New Blood Pressure Meter Does Not Require Cuff

Nov 20, 2012
Takuya Otani, Nikkei Electronics & Digital Health Online
Blood pressure being measured by using a forefinger
Blood pressure being measured by using a forefinger
[ If it clicks, the expanded picture will open ]
A demonstration of the breast cancer checker. The sensor responded to the reddish area.
A demonstration of the breast cancer checker. The sensor responded to the reddish area.
[ If it clicks, the expanded picture will open ]

Nihon University exhibited a blood pressure meter that enables to measure blood pressure just by touching it with a finger.

The meter was shown at Medica 2012, which took place in Dusseldorf, Germany, from Nov 14 to 17, 2012. With the meter, blood pressure can be measured without using a cuff, making it easy to measure the blood pressures of babies and elderly people.

Blood pressure is measured by touching a button-shaped small area on the meter. There are LEDs and photo transistors embedded in the area. The light emitted from the LEDs is reflected on a finger and detected by the photo transistors.

Though the university did not disclose the details of the measurement method, it said that the blood pressure meter was developed based on a technology that is called "Phase Shift Method" and was developed by Sadao Omata, professor at the College of Engineering, Nihon University. The Phase Shift Method does not use an external power supply for driving and drives a system by using sensed signals.

"The method reduces the number of components, makes it easy to reduce size and drastically improves S/N ratio," Omata said.

This time, the university also exhibited a "breast cancer checker" using the Phase Shift Method. Though it showed such a checker in the past year at Medica, it drastically reduced the size and added a new function that emits sound and light to announce test results.

If cancer exists, the color of the cancer-affected area is slightly different from the surrounding area (more reddish). As a result, more light is absorbed, reducing the amount of reflected light. And the checker detects this difference.