SIGNAL AVERAGER

• US 3,705,297 A
• Filed: 06/28/1971
• Issued: 12/05/1972
• Est. Priority Date: 06/28/1971
• Status: Expired due to Term

• Current Assignee: Erwin Roy John
• Original Assignee: Erwin Roy John
• Inventors: John, Erwin Roy
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US05/157,363
• Time in Patent Office: 526 Days
• Field of Search: 235/183,184,193,193.5,151.1,151.13,151.3,151.31,152,156,150.53 128/2.1B
• US Class Current: 708/3
• CPC Class Codes: G06G 7/20 for evaluating powers, roots, polynomes, mean square values, standard deviation G06G7/122, G06G7/28 take precedence; gamma correction in television systems H04N5/20, H04N9/69

Abstract

A special purpose computer is used to calculate the statistical T-test as a measure of the significance of the difference between two sample populations. The computer includes a four channel average response computer, squaring circuits, square root circuits, dividing circuits, differential circuits and summing circuits.

Claims

1. A special purpose computer for the computation of the '"'"''"'"''"'"''"'"'t'"'"''"'"''"'"''"'"' test, including a first squaring means to provide the squares of a sequence of voltage values X and Y to provide their squared values X2 and Y2;

an average response computer connected to the output of said first squaring means and having a first summing means which provides the sum of the voltage values X over repeated cycles providing Sigma X and the sum of a different set of voltage values Y over repeated cycles providing Sigma Y and the sums of the squared values Sigma X2 and Sigma Y2, counter means for counting the repeated cycles to provide Nx and Ny, and A first division means connected to the output of said summing means and to the counter means to divide each of said sums by the number of;

the repeated cycles Nx and Ny;

a second squaring means connected to the output of said average response computer to provide the square of the sums ( Sigma X/Nx)2 and ( Sigma Y/Ny)2;

a first differential means connected to the output of said second squaring means and to said average response computer to generate the quantities ( Sigma X2/Nx) - ( Sigma X/Nx)2 sigma x2 and ( Sigma Y2/Ny) - ( Sigma Y/Ny)2 sigma y2;

a second divider means connected to the output of said differential means and to the counter means to divide the respective variances by the number of repeated cycles to provide averaged variances sigma x2/Nx and sigma y2/Ny;

addition means connected to the output of said second divider means to add said averaged variances;

a square root means connected to the output of said addition means to provide the square root of said added variances;

a second differential means connected to said average response computer to provide the subtraction Sigma X/Nx - Sigma Y/Ny; and

a third divider means connected to the outputs of said second differential means and to said square root means to provide the signal corresponding to the T-test result of Sigma X/Nx Sigma Y/Ny / ( sigma x2/Nx + sigma y2/Ny)1/2.

2. A special purpose computer including the special purpose computer for the computation of the T-test as claimed in claim 1 and further including storage means responsive to the signal corresponding to the said T-test result, said storage responsive means storing the signals corresponding to the T-test results of a first and a subsequent second analysis of a process, comparison means comparing the said two stored signals, and means producing a signal which corresponds to the said comparison.

3. A special purpose computer including the special purpose computer for the computation of the T-test as claimed in claim 1 and further including comparison means which is responsive to the signal corresponding to the said T-test result and compares that signal with a predetermined standard, and means producing a signal which corresponds to the said comparison.

4. A special purpose computer module for the computation of the T-test, said module connectable to an average response computer having four channels, said average response computer having a first summing means which provides the sum of the voltage values X over repeated cycles providing Sigma X and the sum of a different set of voltage values Y over repeated cycles providing Sigma Y and the sums of the squared values Sigma X2 and Sigma Y2, counter means for counting the repeated cycles to provide Nx and Ny, and a first division means connected to the output of said summing means and to the counter means to divide each said sums by the number of the repeated cycles Nx and Ny;

said computer module including;

a first squaring means having an input and an output, the input connectable to receive a sequence of voltage values X and Y and the squaring means providing at its output the squared values X2 and Y2, said squaring means having its output connectable to the input of said average response computer;

a second squaring means connectable to the output of said average response computer to provide the square of the sums ( Sigma X/Nx)2 and ( Sigma Y/Ny)2;

a first differential means connected to output of said second squaring means and connectable to said average response computer to generate the quantities ( Sigma X2/Nx) - ( Sigma X/Nx)2 sigma x2 and ( Sigma Y2/Ny) - ( Sigma Y/Ny)2 sigma y2 a second divider means connected to the output of said differential means and connectable to the counter means to divide the respective variances by the number of repeated cycles to provide averaged variances sigma X2/Nx and sigma Y2/Ny;

addition means connected to the output of said second divider means to add said averaged variances;

a square root means connected to the output of said addition means to provide the square root of said added variances;

a second differential means connectable to said average response computer to provide the subtraction Sigma X/Nx - Sigma Y/Ny ; and

a third divider means connected to the outputs of said second differential means and to said square root means to provide the signal corresponding to the T-test result of Sigma X/Nx -Sigma Y/Ny / ( sigma X2/Nx + sigma y2/Ny)1/2.

5. A special purpose computer including the special purpose computer module for the computation of the T-test as claimed in claim 4 and further including storage means responsive to the signal corresponding to the said '"'"''"'"''"'"''"'"'t'"'"''"'"''"'"''"'"' test result, said storage responsive means storing the signals corresponding to the T-test results of a first and a subsequent second analysis of a process, comparison means comparing the said two stored signals, and means producing a signal which corresponds to the said comparison.

6. A special purpose computer including the special purpose computer module for the computation of the T-test as claimed in claim 4 and further including comparison means which is responsive to the signal corresponding to the said T-test result and compares that signal with a predetermined standard, and means producing a signal which corresponds to the said comparison.