Loss: Using hybrid splitters / hybrid dividers / hybrid combiners, much less power is lost than if a resistive function had been used. When used as a splitter or divider the main level reduction is caused by the action of dividing the power between several ports.
Most scientific study has focused on ANP and BNP. Measurement of BNP helps doctors diagnose and treat congestive heart failure. In this condition, the heart is unable to pump blood efficiently, and the heart chambers swell with blood. As the heart cells stretch, they produce extra BNP, which pours into the bloodstream. By measuring blood levels of BNP, doctors can spot signs of congestive heart failure in its early stages, when it may be hard to distinguish from other disorders. A normal BNP level is about 98% accurate in ruling out heart failure.
Both substances are secreted in response to changes in pressure that occur with heart failure. BNP and NT-pro-BNP levels in the blood increase when heart failure symptoms worsen, and decrease when the heart failure condition is stable. The test is able to detect heart failure over 80% of the time. BNP and NT-pro-BNP levels in a person with heart failure -- even someone whose condition is stable -- are higher than in a person with normal heart function.