fiducial point

A fiducial point also figures in the calculation of astrological ages.

Such fiducial points or markers are often created in magnetic resonance imaging and computed tomography images by using the N-localizer.

Similarly, fiducial points established during MRI can be correlated with brain images generated by magnetoencephalography to localize the source of brain activity.

In radiotherapy and radiosurgical systems such as the CyberKnife, fiducial points are landmarks in the tumour to facilitate correct targets for treatment.

In electrocardiography, fiducial points are landmarks on the ECG complex such as the isoelectric line (PQ junction), and onset of individual waves such as PQRST.

While most astronomers and some astrologers agree that the fiducial point occurred in or around the 3rd to 5th centuries AD, there is no consensus on any exact date or tight timeframe within these three centuries.

The locations of the fiducial points in each data set are then used to define a common coordinate system so that superimposing the functional MEG data onto the structural MRI data ("coregistration") is possible.

However this fiducial point is difficult to determine because while there is no ambiguity about the tropical zodiac used by western astrologers, the same cannot be said of the sidereal zodiac used by Vedic astrologers.

The electrical and impedance signals are processed to determine fiducial points, which are then utilized to measure and calculate hemodynamic parameters, such as cardiac output, stroke volume, systemic vascular resistance, thoracic fluid content, acceleration index, and systolic time ratio.

The two sets of data are combined by measuring the location of a common set of fiducial points marked during MRI with lipid markers and marked during MEG with electrified coils of wire that give off magnetic fields.