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The Shunt equation (also known as the Berggren equation) quantifies the extent to which venous blood bypasses oxygenation in the capillaries of the lung.. “Shunt” and “dead space“ are terms used to describe conditions where either blood flow or ventilation do not interact with each other in the lung, as they should for efficient gas exchange to take place.
An uncorrected left-to-right shunt can progress to a right-to-left shunt; this process is termed Eisenmenger syndrome. [3] This is seen in Ventricular septal defect, Atrial septal defect, and patent ductus arteriosus, and can manifest as late as adult life. This switch in blood flow direction is precipitated by pulmonary hypertension due to ...
The alveolar gas equation is the method for calculating partial pressure of alveolar oxygen (p A O 2). The equation is used in assessing if the lungs are properly transferring oxygen into the blood. The alveolar air equation is not widely used in clinical medicine, probably because of the complicated appearance of its classic forms.
This must be balanced with adequate oxygenation and systemic delivery of oxygenated blood. This modified circulatory system is established by detaching the superior vena cava from the right atrium and connecting the cranial part of the SVC to the pulmonary arteries (shunt). This is an example of a surgical anastomosis. As a result, the venous ...
The continuity equation states that the flow in one area must equal the flow in a second area if there are no shunts between the two areas. In practical terms, the flow from the left ventricular outflow tract (LVOT) is compared to the flow at the level of the aortic valve.
Eisenmenger syndrome or Eisenmenger's syndrome is defined as the process in which a long-standing left-to-right cardiac shunt caused by a congenital heart defect (typically by a ventricular septal defect, atrial septal defect, or less commonly, patent ductus arteriosus) causes pulmonary hypertension [1] [2] and eventual reversal of the shunt into a cyanotic right-to-left shunt.
Figure 2. Calculation of Tau (Glantz method) Tau represents the exponential decay of the ventricular pressure during isovolumic relaxation. Several studies have shown that Tau is a preload-independent measure of isovolumic relaxation. The accurate estimation of Tau is highly dependent on the accuracy of ventricular pressure measurements.
RF MEMS switched capacitors are capacitive fixed-fixed beam switches with a low capacitance ratio. RF MEMS varactors are capacitive fixed-fixed beam switches which are biased below pull-in voltage. Other examples of RF MEMS switches are ohmic cantilever switches, and capacitive single pole N throw (SPNT) switches based on the axial gap wobble ...