BSL PRO Software Guide - Biopac

Analysis Functions 167MEASUREMENT Area EXPLANATIONMaxMax TMeanMedianMinimum area:1 sampleUses:All points ofselected areaMinimum area:1 sampleUses: All pointsMinimum area:2 samplesUses:All points ofselected areaMinimum area:2 samplesUses:x – values of points at horizontal axis ( x1– the first point,ipoint);fx i- values of points of a curve ( vertical axis).xn– the lastNote: For a single point, Lin_reg computes the linear regression of theline drawn between the two samples on either side of the cursor.Results:If the data value at the starting location is greater than the data value atthe ending location of the cursor, then a negative delta will result.Otherwise, a positive delta will result.Units: Volts/sec.This value is normally expressed in unit change per second (time ratherthen samples points) since high sampling rates can artificially deflate thevalue of the slope. If the horizontal axis is set to display Frequency orArbitrary units, the slope will be expressed as unit change incorresponding vertical axis values (frequency or arbitrary units,respectively).Sample data file: “ValidateMeasurements.ACQ”Result: 230.00 Volts/sec. (for 1-4 samples) and–170.00 Volts/sec. (for samples 4-7).Max (maximum) shows the maximum amplitude value of the data samplesbetween the endpoints of the selected area. To compare peak heights,select each peak — you can easily see the maximum peak values or pastethe results to the journal. Also, since you can simultaneously obtainmeasurements for different channels, you can easily compare maximumvalues for different channels.Note: For a single point, Max shows the amplitude value in this point.Units: VoltsMax T shows the time of the data point that represents the maximumvalue of the data samples between the endpoints of the selected area.Note: For a single point, Max T shows the time value in this point.Units: SecondsMean computes the mean amplitude value of the data samples betweenthe endpoints of the selected area, according to the formula:1Mean = f nn i1x iWhere:n – number of samples;i – index (i = 1.n);xi– values of points at horizontal axis; ( x1– the first point,point);f - values of points of a curve ( vertical axis).x iUnits: VoltsSample data file: “ValidateMeasurements.ACQ”Result: 1.538462 Volts (for whole wave).xn– the lastMedian shows the median value from the selected area.Note: The median and calculation is processor-intensive and can take along time, so you should only select this measurement option when youare actually ready to calculate. Until then, set the measurement to “none.”