON developed a proprietary method that detects electrical capacitance changes. This led to the development of a MEMS pressure sensor capable of delivering accurate blood pressure readings regardless of environmental conditions.
Donut-shaped MEMS pressure sensor built into digital blood pressure monitors
- A conventional disc-type sensor can use only 10% of its total area for sensing.
- MEMS-based donut-type sensor can increase the sensing area to 50% of its total area.