SIGNAL DETECTION SYSTEM

• US 3,848,586 A
• Filed: 12/18/1972
• Issued: 11/19/1974
• Est. Priority Date: 12/17/1971
• Status: Expired due to Term

• Current Assignee: Takaji Suzuki, Toshio Ogawa
• Original Assignee: Takaji Suzuki, Toshio Ogawa
• Inventors: Suzuki, Takaji, Ogawa, Toshio
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/316,019
• Time in Patent Office: 701 Days
• Field of Search: 128/2R,2.5R,2.6RA,2.1B,2.6RB,2.1R 307/235R,106 328/151,165,167,168 325/65 235/183 340/146.2
• US Class Current: 600/508
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: Y10S 128/901 Suppression of noise in electric signal

Abstract

A signal detection system comprising detecting means for detecting the differential between a first and a second sampled value of an electrical signal subjected to sampling, comparing means for comparing the output of the detecting means with a predetermined first threshold value, discriminating means for discriminating the polarity of the output of the detecting means, adding means controlled by the output of the discriminating means for adding a predetermined second threshold value to the first sampled value, and means controlled by the output of the comparing means for deriving the result of addition from the adding means. The signal detection system serves for reducing or removing noises involved in or superposed on an electrical signal and more particularly a bioelectrical signal such as one recorded on an electroencephalogram or electrocardiogram.

Claims

1. A signal detection system comprising holding means for holding an electrical signal subjected to sampling, detecting means for detecting the differential between sampled values xi and xi 1 (where i is an integer) held in said holding means, comparing means for comparing the output of said detecting means with a predetermined first threshold value, discriminating means for discriminating the polarity of the output of said detecting means, adding means controlled by the output of said discriminating means for adding a predetermined second threshold value to the sampled value xi in response to the appearance of the sampled value xi 1, means for applying the result of addition by said adding means to said detecting means for the purpose of detecting the differential between the result of addition and another sampled value xi 2, and means controlled by the output of said comparing means to be connected to said adding means in lieu of said holding means for deriving the result of addition from said adding means, said result of addition and said sampled value being selectively derived depending on the appearance or disappearance of the output from said comparing means.

2. A signal detection system as claimed in claim 1, further comprising integrating means for integrating the differential between said result of addition and said sampled value for a predetermined period of time, another comparing means for comparing the output of said integrating means with a predetermined third threshold value, and means for displaying the output of said comparing means.

3. A signal detection system comprising holding means for holding an electrical signal subjected to sampling, a pair of first detecting means for detecting the differentials between sampled values x1 and xi 1 and between sampled values xi 1 and xi 2 respectively (where i is an integer) held in said holding means, second detecting means for detecting the differential between the outputs of said first detecting means, comparing means for comparing the output of said second detecting means with a predetermined first threshold value, discriminating means for discriminating the polarity of the output of said second detecting means, adding means controlled by the output of said discriminating means for adding a predetermined second threshold value to the sampled value xi in response to the appearance of the sampled value xi 2, means for applying the result of addition by said adding means to said first detecting means for the purpose of detecting the differential between the result of addition and the sampled value xi 2, and means controlled by the output of said comparing means to be connected to said adding means in lieu of said holding means for deriving the result of addition from said adding means, said result of addition and said sampled value being selectively derived depending on the appearance or disappearance of the output from said comparing means.

4. A signal detection system as claimed in claim 3, further comprising integrating means for integrating the differential between said result of addition and said sampled value for a predetermined period of time, another comparing means for comparing the output of said integrating means with a predetermined third threshold value, and means for displaying the output of said comparing means.

5. A signal detection system comprising holding means for holding an electrical signal subjected to sampling, detecting means for detecting the differential between sampled values xi and xi 1 (where i is an integer) held in said holding means, means for dividing the output of said detecting means into 1/2 , comparing means for comparing the output of said detecting means with a predetermined first threshold value, adding means for adding the output of said dividing means to the sampled value xi, determining means for determining the pattern of said electrical signal depending on the appearance or disappearance of the output from said comparing means, and means controlled by the output of said determining means to be connected to said adding means in lieu of said holding means for deriving the result of addition from said adding means, said result of addition and said sampled value being selectively derived depending on the appearance or disappearance of the output from said determining means.

6. A signal detection system comprising holding means for holding an electrical signal subjected to sampling, detecting means for detecting the differential between sampled values xi and xi 1 (where i is an integer) held in said holding means, comparing means for comparing the output of said detecting means with a predetermined threshold value, measuring means controlled by the output of said comparing means for measuring the period of time between successive outputs of said comparing means, determining means for determining the pattern of said electrical signal depending on the appearance or disappearance of the output from said comparing means, a function generator for generating a linear function on the basis of the sampled value xi and the output of said measuring means, and means controlled by the output of said determining means for deriving the sampled value xi 1 in lieu of the linear function, said linear function and said sampled value being selectively derived depending on the appearance or disappearance of the output of said determining means.

7. A signal detection system comprising holding means for holding an electrical signal subjected to sampling, detecting means for detecting the differential between sampled values xi and xi 1 (where i is an integer) held in said holding means, comparing means for comparing the output of said detecting means with a predetermined first threshold value, discriminating means for discriminating the polarity of the output of said detecting means, adding means controlled by the output of said discriminating means for adding a predetermined second threshold value to the sampled value xi in response to the appearance of the sampled value xi 1, means controlled by the output of said discriminating means for supplying the predetermined second threshold value to said adding means for addition to thereby said result of addition, and means controlled by the output of said comparing means to be connected to said adding means in lieu of said holding means for deriving said result of addition from said adding means, said result of addition and said sampled value being selectively derived depending on the appearance or disappearance of the output from said comparing means.